Attitude control of targets captured by tethered space robots based on the quaternion theory

For better understanding of tethered space robot systems to be used in the future on- orbit service, the attitude control problem of targets captured by tethered space robots was in-vestigated. Firstly, based on the quaternion theory, the governing equations for the combined body of the target and the tethered space robot were constructed. Secondly, a projected Runge- Kutta method was developed for the Issue of constraint systems, and this method is explicit and can preserve the norm of quaternions. Finally, a numerical example was given to validate the proposed model and the numerical method, where 3 kinds of control strategies were compared in terms of control effectiveness and energy consumption.