滚珠丝杠式电动舵机系统非线性特性分析

Nonlinear Factors Analysis of EMAwith Ball Screw Drive

摘要:

针对速度反馈控制的滚珠丝杠式电动舵机系统,建立更加完整的系统模型,模型中充分考虑间隙和摩擦等非线性因素的影响,并通过数值仿真,观察分析不等间隙和摩擦对系统输出的影响规律。采用LuGre模型和死区模型分别描述电动舵机运行时的摩擦和间隙行为,然后根据传动链结构特点提出非线性研究方案,并根据此方案将非线性环节加入所建立的电动舵机二阶模型中,分别对间隙和摩擦的影响进行仿真分析。仿真结果表明,间隙和摩擦会使伺服系统产生跟踪误差,影响定位精度,甚至影响系统稳定。

Abstract:

For electromechanical (EMA) flight surface actuation systems, the controller of which use proportional control with a velocity feedback, this manuscript sets up a more complete simulation model considering the presence of the backlash and the friction to analyze the effects of both nonlinear factors. Based on the characteristics of the driving chain, a strategy for the research of the nonlinear factors is proposed, according to which LuGre friction and dead zone model are applied into the second-order EMA system. Our results indicate that free play in driving mechanisms and friction can lead to the tracking error and affect the stability of the EMA system.