Application of improved generalized predictive control for frequency control in ultrasound therapy instruments

Aiming at the phenomenon that the output frequency and power of ultrasonic therapeutic instrument can not reach the expected result due to poor precision and resonant frequency drift after long-time use, an improved generalized predictive control algorithm was proposed to optimize the output. Based on the input and output of ultrasonic transducer, the control system model is built, and the parameters of the controlled object are identified online by the recursive augmented least square method with forgetting factor. The controller can predict the future variation trend according to the current output and compensate the current control quantity. Experimental results show that this method can compensate the output quickly, improve the control efficiency, and greatly improve the stability and anti-interference ability of the system. Compared with the traditional PID control method, the stabilization time is greatly shortened and the control accuracy is higher.