二自由度行波型超声波电机的轨迹控制

Trajectory control of a 2-DOF traveling wave type spherical ultrasonic motor

对二自由度球形超声波电机来说,轨迹控制是输出性能的重要环节。对二自由度球形超声波电机进行了轨迹(路径)控制。首先以定子表面行波波峰点周向角速度的极小范数为优化目标,结合单个定子的调速和电机运行矢量原理作为电机运行模式的模型。为了实现球转子姿态的测量,采用了一种类似机械鼠标原理的球转子位置检测方法,再结合电机运行模式求出各个定子驱动电压的相位差,然后采用神经元PID算法来实现电机闭环轨迹控制。闭环控制下,电机转子运行时各个方向的误差控制在2个脉冲以内。

The trajectory control is an important link of output performance for a 2-DOF spherical traveling wave type ultrasonic motor. Here, the trajectory tracking control was presented with a 2-DOF spherical ultrasonic motor with 3 stators. Firstly, the minimum norm of the circumferential angular velocity of the traveling wave peak point on the surface of the stators was taken as an optimizing target for the motor. Then combination of a single stator＇s speed adjusting and the vector principle of a motor＇s operating was taken as the model of the motor＇s operating mode. In order to measure the attitude of the spherical rotor, a method to detect its position based on the operating principle of a mouse was adopted. Then, the phase-difference of the driving voltage of each stator was calculated with the moror＇s operating mode. With a neuron PID algorithm, the closeloop trajectory tracking control of the motor was realized. The results showed that in every direction the error is controlled within 2 pulses. The study results provided a reference for design and performance improvement of multi-DOF spherical traveling wave ultrasonic motors.