To solve the problems of poor working conditions and high labor intensity for artificially pruning jujube trees, a pruning scheme using a manipulator is put forward in the present paper. A pruning manipulator with five degrees of freedom for jujube trees is designed. The key components of the manipulator are designed and the dimension parameters of each joint component are determined. The homogeneous transformation of the DH parameter method is used to solve the kinematic equation of the jujube pruning manipulator, and the kinematic theoretical model of the manipulator is established. Finally, the relative position and attitude relationship among the coordinate systems is obtained. A three-dimensional mathematical simulation model of the jujube pruning manipulator is established, based on MATLAB Robotics Toolbox. The Monte Carlo method is used to carry out the manipulator workspace simulation, and the results of the simulation analysis show that the working space of the manipulator is −600~800 mm, −800~800 mm, and −200~1800 mm in the X, Y, and Z direction, respectively. It can be concluded that the geometric size of the jujube pruning manipulator meets the needs of jujube pruning in a dwarf and densely planted jujube garden. Then, based on the high-speed camera technology, the performance test of the manipulator is carried out. The results show that the positioning error of the manipulator at different pruning points of jujube trees is less than 10 mm, and the pruning success rate of a single jujube tree is higher than 85.16%. This study provides a theoretical basis and technical support for the intelligent pruning of jujube trees in an orchard.

Aiming at the problem of high impurity rate in the recycled residual film, combined with the existing installation (4JMLE-210 agricultural residual film recycling machine), the removal mechanism of light impurities on the film surface was analyzed. The statics and kinematics analysis of light impurity particles in different spatial positions were carried out to determine the conditions for the movement of impurity particles. By analyzing critical conditions, such as ideal collision and throwing capacity, the structural dimensions of the straight pipe section and its outlet section were determined. Using Origin 2018 software, the movement track of the impurity particles left from the upper and lower limit positions and the ideal curve of the throwing arc were plotted, and the trapezoidal section was determined at the outlet of the throwing arc section. Finally, trial-produce prototype, and a field test was carried out on the performance of the machine by selecting the impurity rate in the recovered residual film as the test index. The results showed that when the forward speed of the machine and the rotating speed of the cutter roll were in the range of 5.4–5.8 km/h and 1440–1460 r·min⁻¹, the light impurity rate and working efficiency could keep a good balance. The light impurity rate in the recovered residual film was between 10.9% and 31.4%, and the average light impurity rate was around 18.7%, which met the design and application requirements.

In view of the serious film wrapping phenomenon and poor film removal effect of the film removal devices of residual film recovery machines, a combined “mechanical + air flow” film removal device is designed. It is mainly composed of vane-type film removal rollers and diversion shells and can complete film removal and film transportation in turn. The analysis and parameter design of the key working parts, named film stripping blades, are carried out. The condition of film removal is calculated by force analysis, and the internal flow field of the device is simulated based on the Fluent software. Taking rotating speed of the vane-type film removal roller, the inclination angle of the film stripping blade, and the diameter of the roller as test factors, and the area ratio of the vortex region to the effective region as the evaluation index, a three-factor three-level orthogonal simulation test is designed. The response surface model of each test factor is established, and the significance of each test factor on the evaluation index is analyzed. Through optimization, the optimal parameter combination suitable for the film removal flow field is obtained as follows: the rotating speed of the vane-type film removal roller is 283 r/min, the inclination angle of the film stripping blade is 25° and the diameter of the roller is 219 mm. Under the optimal combination of parameters, the device is manufactured, and the effect of the device is verified by a field test. The results show that the film removal rate of the device is 98.04%, and there is no film wrapping phenomenon in the operation process, which can meet the needs of residual film recovery before sowing.

In order to solve the problem of high straw content in recovered residual film and the low rate of qualified straw crushing in combination with a front-mounted cotton-straw-crushing device, the cutting and crushing mechanisms of cotton stalks were studied based on ANSYS/LS-DYNA. The height h and dip angle α of the fixed blade were determined to be 30 mm and 75° through a finite element analysis. On the basis of the device design, explicit dynamic models of the cutting and crushing of a single cotton stalk were established based on ANSYS/LS-DYNA. The results of the dynamic analysis revealed the cutting mechanism of the cotton stalk, and the influences of the cutting edge angle γ and front baffle height h₁ on cotton stalk cutting were studied by using single-factor simulation tests. An edge angle of γ = 45° and a height of h₁ = 265 mm were determined. Meanwhile, the mechanism of cotton straw crushing was revealed, and the motion states of the straw were studied at different times. The results of the simulation experiments on the influence of the cutter shaft’s rotational speed showed that with an increase in the cutter shaft’s speed, the rate of qualified crushing and the removal rate were both increased. At the design speed of n = 1800 RPM, the rate of qualified crushing was 84.6%, and the removal rate was 95.1%. Then, field experiments were carried out. The test results were as follows: the stubble height was 8.0 cm, the rate of qualified straw crushing was 91.8%, the clearance rate of film-surface impurities was 92.3%, and the film content was 3.6%, which met the working quality requirements (not less than 85%) of NYT 500-2015: “Operating quality for straw-smashing machines”.