基于自抗扰控制方法的双叶片式摆动缸转矩控制

Torque Control of Double Vane Swing Cylinder Based on Active Disturbance Rejection Control Method

双叶片式伺服摆动缸是液压执行元件的一种,能将液压能转化成旋转的机械能。当其作为液压腿足式机器人的关节驱动元件时,具有结构紧凑、重量轻、直接输出关节转矩等优势。由于液压系统的非线性特性以及足式机器人自身易受冲击、对系统产生干扰等因素,传统的PID控制方法难以满足关节转矩的控制需求。利用自抗扰控制(ADRC)方法实现叶片摆动缸的转矩控制,利用扩张观测器来观测和补偿系统外部负载力的不确定性,有效地抑制了外部扰动对系统的影响。建立了伺服阀控制叶片式摆动缸的数学模型并设计了线性自抗扰控制器,在恒负载、变负载等多种工况下采用ADRC进行力矩闭环控制,并与PID控制方法进行比较。仿真表明,ADRC控制器可以有效抑制外部扰动,与PID控制器相比,在受到干扰后的平均误差缩小了30%以上。

Double vane servo swing cylinder is a kind of hydraulic actuator,which can convert hydraulic energy into mechanical energy in form of rotary motion.The double vane servo swing actuators are often used as the joint driving element of hydraulic legged robot,which have the advantages of compact size,lightweight and direct output of joint torque.However,the nonlinear characteristics of the hydraulic system,as well as the robot's susceptibility to impacts and system interference,pose challenges for traditional PID control methods in meeting the torque control requirements.To address these issues,the utilization of ADRC is proposed.ADRC incorporates an extended observer to observe and compensate for uncertainties arising from external load forces acting on the system.This approach effectively suppresses the influence of external disturbances on the system.In addition,a mathematical model is established for the servo valve controlling the vane swing cylinder and design a linear ADRC.The performance of the ADRC and PID control methods are compared in torque closed-loop control under various working conditions,including constant load and variable load scenarios.Simulation results demonstrate that the ADRC controller can effectively suppress external disturbances,reducing the average error after a disturbance by over 30%compared to the PID controller.