Experimental Verification of Discrete Switching Vibration Suppression

Abstract

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.