Dead-reckoning inverse and direct kinematic solution of a 4W independent driven rover

Abstract

We tackle the problem of trajectory control of a four-wheel driven skid-steering (4WDSS) robotic platform with asynchronous wheels velocity. A practical mathematical formulation for solving inverse and direct kinematics is provided. This approach also includes the formulation and implementation of a home made arrange of accelerometers to infer robot displacements in global coordinates system. Although we provide a direct kinematics solution, we further establish an inverse kinematics formulation using four parameters to exert trajectory control, namely instantaneous linear velocity, angular velocity, and robot Z-turning axes. The formulation for robot angular velocity is given differently from other research approaches, where it is stated in terms of the robot's geometry, which directly impacts the robot's swift capability. Trajectory control is yielded by controlling the location of the robot turning Z-axis with respect to the instantaneous center of rotation by direct control of the wheels speeds.