一种用于电液位置伺服系统控制的高阶滑模控制器的设计

Design of a High Order Sliding Mode Controller For Electro-Hydraulic Position Servo System

这里提出了一种用于电液位置伺服系统控制的高阶滑模控制器的设计,以提高电液位置伺服系统的控制准确度。从电液伺服系统的构造出发,分析了其组成结果与工作过程。以外界输入电压为依据,求取了滑阀的动力学模型,通过液压缸两个子缸压力差值形成的负载压力,计算出了滑阀动态运动时产生的流量,并通过负载压力得出了负载的位移平衡方程,进而以滑阀位移、负载位移及输入电压等系统的状态参数,获取了电液伺服系统的动力学模型。引入超螺旋控制器和广义超螺旋控制器的一般表达形式,以输入电压误差及负载位移误差为依据,构造了系统的滑动面函数,并将滑动面函数的导师与超螺旋控制器相结合,构造了基于超螺旋控制器的滑模控制器,为了提高系统的收敛速度,在基于超螺旋控制器的滑模控制器的基础上,借助广义超螺旋控制器,构造了高阶滑模控制器,以对电液位置伺服系统进行控制。实验结果表明,所提算法不仅具有较好的响应速度,而且对电液位置伺服系统的控制准确度较高,在对目标轨迹跟踪时,所提方法比模糊干扰观测器方法的跟踪准确度提高了33.11%。说明所提方法对电液位置伺服系统具有较好的控制性能。

A design of high-order sliding mode controller for electro-hydraulic position servo system is proposed to improve the control accuracy of electro-hydraulic position servo system.Starting from the structure of electro-hydraulic servo system,its composition results and working process are analyzed.Based on the external input voltage,the dynamic model of the slide valve is obtained.Through the load pressure formed by the pressure difference between the two sub cylinders of the hydraulic cylinder,the flow generated during the dynamic movement of the slide valve is calculated,and the load displacement balance equation is obtained through the load pressure.Then,based on the state parameters of the system such as slide valve displacement,load displacement and input voltage,The dynamic model of electro-hydraulic servo system is obtained.The general expressions of super screw controller and generalized super screw controller are introduced.Based on the input voltage error and load displacement error,the sliding surface function of the system is constructed,and the mentor of the sliding surface function is combined with the super screw controller to construct a sliding mode controller based on the super screw controller.In order to improve the convergence speed of the system.Based on the sliding mode controller based on super screw controller and with the help of generalized super screw controller,a high-order sliding mode controller is constructed to control the electro-hydraulic position servo system.The experimental results show that the proposed algorithm not only has good response speed,but also has high control accuracy for the electro-hydraulic position servo system.When tracking the target trajectory,the tracking accuracy of the proposed method is 33.11%higher than that of the fuzzy disturbance observer method.It shows that the proposed method has good control performance for electro-hydraulic position servo system.