Constellation attitude tracking control of the space gravitational wave observatory under configuration disturbances

Space based gravitational wave detectors require a precision relative attitude pointing control in science mode. Their configuration drifts under the influence of perturbations. The spacecraft and telescope optical assembly attitude control loops need to respond to this change in real time. In particular, the constellation reference attitude of the detectors orbiting the earth changes much more than the detectors orbiting the sun, which posing a great challenge to the control system. This article focuses on the constellation attitude tracking problem of the space gravitational wave observatory under configuration disturbances, and systematically analyzes the evolution of the constellation reference attitude. A control method based on finite frequency optimization combine with an improved error-disturbance based observer is proposed. Numerical algorithm simulations show that the method can obtain precise attitude tracking in the measurement bandwidth while effectively suppress the unknown disturbances. Compare with the disturbance based observer controller, the overall error can be reduced by 55% of the original.