Design and Test of Auxiliary Steering System of High Clearance Sprayer Chassis Based on Self-steering Structure

Abstract

A hydraulic assisted steering method was proposed to solve the problem of steering instability caused by insufficient reverse resistance moment of wheel hub motor in four-wheel independently electrically driven high clearance sprayer. Firstly, the principle of steering chassis structure of four-wheel independently electrically driven high clearance sprayer is briefly introduced. On this basis, hydraulic auxiliary steering system is designed. Then a simplified 2-DOF vehicle steering model is established to analyze the Angle control of the auxiliary steering system. Finally, simulation and road surface test are carried out respectively to verify the performance of steering and auxiliary steering coordination control. Under the working conditions of the steering system alone and the steering system and the auxiliary steering system together, the four-wheel electric drive sprayer carried out the obstacle crossing test and the downslope test with the slope of 15° respectively at the speed of 1 m/s on the smooth road surface. The test results show that in the downhill test, the maximum tracking deviation of the steering system alone is 6.1°, the maximum tracking deviation of the steering and auxiliary steering coordination is 0.9°, the maximum tracking deviation of the steering system alone is 12.0°, and the maximum tracking deviation of the steering and auxiliary steering coordination is 1.2° in the obstacle breaking test. The test results verify the feasibility and stability of the hydraulic steering system proposed in this paper. The system has good test performance and can meet the practical requirements.