Coupling vibration analysis for harmonic drive in joint and flexible arm undergoing large range motion

The effect of coupling vibration always exists in a system of mechanical arm, especially in the system of which is undergoing large range motion with different speeds. The system considered here is a single mechanical arm driven by servo motor through a harmonic reducer. The harmonic drive in joint is modeled as a linearly elastic torsional spring. The nonlinear mechanics behavior of mechanical arm with harmonic reducer is adopted in the dynamic modeling, and thus the coupling vibration is captured. This paper carries out a series of experimental investigation on coupling vibration between harmonic drive in joint and flexible arm. Experiment results show that the vibration frequency raises distinctly with the increase of motor speed, which indicates that the stiffness of traction motion can be enhanced by undergoing a large range motion. The encouraging results provide a new method to investigate the coupling vibration of mechanical system effectively.