Abstract: To improve the position control accuracy of electro-hydraulic servo system for surface milling machine,a control strategy of milling face's electro-hydraulic position servo system based on Active Disturbance Rejection Control (ADRC) technique was proposed.According to the characteristics of valve controlled asymmetrical cylinder in two different conditions of extend and retract,the corresponding fluid dynamics model were established,and the transfer function of system was deduced by other links.The three order ADRC strategy was designed on the basis of the system characteristics,and the extended state observer was used to estimate and compensate the time-varying of system parameters and external disturbance.The performance of designed control strategy was verified by simulation and industrial field experiments.The results showed that ADRC strategy could make the position output of system not affect by the change of control object's parameters,and had better internal robustness and anti-interference ability than traditional PID control strategy,which could suppress the external disturbances on the system effectively.

Key words: surface milling machine, valve controlled asymmetrical cylinder, PID, active disturbance rejection control, electro-hydraulic position servo system

摘要： 为了提高铣面机床电液伺服系统的位置控制精度,提出一种基于自抗扰控制的铣面机床电液位置伺服系统控制策略。根据伺服阀控非对称伺服缸在伸出和缩回两种不同工况下的特点分别建立了相应的流体动力学模型,并结合其他环节推导出铣面机床电液位置伺服系统的闭环传递函数;依据该系统的特点设计出三阶自抗扰控制策略,通过扩张状态观测器对系统参数时变和外部扰动进行估计和补偿,并采用仿真和工业现场实验对所设计的控制策略性能进行了现场应用验证。仿真及现场应用表明,所设计的自抗扰控制策略能够使系统的位置输出基本不受控制对象参数改变的影响,具有比传统PID控制策略更好的内部鲁棒性和抗干扰能力,有效抑制了外部扰动对系统位置控制精度的干扰。

关键词: 铣面机床, 阀控非对称缸, PID控制策略, 自抗扰控制, 电液位置伺服系统