A collision-free visual servoing method for two space manipulators capturing tumbling satellites

A novel visual servoing method is proposed to synchronously capture a malfunctional satellite's docking ring by two space manipulators. Due to the lack of conspicuous visual marks, structured light is implemented to estimate the ring's pose. To ensure the capturing process's security, two aspects are investigated. Spatially, capturing target points for two manipulators are planned together by considering the chaser's orientation. As a consequence, collision risk between two manipulators is eliminated. Temporally, by adding duration parameters in trajectory generation algorithm, capturing synchronism for two manipulators is guaranteed. Experimental results show that, by the proposed method, a tumbling target was successfully captured by two space manipulators. Compared to existing methods, the collision risk between two manipulators is thoroughly eliminated and the capturing synchronism is improved remarkably.