Experimental Verification of Discrete Switching Vibration Suppression

Control system design for flexible robotic systems requires special care with regard to the control system design to prevent oscillation in the system´s resonant modes. If the resonant frequencies of such a system are known, it is possible to determine a switching command that delivers comparable actuation without exciting these natural modes of vibration. If there is redundancy in actuation, it can be exploited to suppress vibration with a reduced amount of actuator changes in state. Minimum switching discrete switching vibration suppression (MSDSVS) involves choosing a switching function with integer amplitudes and continuously variable switch timings to force the root of the residual oscillation function with respect to frequency to be at a resonance. By minimizing the one norm of the vector of amplitudes, we obtain several desired properties. Such a vibration suppression command is developed for a flexible robotic actuator, and experimental results are presented. The proposed command reduces residual oscillation by 73% (rms) and 74% (largest Fourier component) and represents a 37% energy savings over vibration suppression commands that do not exploit the redundancy in actuation.