Motion Control of Industrial Robot Using New Notch Filtering System for Vibration Suppression and Little Phase Error

This paper proposes a new generation method of position reference without the resonant frequency and phase error for industrial robots. It is important for industrial robots to drive high speed and high accuracy. However, the vibration phenomenon is generated by the resonant frequency in such cases. Conventionally, the notch filter is used to suppress the vibration phenomenon. It is able to eliminate a particular frequency. However, it also has a disadvantage that the reference phase error is generated. Generating the phase error in the reference causes the critical error in the locus which the robot draws. Therefore, the accuracy of the robot is deteriorated by using the notch filter. The proposed method overcomes this problem by using the compensation gain. The compensation gain is used to calculate the reference phase error. The compensation of the reference phase error is performed by the feedforward. The numerical and the experimental results show that the proposed method is superior to suppress the resonant frequency and improves the phase error.