A Collision-Free Target Tracking Controller With Uncertain Disturbance Rejection for Quadruped Robots.

With respect to the dynamic target tracking issue in the obstacle environment, this paper provides a collision-free tracking framework combining a modified guidance vector field (GVF) and a disturbance rejection controller. More specifically, two primary improvements are implemented compared with the existing GVF methods. The first improvement involves designing a variable property vector deforming the elliptic integral curves to straight lines pointing to the target point, which prevents the robot from detouring. The other improvement is to construct an adjustable parametric function for blending the attractive field and repulsive field so as to refine the obstacle avoidance performance. Meanwhile, a generalized proportional integral observer (GPIO) based steering controller and a sliding mode based approaching controller are provided to enhance the capability of disturbance rejection. Furthermore, simulation and experimental results demonstrate that the proposed method is efficient in the multi-obstacle environment in terms of tracking the virtual dynamic target and the dynamic quadruped robot target even in the environment with uncertain disturbances.