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When it comes to harvesting operations, precision agriculture needs to consider both combine harvester technology and the precise execution of the process to eliminate harvest losses and minimize out-of-work time. This work aims to propose a complete control framework defined by a two-layer-based algorithm and a simulation environment suitable for quantitative harvest loss, time, and consumption analyses. In detail, the path-planning layer shows suitable harvesting techniques considering field boundaries and irregularities, while the path-tracking layer presents a vision-guided Stanley Lateral Controller. In order to validate the developed control framework, challenging driving scenarios were created using IPG-CarMaker software to emulate wheat harvesting operations. Results showed the effectiveness of the designed controller to follow the reference trajectory under regular field conditions with zero harvest waste and minimum out-of-work time. Whereas, in presence of harsh road irregularities, the reference trajectory should be re-planned by either selecting an alternative harvesting method or overlapping the harvester header by some distance to avoid missing crops. Quantitative and qualitative comparisons between the two harvesting techniques as well as a relationship between the level of irregularities and the required overlap will be presented. Eventually, a Driver-in-the-loop (DIL) framework is proposed as a methodology to compare human and autonomous driving. [ABSTRACT FROM AUTHOR]

Combine harvesters' performance during wheat harvests can be analyzed using various methods. These methods typically rely on traditional field-level metrics, such as those defined by ASABE, to address average performances in terms of field or machine. However, next-generation digital agriculture technologies have significantly increased the operation precision of agricultural activities. As a result, the evaluation of instantaneous performance becomes possible. This work introduces a novel methodology that enables fully automated, low-cost, and high-resolution (both in time and space) instantaneous combine performance analyses based on global navigation satellite system (GNSS) positioning records. The methodology incorporates a multi-step, easy-to-follow workflow with customizable modules for efficient and effective data processing. This way, the computation of traditional field capacity metrics can be fully automated even if multiple combines cooperate in harvesting the same field. Furthermore, two groups of novel metrics are proposed: Swath Utilization and Spatial Field Capacity. They enhance traditional metrics by analyzing machine performances both temporally and spatially on a finer scale. As a case study, we computed these metrics for seven fields in Colorado, USA, during wheat harvests across five different years. We compared the results with typical values from ASABE standards to validate the correctness of our data processing methodology. We also provided four analysis examples with a rich set of temporal and spatial visualizations to showcase how our metrics can accurately assess combine performances, quantitatively uncover harvest details, and effectively compare operations in different fields/years for better practice. These new analyses enabled by our methodology are required to harness the full potential of digital agriculture. [ABSTRACT FROM AUTHOR]

Path planning is a critical aspect of the harvesting process for unmanned combine harvesters, and the headland turning paths play a crucial role in connecting two parallel paths. However, previous studies have often simplified the combine harvester as a mass point, leading to suboptimal or meaningless planned paths. In this paper, a simplified geometrical model for a tracked combine harvester that considers the influence of the header and tracks on headland turning was developed. Using this model, new calculation formulae for path length, turning time, and headland width for four commonly used headland turning types: fishtail turn, bulb turn, semicircle turn, and u turn were deduced and deeply analysed. The results revealed that the semicircle turn achieved the greatest reduction in path length, turning time, and headland width, reaching up to 79.0%, 74.0%, and 36.1%, respectively, if the harvester turned to the left. To ensure sufficient turning area for unmanned harvesting, the field periphery should be cut at least twice for u turns, three times for semicircle turns, three to four times for fishtail turns, and three to five times for bulb turns. It is suggested that the semicircle turn is the preferred option for most situations, and the harvester should switch between the semicircle turn and the u turn in special cases if it has a differential steering function. This approach can significantly improve working efficiency and always determine the minimum required headland width. • A new simplified model for tracked combine harvester is developed. • New formulas of path length, turning time and headland turning width are deduced. • Four common turning types' performances are analysed thoroughly. • Guidance and advice are concluded for better path planning. [ABSTRACT FROM AUTHOR]

In view of the low level of mechanized harvesting of white radish in China and other developing countries and the current situation of "no machine can be used" due to the expensive imported machines, a self-propelled white radish combine harvester was designed based on the material, growth characteristics, and agronomic pattern of white radish. This combines harvester can realize the functions of white radish tassel gathering, deep soil loosening, clamping and conveying, tassel cutting, and collecting. In this research, the overall design of the harvester is described, and the structural and working parameters and kinematic requirements of the tassel gathering device, clamping and conveying device, tassel cutting device, and vibrating deep loosening device are determined by mechanical and kinematic analysis. Innovatively, a range of values for the tassel gathering speed ratio of 1.7–4.2 is proposed for the operation of the tassel gathering device suitable for white radish harvesting. The prototype was bench tested with the loss rate, damaged rate, and impurity rate as performance evaluation indexes. The results show that under the pitch of 240 mm between the taper angle of the tassel-raising device, a speed of 80 rpm for the tassel gathering device gathering claw belt rotation, a speed of 120 rpm for the clamping and conveying pulley rotation, a vibration frequency of 2 Hz and an amplitude of 15 mm for the vibrating deep loosening device, and a forward speed of 0.5 m/s (tassel gathering speed ratio: 1.7). The loss rate was 2.75%, the damage rate was 4.99%, and the impurity rate was 1.64%. During the operation, the innovatively designed white radish leaf gathering device can better fulfill the function of tassel gathering, and the systems worked well together, meeting the requirements of mechanized combined harvesting of white radish, but the adaptability to complex working conditions in the field needs to be further strengthened. This research can provide a reference for the design and optimization of mechanized white radish harvesting equipment. [ABSTRACT FROM AUTHOR]

A variable speed anti-tangling reel mechanism was designed to address the problems of tangling, hanging and rewinding of the tassel wheel and the high paddling loss in the current Chinese rape combine harvester cutting table. The kinematic equations of the reel mechanism were developed, and the analysis showed that the speed in the entry stage is low and the speed in the exit stage is high, and the attitude of the reel teeth change with the rape plant movement during the whole paddling process. A single-factor test and a multi-factor regression orthogonal combination test were carried out using the cutting table loss rate of rape harvesting as the evaluation index. The main and secondary factors affecting the cutting table loss of the variable speed reel were obtained as the reel input speed, the machine travel speed and the ground angle of the frame. The optimal range of the input speed of the reel is from 25 r·min−1 to 31 r·min−1, the optimal range of the forward speed of the implement is 0.8 m·s−1~1 m·s−1, and the optimal range of the rack level angle is from −10°to 10°. A mathematical model of regression of cutter loss and the main influencing factors was established, with the coefficient of determination R2 = 0.9918, the relative error between the test value and the optimised value of the regression equation was 5.36%. The optimal combination of parameters for the variable speed reel was obtained with the lowest cutting table loss rate in rape harvesting as the optimization target: reel input speed 25 r·min−1, frame parallel to the ground and implement travel speed 0.7 m·s−1. Field validation tests and comparative tests of cutting table loss of the two reels were carried out. The test results show that the regression mathematical model of the cutting table loss is more accurate, and the cutting table loss is reduced by 13.9% with the variable speed reel compared to the cam-action reel, and there are no problems with the paddle teeth hanging and tangling during the paddling process. [ABSTRACT FROM AUTHOR]

In order to solve the problem of the threshing performance of a large combine harvester being reduced due to the non-adjustable diameter of the threshing drum, a variable-diameter threshing drum with movable radial plates based on the principle of concentric regulation was studied. It was mainly composed of a mechanism for adjusting the diameter by moving the radial plates, six fixed threshing tooth rods, six retractable threshing tooth rods and the single piston rod hollow hydraulic cylinder. The threshing gap can be adjusted by a stepless change of the drum diameter. By using RecurDyn simulation and field performance tests, the adjustable ranges of diameter and gap of the movable variable-diameter threshing drum were 670~710 mm and 10~30 mm. Based on the feed amount of the combine, the rotation speed of the threshing drum and the threshing gap (the diameter of the drum) as the influencing parameters, and the grain entrainment loss rate, grain un-threshed rate and grain breakage rate as the evaluation indexes, the three-factor and three-level response surface tests were carried out, and the result data were analyzed using Design-Expert 13.0. The optimal threshing gap and rotation speed of the threshing drum were determined under different feeding quantities. A comparative test was carried out to adjust and fix the threshing gap and rotation speed of the threshing drum in real time according to the change in feeding amount. The results showed that when the working parameter combination under different feeding amounts was adjusted in real time, the entrainment loss rate was 0.65%, the un-threshed rate was 0.063% and the breakage rate was 0.47%. Compared with the threshing gap and the rotation speed of the threshing drum being fixed, the entrainment loss rate, the un-threshed rate and the breakage rate were reduced by 44.9%, 27.6% and 34.1%, respectively. A threshing drum with variable diameter was provided for a large multi-crop harvesting combine to realize the concentric stepless adjustment of the threshing gap. [ABSTRACT FROM AUTHOR]

A combine harvester can be one of the most important links for the potatoes gathering and conveying. However, the current potato combine harvester cannot fully meet the large-scale production in recent years, such as the non-ideal performance of impurity removal, the high rate of potato damage, bruising and impure content in the soil cleaning. In this study, a potato combine harvester was designed with the elastic rubbing technology. The harvesting process was also selected by the "double vibration separation, elastic rubbing type, buffering and loss reducing potatoes gathering and conveying". The main components included the excavation, hydraulic control potato soil separation, elastic rubbing impurity removal, as well as the buffering and reducing losses potatoes gathering and conveying device. A systematic analysis was implemented to clarify the movement track and collision characteristics of potatoes, according the optimal structure of the whole machine, the characteristics of harvesting, and the working principle. A combination of structural parameters were then determined for the key components, in order to fully meet the requirements of efficient separation and impurity removal, as well as the loss reduction and prevention. The whole harvesting process was divided into the three sections of the double vibrating potato soil separation, the elastic rubbing type soil cleaning and impurity removal, as well as the buffer potatoes gathering and conveying. The frequency and amplitude of the vibration were adjusted under the harvest conditions in the double vibration adjustable separation device in time. The rates of the potato damage and bruising were then reduced during the process of the potato and soil separation. The longitudinal non-equidistant soil cleaning and impurity removal device was used to reduce the collision frequency of potato, and then slow down the drop impact response, indicating the higher harvest quality, and the lower impurity content. The buffering and reducing losses potatoes gathering and conveying device was optimized to accurately control the drop height and position of potato at the end of the conveyor belt, in order to effectively avoid the drop damage during potato harvesting. The experiment result showed that the loss rates of the prototype were 1.17% and 1.43%, the potato damage rates were 1.30% and 1.27%, the bruising rates were 1.98% and 1.84% and the productivity values were 0.41 and 0.54 hm2 /h, respectively, when the operating velocity values were 3.17 and 4.16 km/h, respectively. All performance indicators were met the requirements of national standards. Once the harvester was operated at a high speed, there was the significant increase in the material flow entering the elastic rubbing impurity removal device in a unit time, indicating the increasing burden of soil cleaning and impurity removal. Among them, part of the soil, seedlings, and vines were remained to mix in the potato cluster, resulting in a high impurity content. By contrast, the low operation speed was greatly contributed to the reduced impurities entering the soil cleaning and impurity removal stage. A better performance was achieved in the removal from the surface soil layer of potatoes in the soil cleaning and impurity removal device. But there was the weak protective effect of the soil on the surface of potatoes, leading to an increase in the frequency of direct contact between potatoes and the soil cleaning and impurity removal wheel. As such, the impurity content was much lower, whereas, there was an increase in the damage and bruising rate of potatoes, compared with the high operation speed. This finding can provide a strong reference for the subsequent research, equipment development, and optimization improvement. [ABSTRACT FROM AUTHOR]

Rice lodging not only brings trouble to harvesting but also reduces yield. Therefore, the effective identification of rice lodging is of great significance. In this paper, we have designed a bilinear interpolation upsampling feature fusion module (BIFF) to decompose the quadruple upsampling of the connected part of encoder and decoder into two double upsampling processes and insert the intermediate feature layer in the backbone network for feature fusion in this process. The global attention mechanism(GAM) attention module is added to the feature extraction network, allowing the network to effectively focus on the lodging regions, thus effectively improving the segmentation effect. The average accuracy of the improved network is 93.55%, mrecall is 93.65%, and mIoU is 88.10%, and the feasibility of the improvement is demonstrated by ablation experiments and comparison with other algorithms. In addition, the angle calculation method is designed by combining the detection algorithm, adding a detection head branch to the output results for reading the distance information from the depth camera, and combining the distance information with mechanical analysis to determine the relationship between the angle of the stalk and the vertical direction when the rice is upright, tilted and fallen. A comparison of the calculated angle with the actual measured angle gives a final average error of approximately 5.364%, indicating that the harvest boundary extraction algorithm in this paper is highly accurate and has value for application in real-time harvesting scenarios. [ABSTRACT FROM AUTHOR]

To improve the operational quality of paddy combine it was proposed to include additional innovative operations in plant process of pre-threshing preparation of rice biomass with anticipating seeds selection which increases seeds separation, reduces injuries, forms stable operation of threshing-separating device of combine harvester. Retrofit feeder house is a solution to ensure the stable uniform feed of assorted biomass into the threshing separation device. Equipped with tool package – harvester feeder house turned to the running control equipment for incoming flow of biomass. The movement of threshed heap inside the modified geometry of feeder house with tools effectively affect on caulis, panicle of rice – screed, and brings the biomass vibration mode i. e., lead to the dynamic separation of rice headed seeds to threshing rotor. Vibration (tossing) of biomass make it possible for free rice seeds pass through caulis to the bottom of feeder house. Development program of innovative driving devices of multifunctional rice seed harvester combine considered the development of preproduction explorational program ensuring the information on harvest loss during various rice harvesting, their separation between main harvester aggregates – collector, auger, elevator, threshing mill. It is proposed to combine, in a single complex, all the control parameters, subordinating their actions, into an active control device of the technological process, affecting the shapes of rolls formed from various varieties and yields of rice. [ABSTRACT FROM AUTHOR]

The current situation in which garlic cultivation is non-homogeneous and modular cannot be adapted to combine harvester operations. In this paper, a single-row harvesting and cutting integrated handheld garlic harvester is designed, and the structure and working principle of the machine are described. By analyzing the mechanics of the machine mechanism, mechanics of the machine harvesting process, and design principle of the machine chassis, the key factors affecting the garlic harvesting machine wounding rate, leakage rate, and net harvesting rate were determined. According to the force and parametric analyses of the test results, it was determined that the machine had the best harvesting effect with a conveying speed of 0.6 m/s, prop speed of 125.6 r/min, digging angle of 15°~25°, forward speed of 0.8 m/s, clamping point height of 62.15 mm, and rollover threshold value of 0.89. Compared with the traditional garlic harvester, the garlic injury rate was 57.1% lower, the garlic leakage rate was 25% lower, and the net harvest rate was 4.0% higher, which meets the requirements of the garlic harvesting operation. [ABSTRACT FROM AUTHOR]

Research on autonomous driving technology is actively underway to solve the facing problems in the agricultural field. Combine harvesters used in East Asian countries, including Korea, are tracked-type vehicles. The steering control system of the tracked vehicle has different characteristics from the wheeled vehicle used in the agricultural tractor. In this paper, a dual GPS antenna-based autonomous driving system and path tracking algorithm were developed for a robot combine harvester. An α-turn-type work path generation algorithm and a path tracking algorithm were developed. The developed system and algorithm were verified through experiments using actual combine harvesters. The experiment consisted of an experiment with harvesting work and an experiment without harvesting work. In the experiment without harvesting work, an error of 0.052 m occurred during working driving and 0.207 m during turning driving. In the experiment where the harvesting work was carried out, an error of 0.038 m occurred during work driving and 0.195 m during turning driving. As a result of comparing the non-work area and driving time to the results of manual driving, the self-driving experiment with harvesting work showed an efficiency of 76.7%. [ABSTRACT FROM AUTHOR]

The feed rate is an important evaluation index of combine harvester performance. The quick identification of the amount of feed rate that enters the combine during harvesting is of great significance for the efficiency and operational quality of the combine harvester. To address this issue, this study proposes a feed rate discrimination method based on association rule mining. A self-designed data acquisition system was designed, taking the wheat combine harvester as object, and collected seven speed signals and three torque signals when the feed rate was 6 kg/s-8 kg/s, 8 kg/s-10 kg/s, and 10 kg/s-11 kg/s, respectively. The collected time series data were discretized so as to facilitate the construction of transaction sets. Then, the association rules in the constructed transaction set were mined by FP-Growth, and the rules with weak or no correlation with the increase in feed rate were filtered using min-support, min-confidence, and min-lift of 1.3, 0.8, and 3, respectively, to obtain strong association rules. Then, the strong association rules were constructed as classifiers. The test results showed that the accuracy of the constructed classifier for the identification of 6 kg/s-8 kg/s, 8 kg/s-10 kg/s, and 10 kg/s-11 kg/s feed rates was 100 %, 96 %, and 98.7 %, respectively. Research results can provide a basis for the adjustment of the working state of the combine harvester. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the efficiency of a new type of corn header equipped with flail knives that shreds corn stubble close to the ground. A field trial was carried out to quantify the influence of the shredding tool design (flail knives, standard knives, horizontal choppers disengaged), harvesting speed (1.5, 3.0, 4.5, 6.0 km/h) and cutting height (approx. 20 cm variation, 4 levels) on the power consumption of the corn header, engine load and fuel consumption of the combine harvester. The regression analyses revealed that modifications of the shredding tool assembly have significant effects on the parameters of the functional relationships. The power consumption of the flail knives configuration was 15 kW/row unit at 6 km/h at the lowest cutting height setting, making it compatible with most current combine harvester models. The additional power demand and fuel consumption that arise when switching to the new shredding tool design (flail knives) show a wide range, depending on the initial situation. Compared to the standard knives at 6 km/h, the additional power consumption was 3.6–5.5 kW/row unit and the additional fuel consumption was 2.6–3.9 L/ha. Compared to the configuration with disengaged horizontal choppers, it was 5.3–6.6 kW/row unit and 3.9–5.1 L/ha, respectively. At 90% engine load the additional power requirement was 1.6–3.1 kW/row unit and the additional fuel consumption was 2.9–5.6 L/ha compared to the standard knives configuration and 2.6–3.6 kW/row unit and 5.6–7.2 L/ha respectively, compared to the configuration with disengaged horizontal choppers. [ABSTRACT FROM AUTHOR]

Nowadays, Combine Harvesters are the most commonly used device for harvesting crops; as a result, a large amount of plant material and crop residue is concentrated into a narrow band of plant material that exits the combine, challenging the residue management task. This paper aims to develop a crop residue management machine that can chop paddy residues and mix them with the soil of the combined harvested paddy field. For this purpose, two important units are attached to the developed machine: the chopping and incorporation units. The tractor operates this machine as the main source, with a power range of about 55.95 kW. The four independent parameters selected for the study were rotary speed (R1 = 900 & R2 = 1100 rpm), forward speed (F1 = 2.1 & F2 = 3.0 Kmph), horizontal adjustment (H1 = 550 & H2 = 650 mm), and vertical adjustment (V1 = 100 & V2 = 200 mm) between the straw chopper shaft and rotavator shaft and its effect was found on incorporation efficiency, shredding efficiency, and trash size reduction of chopped paddy residues. The incorporation of residue and shredding efficiency was highest at V1H2F1R2 (95.31%) and V1H2F1R2 (61.92%) arrangements. The trash reduction of chopped paddy residue was recorded maximum at V1H2F2R2 (40.58%). Therefore, this study concludes that the developed residue management machine with some modifications in power transmission can be suggested to the farmers to overcome the paddy residue issue in combined harvested paddy fields. [ABSTRACT FROM AUTHOR]

Carrots are a type of vegetable with high nutrition. Before entering the market, the surface defect detection and sorting of carrots can greatly improve food safety and quality. To detect defects on the surfaces of carrots during combine harvest stage, this study proposed an improved knowledge distillation network structure that took yolo-v5s as the teacher network and a lightweight network that replaced the backbone network with mobilenetv2 and completed channel pruning as a student network (mobile-slimv5s). To make the improved student network adapt to the image blur caused by the vibration of the carrot combine harvester, we put the ordinary dataset Dataset (T) and dataset Dataset (S), which contains motion blurring treatment, into the teacher network and the improved lightweight network, respectively, for learning. By connecting multi-stage features of the teacher network, knowledge distillation was carried out, and different weight values were set for each feature to realize that the multi-stage features of the teacher network guide the single-layer output of the student network. Finally, the optimal lightweight network mobile-slimv5s was established, with a network model size of 5.37 MB. The experimental results show that when the learning rate is set to 0.0001, the batch size is set to 64, and the dropout is set to 0.65, the model accuracy of mobile-slimv5s is 90.7%, which is significantly higher than other algorithms. It can synchronously realize carrot harvesting and surface defect detection. This study laid a theoretical foundation for applying knowledge distillation structures to the simultaneous operations of crop combine harvesting and surface defect detection in a field environment. This study effectively improves the accuracy of crop sorting in the field and contributes to the development of smart agriculture. [ABSTRACT FROM AUTHOR]

Traditional harvesters of tiger nuts (Cyperus esculentus) face problems including low harvesting efficiency, high loss rate, high impurity rate, and high labor intensity. To solve these problems and improve the harvesting efficiency and quality of tiger nuts, a crawler-type tiger-nut combine harvester that integrates digging, soil removal, picking, screening, and collection was designed. The machinery comprises crawler devices and working devices. The key devices were designed through theoretical analysis. Therein, the digging and hoisting devices consist of digger blades, combined soil-breaking blades, and vibrating hoisting chains. The tuber picking and screening device is composed of the tuber picking drum, double-deck heterodromous vibrating screens, impurity removal blowers, and soil-crushing guide rollers. The crawler devices include the track assemblies and the hydraulic driving systems. SolidWorks was used to establish the virtual prototype model. Combined with simulation using the discrete element software, the law of motion of tiger-nut tubers in the digging, elevation, and screening processes was studied, which verified the feasibility of the design. Finally, a prototype was manufactured and fabricated to conduct field harvesting tests on tiger nuts. Field test results indicate that the harvesting efficiency, harvest rate, and impurity rate of the tiger-nut harvester are separately 0.216 ha/h, 98.14%, and 3.24%, which meet the harvesting requirements for tiger-nut growers. [ABSTRACT FROM AUTHOR]

China is a large flax-growing country, with planting area and production ranking among the top three in the world. However, the cultivation range of flax in China is very broad, complex, and diverse, resulting in different planting scales and patterns, making it difficult to apply foreign large combine harvesters, and China lacks a dedicated flax combine harvester. This research improved the design of the 4LZ-4.0 crawler-type flax combine harvester for the regional features and flax cropping patterns in China. First, the structure, technical parameters, and working principles of the machine were introduced; second, the theoretical analysis and optimization of key components were performed; and finally, with the advancing speed of the machine, the speed of the threshing drum, and the speed of the suction fan as independent variables and the rate of removal and the total loss rate as response values, a three-factor, three-level response surface analysis method was used. For each component and response value, a mathematical model was created, and the factors and their interactions were evaluated and confirmed. The results demonstrated that the three parameters impact the threshing drum speed, advancing speed, and centrifugal fan speed in that order of priority, as well as the total loss rate in that order of priority. The machine's optimal operating settings were 1.5 m·s−1 advancing speed, 788.49 r·min−1 threshing drum speed, and 885.34 r·min−1 centrifugal fan speed, and the validation test results indicated that under the typical dryland dense flax cultivation mode, it had a 97.46% threshing rate and 2.99% total loss rate after the test. This demonstrated that optimizing operational parameters may decrease losses in the process of mechanical flax harvesting, enhance harvesting efficiency, and satisfy the marketable flax harvesting standards. [ABSTRACT FROM AUTHOR]

High labor wages brought on by a shrinking agricultural labor force, as well as promises of increased crop yields and decreased labor requirements, have spurred the adoption of agricultural mechanization in Bangladesh. Due to these factors, the market for more complex agricultural machinery, such as rice transplanters and combine harvesters, is growing substantially in Bangladesh. As a result, a market has developed for agricultural workshops to manufacture spare parts within the local communities. However, the current manufacturing practices of local agricultural workshops limit their ability to produce high-quality parts that can compete with spare parts imported from China. This paper presents the analysis of the manufacturing processes used in the manufacturing of two key spare parts for the mechanization of planting and harvesting in Bangladesh: rice transplanter claws and combine harvester blades. The manufacturing processes proposed in this paper use machine tools and manufacturing processes that are ubiquitous in Bangladesh, such as grinders and drill presses. Additional manufacturing processes, such as blanking and forming with punch and die sets, are proposed as the methods for increasing product quality and reducing the manufacturing time required to produce complex geometries, such as those found on rice transplanter claws and combine harvester blades. The results from the experimental testing and the finite element simulations of the deformation processes indicate that local manufacturing of high-quality rice transplanter claws and combine harvester blades is viable with the proposed manufacturing processes. [ABSTRACT FROM AUTHOR]

To improve the automation level and operation quality of China's beet harvester and reduce the loss due to damaged and missed excavation, this study used a self-developed sugar beet combine harvester and field simulation experiment platform, based on the single-factor bench test of the automatic row following system in the early stage, taking hydraulic flow A, spring preload B, and forward speed C which have significant influence on performance indices as test factors, and taking the missed excavation rate, breakage rate and reaction time as performance indices, the orthogonal experimental study on the parameter optimization of the three-factor and three-level automatic row following system with the first-order interaction of various factors was carried out. The results of the orthogonal experiments were analyzed using range analysis and variance analysis. The results showed that there were differences in the influence degree, factor priority order and first-order interaction, and the optimal parameter combination on each performance index. A weighted comprehensive scoring method was used to optimize and analyze each index. The optimal parameter combination of the overall operating performance of the automatic row following system was A2B2C1, that is, the hydraulic flow was 25 L/min, the forward speed was 0.8 m/s, and the spring preload was 198 N. Under this combination, the response time was 0.496 s, the missed excavation rate was 2.35%, the breakage rate was 3.65%, and the operation quality was relatively good, which can meet the harvest requirements. The comprehensive optimization results were verified by field experiments with different ridge shapes and different planting patterns. The results showed that the mean values of the missed excavation rate of different planting patterns of conventional straight ridges and extremely large "S" ridges were 2.23% and 2.69%, respectively, and the maximum values were 2.39% and 2.98%, respectively; the average damage rates were 3.38% and 4.14%, and the maximum values were 3.58% and 4.48%, which meet the industry standards of sugar beet harvester operation quality. The overall adaptability of the automatic row following system is good. This study can provide a reference for research on automatic row following harvesting systems of sugar beets and other subsoil crop harvesters. [ABSTRACT FROM AUTHOR]

The threshing cylinder of the combine was used for soybean threshing and auxiliary soybean separation. However, soybean in Southern China has a high ratio of grass to grain and immature pods during harvest. The existing nondifferential speed threshing cylinder has poor adaptability to this feature, resulting in low threshing quality, low operating efficiency and high fuel consumption in the harvesting process. Therefore, this study aims to improve the adaptability and comprehensive performance of the threshing cylinder of soybean combine harvester in Southern China. Aims at the high ratio of grass to grain and the proportion of immature pods in soybean harvest in Southern China, a longitudinal axial flow differential threshing cylinder with adjustable cylinder speed difference was designed, it's front cylinder threshes the pods that are easy to thresh at a lower rotating speed, while the rear cylinder threshes the pods that are difficult to thresh at a higher rotating speed. And two types of threshing teeth were made, the full rod tooth threshing teeth was the front and rear cylinders were adopt rod teeth, and the rasp-rod combined threshing teeth was the front cylinder adopts the rasp bar, and the rear cylinder adopts the rod teeth. At the same time, in order to study the impact of the structure and parameters of the threshing cylinder on the threshing quality, the type of the threshing teeth, front cylinder speed and cylinder speed difference related to the threshing cylinder are selected as factors, and the Epicit Dnamics module of ANSYS software was used to analyze the impact of different factors on material changes from the perspective of energy and shape variables. It can be speculated that the cylinder with the rasp-rod combined threshing teeth has lower the percentage of broken, the percentage of unthreshed and the percentage of separation loss grains. In the end, the optimal parameter combination of the differential threshing cylinder and the traditional nondifferential threshing cylinder was obtained through experimental analysis, and the threshing quality, operating oil consumption and maximum operating efficiency of the two threshing cylinders are compared under the optimal parameter combination, evaluated the comprehensive working quality of the threshing cylinder, which provides a reference for the research of soybean harvester threshing device in many aspects. In the field test, due to the limitation of test cycle and safety, it is impossible to measure the fuel consumption and maximum operating efficiency in each group of tests. Therefore, the percentage of broken, the percentage of unthreshed and the percentage of separation loss that reflect threshing quality are taken as evaluation indicators, and a single factor comparative test was conducted, and the fuzzy comprehensive evaluation method was adopted, It was determined that the threshing cylinder most suitable for soybean characteristics in the Southern China was the differential speed threshing cylinder, and the threshing teeth type was the rasp-rod combined threshing teeth. The optimal parameter combination was: the speed of the front cylinder was 450 r/min, the speed difference of the cylinder was 150 r/min, and the optimal rotational speed of the traditional nondifferential speed threshing cylinder with rod tooth was 500 r/min. Under the optimal parameter combination, the comprehensive performance comparison test of two threshing cylinders was carried out. The results showed that the threshing quality of the differential threshing cylinder was higher, its fuzzy comprehensive evaluation value was 0.4 higher than that of the traditional rod tooth threshing cylinder, the fuel consumption was 2.7 L/hm2 lower, and the working efficiency was 10.35% higher, It was proved that the differential speed threshing cylinder with the rasp-rod combined threshing teeth can improve the adaptability and comprehensive working performance of the harvester to soybeans. This discovery provides a favorable technical support for mechanized soybean harvesting in Southern China. [ABSTRACT FROM AUTHOR]

Wheat lodging provides important reference information for self-adaptive header control of a combine harvester. Aimed at real-time detection of wheat lodging, this paper proposed a detection method of wheat lodging location and area based on binocular vision. In this method, the angle relationship between the stem and vertical direction when wheat is upright, inclined, and lodging was determined by mechanical analysis. The discrimination condition of the wheat lodging degree was proposed based on the height of the visual point cloud on the surface of wheat crops. The binocular camera was used to obtain the image parallax of wheat within the harvesting region. The binocular camera optical axis parallel model was used to calculate the three-dimensional coordinate of wheat. Then, the height of the wheat stem was obtained by further analysis and calculation. According to the wheat stem height detected by vision, the location and area of wheat lodging within the combine harvester's harvesting region were analyzed. A field experiment showed that the detection error of the wheat stem height was 5.5 cm and the algorithm speed was under 2000 milliseconds, which enabled the analysis and calculation of the wheat lodging location, contour, and area within the combine harvester's harvesting region. This study provides key information for adaptive header control of combine harvesters. [ABSTRACT FROM AUTHOR]

In order to improve the operational performance of the self-developed 4HLB-4 half-feed four-row peanut combine harvester, single-factor and multifactor field tests were conducted on key operational parameters affecting the quality of harvesting. The response surface methodology was used to study the effects of the forward speed, clamping height, peanut picking roller rotational speed, and cleaning sieve vibrational frequency on the loss rate and impurity rate. A response surface regression model of the loss rate and impurity rate was constructed. A multi-objective integrated optimization was carried out for each factor. The results showed that, in terms of the order of significance, the influence of each factor on the impurity rate was as follows: cleaning sieve vibrational frequency > clamping height > forward speed > peanut picking roller rotational speed. The order of significance of the influence of each factor on the loss rate was as follows: peanut picking roller rotational speed > forward speed > clamping height > cleaning sieve vibrational frequency. The optimal combination of parameters was a forward speed of 0.85 m/s, clamping height of 190 mm, peanut picking roller rotational speed of 550 rpm, and cleaning sieve vibrational frequency of 590 cpm. Under these conditions, the impurity rate of 2.62% and the loss rate of 2.05% were obtained, which effectively reduced the impurity rate and loss rate and met the quality requirements of Chinese peanut mechanized harvesting operations. The results of this study can provide a basis for the improvement and optimization of the 4HLB-4 half-feed four-row peanut combine harvester and the optimization of its operating parameters. [ABSTRACT FROM AUTHOR]

The digging depth is an important factor affecting the mechanized garlic harvesting quality. At present, the digging depth of the garlic combine harvester (GCH) is adjusted manually, which leads to disadvantages such as slow response, poor accuracy, and being very dependent on the operator's experience. To solve this problem, this paper proposes a machine vision-based automatic digging depth control system for the original garlic digging device. The system uses the improved YOLOv5 algorithm to calculate the length of the garlic root at the front end of the clamping conveyor chain in real-time, and the calculation result is sent back to the system as feedback. Then, the STM32 microcontroller is used to control the digging depth by expanding and contracting the electric putter of the garlic digging device. The experimental results of the presented control system show that the detection time of the system is 30.4 ms, the average accuracy of detection is 99.1%, and the space occupied by the model deployment is 11.4 MB, which suits the design of the real-time detection of the system. Moreover, the length of the excavated garlic roots is shorter than that of the system before modification, which represents a lower energy consumption of the system and a lower rate of impurities in harvesting, and the modified system is automatically controlled, reducing the operator's workload. [ABSTRACT FROM AUTHOR]

Soybean is one of the most important grains and oil crops in China, due to a major source of oil and high-quality vegetable protein. It is very necessary to realize the low-loss harvest of soybean fields in the southern and Huanghuaihai regions. In this study, a 4LZ-1.5 type combine harvester was designed to consider the harvest of soybean breeding plots. The operation process was also theoretically analyzed for the soybean reel harvesting, according to the soybean pods easy to be fried at maturity. A numerical model was established for the reel structure and motion parameters. Some parameters were then optimized, such as the reel radius, reel speed ratio, and reel rotational speed. After that, the soil removal mechanism was optimized for the soybeans with the low pods and easy-to-shovel soil, according to the statistical parameters of soybean grain size. Furthermore, a soybean threshing and separation device was designed for the easy threshing and breakage of soybeans at maturity. The arrangement and distribution of the arch teeth were also determined via the increasing characteristics of the second-order arithmetic sequence. The angle of the deflector was adjusted for the various input amount. The blade fan-combined screen cleaning device was designed to optimize the structural parameters of the fan and cleaning screen. The pneumatic grain unloading device was designed to optimize the vortex fan. The plot harvesting required the high soybean mixed seeding, particularly for the breeding plot with a small planting scale and many varieties, compared with the field production. Frequent seed cleaning was required after harvesting to reduce the missed and mixed seeding, according to the harvest requirements of the breeding area. An optimization mathematical model was established to develop the seed cleaning device, together with the objective function and constraint conditions. A numerical simulation was then carried out using MATLAB, in order to determine the structural parameters of the seed-cleaning device. A series of comparative experiments in field harvesting were conducted in the Xinjiang Uygur Autonomous Region, Shandong province, and Hebei province of China. The better operating performance was achieved in the 4LZ-1.5 soybean combine harvester: the loss rate < 3.5%, broken rate < 1.5%, and impurity rate < 1%, fully meeting the soybean harvest requirements in most hilly areas. After harvest testing of 14 soybean varieties in a 3 m×6 m breeding plot, the test results were all achieved: the loss rate < 3.0%, broken rate < 1.5%, impurity rate < 1.0%, mixed seed rate < 0.2%, and the clearing time of 200-270 s, fully meeting the requirements of the harvesting operation indicators in the breeding plots. Compared with the existing soybean harvesting machinery, the harvest loss rate of 4LZ-1.5 soybean combine harvester was reduced by 1.5-5.0 percentage points, the broken rate was reduced by 3.5-6.5 percentage points, and the impurity rate was reduced by 2.0-7.0 percentage points. The findings can provide a strong reference for the structural optimization of operating parameters in soybean harvesters. [ABSTRACT FROM AUTHOR]

Wheat, one of the most important food crops in the world, is usually harvested mechanically by combine harvesters. The impurity rate is one of the most important indicators of the quality of wheat obtained by mechanized harvesting. To realize the online detection of the impurity rate in the mechanized harvesting process of wheat, a vision system based on the DeepLabV3+ model of deep learning for identifying and segmenting wheat grains and impurities was designed in this study. The DeepLabV3+ model construction considered the four backbones of MobileNetV2, Xception-65, ResNet-50, and ResNet-101 for training. The optimal DeepLabV3+ model was determined through the accuracy rate, comprehensive evaluation index, and average intersection ratio. On this basis, an online detection method of measuring the wheat impurity rate in mechanized harvesting based on image information was constructed. The model realized the online detection of the wheat impurity rate. The test results showed that ResNet-50 had the best recognition and segmentation performance; the accuracy rate of grain identification was 86.86%; the comprehensive evaluation index was 83.63%; the intersection ratio was 0.7186; the accuracy rate of impurity identification was 89.91%; the comprehensive evaluation index was 87.18%; the intersection ratio was 0.7717; and the average intersection ratio was 0.7457. In terms of speed, ResNet-50 had a fast segmentation speed of 256 ms per image. Therefore, in this study, ResNet-50 was selected as the backbone network for DeepLabV3+ to carry out the identification and segmentation of mechanically harvested wheat grains and impurity components. Based on the manual inspection results, the maximum absolute error of the device impurity rate detection in the bench test was 0.2%, and the largest relative error was 17.34%; the maximum absolute error of the device impurity rate detection in the field test was 0.06%; and the largest relative error was 13.78%. This study provides a real-time method for impurity rate measurement in wheat mechanized harvesting. [ABSTRACT FROM AUTHOR]

On account of a lack of suitable and specialized harvesting equipment for cabbage species and planting modes in China, in this study, a type of 4GCSD-1200 type cabbage harvester was designed to further optimize the working performance of the cabbage harvester. First, the structure and working principles of the harvester were introduced, and the cabbage harvesting process was analyzed. Based on the test method and theoretical analysis, a single-factor test was carried out on the main working parameters of the sample machine, the advancing speed, rotating speed of the pulling roller, rotating speed of the conveyor belt, and the cutter-head were taken as independent variables, and the qualifying rate of cabbage harvesting was taken as the response value. According to the Box–Behnken test design principles, a four-factor three-level response surface analysis was adopted to establish a mathematical model between all test factors and the qualifying rate of cabbage harvesting, then all test factors and their interaction effects were analyzed. The test results showed that the optimal working parameters of the harvester were: the advancing speed was 1.1 km/h, the rotating speed of the pulling roller was 90 r/min, the rotating speed of the conveyor belt was 205 r/min, and the rotating speed of the cutter-head was 395 r/min. The verification test results showed that the qualifying rate of cabbage harvesting was 96.3%, showing a good harvesting effect, with uniformly cut notches and a low damage rate. The test indicates that by optimizing the working parameters, the damage during the mechanized harvesting of cabbage can be reduced and the qualifying rate of harvesting can be improved; the working effect could, therefore, satisfy the requirements of market harvesting. [ABSTRACT FROM AUTHOR]

The working efficiency of the combine harvester is still very low. It is an important way to realize mechanization to optimize the cutting speed of the harvester and the forward speed of the cutter without increasing economic input. In view of this, the present study briefly summarized the current structure of combine harvester systems. A new type of adaptive control system of combine harvesters was designed from the angle of cutting speed and forward speed of cutter. The sugarcane test base was taken as the test field, and the best matching speed was obtained with the goal of high efficiency of combine harvester and minimum sugarcane damage rate. In the test of cutting speed and forward speed of combine harvester, the optimal cutting speed under different forward speed conditions was recorded. The test results showed that the designed adaptive control system of the combine harvester could control the cutting speed and forward speed of the cutter well. The cutting speed and forward speed adaptive control system can realize the response to the input parameters and meet the design requirements of the harvester. This study can improve the economic benefits of the combine harvester and the quality of the harvested crops. [ABSTRACT FROM AUTHOR]

In this paper, BP neural network is used to collect header height, AMEsim is used to simulate and analyze header height adjustment hydraulic system, and fuzzy PID control is used to adjust header lifting hydraulic cylinder to stabilize header height. The experimental results of harvesting different crops show that under the header height automatic control system, the error between the actual height of crop harvesting and the set height is within 15 mm, and the harvesting effect is good, which can meet the automatic regulation requirements of the header height of the multi crop combine harvester. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate economic and technical feasibility of replacing conventional combines with a new combine harvester. In the new combine that called crusher combine, along with separating the wheat from the cluster and straw, the straw is also crushed and stored in a separate tank that is added to the combine behind the grain tank. Thirty conventional and new combine harvesters were randomly selected and examined. Parameters such as; combine forward speed, reel index, field capacity, pre harvest loss, head loss, threshing and cleaning loss, total loss and quality loss were measured. Results show that total machine loss in conventional and new combines were 3.93% and 4.44% respectively. However, in the conventional combines, all the grain loss are thrown to the ground but in new combine 2.45% of grains fall down in the ground through of platform and 2.46% of grains through of threshing and cleaning units are mixed with straw and collected in straw tank and is used to feed livestock. The amount of straw harvested by the conventional and new combines was 1570 and 2970 kg Ha-1 and yield was, 2770 and 2922 kg Ha-1, respectively. Farmers are keen on the new combine because of gathering more straw, crushing it and storing it in the tank. The rate of seed breakage in seed tank of conventional and new combines were 3.37% and 2.81% and seed germination percentage were 90.8% and 94.7%, respectively. In new harvesters, due to the severe blows to the crushing unit, about 12.5% of the seeds have fracture or invisible damage and are unable to germinate, therefore, the grain harvested with this combine is not suitable for use as a seed. The results show that using the new combine instead of the conventional combine increases the income of the farmer and the combiner by 7 288 790 and 1 636 049 IRR Ha -1, respectively. [ABSTRACT FROM AUTHOR]

t—As the main harvesting machinery, the combine harvester is often due to improper adjustment of its operating parameters resulting in increased crushing rate and grain waste during the harvesting process. To quickly obtain the working range of key operating parameters under low crushing rate, this study conducted field tests on the relevant parameters affecting the crushing rate and finally selected the travel speed, feed rate, threshing drum speed, concave clearance, and crushing rate as node variables for the construction of the Bayesian network model. Based on the “search-and-score” algorithm, the best network structure can be obtained using the combination of the Akaike Information Criterion (AIC) scoring function and the hill-climbing method. In the obtained network, adjusting the proportion of the lowest level of the crushing rate nodes to 100 %, the operation strategy under the condition of low broken rate obtained by the network reasoning was: feed rate < 6 kg/s, travel speed < 5 km/h, concave clearance = 10 mm, threshing drum speed < 900 rpm. Three field trials were carried out using this optimized operation strategy, and the measured crushing rates were 0.93 %, 0.95 %, and 1.07 %, respectively, and the average crushing rate was 0.98 %. At the same time, when the optimized strategy was not used, the crushing rates were, respectively, 1.12 %, 1.41 %, and 1.93 %, and the average crushing rate was 1.48 %. The test results prove that the operation strategy based on Bayesian network inference can effectively reduce the crushing rate in the harvesting process. [ABSTRACT FROM AUTHOR]

When peanuts are harvested, the high rate of pod crush and pods leakage are the main problems in the current peanut fruit picking process. Optimized peanut picking rollers help to improve peanut harvesting efficiency. This paper investigates the fruit picking system of a three-monopoly, six-row semi-feeding peanut combine harvester, in order to reduce the rate of crush and leakage of peanut pods during the picking process. Firstly, this article specifies the structure and basic parameters of peanut picking pairs of rollers. Secondly, this paper combines JKR (Johnson-Kendall-Roberts) model theory, crash model simulation analysis, a field test, and other methods. Motion and force analysis are presented in detail for the peanut picking mechanism and associated harvesting components. The optimum clamping chain speed, the angle of installation of the picking rollers to the clamping chain, and the picking rollers' speed are determined. A three-factor, three-level regression orthogonal combination test was designed to obtain regression models for pod crushed and pods leakage rate. The regression model's response surface analysis concluded that when the clamping chain speed is 0.84–1.2 m/s, the fruit picking roller angle is 10°–11.2° and the fruit picking roller speed is 442 r/min–500 r/min. It is the optimal working parameter for the three-monopoly six-row peanut combine harvester. At this point, the peanut harvesting requirements are met, and the overall performance is significantly improved. This paper lays the foundation for the development of the semi-feeding peanut picking system. [ABSTRACT FROM AUTHOR]

Aiming at the problem wherein a straw crushing and throwing device (SCTD) installed in a rice combine harvester (RCH) has a small throwing width and does not match the harvesting width, this paper proposes an improved plan for installing wind blades (WB) and optimizing the parameters of the deflector. The structural parameters of the WB were determined, and static analysis was carried out. The influence of the number of WB on the airflow field of the crushing chamber (CC) was studied by CFD simulation. The movement of the straw after entering the throwing device (TD) was analyzed. It was determined that the factors affecting the throwing width under the condition of a certain straw speed were the installation angle of the deflector (IAD), and the arc length of the deflector (ALD) through the bench test. The optimal combination of deflectors parameters was determined to match the width of the harvester header. When the straw feeding speed was 4 kg/s, and the straw moisture content was 33.80%, the optimal parameters are that the ALD was 400 mm and the IAD was 9°. The matching degree with the header width (4.50 m) is 98.44%. This study can effectively increase the straw throwing width and create conditions for the smooth implementation of straw returning to the field. [ABSTRACT FROM AUTHOR]

The headers of modern combine harvesters are mainly equipped with passive side dividers. When harvesting lodged and tangled crops (for example, peas), plant mass accumulates on passive side dividers, the harvested strip is poorly separated from the rest of the field, which leads to a decrease in combine productivity and an increase in losses of the grown crop. To eliminate these shortcomings, the design of an active field divider is proposed, the main working body of which is a disk cutter. The article describes the design of the active side divider, provides a laboratory setup and describes the methodology for laboratory research to justify the optimal design and operating parameters of the proposed divider. The studies were carried out using the theory of multifactorial experiment. The optimization criteria are the completeness of separation of tangled stems and the amount of losses of the grown crop. The completeness of the separation of tangled stems is determined visually and by photographing, and the losses are determined by the method of collecting and weighing crumbled grains. As the results of laboratory studies show, the smallest losses are provided with the number of teeth of the disk cutter z=8 pieces, the frequency of rotation of the disk cutter n=125 min-1 and the operating speed of the feed conveyor v=2.0 m/s. At the same time, the active side divider works stably, the completeness of separation of tangled stems is 100%. the smallest losses are provided with the number of teeth of the disk cutter z=8 pieces, the frequency of rotation of the disk cutter n=125 min-1 and the operating speed of the feed conveyor v=2.0 m/s. At the same time, the active side divider works stably, the completeness of separation of tangled stems is 100%. the smallest losses are provided with the number of teeth of the disk cutter z=8 pieces, the frequency of rotation of the disk cutter n=125 min-1 and the operating speed of the feed conveyor v=2.0 m/s. At the same time, the active side divider works stably, the completeness of separation of tangled stems is 100%. [ABSTRACT FROM AUTHOR]

A better understanding of field performances for traditional harvesting methods and tools is essential in facilitating future improvement on their design and overall efficiency. Performance of different manual harvesting tools and methods was evaluated under farmer field conditions for IR841 and Nerica L20 rice varieties in Benin. Results from evaluation showed that an average of 84 to 161 man-hours was required to thresh a hectare of rice field using either the threshing by impact “bambam” or bag beating method. Less time was however required to thresh IR841 than Nerica L20 varieties, irrespective of manual threshing method used. Similarly, 59 to 91 man-hours was required to harvest a hectare of field using either a cutlass or sickle. However, to harvest Nerica L20 required less time than IR841 variety, irrespective of cutting tool used. Harvesting efficiency ranged from 78.9% to 85.3% with the sickle producing better harvesting efficiency than the cutlass irrespective of rice variety. Energy expenditure ranged from 471 W to 491 W for combine harvesting, 685 W to 1161 W for manual cutting with cutlass, 746 W to 860 W for manual cutting with sickle, 676 W to 873 W during threshing by impact “bambam” and 408 W to 409 W during traditional winnowing of threshed paddy. Whereas a mini combine harvester is better at significantly reducing drudgery compared to manual rice harvesting methods, the use of sickle is much preferred to cutlass in the case of manual rice harvesting. However, harvesting IR841 rice variety was generally less laborious than Nerica L20 variety. It is however recommended that further work on performance evaluation of different harvesting systems is carried out under experimental field conditions. [ABSTRACT FROM AUTHOR]

To realize automatic planning and optimization of operation paths for the autonomous navigation of rape combine harvesters during the harvesting operation in unmanned farms, two sets of coverage path planning algorithms for arbitrary quadrilateral fields were proposed in this study through procedures including theoretical analysis, design of algorithms, programming, and simulation and evaluation using examples. First, the fundamental requirements of the coverage path planning problem for the unmanned operation process of the rape combine harvest were defined after analyzing the characteristics of the harvesting process (plant branches intertwined and required to be separated by vertical cutters to reduce harvest loss, and field boundaries generally not crossable in rice/rape rotation regions) and of the combine harvesters (small turning radii and strong mobility of crawler-type machines). Then, full coverage operation paths were generated based on an isometric offsetting process and the scanline filling algorithm, and scheduling optimization was performed using the OR-Tools. The two sets of global operation coverage path planning algorithms for rape harvesting in arbitrary quadrilateral fields included one for the “contour parallel” circular operation paths based on the one-sided vertical cutter header and the other for the “contour parallel + direction parallel” mixed operation paths based on the bilateral vertical cutter header. The latter algorithm first used contour parallel paths to harvest the field to make enough turning space for the machine, and then it used the direction parallel paths to complete the harvesting operation in the central area. Through the test and simulation using the data of four typical actual fields, the stability and reliability of the algorithms were verified, and the algorithm running time was between 0.17 s and 4.73 s, which meets the basic requirements of path planning of rape combine harvesting for unmanned farming. At the same time, compared with the circular operation paths, which are widely used in actual harvesting operation, the total operation length of mixed paths was smaller than that of the traditional circular paths when no optimization was performed and the turning radius was small, and the number of reverses in the operation process was reduced by 36.36%-40.00%. After optimization, the number of reverses was further reduced by 33.33%-60.87%, and the length of non-operation paths was reduced by 7.20%-20.23% compared with the path without any optimization. Results showed that the mixed paths resulted in a better operation effect than the traditional circular operation paths. This study could provide theoretical and technical support for the combined harvesting of winter rape in unmanned farming of rice/rape rotation in the middle and lower reaches of the Yangtze River in China. [ABSTRACT FROM AUTHOR]

For grain combine harversters the correlation between cutting frequency and forward speed is typically based on the theoretical matching value of the cutting pattern. However, in reality cutting frequency is affected by cutting resistance which strongly linked to the physical and mechanical characteristics of the crop stems. Consequently, the field cutting frequency is usually lower the standard setting, resulting in the possibility of increasing losses during harvesting. An optimal cutting frequency model was built firstly based on the cutting pattern but the influencing factors on cutting frequency was analysed, and then a relationship model between cutting energy and cutting frequency was built. A regression model of the influence of wheat stem moisture content and cutting section area on cutting frequency was established by wheat stem cutting experiments. Thus, a cutting frequency compensation control strategy was proposed. To verify the effectiveness of the control strategy, field tests were carried out on uniformly growing wheat fields. The results showed that at the forward speeds of 1 m s−1 and 1.5 m s−1, the maximum deviation between the cutting frequency determined by this proposed approach and the optimal cutting frequency were 0.47 Hz and 1.1 Hz, respectively. Comparing performance without this compensation model, the maximum deviation of the cutting frequency without compensation decreased by 28.33% and 24.60%, respectively. The results indicated that with the proposed approach, the maximum deviation between the field cutting frequency and the predicted optimal cutting frequency could be significantly decreased and the cutting performance of the combine harvester could be observably improved. • Cutting energy model developed with the physical characteristics of wheat stems. • Proposed strategy effectively decreases the cutting frequency. • Provides a theoretical basis to optimise cutting performance. [ABSTRACT FROM AUTHOR]

Huanghuaihai summer maize region (HSMR) is one of the most difficult harvesting areas in the world, particularly in terms of mechanical grain harvesting. In this study, a multi-point experiment was therefore conducted in the HSMR to assess the influencing factors for better implementation of mechanical grain harvesting. 1250 groups of field test datasets were collected, including 20 harvester types and 420 maize varieties, for the grain quality after mechanical harvesting between 2013 and 2019. The harvesting quality of maize grain was determined using the moisture content, breakage rate, impurity rate, and harvest losses from fallen ears and grain. The results show that the moisture content of grain ranged from 11.13% to 44.60%, with an average of 27.38% for the summer maize harvested by a combine harvester. The breakage rate of grain ranged from 1.11% to 33.94%, with an average of 9.29%. The impurity rate ranged from 0 to 12.25%, with an average of 1.68%. The harvest yield loss rate ranged from 0 to 79.82%, with an average of 3.28%. The average moisture content and breakage rate of grain were significantly higher than the national average values. The average moisture contents of grain at harvest were 25.45%, and 25.05% in 2018 and 2019, respectively, whereas, the average breakage rates of grain were 9.07% and 7.88%, respectively. Although the average breakage rate of grain in the HSMR was still higher than the Chinese national standard (breakage rate ≤5%), the harvest quality had significantly improved since 2013. There was a quadratic relationship between the breakage rate and moisture content of grain at harvest. The minimum breakage rate occurred at the grain moisture content of 21.08%. A high breakage rate of grain was currently the main quality issue to restrict the application of mechanical harvesting in this region, due mostly to the high moisture content of grain at harvest. The average impurity rate met the national standard of ≤3%, whereas, the average harvest yield loss rate met the national standard of ≤5%. Nevertheless, the impurity rate of more than 3% was 17.07% of samples, and the harvest yield loss rate of more than 5% was 19.05% of samples. The grain loss accounted for 28.7% of the total loss, and the ear loss accounted for 71.3%. The harvest loss from fallen ears contributed to the main part of harvest loss. There was a large difference in the number of falling ears in the experimental fields, with a variation coefficient of 235.22%. The proportion of maize varieties suitable for mechanical harvesting tended to increase over the study period, indicating better agreement with the continuous decrease in the grain moisture content, breakage rate, impurity rate, and harvest loss rate. Additionally, the yield remained unchanged over the study period. The grain moisture content and breakage rate clearly represented the heat resources with a gradual decrease from south to north, indicating the highest in the north, the second-highest in the middle, and the lowest in the southern region. Consequently, the optimal selection varieties with early maturity and fast dehydration can contribute to reducing the grain moisture content at harvest under the regional climate in the HSMR. Alternatively, an appropriate maize grain harvesting machine with a low grain breakage rate can also be expected to enhance the harvest quality, with emphasis on the high crushing-resistant maize varieties, cultivation technology, and operating procedures of a harvester, even harvesting at the appropriate time. [ABSTRACT FROM AUTHOR]

As a main grain production equipment, the combine wheat harvester plays an important role in grain production, and its technological development level is an important indicator of the degree of agricultural modernization. However, during the harvesting process, the working parts of the harvester interact with the crop to be harvested, so that the dust originally attached to the surface of the crop is disturbed and separated from the surface of the organism, forming floating and flying dust, some of which are scattered around the harvester, seriously affecting The driver’s body is healthy; some infected plants carry diseased dust, which is more harmful to the human body; more dust is dispersed in the air with the wind, causing a wider range of air pollution and increasing the amount of inhalable particles in the air. This has become one of the sources of air pollution during the crop harvest season. In order to understand the dust generation status and the characteristics of the dust composition, this paper first conducts the dust concentration and distribution test on the operation site of the combine wheat harvester .The result is as the header and tail of harvester are the main areas where dust is generated, Excessive dust mass concentration will harm the health of workers .The characteristics of the dust sample was tested results as follows: the proportions of dust with a particle size of 10μm and 100μm or less are 45% and 92%, the dust is mostly composed of minerals, grease and carbohydrates. The dust measurement test revealed for the first time the dust generation and dust composition characteristics of combine wheat harvester operations in the rice-wheat (oil) rotation area in southern my country. On this basis, a dust suppression system installed on the combine wheat harvester was designed. The system adopts the working principle of negative pressure dust suction and filter cartridge dust collection. The system utilizes the power of the existing combine wheat harvester and can change the working parameters of the fan at any time to meet a variety of field working conditions. Conduct field tests on the dust suppression system. Through theoretical analysis to determine the main factors that affect the efficiency of the dust suppression system. Taking the harvester header dust suppression efficiency and harvester tail dust suppression efficiency as the test indicators, and the harvester speed, fan speed and environment humidity as the test factors. Using Box-Behnken central combination test method, the three-factor and three-level test are carried out. A mathematical regression model of various factors and test indicators was established. Through variance analysis and response surface analysis, the influence of harvester speed, fan speed and environment humidity on the test indicators is obtained. Use Design-Export8.0.6.1 data analysis software to fitting and optimization analysis of the test results, the optimal parameter combination is obtained as follows: harvester speed 3.73 km/h, fan speed 3 507 r/min, and ambient humidity 56%. On this condition, the efficiency of the header dust suppression is 76.8%,the efficiency of the tail dust suppression is 79.6%. The optimal working parameters are tested and verified to verify the feasibility of optimizing the optimal parameter combination, the minimum fan speed of the dust suppression system to meet the dust suppression requirements under difficult working conditions is 3 332 r/min. This research can provide a basis for the design of the harvester dust suppression system. [ABSTRACT FROM AUTHOR]

In order to reduce greenhouse gas emissions, fuel efficiency standards and comparisons among models are required for agricultural machinery as well as automobiles. However, a method for quantitatively evaluating fuel consumption of the combine harvester does not currently exist. We examined the effects of harvesting velocity and crop conditions on fuel efficiency during reaping, conveying, threshing, sorting and cutting for head-feeding combine harvesters. We measured hourly fuel consumption under different harvesting velocity and crop conditions and performed a multiple regression analysis using a stepwise regression for hourly fuel consumption under various conditions. The hourly fuel consumption can be explained by the following factors: flow rate of dried crop (kg s−1), grain number of unhusked rice per gram (g−1), and moisture content of unhusked rice (%). The adjusted coefficient of determination was 0.887, and the Standard Error of Calibration was 0.238 L h−1. Through verification of the multiple regression equation for hourly fuel consumption using these conditions as explanatory variables, a difference between these cultivars was not confirmed. Further, we use the multiple regression equation obtained in this study to propose a method for its application to other combines. • Hourly fuel consumption is determined by unhusked rice conditions and flow rate of dried crop. • The cultivar did not affect the calculated values of hourly fuel consumption. • An evaluation method to compare the hourly fuel consumption for harvesting was proposed. [ABSTRACT FROM AUTHOR]

Oil sunflower has widely been served as the characteristic nutritional quality of the vegetable oil industry in Xinjiang Uygur Autonomous Region, China. The planting area of oil sunflower is ever-increasing in recent years, particularly with the adjustment of agricultural industrial structure. Nevertheless, the low level of mechanized harvesting has posed a great challenge to the continuous expansion of planting areas in the rapid development of the oil sunflower industry. The current harvester of oil sunflower is using the wheat combine harvester with the modified cutting table in Xinjiang, where the threshing device and cutting table are not suitable for oil sunflower harvesting. The cutting table device in the machine cannot meet the harvesting requirements of high efficiency and low damage, according to the grain damage rate and loss rate of oil sunflower in the harvest. Structural parameters of oil sunflower rare also significantly different between the varieties and planting modes, such as the thickness and diameter of the faceplate, as well as the diameter and height of the stem. Therefore, it has become an urgent problem to realize mechanized harvesting with high efficiency, low damage, and low loss for the oil sunflower industry. In this study, a specific reel-board cutting table device in a combine harvester was proposed for the mechanized harvesting of oil sunflower, with emphasis on the low loss or damage of grains and reliable operation with high efficiency in harvesting. The structure and working principle of the cutting table devices were also introduced to the special use for the oil sunflower. A movement model of dialing teeth was established to analyze the dynamic characteristics and the movement track for the end point of dialing teeth in the cutting table device. An investigation was made to clarify the changing relationship among the rotational speed of the reel board, the forward speed of the machine, and the circumference of the reel board, in the simulation for the end movement track of the reel board. A MATLAB software was used to write the program and implement simulation, in order to obtain the motion trajectory curve of two adjacent dialing teeth. The performance test results show that the loss rate of oil sunflower was 2.04%in the cutting table disk, where the tilt angle of the guide plate was 25°, the speed of the screw conveyor was 150 r/min, and the distance between the reel board and the guide plate was 170mm. An orthogonal experiment and parameter optimization of field oil sunflower harvesting were utilized to explore the effect of the different combinations of operational parameters, such as the forward speed, the rotation speed of reel board, and the height of the stalk stub, on the loss rate and damage rate of oil sunflower seeds. A Design-Expert system was used to optimize the test data, thereby obtaining the optimal combination of parameters. The experimental optimization results show that the loss rate and damage rate of oil sunflower were 1.90% and 0.65%, respectively, where the forward speed of the oil sunflower harvester was 1.2 m/s, the rotation speed of the reel board was 240 r/min, and the height of the stalk stub was 570 mm. The findings can significantly improve the performance of a combine harvester, particularly on structural design and parameters optimization in a combine harvester for the oil sunflower. [ABSTRACT FROM AUTHOR]

The high harvest losses associated with the mechanical harvesting of maize in China are currently a major barrier to the adoption of this technology. This paper summarizes works of literature regarding harvest losses from the combine harvesting of maize in China and abroad. The main findings are as follows: (1) In 2012-2019, 2987 samples data obtained from the major maize production areas of China showed that the average harvest loss was 345.2 kg/hm² (3.5% of the average yield), with losses ranging from 0 to 9288.5 kg/hm²; (2) The harvest losses from combine harvesting are mainly caused by the dropping of ears. The ear losses include the pre-harvest loss caused by ear abscission, damage caused by maize borer, lodging, and the ear loss during combine harvesting, and the main pre-harvest loss is caused by lodging; (3) Harvest losses are affected by maize variety, planting mode, cultivation management, pests and diseases, weather conditions during harvesting, harvest date, combine harvester type, harvester adjustment, operator proficiency, and the terrain conditions of the maize field; (4) The harvest losses from combine harvesting are also related to the type of header, feeding and threshing methods, the adjustment of header stripping clearance, feeding amount, forward speed, cylinder or rotor speed, and the clearance between the cylinder and the concave of the harvester. However, the combine losses mainly come from header losses. In order to reduce the harvest losses, the following solutions were proposed: (1) Breed and select maize varieties which are resistant to lodging, especially during the field drying of mature grains, as well as those resistant to maize borer and stalk rot; (2) Select varieties suitable for grain harvest--which requires matching the accumulated-temperature demand of the maize hybrids, optimal plant density, row spacing, and irrigation and fertilizer management with the light and heat conditions of the production area while cultivating uniform populations and healthy plants--as well as preventing and controlling damage from maize borer, stalk rot, and ear rot, harvesting at the appropriate time; (3) Develop and select advanced maize combine harvesters, formulate standardized operating procedures for harvesting machinery, and standardize field operation; (4) select appropriate agricultural machinery and agronomic practices, and improve the training of maize producers and harvester operato [ABSTRACT FROM AUTHOR]

The auxiliary roll of the rice combine harvester were developed and manufactured from local material to reduce wearing rate for threshing device also minimize fuel consumption and energy requirements. Replacing auxiliary roll knives arranged in a spiral instead by forks separating on length were 90 cm with seven rows and each row has four blades to increase the efficiency of separating the seed. The measurement indices of the auxiliary roll before and after development were threshing efficiency, threshing capacity, fuel consumption, power required, energy requirements, device mass losses percent, wearing rate, wearing resistance, critical wearing value, specific wear and expected life. during the harvesting operation of rice crop the rustles showed It is recommended to use the knife as a threshing device because auxiliary roll threshing efficiency increased by 0.2% threshing capacity increased by 16.83 %, fuel consumption decreased by 0.16 %, power required decreased by 0.15 %, energy requirements decreased by 0.33 % device mass losses percent decreased by 1.4 %, wearing rate decreased by 0.11 % wearing resistance decreased by 0.12%. critical wearing value increased by 34 %, specific wear decreased by 25 % and expected life increased by 78.60% all this result tested after 500h operating time. [ABSTRACT FROM AUTHOR]

A high grain breakage rate is the main problem that occurs during mechanical maize harvest in China. The breakage sensitivity of different varieties was significantly different, and the breakage resistance is heritable. Therefore, breakage resistant variety screening can help improve the field production efficiency and provide references for breeding work. In this study, 42 varieties of maize were harvested with the same mechanical parameters and the same manipulator on a range of harvest dates at experimental stations in Xinxiang, Henan Province, in 2017 and Changji, Xinjiang Province, in 2018 to determine the sensitivity of grain moisture content on grain breakage rate during machine harvest for different varieties. The integral value of the grain breakage rate curve corresponding to the range of 15% to 30% grain moisture content was used as an index that expressed the sensitivity of maize grains to breakage depending on grain moisture content (BSW). Forty-two varieties were categorized as having weak, intermediate, or strong BSW. Among the same four varieties in the two stations, Lianchuang 825 and Lianchuang 808 were classified as sensitive and fragile varieties, Shandan 650 was classified as an intermediate variety, Zeyu 8911 was divided into weak sensitive and breakage-resistance varieties in Xinxiang and intermediate varieties in Changji. The BSW classification results at the two experimental sites were generally consistent, indicating that breakage sensitivity due to moisture content may be a relatively stable genetic characteristic. This study suggested that the integral method for determining BSW can be used to assess the resistance of different maize varieties to grain breakage during mechanical harvesting. The integral method was used to identify twelve breakage-resistant varieties in Xinxiang Station, and six breakage-resistant varieties in Changji Station. This study provides a method for screening maize varieties that are suited to mechanical grain harvesting and for studying the mechanisms of grain breakage resistance. [ABSTRACT FROM AUTHOR]

A mid-size combine harvester with 2.76 m reaping width and 103.53 hp engine output has been employed in grain corn production, especially by small-scale grain corn farmers. This study attempted to determine field performances of a typical mid-size combine harvester by measuring its effective field capacity (EFC), field efficiency (FE), fuel consumption (FC) and field machine index (FMI). Different types of energy inputs such as fuel, machinery, human, included direct, indirect, renewable and non-renewable energy involved in grain corn harvesting were also measured. The field measurements were carried out in 3 ha of grain corn farm, under similar field conditions using a typical mid-size combine harvester. The average values of EFC, FE, FC and FMI for the mid-size combine harvester were found to be 0.23 ha/h, 34.97%, 37.25 lit/ha and 0.91, respectively. The average equivalent energy values of fuel, machinery and human energy were 1780.70 MJ/ha, 587.73 MJ/ha and 8.53 MJ/ha, respectively. The average values of the direct and indirect energy were 1789.23 MJ/ha and 587.73 MJ/ha, respectively. The average values of renewable and non-renewable energy were recorded at 8.53 MJ/ha and 2368.42 MJ/ha, respectively. The mid-size combine harvester investigated in this study exhibited good field performance characteristic using a reasonable amount of energy consumption as compared to harvesting operation for other grain crops. From the results, it can be concluded that good practice in harvesting operation could improve field performance, and minimise operational costs and energy consumption. [ABSTRACT FROM AUTHOR]

In the design of corn combine harvester, there is a high demand for customization and diversification in China. Aiming at the problems of backward design method, lack of design knowledge and long product development cycle, the discrete beam method is used to establish the corn plant model. The model of subdevice and the vertical and horizontal roller picking device is established by using UG, and the virtual prototype model is established by using ADAMS software. Meanwhile, the simulation experiments on the kinematics and dynamics performance of the separating device, the corn plant and the picking roller are carried out, and the simulation results are verified by field experiments. Through this method, the design parameters of the separating device and the picking roller are serialized, the method of evaluating the separating performance and the picking performance is provided, and the development and design cycle is shortened, which provides certain reference and theoretical basis for the development and design of the corn harvester header. [ABSTRACT FROM AUTHOR]

Farmers have to finish their harvesting with high efficiency, because of time and cost. However, farmers are lacking knowledge and information required for selecting suitable combine harvesters and giving the conditions of their rice fields, because both information factors (combine harvester and field condition) impact the field capacity. The field capacity model was generated from combine harvesters with the Thai Hom Mali rice variety (KDML-105). Therefore, this study aimed to determine the prediction model for effective field capacity to combine harvesters when harvesting the Thai Hom Mali rice variety (KDML-105). The methods began by collecting data of 15 combine harvesters, such as field, crop, and machine conditions and operating times; to generate the prediction model for the KDML-105 variety. The prediction model was then validated using 12 combine harvesters that were collected similarly to the model creation. The results showed a root mean square error (RMSE) of 0.24 m²/s for the model. The prediction model can be applied for farmers to select the proper combine harvesters and give their field conditions. [ABSTRACT FROM AUTHOR]

Breakage rate is one of the most important indicators to evaluate the harvesting performance of a combine harvester. It is affected by operating parameters of a combine such as feeding rate, the peripheral speed of the threshing cylinder and concave clearance, and shows complex non-linear law. Real-time acquisition of the breakage rate is an effective way to find the correlation of them. In addition, real-time monitoring of the breakage rate can help the driver optimize and adjust the operating parameters of a combine harvester to avoid the breakage rate exceeding the standard. In this study, a real-time monitoring method for the grain breakage rate of the rice combine harvester based on machine vision was proposed. The structure of the sampling device was designed to obtain rice kernel images of high quality in the harvesting process. According to the working characteristics of the combine, the illumination and installation of the light source were optimized, and the lateral lighting system was constructed. A two-step method of "color training-verification" was applied to identify the whole and broken kernels. In the first step, the local threshold algorithm was used to get the edge of kernel particles in a few training images with binary transformation, extract the color spectrum of each particle in color-space HSL and output the recognition model file. The second step was to verify the recognition accuracy and the breakage rate monitoring accuracy through grabbing and processing images in the laboratory. The experiments of about 2300 particles showed that the recognition accuracy of 96% was attained, and the monitoring values of breakage rate and the true artificial monitoring values had good trend consistency. The monitoring device of grain breakage rate based on machine vision can provide technical supports for the intellectualization of combine harvester. [ABSTRACT FROM AUTHOR]

Aimed at the problem of high cleaning loss rate, impurity rate and secondary impurity rate due to improper adjustment of main operating parameters of wheat combine harvester double-outlet multi-dults cleaning device, single factor and multi-factor optimization tests that took feed amount, wind door opening, fan speed, upper and lower wind deflector angles as main test factors were conducted. The influences of each test factor on the cleaning loss rate, impurity rate, and secondary impurity rate were studied to find the optimal parameter combination. Firstly, referring to the relevant parameters of Kubota 988 model, which has a large amount of wheat harvester in the market, a test-bed with double air outlet multi-ducts for combine harvesters was built. When there were four ducts, the wheat cleaning loss rate 0.78% and impurity rate 0.48% were the lowest compared to the two or three ducts. Moreover, through single factor test of double air outlet four ducts cleaning device, the optimal range of feed amount was determined from 4.5 to 5.8 kg/s, wind door opening was 0°-20°, fan speed was 1 200-1 600 r/min, upper and lower wind deflector angles were 0°-20°. The results of single factor test showed that the cleaning loss rate increased with the increase of the feed amount and fan speed, and decreased with the increase of the upper and lower wind deflector angles; the impurity rate decreased with the increase of fan speed, and increased with the increase of the feed amount and upper and lower wind deflector angles; the secondary impurity rate increased with the increase of feed amount, and decreased with the increase of the wind door opening, fan speed and upper and lower wind deflector angles. The multi factor bench test and the orthogonal test with five factors and three levels were carried out by using the Box Behnken center combination test design theory. The regression equations about the cleaning loss rate, impurity rate and secondary impurity rate were obtained. The results showed that the factors of fan speed, feed amount, upper wind deflector angle had significant impact on the cleaning loss rate, the factors of fan speed, upper and lower wind deflector angles have impact on the impurity rate, and the factors of upper wind deflector angle, the fan speed and the feeding amount have significant influence on the secondary impurity rate. Through optimization of the target parameters, the optimal parameters combination were the feeding amount 4.5 kg/s, the wind door opening 10.2°, the fan speed 1 548 r/min, the upper and lower wind deflector angles 20° and 0°, at this time, the cleaning loss rate, impurity rate and secondary impurity rate were 0.79%, 0.40% and 0.82% respectively. Furthermore, the bench test under the optimal parameter combination condition was carried out to verify the accuracy of the optimal results. The results of bench test showed that the cleaning loss rate, impurity rate and secondary impurity rate were 0.75%, 0.38% and 0.76% respectively, and the error between test results and optimization results were 5.1%, 5.0% and 7.3% respectively. The results of this study can provide the references for the adjustment operating parameters and technical support for improving the performance of the multi-ducts cleaning device of the combine harvester. [ABSTRACT FROM AUTHOR]