Coupled-System Stability of Flexible-Object Impedance Control

This paper examines the stability of the exible-object impedance controller when coupled to an arbitrary passive environment. A simple representative system is developed to study the problem based on phenomena observed in a more complex, experimental system. Analysis of this representative system leads to several conclusions regarding factors that limit the achievable impedances of a multi-arm system grasping a common object. The ltering of the external force signals and the e ective mass contributed by the manipulators prove to be two of the important factors. Some general guidelines are developed for the successful application of exible-object impedance control to insure coupledsystem stability. These guidelines are applied to both the representative and experimental systems and veri ed.