超声电机驱动的微夹持器的机械漂移机理研究

A Study on Mechanism for Mechanical Drifts of Micro-grippers Driven by Ultrasonic Motors

针对直线超声电机驱动的微夹持器操作末端的机械漂移问题,从直线超声电机以及微夹持器整体结构出发,研究机械漂移的产生机理以及控制方法.首先通过建立电机的力学模型分析直线超声电机产生机械漂移的机理,重点讨论了电机定子左右两边弹性夹持结构在电机停止运行后发生的刚度衰减率不一致对机械漂移的影响;然后根据模型研制直梁型夹持直线超声电机,并进行试验验证,结果表明适当增大夹持元件的切向刚度对电机的机械漂移有较好的抑制效果;最后,通过试验研究了微夹持器机构的机械漂移规律,分析了微夹持器传动部件对操作末端产生机械漂移的影响,提出通过优化操作方式以及降低装配误差的方式减小机械漂移的方法,进而提高微夹持器的稳定性.

To address the problem with mechanical drifts at an operation end of a microgripper driven by linear ultrasonic motors,this paper studies the mechanism and control method of mechanical drifts from the perspective of??linear ultrasonic motor and microgripper structure.A mechanical model for the motors is firstly built,with which the mechanical drift mechanism for linear ultrasonic motors is then analyzed.The influence of the stiffness attenuation rate inconsistency of left and right elastic clamping components on mechanical drifts after the motor stops running is discussed.Based on the model,a straight-beam clamping linear ultrasonic motor is developed and tested.The results show that the mechanical drifts of the motors can be effectively suppressed by using clamping elements with greater tangential stiffness.Finally,the mechanical drift rule of the microgripper is examined through experiments,and influences of transmission parts of the microgripper on the mechanical drifts of the operation end are analyzed.The method to reduce mechanical drifts by optimizing operation mode and reducing assembly errors is put forward to improve the stability of microgrippers.