Method for estimating a brake factor parameter in a braking system, and vehicle implementing the same

Patent metadata

Field	Value
Publication number	US-12319261-B2
Application number	US-202217862270-A
Country	US
Kind code	B2
Filing date	Jul 11, 2022
Priority date	Jul 22, 2021
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

Method for estimating a brake factor parameter, the brake factor parameter being defined as a ratio of a braking torque over a braking pressure, the braking torque being applied on a wheel of a vehicle by a braking wheel sub-system of a braking system of the vehicle, the braking pressure being applied by the braking wheel sub-system to achieve the braking torque on the wheel of the vehicle, the method comprising collecting input parameters and estimating the brake factor parameter as a function of the at least one input parameter, an output of the step of estimating being an open loop estimation of the brake factor parameter.

First claim

The invention claimed is:

1. A method for estimating a brake factor parameter, the brake factor parameter being defined as a ratio of a braking torque over a braking pressure, the braking torque being applied on a wheel of a vehicle by a braking wheel sub-system of a braking system of the vehicle, the braking pressure being applied by the braking wheel sub-system to achieve the braking torque on the wheel of the vehicle, the method comprising the following steps controlled by a braking system control unit:
collecting input parameters;
estimating the brake factor parameter, as a function of the input parameters, using a trained neuron network (TNN) to generate an open loop estimation of the brake factor parameter;
comparing the open loop estimation of the brake factor parameter with a feedback estimation of the brake factor parameter to generate a closed loop estimation of the brake factor parameter; and
updating the estimated brake factor parameter based on the closed loop estimation of the brake factor parameter;
wherein:
the feedback estimation of the brake factor parameter is based on at least one tire parameter, the at least one tire parameter measured by or estimated from information collected by at least two tire sensors placed on a tire of the wheel,
the closed loop estimation of the brake factor parameter is a function of the open loop estimation and the feedback estimation, and
the updated brake factor parameter is used as a control parameter for one or more vehicle functions.

2. The method of claim 1 , where the input parameters comprise:
a temperature, the temperature being measured on a pad and/or on a rotor of the braking wheel sub-system;
a velocity of the wheel relative to the pad of the braking wheel sub-system; and
a normal load of the tire of the wheel.

3. A vehicle comprising a braking system and an electronic control unit configured to implement the steps of the method of claim 1 .

4. The method of claim 1 , wherein the input parameters comprise:
a chamber size of a braking chamber of the braking system,
a lever arm parameter of the braking wheel sub-system, and
a pad wear of the pads of the braking wheel sub-system.

5. The method of claim 1 , wherein the one or more vehicle functions comprise one or more of: a hill start aid (HSA) function, an automatic traction control (ATC) function, an electronic stability program (ESP) function, an antilock braking system (ABS) function, an adaptive cruise control (ACC) function, an emergency braking function, and an external brake request (XBR) function.

6. The method of claim 1 , wherein the at least one tire parameter comprises one or more of: a dynamic rolling radius of the tire, a longitudinal force applied on the tire at a point of contact of the tire and a road, a friction parameter indicative of a friction between the tire and the road, a wheel slip parameter, and a tire wear parameter.

7. The method of claim 1 , wherein the feedback estimation of the brake factor parameter is derived from a braking torque estimation based on the at least one tire parameter divided by a pressure measured in a braking chamber of the braking system.

8. The method of claim 2 , wherein the input parameters further comprise at least one environmental input parameter.

9. The method of claim 8 , wherein the at least one environmental input parameter comprises one or more of: an ambient temperature, an atmospheric pressure, a road surface condition parameter, a tire-road contact parameter, and vehicle mileage.

Assignees

• Volvo Truck Corp

Inventors

• Subramanian Chidambaram

Classifications

• B60T2270/86

  Optimizing braking by using ESP vehicle or tyre model · CPC title

• B60T2210/12

  Friction · CPC title

• B60T8/171

  Detecting parameters used in the regulation; Measuring values used in the regulation · CPC title

• B60T2240/06

  Wheel load; Wheel lift · CPC title

• B60T2240/03

  Tyre sensors · CPC title