Control of Attitude Trajectory of Launch Vehicle Using Optimal LQR-Based PID Controller

The launch vehicle of a spacecraft involves longitudinal and latitudinal control. The longitudinal behavior of a launch vehicle is the primary focus of this paper. The main parameter is the attitude angle that is to be controlled considering the launch vehicle rigid body equations. The controller designed is a PID, where integral and derivative gains are obtained using proportional LQR optimization. The controller synthesis is based on the desired specifications of nominal plant and relative dominance. The efficacy of the proposed technique is validated by its robustness in the presence of perturbations.