Multiple closed-loop control based on improved Smith predictor

In classical electro-optical control systems, the double closed-loop control including speed feedback and position feedback is often used to enhance the closed-loop performance. As the system is subject to internal detection delays and external disturbances, the stability and tracking accuracy of system are greatly challenged. MEMS gyroscopes inertial sensor are widely used in electro-optical control systems due to their advantages of light weight, high resonant frequency, and short response time. However, the Analog-to-Digital conversion and self-filtering characteristics of the sensors determine that there is a certain detection delay, and the system also faces the interference caused by the mechanical resonance. To solve this problem, an improved Smith Predictor method based on inertial sensor-MEMS gyroscope is proposed. The original Smith Predictor is only used to eliminate the effect of delay. Base of that, we modify the predictor's structure and add a branch of disturbance observer to compensate the external disturbance. The control strategy and the formula derivation is given out. The experimental results show that the closed-loop bandwidth of the system's speed loop are significantly improved, and the method effectively improves the system's disturbance suppression performance.