Coordinated Control of Slip Prevention and Energy Management for Four-Wheel-Drive Hybrid Electric Vehicles

For a hybrid electric vehicle (HEV), traction control ensures vehicle safety while energy management improves the fuel efficiency. Since the two strategies both control the torque distribution, the coordination between them is necessary. Therefore, a multi-objective optimization strategy is proposed to concurrently optimize the dynamic performance, slip rate and energy consumption of an HEV. First, an improved vehicle speed estimation method based on the characteristics of the adhesion curves is proposed to accurately estimate the vehicle speed and slip rate. Second, the Gaussian process regression is introduced to identify the tire model and extract the global features of the adhesion curve. Finally, the multi-objective optimization problem is proposed and solved by the technique for order preference by similarity to ideal solution. The strategy outputs torque distribution between the engine, the motor and the brakes. The simulation results show that the proposed strategy can reduce the slip times compared with sliding mode control. Meanwhile, the energy economy is improved because the additional energy consumption caused by slip control is reduced.