Electronic differential control method and system of four-wheel drive electric vehicle

Abstract

The invention discloses an electronic differential control method of a four-wheel drive electric vehicle. The electronic differential control method includes the steps of calculating the turning radiuses of two front wheels and the turning radiuses of two rear wheels according to the turning angles of wheels and the slip angles of tires correspondingly, calculating target wheel speeds of the fourwheels according to the reference vehicle speed and the obtained turning radiuses of the two front wheels and the two rear wheels correspondingly, monitoring the difference between the actual wheel speeds of the four wheels and the target wheel speed in real time, determining the output modification feedback torque of each wheel by multiplying the difference by a preset torque modification proportionality coefficient, modifying the output torque, and obtaining the actual torque of the driving wheels inside and outside a front axle and a rear axle by subtracting the torque difference from the driving wheels inside, adding the torque difference to the driving wheels outside and meanwhile adding the feedback torque based on target wheel speed modification correspondingly. The electronic differential control method is suitable for the four-wheel independent drive electric vehicle, the turning radius and target torque of each driving wheel are calculated independently, the torque can be rapidly and precisely controlled, the slip angles of the tires are introduced to participate in calculation, and precision is improved.

Description

technical field [0001] The invention relates to an electronic differential speed control method of an electric vehicle, in particular to an electronic differential speed control method and system of a four-wheel drive electric vehicle. Background technique [0002] With the increasingly severe environmental protection situation, my country is vigorously supporting the development of the new energy vehicle industry. Among them, the new energy vehicles using in-wheel motors as the power source, because of their stable torque output, short power transmission chain, high energy utilization rate, and Many control degrees of freedom and compact structure make it have unique advantages in safety, comfort, power, energy saving, environmental protection and many other aspects. [0003] New energy vehicles equipped with in-wheel motors eliminate traditional transmission components such as clutches, gearboxes, axle shafts and differentials, which greatly reduces the complexity of the ch...

AI Technical Summary

Problems solved by technology

This method is for electric vehicles with front-wheel steering and two rear wheels independently driven by hub motors. It cannot be applied to electric vehicles with four-wheel independent drive, and cannot perform fast and precise torque control.

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