基于QFT的开关阀控气动位置伺服系统鲁棒控制

ROBUST CONTROL EMPLOYEDQFT FOR A PNEUMATIC POSITIONSERVO SYSTEM USING ON/OFFSOLENOID VALVES

考虑开关阀的滞后特性,建立了高速开关阀控气动位置控制系统的非线性模型,并在原模型的基础上,将系统模型处理为包含滞后环节的数学模型。针对该模型对象参数不确定、摄动量大和负载变化范围大等问题,采用包含小闭环的2自由度控制结构,用定量反馈理论,进行系统的鲁棒稳定性、干扰抑制和跟踪性能设计,设计了具有鲁棒性能的控制器,并且设计了有效的摩擦力补偿器。经过试验验证,系统不仅具有较好的稳定鲁棒性,还具有很好的动态性能和位置精度。

A nonlinear model on pneumatic position servo system based on solenoid valves is builted, in which the hysteresis of the solenoid valves is taken into consideration. Further a parametric uncertainty pseudo linear model with time delay is conducted with feedback linearization. As to deal with the robust control problems against parameter uncertainty, noise and load disturbance, quantitative feedback theory (QFT) is employed to shaping the loop transmission, which is expected to own robust stability, robust disturbance rejection and tracking behaviour. The controller adopts the structure of two DOF, which owns an inner feedback loop in order to increase the damping. Friction compensation is also introduced to promote its performance. Finally the experiments based on the controller verify that the servo system embodies robust stability, dynamic performances of accurate and quick response.