Modeling and motion stability analysis of skid-steered mobile robots

Skid-steered mobile robots are widely used because of the simplicity of mechanism and high reliability. However, understanding of the kinematics and dynamics of such a robotic platform is challenging due to the complex wheel/ground interactions and kinematic constraints. In this paper, we attempt to develop a kinematic and dynamic modeling scheme to analyze the skid-steered mobile robot. We model wheel/ground interaction and analyze the robot motion stability. As an application example, we present how to utilize the kinematic and dynamic modeling and analysis for robot localization and slip estimation using only low-cost strapdown inertial measurement units (IMU). The extended Kalman filter (EKF)-based localization scheme incorporates the kinematic constraints. The performance of the EKF-based localization and slip estimation scheme are presented. The estimation methodology is tested and validated on a robotic testbed.