电动直线加载系统不确定性分析及扰动抑制补偿研究

为测试某型航天电动直线伺服阀实际工作性能,提出了一种永磁同步电机加滚珠丝杠的电动直线加载方案,采用机理建模方法,建立电动直线加载系统数学模型,并分析系统模型不确定性来源:电机模型结构不确定、驱动器参数摄动、滚珠丝杠扭矩波动和舵机不确定性扰动。针对理论模型,提出基于扰动观测器的双回路控制系统设计方法,通过鲁棒内回路控制结构等价变换,以抑制舵机扰动要求为性能权函数,采用H∞混合灵敏度方法设计内回路扰动观测器,外回路以提高加载系统整体性能为要求,采用PID控制算法。试验结果表明,在加载力2000N,加载频率4Hz下,系统多余力抑制比达到86. 4%,且系统静态和动态加载均达到"双十"指标。

Research on Uncertainty Analysis and Disturbance Suppression Compensation of Electric Linear Loading System

In order to test the actual performance of an aerospace electric servo valve,an electric linear load scheme for a permanent magnet synchronous motor plus ball screw was proposed.A mathematical model of the electric linear load system was established using a mechanism modeling method,and the system model was analyzed.Deterministic sources:motor model structure uncertainty,actuator parameter perturbation,ball screw torque fluctuations,and steering gear uncertainty disturbances.Aiming at the theoretical model,a design method of dual-loop control system based on disturbance observer is proposed.Through the equivalent transformation of the robust inner loop control structure,the disturbance performance requirement of steering gear is suppressed as the performance weight function,and the internal loop disturbance observer is designed using the mixed sensitivity method.The external loop uses PID control algorithm to improve the overall performance of the Loading system.The experimental results show that under the loading force of 2000N and the load frequency of 4Hz,the excess force suppression ratio of the system reaches 86.4%,and both the static and dynamic loading of the system reach the"Double Ten"index.