Decoupling Control for Hip Joint of Humanoid Robot Based on ADRC

To improve the control accuracy of robot joints under the influence of coupling, this paper uses a decoupling control method based on the coupling principle analysis to solve the kinematic and dynamic coupling caused by a three-axis concentric hip joint structure, taking the right leg of a 23 degree-of-freedom bipedal humanoid robot as the research object. Simscape is chosen to simulate the physical model of the right leg. And the Active Disturbance Rejection Decoupled Controller with a nonlinear Extended State Observer is designed, in which the derived gravity compensation is added to reduce the control difficulty and improve the observation accuracy. The initial value peaking is avoided by clipping the observer output. The simulation results show that, compared with the PID control with gravity feedback and coupling compensation, ADRDC has better dynamic and steady-state performance, higher position tracking accuracy and stronger anti-interference ability.