Electro-hydraulic composite brake anti-lock coordinated optimization control method for four-wheel hub electric vehicle

Abstract

The invention discloses an electro-hydraulic composite brake anti-lock coordination optimization control method for a four-wheel hub electric vehicle, and belongs to the technical field of vehicle engineering. The invention aims to provide the electro-hydraulic composite brake anti-lock coordination optimization control method for a four-wheel hub electric vehicle, which is used for obtaining experiential expected optimal slip rates of front and rear wheels according to pavement condition information, designing a slip rate model prediction controller in an upper layer and taking a rotating speed of a motor and a residual electric quantity of a battery as constraint conditions in a lower layer. The method comprises the steps of establishing a four-wheel hub electric vehicle braking system model, identifying road adhesion conditions and the optimal slip rate, designing an upper-layer slip rate tracking controller, and designing a lower-layer regenerative braking and friction braking distribution controller. In the invention, the tire slip rate can be rapidly and accurately controlled, a braking distance and braking time are effectively shortened, safety and reliability of emergency braking are improved, and energy feedback efficiency in an emergency braking process is increased.

Description

technical field [0001] The invention belongs to the technical field of vehicle engineering. Background technique [0002] Compared with traditional internal combustion engine vehicles, electric vehicles have added a motor braking system. Under emergency braking conditions, how to coordinate the regenerative braking system and the friction braking system to improve safety and energy efficiency is an important research issue. In a conventional hydraulic braking system, the hydraulic pressure can be controlled by adjusting the solenoid valve with a pulse width modulated signal, thereby avoiding wheel locking. As the hydraulic pressure changes, the hydraulic braking torque can obtain a large relative working range. However, due to the low carrier pulse frequency of the traditional anti-lock braking system (ABS), the dynamic change of the frictional braking torque is slow. There is always a noticeable delayed response to transients, which can seriously affect anti-lock control p...

AI Technical Summary

Problems solved by technology

As the hydraulic pressure changes, the hydraulic braking torque can obtain a large relative working range. However, due to the low carrier pulse frequency of the traditional anti-lock braking system (ABS), the dynamic change of the frictional braking torque is slow. There is always a noticeable delayed response to transients, which can seriously affect anti-lock control performance

In addition, traditional hydraulic brakes will have greater vibration and noise during ABS work, which will affect braking stability and comfort

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