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In order to solve the problem that some pests and diseases can not be found in time during the forest inspection, resulting in economic losses, and the complex road conditions in the forest lead to frequent injury of forest patrollers, this paper proposes a forest pests and diseases tree marking vehicle, which adopts the four-track walking mode of hollow shaft and solid axial cooperation, so that the vehicle can change the position of the marking vehicle by changing the swing angle of the track while completing the front and back movement, It has greatly improved the passing ability and obstacle surmounting ability of the marked vehicle. In this paper, the obstacle surmounting model is established, and the relationship between the parameters of the tree marker vehicle and the obstacle surmounting height is obtained. Through establishing the multi-body dynamics model of the tree marker vehicle for forest diseases and insect pests, the simulation experiments of double-side obstacle crossing and single-side obstacle crossing were carried out, and the transformation laws of the swing arm moment and swing arm angle during obstacle crossing were obtained. The simulation prototype was trial-produced for test, and the results showed that the forest pest and disease marking vehicle could complete the marking of pest and disease trees by adjusting its posture through the obstacles in the forest. [ABSTRACT FROM AUTHOR]

Cotton, one of the main commercial crops in the world, mostly distributes in several major growing regions, including Xinjiang of western China. An important renewable biomass resource, the cotton stalk has received most attention to serving as the poultry feed, paper making, environmental protection materials, and biomass briquette fuel. Particularly, the highly efficient recycling of cotton stalk can be widely expected to bring enormous economic and ecological benefits. However, most previous treatments are focused on pulverizing cotton stalks and returning to the field. A great challenge is still posed on the current pulling machines for cotton stalks, with emphasis on operational requirements, leakage, and breaking rate. In this study, a novel horizontal-roller cotton stalk pulling machine was proposed to efficiently implement the pulling of the whole cotton stalk after harvesting. The machine was mainly composed of traction, gearbox, stalk conveying, transmission system, machine body, road wheel, spacing regulating mechanism, stalk pulling, dam-board, and support frame. Specifically, the power input shaft of the gearbox was connected to the power output shaft of a tractor. In working, the power was transferred to the chain drive by the power output shaft of a gearbox, and then to realize the stalk conveying and pulling operation under the rotation of the toothed belt and the opposite rotation of the stalk pulling roller. A systematic kinematic analysis was conducted to determine the influencing factors in the working process. A field test was also carried out in a farmland in Korla City, Xinjiang Uygur Autonomous Region of China in October 2019. The soil firmness was 467 kPa, and the moisture content of the soil was 15%-20%, due to the perennial drought and little rain in the study area. The average height of cotton stalk was 700 mm, while, the plant spacing was 50 mm in a wide and narrow close planting mode. The power was from a CFD604A wheeled tractor with a calibrated power of 44.2 kW. The test was performed on the national standard of a harvester combine test(GB/T 8097-2008). A three-level quadratic regression orthogonal test was designed, where the forward velocity of the machine, the rod velocity of the deflector, and the speed of the stalk pulling roller were selected as the influencing factors, whereas, the leakage rate and plucking rate were the response factors. A response surface method was utilized to establish the regression equations for the relationship between the factors and assessment indexes. An optimal combination of parameters was obtained, while an experiment was also conducted to verify the mathematical model. The test results demonstrated that there were great effects of factors on the performance of horizontal-roller cotton stalk pulling. The significant effects on the leakage rate were ranked in a decreasing order: the forward velocity of the machine, the rod velocity of the deflector, and the speed of the stalk pulling roller. Correspondingly, the significant effects on the plucking rate were ranked in a decreasing order: the speed of the stalk pulling roller, the rod velocity of the deflector, and the forward velocity of the machine. The verification test indicated that the leakage rate of the cotton stalk was 5.24%, and the plucking rate was 3.75%,when the forward velocity of the machine was 0.68 m/s, the rod velocity of the deflector was 1.75 m/s, and the speed of the stalk pulling roller was 221 r/min. The optimal combination was better consistent with the predicted one in model optimization, indicating a reasonable structural design. The findings can provide a sound reference for the structural design and optimization of operation parameters in the horizontal-roller cotton stalk pulling machine. [ABSTRACT FROM AUTHOR]

The existing oil sunflower threshing device cannot meet the requirements of oil sunflower threshing under different conditions. Aiming at the problems of the low oil sunflower threshing rate and the high breaking rate during the threshing process, a threshing device of oil sunflower with variable clearance based on multi-bar mechanism is designed in this paper. The structure and the working principle of the oil-sunflower threshing device with variable clearance were introduced, and the mechanisms of kinematics of the clearance adjustment mechanism and angle adjustment mechanism of the structure of variable clearance concave screen were analyzed, the motion trajectory analysis and solution were performed to determine the structural parameters, the variable clearance range of the variable clearance concave sieve was 20-60 mm. A test bench of the oil-sunflower threshing device with variable clearance was developed. The threshing test was completed at the Key Laboratory of Innovation Design Laboratory of Xinjiang Agricultural Engineering Equipment. The test object was oil sunflower No. 31 with the disk diameter of 180-220 mm and the disk thickness of 25-40 mm, the weight of single sunflower disk was 300-380 g, the moisture content of the sunflower disk was 29.59%. The test was performed according to the GB/T5982-2017 thresher test method and the DB37/T2878.2-2016 technical requirements. The orthogonal experiment of three factors and three levels was carried out, threshing rate and breaking rate were taken as the indexes and the cylinder speed，the threshing clearance as well as feed rate were the factors. The test results showed that during the threshing process, the factors that affect the oil sunflower threshing rate and breaking rate are threshing clearance, drum speed and feed rate. The optimal combination of operating parameters was that the threshing clearance 35 mm, the drum speed 280 r/min and the feed rate 1.8 kg/s. Through the analysis of variance, it was concluded that the threshing clearance had a very significant effect on the oil sunflower threshing rate and breaking rate, the drum speed was significant, and the feed amount was not significant. Multiple repeated tests were performed under a better combination of operating parameters. The test results showed that the average threshing rate of oil sunflower was 99.01%, and the breaking rate was 2.28%, which met the national standards that the threshing rate greater than 98 % and the breaking rate less than 5%. The better operating parameters of this study are only applicable to the material conditions tested in this paper, but the oil sunflower harvesting operations are complicated, and the factors such as oil sunflower varieties, moisture content, and output are also different. Adjusting the diameter of the threshing concave plate sieve, changing the threshing clearance and other working parameters is to meet the requirements of oil sunflower threshing under different conditions. The research results can provide reference for the design of subsequent oil sunflower threshing device. [ABSTRACT FROM AUTHOR]

The Oilfield is an ultra-deep and ultra-heavy oil reservoir. Flow pressure monitoring of spouted wells is an important data for evaluating oil well energy changes and judging bottom water coning. However, due to the fact that the oil product is over-heavy and meets resistance, the test of high-yield wells affects the timeliness, and the test cost is high, it has been restricting the formation energy monitoring of spouting wells. On the basis of fully investigating the flow pressure testing methods of spouting wells at home and abroad, this paper uses the law of conservation of energy to deduce an alternative method suitable for flow pressure testing in super heavy oil reservoirs. Within 0.19MPa, the accuracy of the ordinary hydraulic formula is greatly improved. increase the production and reserves of a single well in a fixed volume carbonate rock fracture-cavity single well. [ABSTRACT FROM AUTHOR]

The banana stalks are rich in fiber, and the existing returning machines for banana straw and stubble crushed in China have generated a few problems such as overly severe cutting resistance, the fiber of banana straw winding crushing blade roller on the returning machine, working on the unstable condition and serious fuel consumption. In order to deal with the above problems which the existing choppers met with in the working process, with the help of theoretical study and the analysis on the planting model for banana in Hainan Province, this paper put forward a returning method that the moving knives on the front knife roller were used to crush banana straws and the flail knives on the back knife roller were used to break stubble under the earth. The rotational direction of stubble crushing roller in the returning machine was same to the forward direction of the machine providing power, while the rotational direction of straw crushing roller was contrary to that of stubble crushing roller. On the basis of establishing theoretical model and the analysis on the planting model for banana in southern China, the key shaped parameters of the sliding-cutting blade and the structural parameters of crushing blade rollers were determined respectively. Besides, the sliding-cutting and anti-twining returning device for banana straw was put forward. The overall structure and working principle of sliding-cutting and anti-twining returning device were described. The performance of crushing banana straw and the power consumption were evaluated by simulating the breaking operation of banana straw in farmland through a bench test driven by double electric motors. The machine was composed of electrical motors, a tractor powered by electricity, the frame of machines, the straw crushing device and the stubble crushing device. Through Design-Expert software, a quadratic orthogonal rotating experiment was performed. Based on the variance analysis and regression fitting, a multiple regression equation was gained, presenting the effects of the working speed of the returning device, the rotating speed of rotating roller of moving knives and the rotating speed of rotating shaft of stubble breaking on the qualified rate of straw crushing and power consumption. It could be seen that the rotating speed of rotating roller of moving knives had the most influential effect, followed by the rotating speed of rotating shaft of stubble breaking, and the working speed of the returning device had the least influence on the qualified rate of straw chopping. The operation condition was optimized by applying the response surface method. The optimum factors for straw and stubble crushing process were as follows: The rotating speed of rotating roller of moving knives was 1 600 r/min, the rotating speed of rotating shaft of stubble breaking was 500 r/min, and the working speed of the returning device was 1.39 m/s. Based on the theoretical analysis, the higher qualified rate of straw crushing was achieved under the faster rotating speed of rotating roller of moving knives. The smaller power consummation was obtained under the lower rotating speed of rotating roller of moving knives and the lower rotating speed of rotating shaft of stubble breaking. Under the optimal condition, the corresponding qualified rate of straw crushing and power consumption were 95.2%, and 4.96 kW, respectively. The differences between the experimental and the analytical values of the qualified rate of straw chopping and power consumption were 0.31 percentage points and 0.27%, respectively, which indicated that the software analytical value was in great agreement with the experimental value. And by field test, qualified rate of straw crushing of machine proposed in this paper was higher by 1.94 percentage points and power consumption was lower by 11.3%, compared with vertical flail banana stalk crushing machine. Its successful implementation can greatly improve the production efficiency for crushing banana straw and stubble on one hand, and on the other hand prevent the pollution brought by deserted banana straw putridity. [ABSTRACT FROM AUTHOR]

In order to ensure the safe and stable operation of pump station when the suction sump is under the ultra-low water level (the ultra-low water level is higher than the pump installation elevation yet lower than the designed low level of the suction sump), the Tianshan first-grade pump station is taken as study object in this paper. Site research shows that when the pump station runs under the ultra-low water level in long time, the noise and vibration of the pump unit are increased, the impeller and blade are severely caved and the normal operation of pump station is affected. In order to solve these adverse effects, the combined rectification scheme is proposed, which consists of diversion platform, underwater vortex suppression plate and W type diversion pier near the back wall. The flow pattern, the velocity distribution and the axial velocity uniformity of bell-mouth inlet under the original scheme and rectified scheme were analyzed through numerical simulation and experimental research respectively. The numerical simulation results showed that violent vortexes appeared on side wall, bottom and surface of the suction sump due to the ultra-low water level and large velocity gradient in suction sump. These vortexes deteriorated the flow pattern in suction sump, and this situation was exacerbated by excessive hanging height and the distance between back wall and water inlet. But a vortex at the bottom and 2 surface vortexes of the suction sump were completely removed, and the side wall vortex of the suction sump was controlled; the area of backflow and stagnant water shrank dramatically after the combined rectifier scheme was adopted. In addition, the uniformity of axial velocity distribution of bell-mouth inlet was increased from 62.3% to 87.5%, 25.2% higher than before, which greatly improved the water flow pattern in suction sump. In the combined rectifier scheme, the diversion platform eliminated the whirlpool at the bottom of the suction sump, and improved the flow pattern between the bell-mouth and the bottom of the suction sump. The underwater vortex suppression plate effectively suppressed the intake swirl at the surface of the suction sump and weakened the vortex on the side wall. The W type diversion pier near the back wall made the back wall W type, which gave better hydraulic characteristics to the back wall and weakened the backflow and stagnant water near the back wall. It was also observed in the model test and PIV (particle image velocimetry) test that some adverse phenomena such as sixth types intake swirl on the suction sump surface and other serious vortexes on the side wall and bottom of the suction sump disappeared and the velocity distribution of specific area of the suction sump was more reasonable than the suction sump before rectification. In summary, the combined rectification scheme proposed in this paper can provide good water inlet condition for water pump unit under ultra-low water level of suction sump, and provide technical transformation basis for pumping station running under other low water level. [ABSTRACT FROM AUTHOR]

As the uneven settlement and seepage deformation of the soft foundation, the floor void is prone to occurring in the sluices built on soft foundation. The traditional non-destructive testing methods are hardly difficult to detect the floor void of the sluices under water, which are non-real time, and their applications still have certain limitations. For the floor of sluice on the soft foundation, it has been under water during the operation period, and new diagnostic methods need to be studied to realize the real-time detection and diagnosis of the floor void of sluice on the soft foundation. The floor void of sluice on the soft foundation will cause the overall constraint boundary conditions of the sluice to change, thereby changing the overall modal parameters of the sluice. The diagnosis of the floor void of sluice on the soft foundation can be realized by establishing the nonlinear mapping relationship between the modal parameters and the floor void parameters of sluice. The method of diagnosing the floor void of sluice on the soft foundation based on modal parameters can realize real-time detection well. Therefore, a dynamic inversion method of the floor void of sluice on the soft foundation is proposed on the basis of the indoor physical model of the sluice on soft foundation in this research. First, based on mathematical model of multi-parameter variables of the floor void of sluice, a mathematical proxy model reflecting the nonlinear mapping relationship between the void parameters of the sluice floor and the dynamic parameters (modal parameters) of the sluice was improved. Second, the combination of the change rate of multi-order frequency and mode shape of multiple measurement points of the sluice was took as the dynamic sensitive characteristic quantity of the parameters inversion, and an objective function for the dynamic inversion of void parameters of sluice floor was established. Then the objective function is optimized through the genetic algorithm. Finally, a physical model of the indoor sluice on soft foundation had been made, and three different conditions of floor void of sluice on the soft foundation were set in the model. The prototype vibration test of the physical sluice on soft foundation on three conditions was carried out, and the corresponding modal parameters of sluice were identified based on the vibration response signal. And the dynamic inversion method of the floor void of sluice on the soft foundation proposed in the paper was used to invert the floor void of sluice and verified by the physical model. The results showed that the trend of floor void of sluice and the void area determined by the inversion method based on dynamic parameters of sluice were in good agreement with the actual condition of the physical model. With the three different conditions, the relative errors between the calculated void area and the actual void area are 7.47%, 6.78%, and 6.90%, respectively, which can confirm the reliability and rationality of the proposed method. The proposed method can provide a new idea for safety detection of the floor void of actual sluice on the soft foundation. [ABSTRACT FROM AUTHOR]

The immersed tunnel works of Hongkong-Zhuhai-Macao Bridge was completed in 2018, a joint research team on submerged floating tunnel (SFT) was established for CCCC Hongkong-Zhuhai-Macao Bridge island & tunnel project to propose and design a overall basin test of tethered type SFT. The prototype length of 1.2 km long, with a scale of 1:50. After rounds of discussions on test significance, technical feasibility and details, the 1st generation basin test was initiated in early 2019. A special SFT basin was built in Tianjin and a test model was fabricated in a Dalian laboratory. In this paper, we introduced the general test design scheme and its evolution, critical issues encountered, and improvements for 2nd generation test. Main discussions or findings at works were: 1) the overall SFT basin test should be divided by three stages for mechanism, parameters and engineering respectively, in which the basin test is preferably divided by 3 stages targeted at trial, structural behavior, and validation; 2) a supporting system was required to ensure efficiency and quality; 3) model residual buoyancy simulation alternatives were proposed and compared; 4) attention shall be paid to the risk of SFT model damaging from artificially imposed regular waves. [ABSTRACT FROM AUTHOR]

Residual plastic films degrade soil structure and have a detrimental impact on seed germination and the subsequent seedling development and establishment, thereby leading to reductions in crop yield. Removing the films from soil prior to sowing is hence critical to safeguarding crop growth. This paper presents a roller-type device incorporated into ploughing machine to simultaneously strip, collect the films from the soil and then unload them in a row prior to sowing. The device was nail-teeth designed to pick up and strip the residual films. The optimal combination of the structure and working parameters of the device was theoretically analyze using a quadratic regression orthogonal rotation test by taking forward speed of the machine, rotating speed of film pick up roller and rotating speed of film stripping shaft as determinants, and the efficiency of both film pick up rate and film stripping rate to represent the performance of the device. The significance of each determinant in affecting the rate of film pick up and stripping was analyzed using the Design-Expert software. The results show that in terms of impact on film pick up rate, the three determinants were ranked in the order of machine forward speed > rotating speed of film pick up roller > rotating speed of film stripping shaft, while in terms of impact on film stripping rate, the determinants were ranked in the order of rotating speed of film stripping shaft > rotating speed of film pick up roller > machine forward speed. Optimization calculated using MATLAB showed that the optimal working parameters were: device forward speed 1.62 m/s, rotating speed of film pick up roller 90 r/min, and rotating speed of film stripping shaft 1 055 r/min. We verified these optimal results against field experiments and found that the film pick up and film stripping rate was 70.56% and 82.96%, respectively. The differences between the experimental results and the calculated results was small, indicating that the optimized working parameters were reliable and robust. [ABSTRACT FROM AUTHOR]

Agricultural flexible chassis (FC) is a kind of in-wheel motor driving electric vehicle applied for greenhouse. The FC is composed of 4 identical off-centered shaft mechanisms, which can be controlled independently. Through this kind of mechanism, the FC can achieve various motion types. However, it is difficult to maintain the linkage relationship between the 2 front off-centered shaft mechanisms when the FC is in front wheel steering motion, and hard to accomplish smoothly turning. In order to solve this problem, a coupling control strategy for linkage motion was proposed in this study. Firstly, the contour error of the 2 wheel steering angle was deduced based on the Ackermann steering geometry and the cross-coupling control principle. To reduce the contour error during steering, a fuzzy PID control algorithm was designed, which could realize parameters self-tuning. As the electromagnetic friction lock was controlled by pulse width modulation (PWM) signal, the duty cycle of the PWM signal had to be adjusted according to turning situation. Thus, a fuzzy logic method was then introduced to regulate the duty cycle. Namely, the PWM signal duty cycle can be in line with the steering wheel signal size and its change rate, and the motion of the electromagnetic friction lock can match the steering speed of the off-center shaft mechanism. In this way, the coupling control of the 2 front off-centered shaft mechanisms can be achieved. The control strategy was then verified through simulation based on MATLAB/Simulink. To further verify the effectiveness of the control strategy, the control program was loaded into the steering system hardware, and tests were carried out on hard surface road. According to the traditional vehicle steering test methods, step steering test, snake steering test and random steering test were conducted. The effects of front wheel steering under the steering angle allocation control method were compared with coupling control strategy. The simulation results demonstrated that the proposed control strategy was effective and feasible. The test results on hard surface road showed that the FC had a fast steering response in step steering test. The response time of step steering was 0.8s and overshoot was 1.3° under coupling control method during front wheel steering of the FC. The overshoot under allocation control was larger than coupling control and its fluctuation was notable. From the results of the snake steering and random steering, it was obviously that the steering angles of the left and the right front wheels had good tracking performance for their target angles, respectively. The opening and closing of electromagnetic friction lock can match the steering motion of the electric wheel well. The maximum and average following errors of 3 steering modes were less than those under the allocation control method. The maximum and average contour errors of the linkage motion were 1.2° and 0.6° for step steering, 1.1° and 0.6° for snake steering, as well as 1.0° and 0.5° for random steering, respectively. All these errors were also smaller than the allocation control. Under the coupling control, the maximum steering error between simulation and test was 2.2°, and the contour error trend of them was consistent. The simulation model was reasonable and effective. The contour errors of the allocation control in these 3 kinds of tests had more fluctuations and larger range of fluctuations than coupling control. The steering performance under coupling control strategy was obviously better than the allocation control method. The steering angles of the 2 front wheels had maintained Ackerman steering geometry well. The coupling linkage control strategy proposed in this paper has good effectiveness and feasibility. This research can provide references for steering control or other applications of the FC. [ABSTRACT FROM AUTHOR]

This paper gives some methods of field test and evaluation of the performance of the natural gas metering system with the basis of summarizing the test methods of metering instruments relating to a natural gas metering system. Taking a class A trade metering station as an example, the performance of the metering system is tested and evaluated. Through the evaluation, it is found that the ultrasonic flowmeter, temperature meter and flow computer of the station do not reach the accuracy requirements of the class A trade metering station. The application of the on-site evaluation method of the metering system is described with this example, and it is explained that the on-site evaluation of the metering system is necessary. In order to run the system accurately and reliably, it is suggested that an on-site performance evaluation should be carried after getting the traceability of each metering instrument of the metering system. [ABSTRACT FROM AUTHOR]

The application of mechanical transplanting on crops can effectively increase the product of crops and reduce the labor intense as modern cultivation techniques. But the popularization and application are limited by the problem of lower upright degree to some certain extent. A new type cam-swing link type transplanting machine was designed to solve the problem of lower upright degree in current pot seedling planting machine. In addition, the receiving seedling stability of planting apparatus can be guaranteed well, owing to double parallel four-bar mechanism of this planting machine. In this paper, the kinematic model of the transplanting machine was established, including the equations of planting trajectory, planting velocity and planting acceleration for the planting device. For the purpose of high efficiency, interactive GUI design tool had been explored based on the MATLAB/GUI according to these mathematic equations. The influences on the transplanting trajectory of main parameters were analyzed based on MATLAB tool, including the length L1 and original phase angle Φ1 of crank CD, the length L2 and original phase angle Φ2 of swing AB, and the length L5 of link AG. The system parameters which had great effects on the planting trajectory were L1, L2, Φ1 and Φ2. These parameters were analyzed and optimized through the method of orthogonal experiment. The experimental scheme was designed according to orthogonal table off our factors and three levels. By analyzing the range table of residual, the parameter could be ranged as L2, L1, Φ1 and Φ2 from big to small, considering the degree of significant on upright degree of seedlings. The optimal combination could be selected that L1 is 118 mm, L2 is 52 mm, Φ1 is 256°, and Φ2 is 316°. Under the condition of this optimal combination, the motion model of transplanting machine was reestablished to generate a new optimized planting trajectory. The top of this trajectory was smooth to benefit the receiving seedling stability of planting device. As the total height of this trajectory was about 256 mm with 190 mm higher the ridge side, the planting device could avoid touching down seedlings planted effectively. When the planting depth reached 60 mm, the maximum residual of curve at planting seedlings parts was 0.465 mm, the mean residual was 0.253 mm, and penetration angel was 81.05°. The simulation results indicated that this optimized planting trajectory can improved the anteversion problem of seedlings that caused by compaction wheel and ensured the seedling planted higher upright degree. In order to verify the reasonability and accuracy of the theoretical model, the prototype was processed with the optimized parameters. Based on the prototype, field tests were carried out according to relevant standards in Yiyang county industrial park of China in March 2015. No crops were planted and the ridge film was mulched in the test plot before the testing, for simply obtaining test results without effects of the other crops. During the course of experiment, 30 horse-power tractor was selected as the only power. The total height of seedlings used was no more than 150 mm, and the height of seedlings substrate less than 60 mm. The plant vertical degree was considered as the main optimization indicator which influenced by the main parameters mentioned above. The data results showed that the mechanism proposed meet the requirements of pot seedling agricultural plant at the speed of 0.556 meter per second, and planting frequency was 60.7 plant percent minute. The qualified rate of upright degree with the variation coefficient of 2.03% was 95%, lodging rate was no more than 1.67%, and plant spacing error rate was only 0.22% with no lacking of seedlings. The results indicated that this machine had the good planting performances of high upright degree and low spacing error rate under the condition of high efficiency of planting. What this paper studied will provide theoretical reference for the subsequent transplanter research and development. [ABSTRACT FROM AUTHOR]

Pesticides electrostatic spray technology of can improve the deposition efficiency of pesticides on the hidded faces of leaves and reduce the pollution of pesticides to the environment. It has become a hot topic for scholars at home and abroad. In order to clarify the research and industrial status of pesticide electrostatic spray technology and the bottlenecks in the industry, the basic theory, mechanism research and analysis, indoor/outdoor electrostatic spray effect evaluation and electrostatic spray equipment industry status of pesticide electrostatic spray technology was systematically analyzed in this paper. Firstly, the droplets charging modes, the charged droplets dynamics, the charge-to-mass ratio(CMR) and the retention time were mainly overviewed. The conclusions about the main force of the charged droplets, the optimal charging parameter of the inductive charging and the reasonable comparison method for the charge-to-mass ratio were gained that the main force imposed charging droplet were electrostatic force, airflow drag force and gravity; Inductive charging is the most commonly used charging technology for electrostatic spray of pesticides, and the best charging voltage was 6-10kV, the electrode material is nickel or nickel-plated copper material, and the distance between the electrode and the nozzle outlet was 5 mm or less. When comparing the CMR between different sprayers, all the current, spray volume, measuring distance, droplet spectrum and particle size, air velocity and distribution should be expressed. Secondly, the test methods of charge-to-mass ratio, potential, droplet size and droplet velocity in electrostatic spray were introduced. The Faraday barrel, Faraday cage and mesh target method were the 3 main methods to measure the CMR. The application of phase doppler particle analyzer (PDPA) and CFD simulation in electrostatic spray technology were proposed. But the application of these advanced testing technologies and the application details of CFD simulation in electrostatic spray still need further study. Thirdly, the influence mechanism of charged droplet deposition was reviewed from 4 aspects of charging parameters, environmental parameters, working parameters and target parameters. It was believed that the electrostatic spray deposition efficiency was affected by the charging parameters, environmental parameters, target parameters and working parameters, but the mechanism of influence was still unclear and still needs further attention. At last, a large number of electrostatic spray indoor/outdoor effect evaluation tests showed that the charged droplets were driven by electrostatic force, airflow drag force and gravity, which contribute to the deposition of mist droplets in the leaves, but the electrostatic spray on the droplets drifting and penetrating properties was still no conclusion. Last for the most, the electrostatic spray technology had the advantage of high efficiency of droplet deposition, but it was still not widely used due to its unsatisfactory application effect. Because of the high sensitivity of various parameters to droplet deposition, the complexity of application environment and objects were the biggest challenges in the application of electrostatic spray technology, and the main bottlenecks were the short retention time and easily adsorbed by the sprayer and the human body. 3 suggestion were listed as: (1) Continue to carry out the research on the matching parameters of the charging parameters, air velocity and the charged droplets, increasing the maximum initial charge, meanwhile ensuring the effective charge when reaching the target.(2) Strengthening the research on mechanism of charged droplet deposition to clarify the key parameters affecting the deposition of charged droplets. (3) In order to ensure the actual effect of electrostatic spray, it is recommended to develop any electrostatic spray equipment in accordance with the specific equipment to develop detailed electrostatic spray operation specifications. [ABSTRACT FROM AUTHOR]

Pesticides electrostatic spray technology of can improve the deposition efficiency of pesticides on the hidded faces of leaves and reduce the pollution of pesticides to the environment. It has become a hot topic for scholars at home and abroad. In order to clarify the research and industrial status of pesticide electrostatic spray technology and the bottlenecks in the industry, the basic theory, mechanism research and analysis, indoor/outdoor electrostatic spray effect evaluation and electrostatic spray equipment industry status of pesticide electrostatic spray technology was systematically analyzed in this paper. Firstly, the droplets charging modes, the charged droplets dynamics, the charge-to-mass ratio(CMR) and the retention time were mainly overviewed. The conclusions about the main force of the charged droplets, the optimal charging parameter of the inductive charging and the reasonable comparison method for the charge-to-mass ratio were gained that the main force imposed charging droplet were electrostatic force, airflow drag force and gravity; Inductive charging is the most commonly used charging technology for electrostatic spray of pesticides, and the best charging voltage was 6-10kV, the electrode material is nickel or nickel-plated copper material, and the distance between the electrode and the nozzle outlet was 5 mm or less. When comparing the CMR between different sprayers, all the current, spray volume, measuring distance, droplet spectrum and particle size, air velocity and distribution should be expressed. Secondly, the test methods of charge-to-mass ratio, potential, droplet size and droplet velocity in electrostatic spray were introduced. The Faraday barrel, Faraday cage and mesh target method were the 3 main methods to measure the CMR. The application of phase doppler particle analyzer (PDPA) and CFD simulation in electrostatic spray technology were proposed. But the application of these advanced testing technologies and the application details of CFD simulation in electrostatic spray still need further study. Thirdly, the influence mechanism of charged droplet deposition was reviewed from 4 aspects of charging parameters, environmental parameters, working parameters and target parameters. It was believed that the electrostatic spray deposition efficiency was affected by the charging parameters, environmental parameters, target parameters and working parameters, but the mechanism of influence was still unclear and still needs further attention. At last, a large number of electrostatic spray indoor/outdoor effect evaluation tests showed that the charged droplets were driven by electrostatic force, airflow drag force and gravity, which contribute to the deposition of mist droplets in the leaves, but the electrostatic spray on the droplets drifting and penetrating properties was still no conclusion. Last for the most, the electrostatic spray technology had the advantage of high efficiency of droplet deposition, but it was still not widely used due to its unsatisfactory application effect. Because of the high sensitivity of various parameters to droplet deposition, the complexity of application environment and objects were the biggest challenges in the application of electrostatic spray technology, and the main bottlenecks were the short retention time and easily adsorbed by the sprayer and the human body. 3 suggestion were listed as: (1) Continue to carry out the research on the matching parameters of the charging parameters, air velocity and the charged droplets, increasing the maximum initial charge, meanwhile ensuring the effective charge when reaching the target.(2) Strengthening the research on mechanism of charged droplet deposition to clarify the key parameters affecting the deposition of charged droplets. (3) In order to ensure the actual effect of electrostatic spray, it is recommended to develop any electrostatic spray equipment in accordance with the specific equipment to develop detailed electrostatic spray operation specifications. [ABSTRACT FROM AUTHOR]

In order to solve the problem that seedlings cultivated by pie-shaped compression matrix can not be planted by the existing transplanter, a semi-automatic compression matrix seedling transplanter was designed in this paper by mimicking the artificially transplanting method of putting seedlings after punching a hole. The compression matrix type seedling transplanter mainly consists of a ground wheel, a swing mechanism, a ratchet wheel, a hole puncher, a displacement mechanism, a seedling clamping mechanism, a conveying device, a transmission system, a rack, and so on. The physical dimensions and mechanical properties of the compression matrix type seedling are the key basis for the design of the seedling planting schemes and structures. Taking watermelon seedlings as the research object, the dimensions of the seedlings were measured, and the friction coefficient of the compression matrix with different water contents and the compressive strength of the compression matrix were determined. The coefficients of friction between the slideways and the flanks of watermelon seedlings with 2 groups of different water contents were determined to be 0.755 and 0.634 respectively by single-factor tests. The relationship between the compression load and the compression amount of the 2 groups was also analyzed. When the load is 0-5 N, as the surface of the seedling is in point contact with the semi-circular thin metal at the initial stage of compression, the compression load increases evenly and the amount increases rapidly. When the load is between 5 and 20 N, as the surface of the seedling is in surface contact with the semi-circular thin metal, the compression load increases evenly with less impact on compression. When the load is greater than 25 N, some external cracks are observed on the surface of the seeding during the test. Comparing the 2 tests, it can be seen that the seedling with high water content is not easily destroyed. The swing mechanism is optimized according to the known movement law of the initial angle of the crank and the output angle of the driven rod. The dimensions of optimized parts are 57, 161, 79 and 170 mm, respectively. When the crank rotates one revolution of 360°, the reciprocating swing angle of the driven rod is 92.3°, which satisfies the working requirements of the four-equal-part ratchet wheel mechanism. The structure and specific size parameters of the hole puncher are determined according to the measurement size and planting depth requirements of the watermelon seedling. The width of the edge surface is 1.5 mm. The inner diameter of the small end is 64 mm, and the height of the tapered part of the hole puncher is 65 mm, and when the incision angle is 21°, the inner diameter of the big end is about 114 mm. The structure parameters of the seedling clamping mechanism are determined according to the mechanical properties and the dimension of watermelon seedling. And it is also concluded that the seedling’s matrix can overcome the self-gravity of the seedling, which ensures that the seedling clamping mechanism can securely grip the seedlings when transplanting with a clamping force of 26 N. The seedling conveying device and the planting holding device are driven by the same power source, ensuring that the feeding speed of the seedlings is synchronized with taking seedling action of the planting holding device. The conveyor belt is used to transport the seedlings, and the conveyor belt was designed to send seedlings at a speed of 40 plants per minute. Using a compression matrix for field planting functional verification tests, the average plant spacing is 98.6 cm when the transplanter moves at a stable speed of 2.1-2.6 km/h. The pass rate of the plant spacing is 90.62% and the lodging rate is 21.9% which is slightly higher. In the follow-up study, dual-ground-wheel driving would be used to improve the reliability of the transmission and obtain uniform spacing; a hole shape with the same level and the same depth should be acquired, and the lodging rate after the landing of pie-shaped matrix would be reduced by increasing the copying mechanism and optimizing the shape and structural parameters of the hole puncher. [ABSTRACT FROM AUTHOR]

Aiming at the problem of poultry entrails easy to be damaged in the poultry eviscerated processing, we designed the manipulator and its control system based on tactile perception in this paper. According to the size and depth of abdominal part of broiler with the general size, the maximum distance from the mechanical gripper when it is opened and the length range of the mechanical finger are respectively determined. Through the analysis of the poultry entrails, the bending degree of the mechanical fingers is determined, and then the envelope space when the mechanical gripper is closed is determined. The three-dimensional model of the mechanical gripper is established by SolidWorks software. The size of mechanical gripper is determined by the movement analysis and the assembly of mechanical gripper. The mechanical gripper is driven by a screw, the rotary motion of the stepper motor is converted into a linear motion of the slider by means of a screw, and then through the connecting rod the movement of mechanical fingers is achieved. STM32 single chip microcomputer is used to generate PWM (pulse width modulation) signal to control the move of mechanical arm in X, Y, Z axis direction, and at the same time to control the positive direction rotation of stepping motor of manipulator, achieving the closing of mechanical paw. The piezoresistive film sensor is used as the tactile sensing part of the mechanical gripper. When the pressure on the sensor becomes larger, the resistance value becomes smaller. On the other hand, when the pressure becomes smaller, the resistance value becomes larger. Single chip microcomputer can collect the voltage signal, but can not directly collect the resistance signal, so the resistance-voltage conversion module is used to make the changes of resistance value of the sensor that is caused by the changeable pressure on the sensor, which becomes the corresponding voltage signal. In this way, the ADC (analog-to-digital converter) module of single chip microcomputer is used to collected the pressure of piezoresistive type film sensor in real time installed in the inside of finger. We make the 4 broilers as a group and conduct the visceral pressure threshold test of broiler with a total of 3 groups of broilers and the pressure threshold of the mechanical gripper is determined. We compare the collected pressure with pressure threshold value that is 7.7 N, and control reverse rotation of stepping motor of manipulator, so as to control the force of manipulator paw to ensure that entrails would not endure too much force to be damaged, or would not fall off due to closing not enough. Qt Creator is used to draw the user graphical interface of poultry eviscerated manipulator, and the interface is mainly composed of serial port, display box, automatic mode, manual mode and operation control, and includes manual and automatic control modes. In automatic mode, you can enter the running distance of the 3 axes to determine the movement state of the manipulator, and at the same time, in manual mode, you can click the manual button to control the action of the robot. The PC (personal computer) and STM32 single chip microcomputer are connected by the serial data cable, and then the system is initialized. In this way, you can operate the control interface. In addition, when the manipulator gets trouble in the working process, you can click the stop button to make all the stepper motors disabled, to ensure the safety of equipment. The results of test showed that mechanical paw with the tactile system could significantly reduce the damage of entrails,the average score of visceral damage decreased from 4.75 to 4, and the evisceration rate was 87.4%. The manipulator has the advantages of stable performance, less damage to entrails, high degree of automation, friendly human-computer interface and easy control, and has high practical value. [ABSTRACT FROM AUTHOR]

Xinjiang has the adequate light and large temperature difference between day and night, and its unique light and heat resources are very suitable for crop growing, such as tomato and pepper; the planting area and productivity of Xinjiang have been ranked the first in China for many years. But due to special climatic conditions in Xinjiang area, crops are generally transplanted on the plastic film, and also need to lay a drip belt. In recent years, Xinjiang has begun to vigorously promote the crop transplanting technology, and the transplanting area of tomato and pepper has continued to increase. However, at present, there are no automatic vegetable transplanting machines available in Xinjiang, and the seedlings transplanting work basically relies on manual operation; some transplanters used are mainly semi-automatic machines, which still need manual work to pick up seedlings and drop seedlings, and also need laying the film and drip irrigation before transplanting, as well as the additional press and soil covering operations after the transplanting. Therefore, it is very important and urgent to study the multi-functional automatic transplanter for plug seedling in Xinjiang. In this paper, the 2ZXM-2 automatic plastic film mulch plug seedling transplanter for tomato and pepper was developed to replace the manual operation and semi-automatic machines transplanting. The mechanism mainly consisted of the frame, the laying film device, the soil covering and pressing mechanism, the automatic seedling pick-up mechanism, the planting mechanism and the automatic seedling feeding system which can feeding seedlings accurately for the pick-up mechanism. The transplanter designed not only can complete automatic seedling transplanting and soil covering and pressing at one time, it can also lay drip irrigation belt and plastic film at the same time. With the 2ZXM-2 automatic plastic film mulch plug seedling transplanter, it is very convenient to complete the multi-channel working procedure of transplanting, and it can also be applied to the transplanting of different crops. In order to verify the performance of automatic transplanter, the test prototype was made and the pepper field transplant experiment was carried out in the Key Laboratory for Xinjiang Production and Construction Corps Agricultural Machinery. The test results showed that when the speed of the machine was 2.8 km/h, the theoretical plant spacing was 20 cm, and the transplanting frequency reached 62 plants/(min·row), the qualified rate of seedlings was 96.3%, the leakage rate of seedlings was 2.8%, the seedling injury rate was 1.25%, the qualified rate of transplanting depth was 93.5%, the qualified rate of the plant spacing was 94.7%, the spacing variation coefficient was 7.9%, and the qualified rate of transplanting achieved 93.4%. Meanwhile, in the process of transplanting test, the drip irrigation pipe was laid and had not been damaged and bent at all again, and the performance of mulch film laying and soil covering was also excellent; by statistics and calculation, the flattening degree of plastic film lighting surface reached 98.2%, the qualified rate of plastic film lighting surface width achieved 97.8%, and the average mechanical damage degree of film surface was only 3.4 mm/m2. Therefore, the performance indices of 2ZXM-2 automatic plastic film mulch plug seedling transplanter can perfectly meet the agronomic requirements of pepper seedling transplanting. In conclusion, the research for this transplanter not only provides some theoretical basis and reference for the study of automatic dry land transplanter in China, and it also has important significance for the development of mechanized seedling transplanting technology in Xinjiang. [ABSTRACT FROM AUTHOR]

A hydrostatic drive system scheme for the high clearance self-propelled corn detasseling machine was proposed and the dynamic performance of the system was simulated and tested in this paper. Although detasseling machines have much higher working efficiency than manual detasseling, they have just been used for a few years in China and mostly were imported from abroad at a high price. Since the machine demanded a high ground clearance, the closed volumetric speed control loop with one pump and four motors was adopted. The engine directly drives the pump to output high pressure fluid to the four-wheel motors, and then the motors drive the hub reducers to turn the wheels. It can be concluded that the vehicle can achieve 3 gears of I, II and III by choosing the appropriate maximum and minimum displacements of motors and reducer gear ratios. To better analyze the performance of the drive system, a detasseling machine model with 15 degrees of freedom was built according to the vehicle structure features. The vehicle model included vehicle body model, wheel model and four-wheel independent suspension system model. Meanwhile, the mathematical model of the hydrostatic drive system was derived, which included pump model, motor model and reducer model. Then, the simulation model of vehicle dynamics of detasseling machine was presented using the software Matlab/Simulink based on the mathematical models. The simulation model was used to study the performance of speed and system pressure of the vehicle at 3 gears. And the results showed that the vehicle could get a maximum travel speed of 15.8, 19.7 and 26.1 km/h, and a steady system pressure of about 6.29, 7.30 and 8.94 MPa at the 3 gears of I, II and III, respectively, which could meet various application conditions. As a special component of detasseling machine, the effect of the suspension system on the drive system was testified. By exerting a road excitation on one wheel, the system pressure of the vehicle with the suspension was contrasted with the one without suspension. The results showed that the pressure of the one with the suspension fluctuated much narrower and smoother than the other, which meant the suspension could effectively improve the performance of the drive system. To verify the mathematical model and to further research the drive system, a high clearance self-propelled corn detasseling machine was designed to conduct the tests. During the process of changing the displacement of pump from the minimum to the maximum value at each gear, the maximum travel speed was recorded, and the variations of the inlet and outlet pressure of the pump and motor were measured. The main test devices contained oil pressure sensors, acceleration sensors, data acquisition card of National Instruments, switching power supply and laptop, and the software LabVIEW was used for data processing. The vehicle tests showed that with the increase of pump displacement, the system pressure of the high pressure side first trended to increase sharply and then decreased to a stable value of 6.361, 7.286 and 8.717 MPa at the 3 gears of I, II and III, respectively, which was consistent with the simulation results. And the pressure of the low pressure side was about 2.4 MPa, which was equal to the system charge pressure. In addition, the maximum driving speed of the machine at the 3 gears was 15, 19 and 24 km/h respectively, which was lower than the theoretical values. That was mainly due to the leakage loss of hydraulic components and the mechanical friction loss. The simulation and test results showed that the vehicle drive system had a rapid response and a good performance, and the correctness of the mathematical model of the machine was also verified. The study can provide a technical reference for the independent research and development of the high clearance self-propelled corn detasseling machine in China. [ABSTRACT FROM AUTHOR]

In order to improve the blocking issue of logistics system in sugarcane harvester, by the methods of simulation analysis and experimental research, the cutter spiral lifting mechanism and the effects of friction coefficient and working parameters on the sugarcane material flow were studied and discussed. The average residence time of sugarcane in the transmission device of the screw conveyor was considered as test index and the virtual prototype simulation model was established by the software ADAMS and Unigraphics. Simulation results indicated that increasing friction coefficient of cutter spiral lifting mechanism could improve the delivery rate of the sugarcane and effectively inhibit the clogging problem. The high-speed photography results of experimental prototype showed that while a tyre rubber with high friction coefficient was used as the covering layer for the cutter spiral lifting mechanism and the cutter speed was about 750 r/min, the retention time of sugarcane was shortened by 17% compared to original rebar spiral lifting mechanism. This characteristic could improve the congestion problem of logistics system, and verify that the friction coefficient was exactly the main affecting factor. Based on this principle, this paper worked out the structure improvement of the cutter spiral lifting mechanism. The helical circular cross section was changed into a helical rectangular cross section, which made the contact way of the cutter spiral lifting mechanism and sugarcane change from point contact originally to line contact. The computer simulation experiments under different structures’ transmission speed, displacement, force and so on were conducted, and the analysis indicated that for the 20 mm cutter spiral lifting mechanism that was improved, the sugarcane residence time was shortened by 32% comparing with the original cylindrical spiral. Meanwhile, after the sugarcane head entered the spirals, the loading time from the spiral to the sugarcane head relatively decreased and the time of the loading process was shorter, and the universal impact force for the sugarcane was bigger, which made the cane’s feeding into the system more easily and rapidly. Before the sugarcane tail left the spiral, the favorable impact from spiral still existed, its impulse changed by 11.1 N·s, and the backward displacement of the sugar cane increased. And in the comparison of different width of spiral plane, the spiral retention time of sugarcane decreased by 18.5% when the plane width increased from 12 to 20 mm. If the width of spiral plane continued to increase to 24 mm, the trapped time of sugarcane increased by 17.6% compared to 20 mm width. When sugarcane tail left the spiral, the spiral with 12 and 24 mm width would have an adverse impact on sugarcane, which was unfavorable to the sugarcane conveying, while the spiral with 16 and 20 mm width would not only make the time of cane heading into the spiral shorter, but also produce more favorable impact when sugarcane tail left the spiral. Consequently, the experimental results showed that it could increase the friction conveying force and reduce the sugarcane retention time by appropriately widening the cutter spiral lifting mechanism width. It was advantageous to improve the transportation performance of sugarcane. Compared with 16 mm wide spiral, 20 mm wide spiral offered the equivalent total impulse after the sugarcane head entered the spiral. That made it easier for the sugarcane to enter the feeding roller, and before the sugarcane’s tail left the spiral, the loading time from the spiral to the sugarcane’s tail was more concentrated, the impact force was more balanced, and the backward transmission of the sugarcane was faster and more stable, which could effectively restrain the blocking problem of the front end of conveying system. The results provide the design basis for the construction of the late test platform and the development of the physical prototype. [ABSTRACT FROM AUTHOR]

To solve the problems of cable core's temperature calculation，including the indirect measure ment and the influence of cable laying environment on the temperature, this paper establislied the real time thermal circuit model of cable core's temperature based on the real - time monitoring of cable surface temperature, and calculated the core temperture by solving differential equations with Runge - Kutta method. By comparing the results of calculation and experiment through the established cable temperature rise platform，it is proved that the the temperature calculation based on the real - time monitoring of surface temperature enjoys higher accuracy, which meets the requirements for state monitoring and fault early warning. [ABSTRACT FROM AUTHOR]

Aiming at influences of different inlet flow on non-overload performance of Serial-Parallel Centrifugal Pump (SPCP), establishment of accurate prediction methods is necessary. In fact, the motor of the pump can easily burn out when the pump is working with a large flowing capacity and a high head. A pump is deemed as one with non-overload characteristics when its motor power is larger than 120% of the max shaft power, therefore the non-overloaded characteristic analysis of the SPCP plays a significant role for the safe running of the pump. In this paper, the average angle of inlet velocity (θ), which the impeller inlet flow distribution can be efficiently assessed, is firstly introduced to calculate the maximum shaft power (Pmax) of Single-Stage Model Pump (SSMP) in the case of impeller inlet about no-pressure straight pipe, and relevant flow ( Q't ) formula based on velocity triangle theory. Then, having researched the applications of SPCP in the case of two different impeller inlets: No-pressurehalf spiral and pressurehalf spiral. Once more, Computational Fluid Dynamics (CFD) is used to simulate the external characteristic curve of each model, and the enclosed experiment settings are adopted to firstly conduct analysis on the single stage model pump and then on SPCP after modifying the inlet and outlet pipes. In conclusion, analysis indicates that the results of calculation and experiments coincide with each other well. Under the design condition, the head error and the power error are respectively 1.20% and 2.40%, and when the SPCP is in the serial working condition, the head error and the power error are respectively 3.80% and 4.10%; in parallel working condition, the head error and the power error are respectively 2.90% and 3.50%. Therefore, those head errors and power errors are less than 5%, which proves the correctness of numerical simulation. What's more, with the different inlet flow state, axial velocity is distributed uniformly with a little change while the value of γ, the angle between the speed vector of unit nodes and the axial-surface streamline, has a big change. By comparing the values of the γ in different working conditions, it can be found that the non-uniform flow in serial working status is more obvious than that in parallel working status. In addition, a.k.a. θ̅ =γ , by putting these results into formulas, the theoretical Q't and Pmax values can be obtained, which are later compared with the experimental results. The Q't and Pmax values in non-overloaded working condition have much smaller errors when compared with experiment results, which are respectively 1.38% and 0.47% in the SSMP. However, when the SPCP is in serial working condition, it is easy to go overload. When Q'St =78.10 m3/h, the pump is at its max power point; in parallel working condition, with Q'Pt =168.50 m3/h, the pump is at its max power point, since the volume of flow is double that of before, for single-stage single-suction centrifugal pumps, it has its max power point only when Q't =84.25 m3/h. In actuality, when the rated power of a SPCP motor reaches motor max P ≥P , e.g. motor P ≥ 56.64 kW, the pump can achieve its non-overloaded characteristics. This research shows an excellent theoretical innovation, holds a high perspective and provides theoretical reference for designing the hydraulic property of SPCP. [ABSTRACT FROM AUTHOR]

The basic principle of 3D laser scanner, and the test methods of its positional accuracy in pile surveying were introduced in this paper. According to engineering requirements, we arranged control points, chose columns under the viaduct in land as observation target, measured the center coordinates respectively using 3D laser scanner and total station, analyzed the measuring accuracy of 3D laser scanner based on total station measuring results, and explored its application in engineering surveying. [ABSTRACT FROM AUTHOR]