Research on torsional vibration characteristics and resonance mechanism of industrial robot joint transmission system based on electromechanical coupling

Torsional vibration in industrial robot joints inevitably causes electromechanical parameter coupling in the transmission system during routine operation. This coupling triggers complex vibrations within the system, affecting its dynamic properties and stability, making it more difficult to obtain accurate health information about the system. To address these challenges, this study explores the torsional vibration behaviors and resonance mechanisms in the joint transmission systems of industrial robots, with a focus on the electromechanical coupling effects. First, a dynamic model of the joint transmission system with electromechanical coupling and its vibration simulation model is established. The impact of crucial mechanical parameters of the joint structure on both system vibration and the characteristics of its output speed is examined. In addition, a “motor-load” dual-inertia equivalent model of industrial robot joint transmission system considering the reduction ratio is proposed. The resonance equations are constructed, and the resonance mechanism is analyzed. The effects of key mechanical parameters on the joint resonance are fully considered. Additionally, the Kalman filter method is applied to determine the steady-state condition of the joint. The validity of the proposed model is confirmed through experimental data obtained from an industrial robot. The research can provide an important basis for studying industrial robots‘ mechanical torsional vibration characteristics and resonance mechanisms.