Visual Servoing using Mixed Sensitivity $\mathbf{H}_{\infty}$ Control for Yaw-Pitch Camera Platform

This paper describes a robust control technique based on mixed sensitivity H_∞ control on visual servoing for Yaw-Pitch camera platform. H_∞ control technique can guarantee robustness and performance which can resist high disturbance and ensure stability in the closed-loop control system. The main function of the controller is to keep the object at the center of the field of an image displayed by the camera. The platform consists of two models, the first is motor servo dynamics and second is a single object movement model in image space. Weighting function is chosen such that the system could meet the performance specifications and robust stability requirements. The system used in this study is the SONY FCB-EV7520 camera which is placed on the Yaw-Pitch platform which consists of two servo motors. The control signal generated from the controller is used to adjust the servo motor so that it can direct the camera to the tracked object. The results obtained from the experiment show that the controller designed with mixed sensitivity H∞ control has a good control behavior with fast transient and small overshoot.