Linear reactive control of three-dimensional bipedal walking in the presence of noise and uncertainty

Walking control of biped robots is a challenging problem, and improving robustness to noise and uncertainty remains difficult. We recently developed a novel control framework for 3D bipedal walking that we call "linear reactive control." It is linear because control torques are computed as simple weighted sums of sensor states. It is reactive because it depends only on the model's current state. The present simulation study shows that this controller performs reliably in the presence of realistic models of joint actuation, sensor noise, and uncertainty in model and contact parameters. The controller is able to maintain a stable gait in the presence of noisy sensor inputs and low-impedance actuation. It also performs reliably on models with high uncertainty (up to 20%) in measurements of their dynamic parameters and widely varying ground contact parameters. The robustness of this controller to realistic conditions validates this method as a promising avenue for bipedal control.