A Comparative Study of Ackerman Two-Axle Steering and Skid-Steering Mechanisms for Unmanned Ground Vehicles

The steering mechanism employed in unmanned ground vehicles (UGVs) plays a significant role in mobility, maneuverability, and overall functionality. This article compares two common steering types for four-wheeled UGVs, namely the Ackerman two-axle steering and the skid-steering types. Their kinematic models are established. The relationship between wheelbase and turning radius for Ackerman two-axle steering has been examined, and the formula in terms of the speed difference of the left and right wheels and the turning radius for the skid-steering is also derived. The turning radius of the Ackermann two-axle steering system is constrained by the wheelbase and steering angle, while the skid-steering system can achieve zero-radius turns. Simulations are carried out to evaluate maneuverability for these two steering types. The different turning trajectories are obtained under various conditions. Comparing the steering trajectories of the two steering types. The simulations unveil the advantages and limitations of the two steering types for different terrains.