电液位置速度复合伺服系统控制策略

Control Strategy of the Electro-hydraulic Position and Speed Hybrid Servo System

在电液伺服控制系统的许多实际应用场合,如塑料注塑机、压力机等成型机械,不仅要求较高的位置控制精度,还要求能够控制执行器运动过程的速度,以减小冲击,提高产品质量和生产效率。针对电液伺服系统速度/位置复合控制的要求,考虑力负载对位置控制精度的影响,提出带负载力补偿的速度前馈和位置反馈复合控制策略。导出速度前馈控制量计算模型,该模型能够反映实际负载大小和给定速度的要求;设计位移和速度给定信号发生器,实现了速度前馈控制和位置反馈控制的无扰切换;采用试验和数据拟合的方法,得出负载力补偿量计算公式。仿真和试验研究表明,采用所提出的控制策略,实现了速度和位置的同时控制,在不同负载下,对于不同的期望速度,不需要调节控制器参数,无论正向还是反向运行,都可以获得较好的控制性能。

For many application fields of the electro-hydraulic servo control system,such as plastics injection molding machine and press machine,in addition to the requirement of high position control accuracy,it’s necessary to control the moving speed of the actuator to minimize the impact and therefore to improve the production efficiency and product quality.To meet the requirement of position and speed hybrid control in the electro-hydraulic servo system,considering the effects of the force loads on the positioning accuracy,a compound control strategy with speed feedforward and position feedback and load compensation is proposed.The speed feedforward model is deduced,which reflects the magnitude of the load and the requirement of the given speed.And the generator of the given speed and position signals is designed,by which the undisturbed switching of the speed feedforward control and the position feedback control is realized.And the force load compensation formula is obtained through experiments and data fitting.The simulation and experimental results show that the position and speed of the actuator can be controlled simultaneously.And better performance can be achieved in both forward and reverse moving directions under different loads and with different desired speeds,without adjusting any control parameters.