基于变论域模糊PID控制的转向执行机构研究

Research about the Executive Mechanism of Steering System Based on Changing Domain Fuzzy Self-adaptive PID Controller

针对重载车辆转向执行机构系统,提出了基于变论域模糊PID控制的液压缸位置控制结构。传统的控制方法常采用模糊PID控制,虽然控制效果好于PID控制,但普通模糊控制精度低、超调量大,因此有必要采用变论域方法。该方法通过伸缩因子改变模糊输入和输出变量的论域,使论域自调整,以较少的控制规则实现了较高精度的控制。Matlab仿真表明,与传统的模糊PID控制系统相比,该方法的超调量小,控制精度高,控制效果明显好于模糊PID控制。

For the executive mechanism of steering system for heavy vehicles, a hydraulic cylinder position control mode based on changing domain fuzzy PID controller is proposed. Traditional control methods often adopt fuzzy PID controller. Although it is better than PID control, the ordinary fuzzy control has low accuracy as well as high overshoot, so it is necessary to introduce changing domain method. By means of contraction-expansion factors changing fuzzy input and output variables, this method can make self-adjusting domain to achieve a high precision control with less rules. Matlab simulation shows that this control method is provided with small overshoot and high control accuracy compared with traditional fuzzy PID control system, effectiveness is better than the fuzzy PID control.