An electric vehicle electro-hydraulic composite braking system and its optimization method

Abstract

The invention discloses an electric-hydraulic composite braking system for an electric automobile and an optimization method of the electric-hydraulic composite braking system. The electric-hydraulic composite braking system for the electric automobile comprises a motor regeneration braking force module, a hydraulic braking force module and a composite braking force control module. The motor regeneration braking force module comprises two hub motors, a brake pedal position sensor, four wheel speed sensors, an automobile speed sensor, a super-capacitor, a two-quadrant DC-DC converter and a first ECU. The hydraulic braking force module comprises an oil pump motor, a hydraulic oil pump and a second ECU. In the traveling process of the automobile, through detection of the automobile speed and the wheel speed of automobile traveling and brake pedal position signals, the composite braking force control module controls the distribution ratio between the motor regeneration braking force module and the hydraulic braking force module. Meanwhile, through multi-objective optimization conducted on the electric-hydraulic composite braking system, the braking pedal feeling and motor recovered energy serve as objects, and under the ECE laws and regulations, the relatively high energy recovery rate and the proper brake pedal feeling are obtained.

Description

technical field [0001] The invention relates to the field of electro-hydraulic composite braking systems for electric vehicles, in particular to an electro-hydraulic composite braking system based on electric vehicles and an optimization method thereof. Background technique [0002] Compared with the traditional hydraulic braking system, the electro-hydraulic composite braking system has the advantages of good braking stability and a certain energy recovery rate. Since the system can recover part of the braking energy during the braking process, it can When braking, the ECU can increase the ratio of the regenerative braking force of the motor to increase the energy recovery rate. On the contrary, during high-intensity braking, the braking force can be completely provided by hydraulic braking force to ensure braking efficiency. [0003] However, in the existing research on the electro-hydraulic hybrid braking system of electric vehicles, there is still very little research o...

AI Technical Summary

Problems solved by technology

In the actual braking conditions of electric vehicle compound braking, on the one hand, under the same brake pedal angle, due to the different dynamic characteristics of regenerative braking and hydraulic friction braking output, the driver often has different braking modes. inconsistent brake feel

On the other hand, even in the same braking mode, the braking force response characteristics due to different braking force distribution ratios are also different, which will cause the driver to have inconsistent braking feeling

Obviously, these inconsistent braking sensations will not only cause braking stability problems caused by the driver's nervousness and misuse, but also limit the recovery effect of braking energy to a large extent

At present, the multi-objective optimization design of the electro-hydraulic composite braking system for the brake pedal feeling, so that the system can obtain a higher energy recovery rate and achieve a better brake pedal feel has not yet been published.

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