Standing Balance Control of Humanoid Robot Based on Three-link Dynamic Model

In order to solve the anti-disturbance control problem for humanoid robot standing balance, a three-link dynamic model is proposed as the simplified model of humanoid robot, in which the distributed mass of the leg, body and arm on their links is considered. Thus, the model will be more accurate than the traditional linear inverted pendulum or the plus flywheel model. Based on this model, an anti-disturbance controller is designed for humanoid robot standing balance. Firstly, the humanoid is simplified as the three-link model, the structural parameters are obtained by parameter identification method, and the complex nonlinear dynamics model is linearized by linearization. Then, the balance controller is designed by using the linear quadratic regulator (LQR). The experiments are carried out on the humanoid robot KONG-II, and the ankle joint is set up as an under-actuated state with certain damping characteristics to match the three-link model. By comparing the anti-disturbance performance of the robots with double-link dynamic model and with three-link dynamic model, the effectiveness and robustness of the proposed method are verified.