CN-122009110-A - Emergency braking control method, device and storage medium

CN122009110ACN 122009110 ACN122009110 ACN 122009110ACN-122009110-A

Abstract

The application discloses an emergency braking control method, an emergency braking control device and a storage medium, which relate to the technical field of emergency braking control and comprise the steps of obtaining the speed, the braking pressure and the current slip rate of a vehicle during emergency braking; when the vehicle speed is smaller than a preset vehicle speed threshold value, determining a wheel end braking torque feedforward value of the vehicle according to the vehicle speed, the braking pressure and the current slip rate, determining a wheel end control torque feedback value based on the vehicle speed and the braking pressure, and performing emergency braking control on the vehicle based on the wheel end braking torque feedforward value and the wheel end control torque feedback value. Two different vehicle speed sections are divided by the starting vehicle speed of emergency braking, a feedforward and feedback control strategy is adopted for low-speed-domain emergency braking, wheel end braking torque is actively regulated and controlled before the vehicle enters ABS control, the situation that the vehicle enters the ABS control quickly, excessive pressure is released after the wheel is locked too deeply, the pressure amplitude of the wheel end is regulated to be too large, and the stability and safety of low-speed-domain emergency braking are improved.

Inventors

ZHANG WEIYE
HUANG JUN

Assignees

东风汽车有限公司东风日产乘用车公司

Dates

Publication Date: 20260512
Application Date: 20260325

Claims (10)

1. An emergency brake control method, characterized by comprising: acquiring the speed, the braking pressure and the current slip rate of the vehicle during emergency braking; when the vehicle speed is smaller than a preset vehicle speed threshold value, determining a wheel end braking torque feedforward value of the vehicle according to the vehicle speed, the braking pressure and the current slip rate; determining a wheel end control torque feedback value based on the vehicle speed and the brake pressure; and performing emergency braking control on the vehicle based on the wheel end braking torque feedforward value and the wheel end control torque feedback value.
2. The method of claim 1, wherein the step of determining a wheel end brake torque feedforward value of the vehicle based on the vehicle speed, the brake pressure, and the current slip ratio when the vehicle speed is less than a preset vehicle speed threshold value comprises: when the vehicle speed is smaller than a preset vehicle speed threshold value, acquiring the current slip rate change rate; and when the current slip rate is larger than a first slip rate threshold value and smaller than a second slip rate threshold value, the current slip rate change rate is larger than a preset slip rate change rate threshold value and the braking pressure is larger than a preset braking pressure threshold value, determining a wheel end braking torque feedforward value of the vehicle according to the vehicle speed and the braking pressure.
3. The method of claim 2, wherein the step of determining a wheel end brake torque feedforward value for the vehicle based on the vehicle speed and the brake pressure when the current slip rate is greater than a first slip rate threshold and less than a second slip rate threshold, the current slip rate change rate is greater than a preset slip rate change rate threshold, and the brake pressure is greater than a preset brake pressure threshold comprises: Determining a load transfer amount of the vehicle when the current slip rate is greater than a first slip rate threshold and less than a second slip rate threshold, the current slip rate change rate is greater than a preset slip rate change rate threshold, and the brake pressure is greater than a preset brake pressure threshold; calculating a braking torque from the braking pressure; And inquiring a feedforward parameter mapping table according to the vehicle speed, the braking torque and the load transfer quantity to obtain a corresponding wheel end braking torque feedforward value of the vehicle.
4. The method of claim 2, wherein the step of determining a wheel end control torque feedback value based on the vehicle speed and the brake pressure comprises: determining a target slip rate change rate from the vehicle speed and the brake pressure; Calculating a slip rate change rate difference value according to the current slip rate change rate and the target slip rate change rate; and obtaining a wheel end control torque feedback value according to the slip rate change rate difference value.
5. The method of claim 1, wherein the step of emergency brake control of the vehicle based on the wheel end brake torque feedforward value and the wheel end control torque feedback value comprises: According to the wheel end braking torque feedforward value and the wheel end control torque feedback value, a target control torque is obtained; And adjusting the wheel end braking torque of the vehicle through the target control torque so as to carry out emergency braking control on the vehicle.
6. The method of claim 1, wherein the method further comprises: when the vehicle speed is greater than a preset vehicle speed threshold value and the current slip rate is smaller than a second slip rate threshold value, obtaining response torque of a braking system; Inquiring a build-up pressure rate table according to the vehicle speed and the braking torque when the response torque is larger than the preset torque in the preset time, and obtaining a corresponding build-up pressure slope; And controlling the braking pressure according to the pressure build-up slope so as to carry out emergency braking control on the vehicle.
7. The method of claim 1, wherein the step of obtaining the vehicle speed, the brake pressure, and the current slip rate of the vehicle at the time of emergency braking is preceded by the step of: acquiring a brake pedal travel rate, a brake pedal opening and an automatic emergency brake function state; And when the brake pedal travel rate is greater than a preset brake pedal travel rate threshold value and the brake pedal opening is greater than a preset brake pedal opening, or when the automatic emergency braking function state is a trigger state and the deceleration requested by the auxiliary driving control unit to the emergency braking control unit is greater than a preset deceleration threshold value, determining that emergency braking exists on the vehicle, and executing the step of acquiring the speed, the braking pressure and the current slip rate of the vehicle during emergency braking.
8. The method of any one of claims 1 to 7, wherein the method further comprises: and when the current slip rate is larger than a second slip rate threshold value, switching the emergency braking control of the vehicle to ABS control.
9. An emergency brake control apparatus, characterized in that the apparatus comprises: The acquisition module is used for acquiring the speed, the braking pressure and the current slip rate of the vehicle during emergency braking; The determining module is used for determining a wheel end braking torque feedforward value of the vehicle according to the vehicle speed, the braking pressure and the current slip rate when the vehicle speed is smaller than a preset vehicle speed threshold value; The determining module is further used for determining a wheel end control torque feedback value based on the vehicle speed and the braking pressure; And the control module is used for carrying out emergency braking control on the vehicle based on the wheel end braking torque feedforward value and the wheel end control torque feedback value.
10. A storage medium, characterized in that the storage medium is a computer-readable storage medium, on which a computer program is stored, which computer program, when being executed by a processor, realizes the steps of the emergency brake control method according to any one of claims 1 to 8.

Description

Emergency braking control method, device and storage medium Technical Field The present application relates to the field of emergency braking control technologies, and in particular, to an emergency braking control method, an emergency braking control device, and a storage medium. Background When the driver has an urgent braking demand or the auxiliary driving control unit has an urgent braking demand, the braking control unit rapidly controls the brake pressure to increase to meet the braking demand of the driver or the auxiliary driving control unit. The braking distance and braking deceleration are key indicators for evaluating the performance of emergency braking. However, in a braking scene with smaller vehicle speed, the slip rate is very sensitive to the change of the vehicle speed, the slip rate is easy to rise quickly due to smaller braking force, the braking force required by the tire from rolling to locking slip is lower than that in a high-speed scene, the system response time is relatively short, and excessive braking is easy to occur. In the emergency braking of a low speed area, due to low speed, a smaller braking force can cause a slip rate to rise faster, and along with the rising of the braking force, the wheel is locked faster and is locked too deeply, so that the vehicle enters ABS (Anti-lock Brake System) control rapidly, in order to enable the wheel speed of the vehicle to recover rapidly, the ABS system can release pressure, the road surface adhesion force is not fully utilized due to excessive pressure release, further pressure is further increased, but due to excessive system pressure release, insufficient braking liquid amount, small pressure increase of a pressurizing cycle, large fluctuation of pressure regulation in the early stage of ABS control, large fluctuation of deceleration in the ABS control process, small average deceleration, long braking distance and poor braking efficiency are caused. The same set of parameters is used for the full-speed-domain ABS parameters, the braking pressures required by maintaining the same slip rate at high and low speeds are inconsistent, the braking performance difference is large, and particularly, the braking performance of the low-speed domain is poor, and the braking performance of the high-speed domain is good. Disclosure of Invention The application mainly aims to provide an emergency braking control method, an emergency braking control device and a storage medium, and aims to solve the technical problem that the braking effect is poor because a vehicle enters ABS control faster when the emergency braking control is carried out on the vehicle at present. In order to achieve the above object, the present application provides an emergency brake control method, including: acquiring the speed, the braking pressure and the current slip rate of the vehicle during emergency braking; when the vehicle speed is smaller than a preset vehicle speed threshold value, determining a wheel end braking torque feedforward value of the vehicle according to the vehicle speed, the braking pressure and the current slip rate; determining a wheel end control torque feedback value based on the vehicle speed and the brake pressure; and performing emergency braking control on the vehicle based on the wheel end braking torque feedforward value and the wheel end control torque feedback value. In an embodiment, the step of determining the wheel end brake torque feedforward value of the vehicle according to the vehicle speed, the brake pressure and the current slip ratio when the vehicle speed is smaller than a preset vehicle speed threshold value includes: when the vehicle speed is smaller than a preset vehicle speed threshold value, acquiring the current slip rate change rate; and when the current slip rate is larger than a first slip rate threshold value and smaller than a second slip rate threshold value, the current slip rate change rate is larger than a preset slip rate change rate threshold value and the braking pressure is larger than a preset braking pressure threshold value, determining a wheel end braking torque feedforward value of the vehicle according to the vehicle speed and the braking pressure. In an embodiment, the step of determining the wheel end brake torque feedforward value of the vehicle according to the vehicle speed and the brake pressure when the current slip rate is greater than a first slip rate threshold and less than a second slip rate threshold, the current slip rate change rate is greater than a preset slip rate change rate threshold, and the brake pressure is greater than a preset brake pressure threshold comprises: Determining a load transfer amount of the vehicle when the current slip rate is greater than a first slip rate threshold and less than a second slip rate threshold, the current slip rate change rate is greater than a preset slip rate change rate threshold, and the brake pressure is greater than a preset brake pressure th