Suppression of resonant vibration due to angular transmission errors of reduction gearing in industrial robots

This paper presents a vibration suppression approach by variable notch filters for mechanical resonant vibrations due to angular transmission errors (ATEs) of harmonic drive gearings (HDGs) in industrial robots. Robot arm joints including HDGs especially excite resonant vibrations in the condition that frequency of synchronous components in ATEs corresponds to the critical one of mechanical resonance. In this research, a variable notch filter whose angular frequency is synchronizing with motor velocity is designed to suppress the vibration during the robot motion. The proposed control approach has been verified by experiments using an actual industrial 6-axis robot.