Design and Experiment of Spray Machine Drive Anti-skid System Based on Variable Motor Control

Abstract

The self-propelled sprayer for high ground clearance is prone to wheel slippage in complex operating environments, which can affect the flow and pressure stability of the static hydraulic drive system. In severe cases, this can lead to a loss of maneuverability, necessitating the implementation of anti-skid control to ensure stable driving performance and the ability to escape from difficult situations. A static-hydraulic drive system anti-skid control scheme was proposed for a large-scale self-propelled sprayer for high ground clearance. It defined the relationship between slip ratio and adhesion coefficient by using a bilinear model, and a sliding mode controller was designed. Field off-road tests were conducted to validate the control performance of the anti-skid system. The experimental results demonstrated that the system can control the sprayer’s slip ratio within 0.15. Under conditions of initial acceleration and constant speed, the mean slip ratios were 0.020 and 0.019, respectively. Moreover, under ditch-crossing conditions, the entire machine can be rapidly freed within 2s. These results confirmed that the designed sliding mode anti-skid system for the sprayer exhibited excellent anti-skid performance, ensuring smooth operation under typical conditions and effectively reducing the impact of unfavorable ground conditions on overall stability. The research did not utilize flow control valves or diverter valves, ensuring high control precision. It held the potential to achieve comprehensive and continuous anti-skid control for large-scale high ground clearance sprayers, thereby enhancing their driving stability, ground traversability, and active escape capability.

Keywords:sprayer; hydraulic driving; anti-skid control; sliding mode control; slip rate