电动舵机极限环机理分析和抑制措施

针对电动舵机结构,建立了一种考虑减速器等效刚度的舵机模型.利用描述函数法,分析了舵机在考虑传动间隙情况下诱导的极限环,进而分析了在有无舵片所受摩擦力情况下极限环的频率特性.针对该类传动非线性,提出了一种工程上可实现的负反馈力矩机制来改变舵机在间隙区间的运动模态,从而抑制极限环振荡,并且给出了负反馈系数的选取准则.最后进...

Analysis and suppression of the limit cycle about electric actuator

To study the electric actuator,a model is established with backlash nonlinearity and equivalent rigidity considered.Applying the describing function,the limit cycle of the actuator system is analyzed,and the characteristics of the limit cycle’s frequency and amplitude are also analyzed.A method adding negative feedback moment to the load is proposed.The feedback moment can suppress the limit cycle of the actuator by changing the motion state of the load.The effect of the feedback moment to the servo system is analyzed and the principle of the feedback coefficient is given.The simulation results show the effectiveness of the describing function in predicting the limit cycle in the nonlinear system,and the proposed method does not affect the servo performance of the system and the negative feedback moment is valid in suppressing the limit cycle of the electric actuator with the backlash nonlinearity.