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An automatic feeding device for substrate filling was designed to address the challenges of difficult feeding and low efficiency in the citrus seedling pot filling and transferring machine. The device comprises a framework, tracks, overturning frame, drive system, etc. In order to ensure optimal performance, the frame's turning angle was set at a minimum of 110° and the angle between the frame's horizontal plane and slope was determined to be 120°. Following optimization, the number and intensity of sudden changes in velocity, angular velocity, and thrust were reduced, thereby prolonging the device's service life. The prototype test demonstrated that the device has an average feeding time of 9.86 s, is capable of raising 0.14 m3 of substrate in a single cycle, and has a handcart turning angle of 111°. Furthermore, no residual substrate remained in the handcart, and the handcart fixing mechanism operated correctly. The torque measurement results of the motor output shaft were found to be consistent with the simulation results in ADAMS, with a maximum force difference of only 298 N. The simulation was found to be accurate, with an error rate of only 3.67%. This model can be utilized as a dependable reference for the optimization of the design of the automatic feeding device. [ABSTRACT FROM AUTHOR]

Multi-robot systems can perform more complex tasks with high precision and large loads than single-robot systems. The calibration of the base coordinate system is the basis and premise to ensure the collaborative operation between the dual-robot. In this study, a dual-robot calibration system based on calibration tooling components was established, which could quickly and accurately obtain the relative position between dual robots. Based on three reference measurement points of the orthogonal distribution in the calibration tool coordinate system, a mapping relationship between the distance from the reference measurement point to the robot end point and the parameters of the robot base system was established, and a fast dual-robot base system parameter calibration solution method based on "three-point measurement calibration" was proposed. The experimental results show that this method can quickly and accurately obtain the transformation relationship between the dual robot base coordinate systems. The accuracy and efficiency of the calibration have been greatly improved. It is of great significance for meeting the requirements of high efficiency, low cost, and easy operation in the factory application process. [ABSTRACT FROM AUTHOR]

In Southeast Asia, many varieties of citrus are grown in hilly areas. Compared with plain orchards, it is difficult for large spraying equipment to move in hilly orchards. Small spraying equipment can enter hilly orchards, but their spraying power cannot make droplets penetrate into the canopy, resulting in low deposition rates within the canopy. As a kind of unstructured narrow space, the branches within the canopy are interlaced, thus a flexible manipulator that can move within the canopy is required. In this paper, a novel remote-controlled, cable-driven target spray robot (CDTSR) was designed to achieve a precise spray within the canopy. It consisted of a small tracked vehicle, a cable-driven flexible manipulator (CDFM), and a spray system. The CDFM had six degrees of freedom driven by a cable tendon. The forward and inverse kinematics model of the CDFM were established and then the semispherical workspace was calculated. Furthermore, while considering precise control requirements, the dynamics equations were derived. The experimental results demonstrated that the CFDM could move dexterously within the canopy with interlacing branches to reach pests and diseases areas in the canopy. The entire operation took 3.5 s. This study solved the problem of a low spray deposition rate within a canopy and has potential applications in agricultural plant protection. [ABSTRACT FROM AUTHOR]

Walnut shell breaking is the first step of deep walnut processing. This study aims to investigate the mechanical properties and fracture state of the Qingxiang walnut shell under unidirectional load and guide the complete separation of the walnut shell and kernel. The spherical thin shell model of the walnut (the fitting error is less than 5%) was established and verified. The process from the initiation to the expansion of walnut cracks was analyzed. The crack expansion rate was estimated in terms of the crack fracture regularity on the shell's surface. Based on the momentless theory and finite element simulation analysis, we found that the stress on the shell surface in the concentrated force action region was gradient distributed from inside to outside and that the internal forces were equal in all directions in the peripheral force action region. The unidirectional impact shell-breaking experiments confirmed the reliability of our spherical thin shell model and verified our hypothesis of walnut shell fracture along the longitudinal grain. Our results can provide a theoretical basis for the development and structural optimization of shell-breaking machinery. [ABSTRACT FROM AUTHOR]

To solve the problems of agricultural machinery simplification, lack of universality and uneven land in mountain orchards, a light self‐propelled universal mobile platform for mountain orchards is studied in this paper. A light crawler chassis, an electric drive system and a multi‐sensor control system are designed. Through the kinematics and dynamics modelling of the general platform, the prediction model of the motion system of the general mobile platform is determined. Then the observation model of the system motion is determined based on the multi‐sensor fusion, and the multi‐sensor fusion navigation control system is established. Based on the energy consumption model of mobile platform, the energy consumption optimal trajectory planning is carried out. The energy consumption optimal trajectory radius is 2.5 m and the deflection angle is 36.9°, and the optimal trajectory radius of energy consumption is 1.9 m. Orchard experiments show that the maximum lateral displacement deviation of the universal mobile platform is less than 0.1 m, which can basically achieve the expected trajectory autonomous walking function. [ABSTRACT FROM AUTHOR]

Preoperative rehearsal is very important before the operation, because of its particularity and difficulty, traditional printing can hardly achieve it, and thus a new kind of fixture for the 3D printing of pelvis model is critical. Fixture design in manufacturing system is very important and directly affects the processing quality, production efficiency and manufacturing costs. As a new method of manufacturing, the alternative style of additive and subtractive manufacturing is potential in market prospect. New requirements on the performance and structure of the fixture were put forward due to the high complexity of product surface in alternative manufacturing, as well as the force characteristics of numerical control (NC) processing. In this paper, we propose a novel type of fixture which is capable of completing printing tasks in preoperative rehearsal. An experiment is performed to validate the rationality and universality of the fixture. A 3D printing practical case of pelvis model before pelvic correction surgery is used to demonstrate the effectiveness of the present fixture. [ABSTRACT FROM AUTHOR]

Laron syndrome, also known as growth hormone insensitivity syndrome (GHIS), is an autosomal recessive genetic disorder associated with severe postnatal growth failure, and normal and/or elevated growth hormone. This disease is frequently caused by a point mutation in the growth hormone receptor gene (GHR). Here, we identified a novel homozygous substitution mutation (E42K: GAG-->AAG at codon 42 cDNA) of the GHR gene in a Chinese girl with Laron syndrome. This mutation was predicted to impair the GHR binding affinity to human growth hormone (hGH), and was responsible for low levels of insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3, and GH binding protein (GHBP) in serum.