Reducing the Effects of Uncertainties on Spacecraft Attitude Control Performance with Robust Optimization Approach

In this paper, the performance of a spacecraft attitude control under uncertainties is enhanced with robust optimization method. Control pointing accuracy in rest-to-rest maneuver has been selected as main performance index. An anti-windup observer-based modified proportional-integral-derivative (MPID) controller is utilized as controller. Modified PID controller is anti-windup and prevent actuator saturation, thus improving the performance index. Reaction wheel actuator is used to control a single-axis rigid satellite. It is modeled with first-order dynamic and to consider practical limitation, maximum generation momentum is limited. Standard deviation and mean of the absolute value of the pointing error are selected as statistical objective function in robust optimization. Uncertainty is considered on moment of inertia, amplitude and frequency of external disturbance, and reaction wheel model. For fair comparison, deterministic and robust optimization results are compared together versus uncertainties and disturbance. The performance index is investigated versus uncertainties. Achieved numerical solution results indicate that tuned controller with robust optimization has better performance in the presence of uncertainties. This method has been able to reduce the effect of uncertainties by using the statistical properties of performance index in optimization process. Furthermore, the use of modified PID is also improved performance index.

کلیدواژه ها:

Satellite Attitude Control ، Robust Optimization ، Modified PID ، Reaction Wheel Actuator ، Uncertainty