Energy Efficient Pivot Steering Control of Differential Steering Vehicle

The differential steering vehicle (DSV) is designed to realize pivot steering (PS) as enhance structural robustness. Lacking steering systems, the DSV steers until the differential moment generated by longitudinal force counteracts the resistive moment produced by lateral force, resulting in excessive energy consumption. Besides, since the DSV discarded steering system, both slipping and skidding are inherent during pivot steering, which consumes an extra amount of energy. This paper developed an energy efficient pivot steering control algorithm for DSV. The dynamic model of DSV and wheel are built firstly to analyze constraints and relationships between wheel force and speed on friction circle. Then the power optimization problem is formulated as a function of front-middle and front-rear force factors and solved by discretizing feasible domain online. Finally, the pivot steering of DSV is controlled via speed-adaptive control, whose wheel reference speed is adjusted by the results of the optimization. The algorithm is validated in Trucksim-Simulink co-simulation with a comparison with middle axle wheel free (MWF) and identical reference speed (IRS) method. The results demonstrate the validity of the proposed algorithm to realize the same vehicle yaw rate with less power because of small slip.