Experimental Comparison of H-Infinity Synthesis and Feedback Linearization on a MIMO Gimbal Example

This study investigates the controller types and effects of the design techniques on gimbal stabilization. Since implementing the controllers and determining the system’s robustness is straightforward, the frequency domain design approaches are widely used with linear controllers in electro-optical inertial stabilized systems. Besides, the required system models can be obtained from experimental data easily. Nevertheless, the system model could change in the operational conditions. Therefore, nonlinear controllers are needed in this situation. In this investigation, we obtained a proper system model using system identification methods to design a mixed-sensitivity H
∞
controller. Then, we proposed an input-output feedback linearization controller with a linear quadratic regulator (LQR) based state feedback controller design to stabilize the 2 degrees of freedom (DOF) gimbal. Finally, we compared these two controllers regarding reference tracking, sensitivity function, and disturbance rejection performances on the experimental setup under 6 DOF disturbance profiles.