Accuracy improvement of three-axis stabilization using an onboard computer☆

Abstract An attitude control scheme for a three-axis stabilized satellite having reaction wheels as control elements is proposed. The scheme is based upon the linear quadratic Gaussian formulation of the whole system. An improved control accuracy over that of conventional methods is obtained through the real-time estimation and complete cancellation of disturbances of deterministic nature and through the reduction of influences of random disturbance torques and sensor-and instrument noises. Numerical results are presented to show the improvement in accuracy as compared to the classical PD-controller. The insensitivity in control accuracy of the proposed scheme to various modeling and parameter errors is shown through the covariance analysis. It is estimated that the capability of existing onboard computers can meet the increased computational burden due to the adoption of the scheme.