Nonlinear Bang-Bang Impact Control: A Seamless Control in All Contact Modes

This paper presents stability analysis and experimental results of the nonlinear bang-bang impact controller for robotic manipulators. A stability condition has been derived based on the analysis in Ln ∞ space and its physical interpretation has been given. The analysis shows that the stability of nonlinear bang-bang impact control depends on sampling time and the accuracy of inertia estimation. Stability is enhanced with the decrease of changes in the Coriolis, centrifugal, and disturbance forces. The stability condition is verified by simulations and experiments. Experiments show that overall performance is comparable to or better than existing impact control techniques which employ more complicated control strategies.