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Current rice planting operations are mainly transplanting and direct seeding. However, many operational procedures involving transplanting use poor quality of machinery resulting in high labour costs and low working efficiency. Here a no-tube seeding (NTS) method is proposed and the effects of technical parameters (travel speed, seeding wheel rotational speed and ground clearance) on the seeding quality (accuracy, dispersion and uniformity) are investigated using a single factor bench test. A multifactor bench test was carried out to optimise the technical parameters based on the requirements of different seeding rate. The optimal value of the travel speed was constant at 0.80 m s−1 at different seeding rates, the optimised range of seeding wheel rotational speed and ground clearance is 17.5–23.53 r min−1 and 81.2–85.6 mm, respectively. A field experimental comparison between NTS, traditional tube seeding (TTS) showed that the seeding quality of NTS was significantly better than that of TTS. Compared with transplanting, rice growth status at booting stage for NTS and TTS was not significantly different with rows closed. However, the number of panicles per unit area was greater which was beneficial to the formation of high yield. The maximum and average yield of NTS increased by 10.1% and 6.7% compared with TTS and compared with transplanting it maximum and average yield increased by 11.6% and 9.3% respectively. These results indicate that NTS is feasible and efficient method.

In this paper, the safe sealing temperature range of tempered glass was determined to be no more than 300 °C by experiments. On this basis, the feasibility of silver oxide system low melting solder (SOSLMS) used in tempered vacuum glazing (TVG) sealing was explored by sealing strength experiment, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and other test methods. The results of sealing strength experiment showed that the bonding strength of the sealing layer was inversely proportional to the sealing temperature. The bonding strength of the sealing layer in the range of 260 °C–290 °C met the standard requirements (not less than 0.6 MPa) except for the failure of the sample sealing at 300 °C. The observation results of SEM showed that when the sealing temperature was 260 °C and 270 °C, the solder layer had uniform fusion and dense structure, and the sealing layer was tightly bonded. With the increase of sealing temperature, the solder layer began to produce large holes, and there was obvious open gap between solder layer and glass substrate after stretching. The analysis results of EDS showed that the Ag and V elements all diffused into the glass at each sealing temperature, the difference of diffusion concentration and distribution was not significant. The analysis results of XRD showed that when the sealing temperature was in the range of 260 °C–270 °C, there was no crystallization phenomenon in the SOSLMS. When the sealing temperature was in the range of 280 °C–300 °C, Ag2VO2PO4 crystals began to precipitate, and with the increase of temperature, the higher the crystallinity was, the greater the crystal content was. In conclusion, in the range of 260 °C–270 °C, the SOSLMS showed good sealing performance, which was suitable for TVG sealing.

To overcome the problems of machine matching and environmental adaptability existing in the automatic driving technology of agricultural machinery, this paper proposed a automatic driving system of motor type agricultural machinery, and introduces the system's composition, working process and control strategy from the overall level. A coaxial angular displacement measuring device is innovatively designed, which improves the matching of machine tools. An innovative GNSS/INS/vehicle combination navigation method is proposed to reduce the accuracy requirement of inertial measurement unit and improve the environmental adaptability of the system. In order to reduce the working intensity of agricultural mechanics, human-computer interaction interface is designed to make the manipulation more concise and clear. The indexes of straightness accuracy and spacing accuracy of connecting lines are put forward to evaluate the system operating accuracy, and the experiments are carried out. The results show that the straightness accuracy is 1.678 cm and 1.965 cm under the two different speeds of 0.5m/s and 2.5m/s, and the accuracy of connecting line spacing is 2.428 cm and 2.525 cm. The operation accuracy is high.

In this paper, a prediction method of the heat transfer coefficient of composite vacuum glazing (CVG) is proposed. By analyzing the heat transfer process of CVG, the theoretical calculation formula for the heat transfer coefficient of CVG is established. CVG temperature variation under the test conditions specified in the national standard is simulated using ANSYS. The CVG heat transfer coefficient is calculated by combining the theoretical formula and simulation results. The simulation results are then verified by comparison to a physical experiment. The results show that the deviations between the experimental and predicted values are ≤3.8%, verifying the accuracy of the simulation results and proving that the model can be used in engineering practice. Furthermore, the effects of different coating positions on the heat transfer performance of CVG are studied. The results show that different coating positions have a significant impact on the heat transfer coefficient of CVG. The heat transfer coefficient is shown to be lowest to highest under the following conditions: when the Low-E coatings are located on both sides of the vacuum layer (2LC-V), followed by Low-E coatings on the side of glass pane II near the vacuum layer (1LC-V), Low-E coatings located on the side of glass pane I near insulating layer (1LC-I), and finally, when there are no Low-E coatings (NLC) on the glass panes. Overall, this model is an effective and accurate analysis method of the heat transfer coefficient.

Current approaches to topdressing and weeding operations for rice cultivation present several disadvantages, such as poor precision, low efficiency, serious environmental pollution, and so on. This paper presents a row-controlled fertilizing–weeding machine to improve the precision of fertilizing and weeding operations and to reduce the heavy pollution associated with rice cultivation. A proportional–integral–derivative algorithm was adopted to realize accurate fertilization control, and an automatic driving system for agricultural machinery based on BeiDou navigation was used for accurate row-controlled operation. Accuracy testing and field experiments were carried out. The results show that the fertilization control system can stabilize the speed to within 0.55 s of the desired speed with a standard deviation of around 0.32 r·min−1. The row-controlled operation ensures the lateral deviation is within ± 5 cm at operating speeds below 5 km·h−1. The high uniformity and accuracy of fertilization meet agronomic requirements and rice cultivation standards, and the weeding performance is acceptable at working speeds below 5 km·h−1.

Aiming at the problem of uneven distribution of surface stress and deformation in tempered vacuum glazing (TVG) caused by vacant support pillars, which would easily cause glass surface damage and affect product safety and service life. This paper established the mechanical model of TVG and studied the mechanical properties of TVG with continuous vacant support pillars (CVSP). The maximum surface stress (σmax) and deformation of 1.2 m by 0.8 m double evacuated glazing with 5 mm thick tempered glass panes with no more than 4 CVSP (0.3 mm height, 0.6 mm diameter and 50 mm spacing cylindrical stainless steel support pillars) in different areas and arrangement were obtained by ANSYS. The simulation results showed that the mechanical properties of TVG were worse with the increase of the number of CVSP. Under the condition of other factors being the same, the mechanical properties of TVG were the worst with CVSP in the middle, and were the best with CVSP arranged in linear. Based on the rule of simulation results, the license definition conditions of TVG with CVSP were formed. Meanwhile, some samples of TVG with CVSP were made, and the σmax was measured by the stress analyzer. The results showed that the relative error between the measured and simulated values of σmax was −4.25%–3.66%, the simulation results were reliable, and the license definition conditions of TVG with CVSP were valid.

In order to solve the problem of poor uniformity and low depth stability in traditional tube seeding (TTS), this paper proposes a no-tube seeding (NTS) method for wheat sowing. A NTS test platform was constructed, and accuracy and uniformity of seeding quality were optimized with the ground clearance as the experimental factor. It was found that the ground clearance with the seeding accuracy and uniformity were both quadratic functions. The seeding quality was good in ground clearance range of 5∼8.8 cm, and ground clearance of 7 cm was in line with the actual seeding conditions, the corresponding seeding accuracy was 83.84 % and the variation coefficient of seeding uniformity was 14.68 %. The NTS machine was designed and grooving scheme for seeding was optimized by adopting a convex plate on the cylindrical surface of press wheel. The depth and width stability of the grooving operation was 87.35 % and 83.13 %, respectively. Experimental comparison between TTS and NTS was carried out in the field. The results showed that the seeding accuracy of NTS was 83.13 % and the variation coefficient of seeding uniformity was 15.12 %. The results also showed that accuracy of NTS was consistent with theoretical value, and was significantly better than that of TTS. Meanwhile, NTS can save 6% seeds and 5% fertilizer. The wheat emergence of NTS was robust with a wide belt and no leaking, the emergence rate of NTS was 90.46 % with higher plant height and more root quantity than that of TTS. This research fills in a literature gap for wheat precision seeding technology.