关键词: 四轮独立电动汽车, 集成控制, 模糊滑模控制, 变传动比, 附加横摆力矩

Abstract: Four-wheel independently actuated electric vehicles feature independently controllable wheels, which facilitates integrated vehicle control. However, due to their multi-degree-of-freedom characteristics, they exhibit unstable driving behavior during steering maneuvers. To address the steering stability problem of such vehicles, an integrated control strategy combining four-Wheel Steering (4WS) and Direct Yaw moment Control (DYC) is adopted, denoted as 4WS+DYC. The control strategy is based on a layered control concept,targeting reference model tracking. The stability control layer uses a fuzzy sliding mode controller to compensate for the additional yaw moment and rear-wheel angle needed for stable vehicle operation. The front wheel angle is controlled using a variable transmission ratio method,calculating the front wheel angle to achieve basic vehicle steering. The torque distribution layer uses a load distribution-based control algorithm,considering constraints to achieve four-wheel torque distribution. Finally,it verifies the effectiveness of the integrated control strategy for four-wheel steering and direct yaw moment under the conditions of low speed,low adhesion dual lane shifting,and high speed,high adhesion sinusoidal conditions. Results show that this strategy improves the tracking performance of yaw rate and sideslip angle,with the fuzzy sliding mode controller demonstrating good convergence,thereby enhancing vehicle stability during steering motion.

Key words: four-wheel independent electric vehicle, integrated control, fuzzy sliding mode control, variable transmission ratio, additional yaw moment