Kinematic stability of robot manipulators under force control

The author investigates the kinematic instability problem associated with some well-known force control approaches. His intent is to establish qualitative evaluations of the stability of hybrid control and stiffness control. He first constructs a state-space model and then demonstrates the kinematic stability or instability of the two force control formulations by making use of a necessary and sufficient condition for a multivariate linear system. The author also discusses issues such as critical damping in stable force control approaches and stabilizing measures for unstable force control methods