Parking Brake Friction Control for Slippery Surface Holding

Solution Overview

Problem

The existing parking brake systems in motor vehicles are not adequately designed to handle varying friction conditions, leading to increased wear and cost due to the need for robust construction, and may fail to secure the vehicle on slippery surfaces.

Innovation Solution

A method that dynamically adjusts the activation of parking brakes based on the friction between the wheels and the ground, increasing the clamping force on wheels with higher friction to ensure safety and reducing wear on wheels with lower friction, using sensors and environmental data to determine friction levels and adjust brake pressure accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If brake pads are always applied with maximum force against the brake disc, then the vehicle is securely prevented from moving even on slippery surfaces, but wear of brake components increases and robust (expensive) design is required

Engineering Contradiction:

Improvevehicle security against unintentional movementVSAvoidwear of brake pads and brake disc

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The parking brake system dynamically adjusts the clamping force based on real-time friction detection. Sensors measure the friction coefficient between wheel and ground, and the control unit modulates the actuator to apply only the necessary braking force. This dynamic adaptation allows sufficient braking performance on slippery surfaces without continuous maximum force application, reducing wear while maintaining reliability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the parking brake by detecting friction conditions and adjusting the clamping force accordingly. On high-friction surfaces, lower clamping forces suffice, while on low-friction surfaces, the system increases clamping force only when needed. This parameter adjustment resolves the contradiction by matching brake force to actual environmental conditions rather than using fixed maximum force.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If brake pads are always applied with maximum force against the brake disc, then the vehicle is securely prevented from moving even on slippery surfaces, but manufacturing costs increase due to robust design requirements

Engineering Contradiction:

Improvevehicle security against unintentional movementVSAvoidmanufacturing costs and complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The parking brake system dynamically adjusts the clamping force based on real-time friction detection. Sensors measure the friction coefficient between wheel and ground, and the control unit modulates the actuator to apply only the necessary braking force. This dynamic adaptation allows sufficient braking performance on slippery surfaces without continuous maximum force application, reducing wear while maintaining reliability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses sensors to automatically detect friction conditions and self-regulates the parking brake force without manual intervention. The control unit processes sensor data and adjusts actuator output accordingly, enabling the system to serve itself by adapting to environmental conditions. This eliminates the need for overly robust mechanical design, reducing manufacturing costs while ensuring adequate performance.

Inventive Principle:

Principle #25Self-service

3Reliability

If parking brakes are designed with robust components to handle maximum force, then they can secure the vehicle on any surface, but weight and cost increase

Engineering Contradiction:

Improveparking brake performance on all surfacesVSAvoidweight of parking brake components

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The parking brake system dynamically adjusts the clamping force based on real-time friction detection. Sensors measure the friction coefficient between wheel and ground, and the control unit modulates the actuator to apply only the necessary braking force. This dynamic adaptation allows sufficient braking performance on slippery surfaces without continuous maximum force application, reducing wear while maintaining reliability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the parking brake by detecting friction conditions and adjusting the clamping force accordingly. On high-friction surfaces, lower clamping forces suffice, while on low-friction surfaces, the system increases clamping force only when needed. This parameter adjustment resolves the contradiction by matching brake force to actual environmental conditions rather than using fixed maximum force.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances safety by preventing unintentional movement on slippery surfaces while reducing wear and manufacturing costs by optimizing brake force distribution and material usage.

Implementation Method 1

The two components interact in a particularly frictional but not positive manner. In other words, there is no locking mechanism or anything similar.

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP4349671A1Method for operating a motor vehicle

Publication Date: 2024.04.10 AUDI AG

Figure 1~2

AI summary

The invention relates to a method (36) for operating a motor vehicle (2) having two wheels (4), each of which is assigned a parking brake (16). The parking brakes (16) are controlled depending on friction between the respective wheel (4) and the ground (8). The invention further relates to a motor vehicle (2).