关键词: 轮式机器人, 四轮独立转向, 控制策略, PID参数整定

Abstract: Aiming to achieve coordinated control of steering wheels for agricultural wheeled robots, a steering motion control method is proposed in this paper. Based on the chassis structure of a fourwheel independent steering robot driven by inwheel motors, a coordinated steering control strategy of wheel following linkage is constructed using the PID control method. The hardware and software systems for the steering control of wheeled robots are designed, and the PID control parameters are tuned. Prototype bench tests and pavement verification tests were carried out. The results show that the method can accurately control the speed of the hub motor. The optimal PI control parameters are Kp=0.45 and Ki=0.02. In the bench test, there was a 1°-3° steering error when the chassis started, but over time, each wheel gradually conformed to the Ackerman steering relationship. In the road test, the steering angle can be adjusted in realtime with the target signal to maintain the Ackerman steering relationship. The angle error was 2°-3°, and the steering time was less than 3 s, which met the operating requirements of the wheeled robot.

Key words: wheeled robot, fourwheel independent steering, control strategy, PID parameter tuning