Whole Body Compliance Control for Mobile Manipulators
Mobile manipulators performing sustained contact tasks must simultaneously regulate contact forces and track trajectories beyond the manipulator’s reachable workspace. Existing QP-based whole-body controllers generally lack explicit force regulation, while force-capable approaches often assume a fixed base or decouple the base and arm. We propose a Whole-Body Compliance Controller (WBCC) that addresses these limitations in a unified quadratic programming framework by modeling the mobile base and manipulator as a single kinematic chain. Force regulation is incorporated as an asymmetrically weighted soft task, where force tracking is prioritized over trajectory tracking when constraints prevent exact satisfaction of both. A Cartesian compliance formulation further improves robustness during contact and near singular configurations.The proposed controller operates without modification on both holonomic and nonholonomic platforms. Simulation results demonstrate force RMSEs of 9.29 N and 8.60 N, and trajectory RMSEs of 1.35 mm and 2.79 mm for holonomic and nonholonomic systems, respectively. Real-time feasibility is achieved with QP solve times of approximately 2.3 ms at 100 Hz. These results demonstrate a practical and robust framework for contact-rich mobile manipulation tasks, including surface finishing, inspection, and large-scale assembly.