Abstract:Conventional agricultural chassis was difficult to adapt to the slope which put a severe test during the operation. Taking the auto leveling system as the research content, a twodegree of freedom platform and its selfcontrol system was developed. The mechanicalelectricalhydraulic multiphysics simulation model was established based on SimMechanics and SimHdraulics, which helped to analyze spatial kinematics through SimMechanics while hydraulic system simulation through SimHdraulics. Due to dualacting asymmetric hydraulic cylinders, a dualchannel PID control strategy was used to control following response, displacement error, velocity respectively and dualaxis inclination. The hydraulic cylinder with push and return movements could be regarded as different hydraulic cylinders with different piston areas. The characteristic of dualchannel PID control meant when errors were adjusted with different PID parameter values. The simulation results showed that the maximum following error was 1.90mm and the response time was 0.228s under dualchannel PID control. The equilibrium time in the limit state was 2.98s. Compared with singlechannel PID control, the maximum control error was reduced by 49.3%, and the response speed was increased by 45.8%. Tests under eight different gradients were performed. These results showed that the response time of the auto leveling system was 0.328s. With the increase of gradient, the maximum error of the test platform leveling was 1.14°, and the maximum root mean square error was 0.299°. The auto leveling system had a fast response, small following error, good followability and high control accuracy under the dualchannel PID control and it can meet the requirements of ring slope operation.