Hub motor electromechanical composite brake ABS control method and system

Abstract

The invention relates to the technical field of automobile control, in particular to a hub motor electromechanical composite brake ABS control method and system. A super-capacitor energy management unit is arranged, whether a brake pedal is stepped down or not is detected, if yes, a brake mode is started, and if the electric quantity of a super-capacitor is larger than a set electric quantity threshold value, an ABS controller controls an EMB controller to conduct mechanical braking; if the electric quantity of the super capacitor is not larger than the set electric quantity threshold value and the braking force required by each wheel is smaller than the maximum regenerative braking force provided by the motor, the ABS controller controls the motor controller to carry out regenerative braking; and if the electric quantity of the super capacitor is not larger than the set electric quantity threshold value, and the braking force required by one or more wheels is not smaller than the maximum regenerative braking force provided by the motor, the ABS controller controls the motor controller and the EMB controller to perform electromechanical composite braking. And the high-power charging and discharging requirements of the hub motor are met, so that the braking energy recovery is not limited by the battery charging power any more.

Description

technical field [0001] The invention relates to the technical field of automobile control, in particular to an ABS control method and system for hub motor electromechanical composite braking. Background technique [0002] Anti-lock brake system (antilock brake system) referred to as ABS. Its function is to adjust the braking pressure of the four wheel cylinders through the solenoid valve according to the change of the wheel speed of each wheel during the braking process of the car, so as to obtain better longitudinal and lateral adhesion characteristics, so that the wheels will not be locked. It is in the state of rolling and slipping (slip rate is about 20%) to ensure the maximum ground adhesion of the wheels. [0003] In the traditional braking scheme, based on the consideration of braking priority, the ABS will exit the energy recovery mode when it intervenes, and the driver's braking intention is completely executed by the hydraulic brake, and the energy recovery rate i...

AI Technical Summary

Problems solved by technology

[0003] In the traditional braking scheme, based on the consideration of braking priority, the ABS will exit the energy recovery mode when it intervenes, and the driver's braking intention is completely executed by the hydraulic brake, and the energy recovery rate is low; and the braking energy recovery only acts on the battery , limited by the charging power of the battery, the energy recovery rate is low, and the battery cannot meet the high-power charging and discharging requirements of the hub motor

In addition, compared with the electromechanical braking system, the hydraulic braking force cannot be accurately controlled, and the response time of the hydraulic brake actuator is longer; at the same time, due to the presence of brake fluid, after excessive heating, part of the brake fluid will vaporize, and in the pipeline The formation of air bubbles seriously affects the hydraulic transmission and reduces the performance of the brake system, or even completely fails

[0004] In addition, the traditional ABS control needs to install a wheel speed detection device on each wheel to measure the wheel speed of each wheel, and the wheel speed detection device generally consists of a magnetic encoding ring, a wheel speed sensor probe, a wiring harness, a connector, an outer cover, a fixing bolt, etc. Composed of many parts, the magnetic coding ring integrated on the hub motor bearing increases the volume and weight of the hub bearing unit

However, the radial gap between the magnetic coding ring and the wheel speed sensor probe is very small. Due to manufacturing and assembly errors, use impact, insufficient protection level, etc., scratches may occur between the magnetic coding ring and the magnetic wheel speed sensor probe during rotation. Failure to monitor the vehicle wheel speed correctly and effectively leads to the failure of the ABS system, which poses a safety hazard

In addition, the wheel speed sensor probe is facing the magnetic encoding ring, and it is necessary to find a fixed point for the wheel speed sensor probe in the already tight space at the wheel end, which increases the difficulty of integrating the hub motor.

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