Biomimetic backstepping slip prevention for a dexterous hand via wrist velocity feedback

A proportional controller is compared to a nonlinear backstepping controller for a dexterous anthropomorphic hand. The tracking results from the proportional and backstepping controllers are compared in simulation and with the actual hand. Results from the simulation and the actual system show a reduction in system error and an improvement in tracking a sinusoidal trajectory. A multi-joint backstepping control scheme which autonomously modulates grip force in accordance with wrist velocity is also introduced. The biomimetic controller can successfully increase grip force in response to wrist velocity increases in a robustly stable fashion. Results show a close correlation in grip force modulation characteristics between the backstepping control scheme and human test subjects. Experimental data also demonstrate the slip prevention capabilities of the backstepping control scheme.