High-clearance self-propelled sprayers have been widely used in modern agriculture in recent years, due to the operating speed, ground clearance, and tank capacity. It is very necessary to equip the suspension system with a better vibration-damping effect. Once the sprayer is operating under complex conditions, a faster driving speed is required by the sprayer suspension to fully dissipate the vibration energy that is transferred from the ground to the body for better comfort and smoothness. Ground friendliness (i.e., without the excessive dynamic tire load) can cause soil compaction and damage during spraying. The tilt and pitch movement of the vehicle can trigger the sloshing impact of the liquid in the tank under the excitation of a complex road surface. The spring-loaded mass of the vehicle and the height of the center of mass can be used to balance the change of liquid filling conditions during spraying in the suspension system under the best matching parameters. It is difficult to guarantee the smoothness of the whole vehicle, due to the liquid sloshing in the tank and the time-varying quality for the complex working conditions of a high clearance self-propelled sprayer. In this study, the equivalent mechanical model of the liquid sloshing in the tank was constructed using the dynamic characteristics of the liquid shaking and the mechanical model equivalence criterion. The model parameters were selected, according to the mechanical model equivalence criterion. The equivalent model was fused to establish a seven-degree-of-freedom nonlinear vertical dynamics model of the chassis, considering the liquid sloshing factor. A theoretical model was provided to realize the operation of the multi-objective optimization for the suspension system parameters. The following simplifications were made when modeling the whole vehicle. There was no cushioning mechanism between the liquid tank and the body, which was regarded as a rigid connection. The center of the body tilting and pitching motion coincided with the center of the bottom of the tank. The liquid in the tank was shaken in the form of a tipping force and moment acting on the body. A genetic algorithm (GA) was used to optimize the four variable parameters of front and rear suspension stiffness and damping. The GA tool in Matlab Optimization, and the Sim function were used to realize the operation of the Simulink dynamics simulation model and the invocation of the simulation. The optimal parameter matrices of suspension stiffness and damping were obtained for different road surfaces and fluid-filled conditions after optimization. The results show that the suspension stiffness parameter was significantly reduced, compared with the initial. By contrast, the suspension damping parameter slightly increased relative to the initial value. The optimal stiffness and damping values increased with the increase of the liquid filling ratio of the drug tank. At the same time, the optimal optimization of the vehicle body vertical acceleration, lateral tilt angle speed, pitch angle speed and dynamic wheel load under the optimal parameters reached 27.5%, 16.4%, 25.8%, and 17.6%, respectively. The optimization of vehicle vertical acceleration and pitch angle velocity gradually decreased with the increase of the liquid filling ratio, while the best optimization effect of dynamic wheel load and lateral tilt angle velocity appeared at a liquid filling ratio of 0.5 and 0.6, respectively. In addition, there was also a different optimization effect in the two operating conditions of the sprayer, in which the dynamic wheel load in the transit transport condition was often lower than that of the spraying operation under each liquid filling condition. The other three groups of variables were mostly better in transit. A complete spraying machine test platform was built to carry out the complete spraying machine tests. The test also used the acceleration and angle sensors. A typical working condition was used to measure the body acceleration, each suspension unsprung mass acceleration, body pitch angle velocity, and lateral tilt angle velocity. Four sets of replicated experiments were conducted with the road conditions and suspension parameter conditions as experimental variables. The test results show that the vertical acceleration of the sprayer's spring-loaded mass was much smaller than that of the unsprung mass, due to the vibration-damping effect of the suspension. Once the suspension was adjusted to the optimal parameters, the body vertical acceleration was reduced by 15.58% and 18.72% under the two road conditions, and the body roll/pitch angular velocity was reduced by more than 10%. The findings can provide a strong reference for the design, parameter optimization, and control of chassis suspension in tank-type vehicles.

To explore the influence of the lateral sloshing and the time-varying mass of the liquid in the tank on the ride comfort of the high-clearance sprayer, a spring-mass-damping equivalent mechanics that can describe the lateral sloshing of the liquid under different filling ratios was constructed based on the equivalent criterion. The Fluent was used to simulate the moment acting on the wall of the tank by the lateral sloshing of the liquid, and then the parameters of the equivalent mechanical model are obtained by fitting and solving. Comparative analysis of Fluent simulation and bench test on lateral sloshing of tank liquid under different filling ratios. The results show that the lateral sloshing trend of the tank liquid level obtained from the Fluent simulation and the bench test was consistent, which proved the accuracy of the Fluent fluid simulation process and the correctness of the required equivalent mechanical model parameters. Incorporating a liquid sloshing equivalent model, a four-degree-of-freedom vertical dynamic model of the sprayer half-car was established. Subsequently, the performance of the sprayer was systematically analyzed and compared under the excitation of a bump road and a random E-level road. This investigation took into account varying liquid filling ratios of 10%, 50%, and 90%. The focus lay on evaluating the vertical acceleration of the sprayer body, dynamic deflection of the suspension, and dynamic load on the tires in response to these road conditions. This analysis is conducted independently of the liquid sloshing factor. The results show that the lateral sloshing of the liquid medicine significantly reduces the ride smoothness of the machine, and makes the vibration response of the machine produce a certain hysteresis effect. With the reduction of the quality of the liquid medicine in the spray tank, the vibration amplitude of the sprayer body gradually decreases, the hysteresis effect is also gradually weakened. The results presented in this study offer a theoretical foundation for the analysis of ride comfort and the optimization of chassis structure in high-clearance sprayers.

Liquid fertilizer sloshing can often occur within storage tanks of manure applicators during transportation or operation. It is very necessary to improve the smoothness and the quality of fertilization in the liquid manure applicator. This study aims to optimize the wave proof plate within the tank using advanced CFD (Computational Fluid Dynamics) simulation with the Finite Element method (FEM). A systematic investigation was also conducted to clarify the longitudinal impact of liquid fertilizer on the tank wall. The primary metric system was taken as the loading peak of the total longitudinal impact on the fertilizer storage tank. A specific evaluation was also carried out to determine the influence of various parameters on the performance of wave proof plate. These parameters included the lower edge height of wave proof plate, the position height and diameter of wave proof holes, the number of wave teeth on the wave proof plate, as well as the height of trapezoidal teeth. The optimal combination of parameters was determined for the anti-slosh baffle using Response Surface method (RSM) with CFD simulation. Specifically, the optimal combination of parameters was achieved, where the height of the lower edge was 345 mm, the position height and diameter of wave proof hole were 133 and 622 mm, respectively. In addition, two similar devices of fertilizer storage tanks were constructed to further validate the effectiveness of the optimized anti-slosh baffle. One tank was equipped with a commercially available wave proof plate structure, while another was fitted with the self-developed wave proof plate. The similarity ratio was used to derive the positions of impact load monitoring points on the heads of the similar tanks and the anti-slosh baffles. The sloshing suppression tests demonstrated that the fertilizer storage tank was reduced the sloshing amplitude of liquid fertilizer during braking. The superior performance was achieved to suppress the sloshing of liquid fertilizer, particularly for the better smoothness of the applicator and the high quality of fertilization. Notably, there was the less than 7% relative error between the CFD simulated and sensor-monitored peak values of the total longitudinal impact load. The accuracy of CFD simulation model was further validated for the similar criterion. Furthermore, a series of experiments were then conducted to investigate the impact of the baffle on the overall stability of the machine. The better performance was achieved to suppress the liquid fertilizer sloshing, particularly in the demonstration cases at the filling ratios of 0.5 and 0.8. The overall stability tests demonstrated that the fertilizer storage tank was significantly improved in the pitch angular speed and lateral angular speed, compared with a commercial tank. Specifically, the improvements were 20% and 17%, respectively, on field roads; while the improvements were 25% and 17.2%, respectively, on off-field roads. In conclusion, the CFD model and similarity criterion were verified to restrain the slosh of liquid fertilizer for the high stability and accuracy of fertilizer storage tank in the whole machine. This finding can also provide the valuable insights and strong reference to design the wave proof plates in the storage tanks for the liquid manure fertilizer applicators.

The production of Lycium barbarum L. is a labor-intensive industry. Multiple manual harvests are required during the harvesting season, which contributes to the high harvesting costs. The cultivation conditions of L. barbarum were investigated to increase efficiency and mitigate harvesting damage. A torsion harvester was designed according to the characteristic of infinite inflorescence and the distribution of detachment force, and the kinematics model of the harvester was established. The vibration responses of ripe and unripe fruit were obtained through ADAMS simulation of the branch model, and the influencing factors and value range of the torsion harvester were also determined. The mathematical models of ripe fruit harvesting rate, unripe fruit harvesting rate, ripe fruit damage rate and torsion angle, vibration rods distance, and vibration frequency were established by the Box-Behnken test. The influences of various factors on ripe fruit harvesting rate, unripe fruit harvesting rate, and ripe fruit damage rate were analyzed, and the best parameter combination was obtained: torsion angle 73.66°, vibration rods distance 35.51 mm and vibration frequency 19.12 Hz. Field experiment showed that the harvesting rate of ripe fruit is 95.67%, the harvesting rate of unripe fruit is 4.68%, and the damage rate of ripe fruit is 3.70%. The research results can promote the mechanization process of L. barbarum harvest, and provide a reference for vibration harvest of berries.

In response to the problems of poor speed stability and degraded spraying quality of 4WID high-clearance self-propelled electric sprayers caused by changes in external road gradients and lowered payloads resulted from internal liquid spraying under complex operating conditions，a fixed-speed cruise control algorithm with a layered control approach is proposed based on an analysis of the structure and longitudinal dynamic characteristics of 4WID high-clearance self-propelled electric sprayers. The control algorithm model receives the user-specified desired speed and inputs acceleration control signals to the longitudinal dynamic system model through algorithmic calculation to realize the tracking of the sprayer to the desired speed. The structure of the longitudinal dynamic system mainly includes five parts：the inverse longitudinal kinematic model，the acceleration-braking switching model，the torque allocation model，the motor model，and the longitudinal kinematic model. The inverse longitudinal kinematic and longitudinal kinematic models of the sprayer can be obtained by analyzing the force on the body of the sprayer under the condition of driving on a slope. Meanwhile，in order to establish a reasonable four-wheel torque allocation strategy，the analysis is conducted under the condition that the sprayer has both pitching and tilting motions of the body，and the slip rate of each driving wheel is used as the basis for allocation，ensuring the optimal torque moment of each wheel under different operating conditions and ensuring the balanced power of the sprayer. The speed cruise control adopts a layered control approach，which realizes the effective tracking of the speed of the spraying machine through the establishment of the upper PID control and the lower fuzzy PID control. By defining fuzzy control rules，the PID parameters of the lower layer controller are automatically adjusted to ensure the good adaptability of the speed cruise control system to various complex operating conditions. A control model is established using Matlab/Simulink，and the control system is simulated and analyzed. The experimental results show that the designed speed cruise control system can effectively control the speed of the sprayer under typical operating conditions. Specifically，the performance of the system is excellent under conditions of external disturbance and self-weight variation，with overshoot less than 2%，response time less than 0.2 s，and steady-state error approaching 0，verifying the accuracy of the control algorithm used.