Method for controlling and distributing torque of four-wheel drive electric vehicles on basis of slip ratios

Abstract

The invention discloses a method for controlling and distributing torque of four-wheel drive electric vehicles on the basis of slip ratios. The method includes computing the slip ratios for the four-wheel drive electric vehicles, controlling and distributing tire force for the four-wheel drive electric vehicles, judging whether tires are in stable states or not according to the slip ratios, solving target slip ratios by the aid of tire inverse models if the vehicles are in stable states, controlling the slip ratios and distributing wheel torque; controlling the wheel torque by the aid of sliding-mode extreme value search algorithms of the vehicles are in unstable states so as to implement the optimal slip ratios and the maximum tire force. The method has the advantages that the kinetic characteristics of the tires are considered, the tire force can be accurately controlled on the basis of the slip ratios, wheel locking or slipping due to excessively high slip ratios of the wheels can be prevented, and the kinetic safety performance of the four-wheel drive electric vehicles can be effectively improved.

Description

technical field [0001] The invention relates to the field of vehicle dynamics control, in particular to a slip ratio-based torque control distribution method for four-wheel drive electric vehicles. Background technique [0002] In the four-wheel independent drive electric vehicle based on the in-wheel motor, the torque of the four wheels is independently controllable, and the dynamic performance of the vehicle can be improved through torque control distribution, which increases the degree of freedom of dynamic control. In addition, the motor can both drive and brake. Compared with the traditional internal combustion engine and hydraulic brake system, its torque response speed and control accuracy are higher, which is conducive to improving the performance of the dynamic control system. Therefore, four-wheel independent drive electric vehicles have obvious advantages in dynamics control, and have gradually become a research hotspot in recent years. [0003] Wheel torque cont...

AI Technical Summary

Problems solved by technology

At the same time, in the process of slip ratio control, it is necessary to prevent the wheel slip ratio from being too large, resulting in wheel locking or slipping, which will affect the safety of the vehicle.

This also poses a challenge to the current slip rate based control

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