Digital micro-thruster arrays can be used for special missions of micro/nano-satellites with the requirements of high precision and small impulse. This paper presents a novel control allocation algorithm for the digital micro-thruster array, namely status graph based control allocation (SGBCA) algorithm, which aims at finding the optimal micro thrusters combination scheme to realize the sequential control synthesis for micro/nano-satellite during real-time orbit control tasks. A mathematical model is set up for the control allocation of this multivariate over-actuated system. Through dividing thrusters into disjoint segments by offline calculation and combining segments dynamically online to provide a sequence of the required impulse for the micro/nano-satellite, the time complexity of the control allocation algorithm decreases significantly. All levels of impulse can be generated by the digital micro thruster arrays and the service life of the arrays can be extended using the segment converting strategy proposed in this paper. The simulation indicates that the algorithm can satisfy the requirements of real-time orbit control for micro/nano-satellites.
ZHANG Dandan,ZHANG Yunyi,DONG Ke,LI Haiwang,WANG Shaoping.A Status Graph Based Control Allocation Algorithm of Digital Micro-Thruster Array for Micro/Nano-Satellites Orbit Control Application[J].Transactions of Nanjing University of Aeronautics & Astronautics,2019,36(5):779-788