Autopilot design for dual-spin projectile based on PI and feedback linearization control

In this paper, a new autopilot for a projectile equipped with a course correction fuze is presented. In contrast to the missile systems, the pitch and yaw motions are strongly coupled in the projectile model. In addition, there exists highly nonlinear, rapidly changing dynamics during the flight. To overcome these difficulties, this study suggests a cascade structure design for acceleration controls based on PI (proportional-integral) control and nonlinear FBLC (feedback linearization control) methodology; the inner loop controller is designed to track the desired body rates by applying FBLC and the rate controllers (i.e., inner loop) which are augmented by the outer loop PI controller to finally provide the desired accelerations. In this paper, the performances of the pitch and yaw acceleration controller are examined using a nonlinear simulation.