Time-lag Liquid Crystal Optical Phased Array Beam Deflection Control Method Based on Smith’s Prediction Compensation

Aiming at the response delay problem in the liquid crystal optical phased array (LCOPA) system, this paper proposes a time-lagged liquid crystal optical phased array beam deflection control method based on Smith prediction compensation to compensate for the hysteresis that exists in the system, improve the oscillations and overshoots brought about by data transmission and processing hysteresis, and eliminate the adverse effects of hysteresis, so as to realize the fast, accurate and stable deflection of the light beam by the liquid crystal optical phased array. According to the time lag fractional order model of liquid crystal optical phased array system, the Smith predictor compensator and fractional order control system are designed, the Smith predictor is used to compensate for the delay of the system, the fractional order PID controller is used to finely adjust the response of the system, and the sparrow search algorithm is proposed to be utilized for the tuning of the controller parameters. The time-lagged system was evaluated using step response, beam deflection tracking, and robustness tests. The simulation results indicate that the liquid crystal optical phased array beam deflection system, equipped with a Smith predictor and a fractional-order controller, demonstrates rapid responsiveness, precise control, effective tracking capabilities, and strong robustness.