基于CAN-Bus的农业车辆电动转向系统研究

Research on electric steering system for agricultural vehicle based on CAN-Bus network

为实现农业车辆精准快速地自动转向,建立了转向系统模型并设计了转向控制算法。试验平台以车载计算机为CAN主节点,采用CAN-Bus通信网络与各个监测控制从节点相通信,CAN从节点包括前轮转角测量节点、行驶速度测量节点,转向电机控制节点与车辆行驶速度控制节点。根据输入量与输出量之间的物理关系建立了转向系统的二阶模型,通过稳定性分析,设计了基于ITAE性能指标的最优PD控制器。试验结果表明,对系统施加±20°的阶跃输入信号,车辆在农田路面与水泥路面下分别以0.3、0.5、0.7 m/s的速度行驶时,最优PD控制器均能使系统平稳地跟踪期望的前轮转角,调节时间均在0.35 s以内,稳态误差小于0.5°。

In order to track the desired front wheel angle accurately and rapidly,a steering system model was established and a steering control algorithm was designed for the agricultural vehicle.In the system,the master node（an on-board computer） communicated with four slave nodes（front wheel angle measure node,speed measure node,steering motor control node,driving speed control mode） by CAN-Bus communication network.According to the relationship between the input and output of the steering system,a second-order model was built.And an optimal PD controller based on the ITAE（integral time absolute error） performance index was designed to enhance steering performance.The tests were discussed when the vehicle was driving on the farmland and the cement road at the speed of 0.3 m/s,0.5 m/s,0.7 m/s respectively.Test results showed that the steering system tracked the desired front wheel angle smoothly under the desired input signals（±20°of the front wheel angle）.The adjusting time was within 0.35 s and the steady-state error was less than