Constrained Spacecraft Attitude Optimal Control via Successive Convex Optimization

Rapid attitude path planning is the key technique in autonomous spacecraft operation missions. An efficient method is proposed for energy-optimal spacecraft attitude control in presence of constraints. Firstly, Gauss pseudospectral method is utilized to discretize and transcribe the primal continuous problem to a nonlinear programming problem. Then a set of convexification techniques are used to convexity the nonlinear programming problem to a series of second-order cone programming problems, which can be solved iteratively by the interior-point method. A solution to the nonlinear programming problem is obtained as the iteration converges. Numerical results show the method could obtain a valid energy-optimal attitude control plan more rapidly than traditional methods.

Reset and prescribed performance approach to spacecraft attitude regulation

Purpose This paper aims to investigate the attitude regulation for spacecraft in the presence of time-varying inertia uncertainty and exogenous disturbances. Design/methodology/approach The high gain approaches are typically used in existing researches for theoretical advantages, bringing better performance but sensitive to parameter selection, making the controller conservative. A reset-control policy is presented to achieve the spacecraft attitude control with easy control parameter tuning. Findings The reset-control policy guarantees satisfying control performance despite using performance tuning function and saturation function besides reducing the conservativeness of the controller, thus reducing the effort in tuning control parameters. Originality/value Notably, the adaptive function owns a reset mechanism, which is reset to a preset condition when the controlled variable crosses zero. The mathematical analysis also shows the system trajectory can converge to a set centered at the origin.

Spacecraft attitude control with mutating orbital rate and actuator fading under Markovian jump framework

Purpose This paper aims to study the attitude control problem with mutating orbital rate and actuator fading. Design/methodology/approach To avoid malicious physical attacks and hide itself, the spacecraft may irregularly switch its orbit altitude within a specific range, which will bring about variations in orbital rate, thereby causing mutations in the attitude dynamics model. The actuator faults will also cause changes in system dynamics. Both factors affect the control performance. First, this paper determines the potential switching orbits. Then under different conditions, design controllers that can accommodate actuator faults according to the statistical law of actuator fading. Findings This paper, to the best of the authors’ knowledge, for the first time, introduces the Markovian jump framework to model the possible unexpected mutating of orbital rate and actuator fading of spacecraft and then designs a novel control policy to solve the attitude control problem. Practical implications This paper also provides the algorithm design processes in detail. A comparative numerical simulation is given to verify the effectiveness of the proposed algorithm. Originality/value This is an early solution for spacecraft attitude control with dynamics model mutations.