Preliminary Attitude Control Studies for the ASTER Mission

16th Brazilian Colloquium on Orbital Dynamics

Sarli, Bruno Victorino^1 ; Da Silva, André Luís^2 ; Paglione, Pedro^1

Instituto Tecnológico de Aeronáutica, ITA, São José dos Campos, Brazil^1

Universidade Federal Do ABC, UFABC, Santo-André, Brazil^2

关键词: Autonomous operations;    Gravitational torque;    Linear quadratic costs;    Linear quadratic regulator;    Nonlinear control technique;    Numerical minimization;    Proportional integral;    Rotational kinematics;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/465/1/012004/pdf
DOI  :  10.1088/1742-6596/465/1/012004

来源: IOP

【 摘 要 】

This work discusses an attitude control study for the ASTER mission, the first Brazilian mission to the deep space. The study is part of a larger scenario that is the development of optimal trajectories to navigate in the 2001 SN263 asteroid system, together with the generation of orbit and attitude controllers for autonomous operation. The spacecraft attitude is defined from the orientation of the body reference system to the Local Vertical Local Horizontal (LVLH) of a circular orbit around the Alpha asteroid. The rotational equations of motion involve the dynamic equations, where the three angular speeds are generated from a set of three reaction wheels and the gravitational torque. The rotational kinematics is represented in the Euler angles format. The controller is developed via the linear quadratic regulator approach with output feedback. It involves the generation of a stability augmentation (SAS) loop and a tracking outer loop, with a compensator of desired structure. It was chosen the feedback of the p, q and r angular speeds in the SAS, one for each reaction wheel. In the outer loop, it was chosen a proportional integral compensator. The parameters are tuned using a numerical minimization that represents a linear quadratic cost, with weightings in the tracking error and controls. Simulations are performed with the nonlinear model. For small angle manoeuvres, the linear results with reaction wheels or thrusters are reasonable, but, for larger manoeuvres, nonlinear control techniques shall be applied, for example, the sliding mode control.