Compliance resistance collision control for operating a space robot to capture a non-cooperative spacecraft

Collision between the grasper and the target is unavoidable in robotic-arm-based non-cooperative spacecraft capture missions, potentially leading to various adverse effects. For instance, the impact of collision could result in a post-collision separation between the grasper and the target. Additionally, a significant impact can damage the space robot. Both post-collision separation and damage to the space robot result in the failure of the capture mission. To improve the success rate of capturing, this paper first proposes a new one-dimension (1-D) collision control method to reduce adverse effects yielded by collisions, which is named Compliance Resistance Control (CRC). Unlike existing methods, CRC aims to prevent post-collision separation while reducing the maximum contact force. Theoretical analysis validates that this method can achieve the desired objective. Then, to extend the applicability of this method to three-dimensional (3-D) capture missions, we introduce a position-based CRC control scheme. In addition, an output torque correction algorithm is designed to enhance motor response speed. Finally, numerical simulation results demonstrate the effectiveness and robustness of this strategy across various capture scenarios.