Vehicle Ride Height Measurement Using Gravitational Acceleration Sensors

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Solution Overview

Problem

Conventional ride height sensors are prone to electromagnetic interference and wear, leading to deteriorating signal accuracy over time, especially when using magnetic field sensors in chassis joints.

Innovation Solution

The use of acceleration sensors stationary relative to the chassis component and a reference sensor stationary relative to the vehicle body, which are insensitive to electromagnetic interference and wear, allowing for accurate measurement of ride height by evaluating sensor signals generated from gravitational acceleration angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetic field sensors are used to measure angular position of chassis components, then measurement capability is provided, but electromagnetic interference and wear cause signal accuracy to deteriorate over time

Engineering Contradiction:
Improvesignal accuracyVSAvoidsignal integrity over lifespan
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces magnetic field sensors with acceleration sensors that measure gravitational acceleration components. This substitution eliminates the problems of electromagnetic interference and wear affecting magnetic sensors, as acceleration sensors based on gravitational measurement are immune to these issues. The mechanical/physical measurement principle changes from magnetic field detection to gravitational acceleration detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of information

If conventional ride height sensors are used in chassis joints, then ride height information can be obtained, but electromagnetic interference from nearby electrical components distorts the angle signal

Engineering Contradiction:
Improveangle signal distortionVSAvoidelectromagnetic interference
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces magnetic field-based angle sensors with acceleration sensors that measure gravitational acceleration. Since gravitational acceleration is a constant physical reference not affected by electromagnetic fields, this substitution eliminates the distortion caused by electromagnetic interference from nearby electrical components such as wiring and motors.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If mechanical components are used in conventional level sensors, then structural support is provided, but wear and tolerances negatively affect angle signal over the lifespan of the sensor

Engineering Contradiction:
Improvesignal accuracy over lifespanVSAvoidsensor lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent replaces mechanical angle sensing mechanisms with acceleration sensors that electronically measure gravitational acceleration components. This eliminates mechanical wear and tolerance accumulation that plague conventional mechanical level sensors, thereby maintaining signal accuracy throughout the entire lifespan of the sensor without degradation.

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

This solution provides a robust and accurate ride height measurement system that is immune to external interference and wear, maintaining signal integrity over the lifespan of the sensors, enabling precise determination of vehicle height and angular positions.

Implementation Method 1

one or at least one acceleration sensor stationary relative to the chassis component for detecting the acceleration acting on the chassis component

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 2

at least one reference sensor stationary relative to the vehicle body for detecting the acceleration acting on the vehicle body

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3500445B1Height measuring device for a vehicle
Publication Date: 2021.01.27 ZF FRIEDRICHSHAFEN AG
  • EP3500445B1 patent drawingFigure 1
  • EP3500445B1 patent drawingFigure 2
  • EP3500445B1 patent drawingFigure 3~4

AI summary

The invention relates to a height measuring device for a vehicle, comprising a sensor assembly (18, 20), by means of which sensor signals (31, 32) can be generated that characterize the position of at least one chassis component (4) relative to the vehicle structure (5), said chassis component connecting a vehicle wheel (3) to a vehicle structure (5) and being connected to said vehicle structure in an articulated manner, and comprising an analysis device (19) which is connected to the sensor assembly (18, 20) and by means of which at least one piece of height information (33) can be generated that characterizes the height (h) of the vehicle structure (5) by analyzing the sensor signals (31, 32). The sensor assembly (18, 20) comprises at least one acceleration sensor (18) which is stationary relative to the chassis component (4) for detecting the acceleration acting on the chassis component (4), said acceleration sensor being used to generate at least one sensor signal (31) which characterizes the acceleration, and at least one reference sensor (20) which is stationary relative to the vehicle structure (5) for detecting the acceleration acting on the vehicle structure (5), said reference sensor being used to generate at least one sensor signal (32) which characterizes the acceleration.