RESEARCH ON DESIGN AND HYBRID SLIDING MODE CONTROL OF HIGH CLEARANCE SELF-PROPELLED SPRAYER CHASSIS AIR SUSPENSION

According to the operation characteristics of high clearance self-propelled sprayer, an independent vertical shaft air suspension system with auxiliary chamber was designed. On the basis of the damping characteristic analysis and experiment of the air suspension with auxiliary chamber, the sprayer suspension control strategy was developed. Aiming at strong non-linearity and hysteresis for air suspension with auxiliary chamber, and when the sprayer performed road transportation and spraying operation, there was a contradiction between ride comfort and road friendliness, a hybrid sliding mode control method for sprayer chassis suspension based on skyhook reference sliding mode and ground-hook reference sliding mode was proposed. Finally, Matlab/Simulink was used to analyse the effect of the control method in different mixing coefficients. The simulation results showed that according to the requirements of different working conditions of the sprayer, by properly selecting the mixing coefficient γ value, the hybrid sliding mode control could simultaneously take into account the sprayer ride comfort and road friendliness, which was important to improve the sprayer overall performance and operating efficiency.