Research of the Photoelectric Tracking and Pointing Platform Based on the Servo Control System

Abstract

To improve the speed and accuracy of the photoelectric tracking and pointing platform stable tracking, we took the three-axis photoelectric tracking platform, of which the coupling among the rings is ignored, as the research object. Considering the effects of various disturbances, the stable tracking double closed-loop servo control system was built for the azimuth, pitch, and roll rings. In the stabilization loop, output-feedback H∞ controller based on linear matrix inequality was designed to reduce the effects of model perturbations and uncertainties and to maintain the stability of the platform’s inertial space. In the tracking loop, the integral-separation proportional integral derivative (PID) controller was designed to achieve fast and accurate tracking. Smith estimated compensation was adopted to compensate the pure lag caused by video tracking. Finally, the double closed-loop servo control system was built to complete the simulation. The simulation results show that the system not only has good robustness under external disturbances, but also completes the attitude tracking quickly and accurately. Besides, the tracking error is |error| < 5∙e–4 rad, which meets the tracking accuracy requirements.