Electronic Park Brake Speed Threshold Control

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Solution Overview

Problem

Existing electronically controlled vehicle park brake systems lack safe and controlled activation mechanisms, particularly in scenarios where vehicle speed thresholds are not met, leading to potential wheel blocking or unintended deactivation.

Innovation Solution

A method for controlling the vehicle park brake system that locks the brake in an applied status if the vehicle speed is below specific thresholds during and after activation, using an electronically controlled valve assembly and a park brake input device with a controller circuit to achieve proportional braking effects, ensuring safe operation by integrating sensors and a microcontroller for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the park brake is activated without speed threshold control, then the braking effect is achieved, but wheel blocking occurs

Engineering Contradiction:
Improvesafe operationVSAvoidwheel blocking
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system checks vehicle speed before activating the park brake. If the speed is below the threshold, the brake is activated; otherwise, activation is prevented. This preliminary speed verification prevents wheel blocking by ensuring the brake is only applied when the vehicle is already moving slowly or stationary.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors vehicle speed and uses this feedback to control park brake activation. The speed signal from the vehicle's speed sensor is fed back to the park brake control system, which automatically prevents activation when speed exceeds the threshold, thereby avoiding wheel blocking.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If the park brake is deactivated without speed threshold control, then the brake releases, but unintended deactivation occurs during motion

Engineering Contradiction:
Improvebrake controlVSAvoidunintended deactivation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Before deactivating the park brake, the system performs a preliminary speed check. If the vehicle speed is below the threshold, deactivation is permitted; otherwise, it is blocked. This ensures the brake is only released when the vehicle is stationary or moving very slowly, preventing unintended deactivation during motion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses real-time speed feedback to control park brake deactivation. The speed signal is continuously monitored, and when it exceeds the threshold during a deactivation attempt, the system automatically prevents brake release, thereby avoiding unintended deactivation while maintaining ease of operation when conditions are appropriate.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If proportional braking control is implemented, then precise braking effect is achieved, but system complexity increases

Engineering Contradiction:
Improvebraking effect controlVSAvoidcontrol system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a control unit as an intermediary between the driver's brake input and the park brake actuator. This control unit receives the driver's input signal, combines it with speed threshold information, and generates appropriate control signals for the actuator. This intermediary enables proportional braking control with precise adjustment of braking force while keeping the overall system architecture relatively simple and manageable.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2483116B1Method for activating an electronic park brake system
Publication Date: 2013.08.21 RENAULT TRUCKS
  • EP2483116B1 patent drawingFigure 1~2
  • EP2483116B1 patent drawingFigure 3~4D
  • EP2483116B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for controlling a vehicle park brake system, wherein the park brake system is electronically controlled to achieve a proportional braking effect according to signals received from a park brake input device (10) through which a user of the vehicle can control the degree of activation of the park brake, characterized in that when the user has initiated a park brake activation sequence using the park brake input device (10), and has terminated the park brake activation sequence by releasing the input device (10), the park brake is locked in an applied status upon termination of the sequence if the vehicle speed was below a first threshold speed (V1) at park brake activation sequence initiation or below a second threshold speed (V2) at park brake activation sequence termination.