贴片式复合模态型直线超声电机的仿真与试验评价

Simulation and experimental evaluation of a bonded-type hybrid modes linear ultrasonic motor

为了实现结构紧凑、低电压驱动、大推力输出以及高精密定位等性能目标,该研究提出了一种贴片式复合模态型直线超声电机。该电机的定子结构采用贴片式压电陶瓷作为激励单元,通过同时激发定子的B 12和B 2两种弯曲振动模态,实现了两个驱动足处的交替椭圆轨迹运动,借此利用摩擦力驱动动子进行直线运动。首先,应用有限元仿真软件COMSOL对定子的模态和频率响应进行了仿真分析。仿真结果表明,定子上两驱动足处能够实现预期的椭圆运动轨迹。随后,加工了电机的定子并进行了导纳测试,验证了有限元仿真的正确性。最后,制作了超声电机的原理样机,并通过一系列试验评估了其输出性能。试验结果表明:在100 Vpp电压和66.58 kHz频率条件下,电机的最大空载速度和最大推力分别达到了82.9 mm/s和0.52 N;在1.2 N的预压力作用下,电机的启动电压死区为12 Vpp;在周期为20的正弦波电压信号下,电机实现了2.1μm的步进位移。该研究为贴片式复合模态型直线超声电机的设计和应用提供了重要的理论与试验依据。

To achieve the performance of compact structure,low-voltage operation,and large thrust,a bonded-type hybrid modes linear ultrasonic motor was developed.In the stator of the motor,bonded type piezoelectric ceramics were adopted as excitation units.The alternating elliptical motions at two driving feet were achieved by exciting the two bending vibration modes of the stator,B 12 and B 2,thereby driving the slider in a linear motion by friction.First,the modal analysis and frequency response analysis of the stator were carried out using the finite element simulation software COMSOL.The simulation results show that the elliptical motion trajectories can be realized at two driving feet on the stator.Then,the stator was manufactured,and its admittance characteristics were tested to verify the correctness of the finite element simulation.Finally,a prototype of the ultrasonic motor was fabricated,and a series of experiments were carried out to evaluate its output characteristics.The experimental results show that under the voltage of 100 Vpp and the frequency of 66.58 kHz,the maximum no-load speed and maximum thrust of the prototype reach 82.9 mm/s and 0.52 N,respectively.At a preload of 1.2 N,the dead zone of the prototype is 12 Vpp.Under a sine driving wave with a cycle of 20,the motor achieves a step displacement of 2.1μm.This study provides important theoretical and experimental basis for the design and application of bonded-type hybrid modes linear ultrasonic motors.