Brake Booster Position Sensing via Magnetic Rotation Sensors

Solution Overview

Problem

Traditional electric brake boosters face challenges in achieving high precision measurement and robustness due to the limitations of stroke sensors, which are affected by environmental factors and are relatively expensive.

Innovation Solution

The use of rotation sensors kinematically coupled with brake and booster force transmitting elements via a motion converting mechanism, allowing for precise measurement of axial positions and providing higher signal stability, robustness, and cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a stroke sensor is used to monitor the displacement of the brake pedal or brake element, then the motion can be measured, but the measurement precision is low, robustness is poor, and the cost is high

Engineering Contradiction:

Improvemeasurement precisionVSAvoidrobustness

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical stroke sensor with a magnetic field-based detection system. A first magnet is attached to the brake force transmitting element, and a second magnet is attached to the booster force transmitting element. A magnetic sensor detects the positions of these magnets, converting mechanical position measurement into a magnetic field measurement. This substitution eliminates the mechanical contacts and complex structures of traditional stroke sensors, thereby improving measurement precision and robustness while reducing cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If a stroke sensor is used to monitor the displacement of the brake pedal or brake element, then the motion can be measured, but the sensor is easy to be affected by environment factors like magnetic field, contamination and icing

Engineering Contradiction:

Improvesensor operationVSAvoidenvironmental factors

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical stroke sensor with a magnetic field-based detection system. A first magnet is attached to the brake force transmitting element, and a second magnet is attached to the booster force transmitting element. A magnetic sensor detects the positions of these magnets, converting mechanical position measurement into a magnetic field measurement. This substitution eliminates the mechanical contacts and complex structures of traditional stroke sensors, thereby improving measurement precision and robustness while reducing cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a stroke sensor is used to monitor the displacement of the brake pedal or brake element, then the motion can be measured, but the sensor is relatively expensive

Engineering Contradiction:

Improvemeasurement precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical stroke sensor with a magnetic field-based detection system. A first magnet is attached to the brake force transmitting element, and a second magnet is attached to the booster force transmitting element. A magnetic sensor detects the positions of these magnets, converting mechanical position measurement into a magnetic field measurement. This substitution eliminates the mechanical contacts and complex structures of traditional stroke sensors, thereby improving measurement precision and robustness while reducing cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables accurate and reliable control of the electric motor operation, enhancing the precision and reliability of the brake booster's performance while reducing costs.

Implementation Method 1

a first rotation sensor kinematically coupled with the brake force transmitting element via a motion converting mechanism, which is configured for converting a translational motion into a rotational motion

Methodology Applied

Scientific EffectMotion conversion mechanism:

Implementation Method 2

an electric motor for generating the booster brake force

Methodology Applied

Scientific EffectElectric motor:

Implementation Method 3

the electric motor drives the booster force transmitting element via a transmission mechanism which is configured for converting a rotational motion into a translational motion

Methodology Applied

Scientific EffectTransmission mechanism:

Data Source

PatentUS10220823B2Brake booster

Publication Date: 2019.03.05 BOSCH AUTOMOTIVE PRODUCTS (SUZHOU) CO LTD

AI summary

A brake booster for a vehicle brake system includes a brake force transmitting element, a booster force transmitting element, a first rotation sensor, and a second rotation sensor. The brake force transmitting element is moveable in an axial direction for transmitting a pedal brake force from a brake pedal to a primary brake cylinder. The booster force transmitting element is moveable in the axial direction for transmitting a booster brake force to the primary brake cylinder. The first rotation sensor is kinematically coupled with the brake force transmitting element via a motion converting mechanism for measuring the axial position of the brake force transmitting element. The second rotation sensor is kinematically coupled with the booster force transmitting element for measuring the axial position of the booster force transmitting element. The measurements of the first and second rotation sensors are used for controlling the generation of the booster brake force.