Optimal Control Techniques for Spacecraft Attitude Maneuvers

Abstract

The capability of attitude maneuvers and attitude tracking for spacecrafts is required in the current sophisticated space missions. In short, it is to obtain command requirements and attitude orientation after some form of control. With the development of space missions, the ability of rapid and energy-saved large-angle attitude maneuvers is actively expected. And the high requirements for the attitude control design system are increasingly demanded. Consequently, optimal control for attitude maneuvers has become an important research direction in the aerospace control area. From control aspect, spacecraft attitude maneuvers mainly involve trajectory planning (Guidance), attitude determination (Navigation), and attitude control (Control). Further researches about these three key technologies are necessary to achieve optimal control for attitude maneuvers. In this chapter, the necessary background on optimal control for attitude maneuvers of three-axis stabilized spacecraft is provided, and the recent work about guidance and navigation as well as control is summarized, which is presented from three parts as follows: 1. The optimal trajectory planning method for minimal energy maneuvering control problem (MEMCP) of a rigid spacecraft; 2. Attitude determination algorithm based on the improved gyro-drift model; 3. Attitude control of three-axis stabilized spacecraft with momentum wheel system. 1 B 2. Optimal trajectory planning method for MEMCP of a rigid spacecraft The trajectory planning for attitude maneuvers is to determine the standard trajectory for spacecraft attitude maneuvers with multi-constraints using optimization algorithm, which makes the spacecraft move from the initial state to the anticipated state within the specified period and optimizes the given performance index. At present, the optimal trajectory planning problems for spacecraft attitude maneuver mainly focus on the time-optimal and fuel-optimal control. A fuel-optimal reorientation attitude control scheme for symmetrical spacecraft with independent three-axis controls is derived in (Li & Bainum, 1994). Based on the low-thrust gas jet model and Euler's rotational equation of motion, Junkins and Turner (Junkins & Turner, 1980) investigate the optimal attitude control problem with multi-axis maneuvers. They use the closed-form solution of the single-axis maneuver as an initial value and minimize the quadratic sum of the integral of the control torques. Vadali and Junkins (Vadali & Junkins, 1984) have addressed the large-angle reorientation optimal attitude www.intechopen.com