Controller for Attitude Stabilization with Disturbance Rejection for Steady Hover of Rotary-Wing Flying Robot

Abstract

This paper presents the course of development, evolving from a standard SISO feedback controller to an augmented controller required for attitude stabilization with disturbance rejection for steady hover of a Rotary Wing Flying Robot. The main objective is to control the dynamic behavior of the robot, which is complex in shape and motion as nonlinear aerodynamic forces and gravity acts on the system.  Due to limited accuracy of the dynamic model, the attitude dynamics is conditionally stable where a minimum amount of attitude feedback is required for system stability. To compensate for conditional stability, a controller for both roll and pitch dynamics is developed adopting cascade control loop feedback architecture where INS system feedback is used for outer control loop while the gyro feedback is adopted for the inner control loop to attain a high bandwidth, ensuring attitude stability with accelerated response required for steady hover. The provided solution is tested on HIROBO Scheadu50 model and the system performance is analyzed during hover using the proposed controller. Through taut integration of simulation and flight-test validation, a controller is developed that is sufficiently accurate, quite effective and simple enough for handling complex and changing rotorcraft dynamics in hover.