Kinematic modeling of a high mobility Mars rover

The paper describes a method for kinematic modeling of the Rocky 7 Mars rover. The model is derived for full six degree of freedom motions enabling movements in x,y,z directions, as well as pitch, roll and yaw rotations. Forward kinematic equations are derived using wheel Jacobian matrices. The individual matrices are then combined to form the composite equation for the rover. This equation is solved to obtain the rover position and heading in terms of measured wheel velocities and certain rocker joint angles. The inverse kinematics is derived relating the individual wheel velocities and steering angles to the desired forward velocity and turning rate of the rover. Due to the special kinematic configuration of Rocky 7, a geometric approach is developed to determine the steering angles.