Optimizing Space Robot Configurations to Minimize Capture Contact Forces

Space robotics is rapidly becoming essential as satellites and orbital debris continue to increase, creating demand for reliable capture and servicing technologies. A central challenge lies in minimizing the impact forces generated during contact, which can threaten both the robot and the target. This paper addresses the problem by introducing a configuration optimization approach that leverages the concept of integrated effective mass (IEM) to reduce capture contact forces. The contribution of this study is twofold: it demonstrates how IEM serves as a practical performance metric for predicting capture safety, and it validates configuration optimization as an effective strategy for mitigating impact forces in free-floating space robots. The methodology applied a Hunt - Crossley contact model with hysteresis damping to simulate robot-target interactions under various manipulator configurations. A 7-DOF free-floating robot was modeled, and IEM was computed through Jacobian-based dynamic analysis. The coefficient of restitution was also tuned to balance rebound and capture stability. Results reveal a strong nonlinear relationship between IEM and contact force. Configurations with low IEM generated substantially lower forces: for example, an IEM of 0.0413 kg produced only 442 N, while an IEM of 1.7199 kg resulted in forces exceeding 4142 N. By tuning the restitution coefficient to approximately 0.8, rebound effects were minimized without compromising stability. The simulations confirmed that configuration optimization can reduce capture forces by nearly an order of magnitude while avoiding singularities. In conclusion, this work shows that planning manipulator configurations based on IEM analysis is not merely theoretical but a practical tool for safer, more reliable on-orbit servicing and debris removal. These findings reinforce configuration optimization as a cornerstone for the next generation of space robotic operations.