抓草机电动助力转向系统的控制与仿真研究

为了改善农用抓草机的转向操纵灵活性、减轻驾驶员的劳动强度,设计了一种适合抓草机的电动助力转向控制策略。根据简化的抓草机电动助力转向物理模型,给出了抓草机电动助力转向系统的数学模型;设计了合适的助力特性曲线,采用PID和直流斩波控制策略对电动机目标电流进行闭环跟踪控制。仿真结果表明:助力特性与所设计的助力特性基本一致,且随着车速提高,转向盘上的转矩也相应增加。设计的控制要求策略既提高了转向的轻便性,又保持了驾驶员的路感,可满足抓草机在转向操作稳定性要求。

Research on Control and Simulation for Electric Power Steering System of Grabbing Grass Machine

In order to improve the steering control flexibility of the machine and reduce the labor intensity of the driver in working, one kind of electric power steering system control strategy is designed that is suitable for the grabbing grass ma-chine. By the simplified physical model of electric power steering of the machine, the mathematical model of the power steering system of the grab is set up, the appropriate of assisting characteristic curve is designed, the PID and DC chop-per control strategy are used for carry out closed loop tracking control to the motor target current. The simulation results show that the assist characteristics are basically same as the designed, and as the running speed of the machine increa-ses, the torque on the steering wheel is correspondingly increased. So that, the control strategy not only improve the steering portability but also maintain the road feel of driver, it can meet the requirements of the steering operation stability of the grabbing grass machine.