The Research On The Intelligent Control Of The Ultrasonic Motor

Ultrasonic motor (USM) is a newly developed actuator that uses mechanicalvibrations in the ultrasonic range as its drive source. An USM has excellent features suchas high holding torque, high torque at low speed, compact size, silent operation and noelectromagnetic noise. Besides these advantages the USMs have some drawbacks. It isdifficult to derive a mathematical model of USM and the control characteristics of USMare complicated and highly non-linear. Based on the above-mentioned ultrasonicmotor control problems, the paper carried out research from theoretical and experimental.The main contents of this article are as follows:(1) Based on the difficulty in obtaining accurate mathematical model, this paperusing the PID controller to control the ultrasonic motor without understanding of thecontrolled object mathematical model and completed the design of the controller.(2) Based on internal model control theory, Construction of the Internal ModelControl for PID (IMC-PID), and the method is applied in the control of the ultrasonicmotor. Thus the parameter tuning of the PID controller is simplified, andthe control performance is improved.(3) To solve the problem of the ultrasonic motor input and output nonlinear, this paperproposed the neural networks (NN) and the particle swarm optimization (PSO). The authorconstructed a neural network architecture controller, and tuning the parameter of IMC-PID.(4) To solve the problem of the dynamic changes of the characteristics of ultrasonicmotor, traditional neural network weight adjustment strategy has been improved.(5) In this experiment, the IMC-PID control for USM based on NN and PSO isproposed respectively from the theoretical viewpoints and analyzed by the experimentalresults. The nonlinearity and property fluctuation of USM could be compensated stably,and effectiveness of the method proposed in this research is also demonstrated by theresults of experiments.Experimental results show that, smart IMC-PID control method proposed in thisarticle, the ultrasonic motor in the load and no load conditions for reversing control, canget the range in the [-0.0044,0.0044][deg] between the steady-state error, a high-precisioncontrol of ultrasonic motor, which verifies that the proposed smart ultrasonic motor, theIMC-PID control method has good adaptability and stability.