Abstract:
As the actuator of the control system, the ultrasonicin used motor is widely precision-manufactured drive equipment. In this paper, an approximate time-domain mathematical model is established firstly for the selected ultrasonic motor control system, and the parameters of the system models are identified using the least square method. Then, a back-stepping reaching law controller is proposed and designed for the selected ultrasonic motor system, the stability of the ultrasonic motor control system is proved, and the parameter selection method of the designed controller is given. Finally, the proportional integral derivative (PID) control method with large gain and the designed control method are used to track the same position signal, and a better control effect is achieved. The results show that for a position signal with a tracking amplitude of 40 mm, the PID control method has a maximum tracking error of 0.1362 mm, and the maximum tracking error of the back-stepping reaching law control method is 0.0816 mm. Under the same control parameters, after adding a load of 0.3 kg, the maximum tracking errors of the PID control method and the back-stepping reaching law control method are 0.1519 mm and 0.0892 mm respectively. The proposed control method is easy to implement in engineering, and the control method requires few parameters to be adjusted and is easy to adjust, therefore, it has good engineering application value.
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