Safety-Aware Geometric Force-Impedance Control for Manipulators

Abstract

Since its inception, impedance control has emerged as a fundamental framework for robotic interaction control. Recent advancements in geometric impedance control have demonstrated certain advantages over traditional Cartesian impedance control. However, existing geometric impedance control approaches generally lack force regulation capabilities or rigorous stability guarantees. In this paper, we propose a safety-aware geometric force-impedance controller that addresses these limitations. By incorporating an energy tank mechanism, the proposed approach enables precise force tracking while preserving full compatibility with the impedance behavior. Furthermore, an energy injection and freezing mechanism is introduced, allowing dynamic regulation of energy exchange between the tank and the robotic system. Notably, the proposed method eliminates the need for an offline estimation of the initial energy stored in the tank, facilitating real-time adjustments of force controller parameters. To validate the effectiveness of the proposed framework, we conduct extensive polishing experiments on a real robotic platform. The results demonstrate the capability of the proposed controller to achieve stable and precise force regulation.