Active Visual Servo Pan/Tilt Control Design based on Improved Augmented LQR

Aiming at the problem of imbalance between response time and overshoot in traditional visual servo systems, weak disturbance suppression ability and researching after target loss, this paper analyzed the tracking control principle and imaging principle of visual servo Pan/Tilt/Zoom(PTZ), and designed a method based on an improved augmented LQR (IALQR) method for a servo PTZ controller, and proposed a global scan search control method with high engineering feasibility. The mathematical model of the gimbal was established through system identification, and the gimbal controller was designed and verified in a simulation environment. The servo performance of the gimbal and the effectiveness of the global scanning search control method were verified in an experimental platform. The simulation results show that the angle loop controller developed in this paper has shorter adjustment time and less overshoot than the PID control, and can effectively reduce overshoot and compensate for disturbance compared with the traditional augmented LQR method. The experimental results show that the designed PTZ controller can achieve stable servo control. Compared with the traditional single-loop PID servo control, the steady-state error is smaller. At the same time, the probability of researching after the target is lost is more than 90%.