Experimental kinematics modeling estimation for wheeled skid-steering mobile robots

Skid-steering mobile robots, both wheels and tracked vehicles, are widely used because of their simple mechanism and robust. However, due to the complex wheel-ground interactions and the kinematics constraints, it is a challenge to understand the kinematics and dynamics of such a robotic platform. In this paper, we develop a kinematics modeling estimation scheme to analyze the skid-steering wheeled mobile robot based on the boundedness of the Instantaneous Centers of Rotation (ICRs) of treads on the 2D motion plane, and the parameters of this model are determined based on experimental analysis. We study the relationship between the ICRs of the robot treads and two physical factors, i.e., the radius of the path curvature and the robot speed. Moreover, an ICRs coefficient and a nondimensional variable are introduced. An approximating function is used to describe the relationship. To validate the obtained results, the proposed model has been applied to a popular research robotic platform, Pioneer P3-AT. It is empirically demonstrated that the developed model improves dead-reckoning performance of this skid-steering robot.