A Trajectory Shaping Approach for Suppressing the Fundamental Vibratory Mode in Strain Wave Gearing Mechanisms

While strain wave gearing mechanisms, such as harmonic drives, have many practical benefits when properly utilized, they also create challenging problems for control engineers. Namely, these flexible gear reduction mechanisms can create output vibrations which cannot be directly measured or controlled by the actuator. In this paper, an input shaping approach will be proposed to pre-compensate the desired output trajectory to account for the transmission dynamics such that the system’s actual output will follow the original desired trajectory. Several system parameters need to be empirically identified prior to using the proposed procedure. This identification process will also be outlined. Both simulation and experimental results on a 6 degree of freedom industrial robot will be provided to demonstrate the effectiveness of the proposed approach.