大惯量下电动伺服机构非线性特性与控制方法研究

Research on Nonlinear Factor Characteristics and Control Method on Large Inertia Electromechanical Actuator Servo Mechanism

关键词:  电动伺服机构  极限环  间隙  刚度  非线性振荡

Key words:  Electromechanical  Limit cycle  Clearances  Stiffness  Nonlinear oscillations

摘要:

针对高超声速飞行器非线性影响飞行姿态控制问题,分析了电动伺服机构中传动间隙、刚度、摩擦力矩等非线性因素的影响,并讨论了由间隙引起极限环的定义及产生条件。针对传动间隙引起的极限环振荡和较大惯量的翼面加剧振荡问题,建立了系统间隙极限环模型和非线性振动模型,并提出了间隙补偿器设计方法。重点研究了间隙、翼面转动惯量、刚度及干扰力对伺服控制系统的影响规律。通过在内环增加间隙补偿器的基础上,在外环引入速度、加速度负反馈设计方法,解决了大惯量舵面下控制系统抖动问题,仿真和试验结果证明了这一理论是正确的。

Abstract:

For flight attitude control problem affected by nonlinear property of hypersonic vehicle, the influences of nonlinear factors which are driving space, stiffness, friction torque in the electric servo mechanism are analyzed in this paper, and the definition and generation conditions of limit cycle caused by the backlash are also discussed. For the problems of limit cycle oscillation and the airfoil intensified oscillation with large inertia caused by driving space, a system backlash limit cycle gap model and nonlinear vibration model are established, and the backlash compensator methods are proposed. This paper focuses on the influence of backlash, airfoil moment of inertia, servo stiffness and disturbing force to servo mechanism system. Based on increasing backlash compensator by controlling inner ring, the design method of accelerated negative feedback is introduced to the outer ring, solving jitter problem in large inertia system, and the simulation and experimental results demonstrate that this theory is correct