Electric Parking Brake Release Sequencing to Reduce Jolt

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Solution Overview

Problem

Electric parking brakes in vehicles often cause a jolt when released, which can be unpleasant for occupants and may alarm them about a potential vehicle malfunction.

Innovation Solution

A two-stage release method for the parking brake, controlled by an electronic control unit, where the release is interrupted at a predetermined force threshold and resumed based on hydraulic pressure or time elapsed, dividing the jolt into two smaller, imperceptible jolts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the parking brake is released in a single step, then the release process is simple and quick, but a large jolt is felt by the vehicle occupants

Engineering Contradiction:
Improveparking brake release simplicityVSAvoidjolt intensity
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The parking brake release process is divided into multiple sequential steps with different clamping force reduction rates. The first step reduces clamping force at a first rate, then interrupts, then resumes at a second rate (different from the first). This segmentation of the release process distributes the jolt into smaller, imperceptible increments rather than one large jolt, thereby maintaining operational simplicity while eliminating the harmful jolt effect.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If the parking brake release is interrupted and resumed in two stages, then the jolt intensity is reduced, but the release process takes longer

Engineering Contradiction:
Improvejolt intensityVSAvoidrelease duration
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The parking brake release employs periodic action by implementing an interrupted two-stage process. The release is paused at an intermediate clamping force level, then resumed. This periodic interruption and resumption allows the system to manage jolt perception while maintaining reasonable overall release time. The controlled pacing of the release stages optimizes the balance between comfort and time efficiency.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4436843B1Parking brake electric control method
Publication Date: 2025.11.12 ASTEMO FRANCE
  • EP4436843B1 patent drawingFigure 1~2
  • EP4436843B1 patent drawingFigure 3A~3C

AI summary

The invention relates to a method for electrically controlling a parking brake for a motor vehicle, wherein a release of the parking brake is controlled (3) in two steps (D1, D2) separated by an interruption (I) of the release for a period of time linked to the fulfilment of a predetermined condition. This condition depends, according to one embodiment, on a hydraulic pressure (5) exerted by a hydraulic actuator of a service brake of the vehicle, and, according to another embodiment, on a predetermined time that has elapsed from the interruption.