Impact control of grasping (robot manipulators)

The stabilization effect of collision in impact-controlled manipulator-object systems is discussed. The stability of system behavior is analyzed by the Lyapunov direct method. Some simulation results are shown to confirm the effect. Collision is one of the nonlinear problems where the dynamical structure changes. In industrial fields, the phenomenon is utilized effectively to suppress vibrations, but collision is a difficult problem to treat in the field of control because the methodology is mostly based on linear theory. The nonlinear impact force is modeled as a Hertz-type force with damping. A nonlinear matrix and a quadratic form is defined to examine system stability. As a results, stable control with collision phenomena is obtained. >