Robot Joint Vibration Suppression Method Based on Improved ADRC

This article proposes an innovative joint vibration suppression method for six-axis collaborative robots. A permanent magnet synchronous motor (PMSM) and harmonic reducer are considered as a whole system in the design. A novel active disturbance rejection control (ADRC) scheme has been implemented by applying vibration suppression measures to the low-speed end of joint reducers. The mechanism of vibration generated by robot joints was analyzed. A vibration model for harmonic reducers was built. A new extended state observer model was designed to analyze the position disturbance data of two encoders in robot joints. Vibration signals were extracted and input into the ADRC algorithm to suppress joint vibration. A six-axis robot experimental platform was built and used to explore the changes in robot vibration trajectories under different speed conditions by applying the ADRC algorithm. The experimental results clearly show that the fluctuation amplitude of the trajectory of the robot has been reduced. The experimental results clearly show that by applying the new vibration suppression algorithm, the amplitude, vibration velocity, and acceleration of the robot at low speed have decreased 0.533 mm, 10.12 mm/s, and 0.49 mm/s2, respectively, and at the same time, the velocity stability of the PMSM has been improved. This article accurately evaluates the vibration suppression performance of the ADRC algorithm at different speeds of robots, effectively suppressing the vibration of robot joints.