工业重载液压系统的位置伺服控制

Position servo control of industrial heavy-load hydraulic system

中文关键词  荒磨机  液压位置伺服控制  参数辨识

英文关键词  rough grinding machine  hydraulic position servo control  parameter identification

中文摘要

      本文以清华大学自动化系设计并制造的国内首台具有自主知识产权的HMK 1800重载轧辊荒磨机为背景,介绍其液压系统的位置伺服控制方法. 液压系统是荒磨机最关键的执行机构, 本文设计的位置伺服控制系统采用双闭环结构, 内环是活塞速度闭环, 外环是油缸位置闭环, 位置设定值通过线性插补的方式给定. 这种结构在恒位置磨削的时候可以保证位置控制精度, 在磨削臂进给的时候可以控制进给速度. 本文整定了两套PID参数以适应模型参数的变化, 并采用增量式PID从而实现控制参数的无扰动切换.

英文摘要

      For the HMK 1800 heavy roller rough grinding machine, which is designed and manufactured for the first time in China by Tsinghua University with independent intellectual property rights, this paper introduces the modeling and the position servo control for its hydraulic system. Hydraulic system is the most critical actuator of rough grinding machine, of which the position servo control system adopts a double-loop structure. The inner loop provides a closed-loop control for the piston velocity, while the outer loop is a closed-loop for controlling the cylinder position. The setpoint value of the position loop is determined through the linear interpolation. This structure ensures the precision of position control in constant position grinding; furthermore, it performs the control for the feeding-rate when the grinding arm moves inward. Two sets of PID parameters are adjusted to deal with the variations of model parameters; and a velocity PID is employed to realize the smooth switching between the two sets of control parameters.