Vehicle Pitch-Over Detection Using Multi-Axis Accelerometer Segmentation

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Solution Overview

Problem

Current vehicle rollover and pitch-over detection systems are inadequate in accurately discriminating between deployment and non-deployment conditions, leading to potential misactivation of occupant restraint systems during vehicle pitch-over events.

Innovation Solution

A method and apparatus utilizing a central crash sensor assembly with multiple accelerometers and satellite sensors to monitor crash acceleration signals, processed by a controller executing algorithms to determine vehicle pitch-over conditions and control the actuation of occupant restraint devices, including airbags and seat belt pretensioners, by filtering and comparing acceleration signals against thresholds to differentiate between deployment and non-deployment scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current rollover and pitch-over detection systems are used, then vehicle safety monitoring is provided, but accuracy in discriminating between deployment and non-deployment conditions deteriorates

Engineering Contradiction:
Improveaccuracy of pitch-over detectionVSAvoiddiscrimination accuracy between deployment and non-deployment conditions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The detection system is segmented into multiple independent accelerometer sensors positioned at different locations (front, rear, left, right) of the vehicle. Each sensor independently monitors acceleration in multiple directions, allowing the system to segment the complex pitch-over detection task into multiple measurable components that are then综合分析 to improve discrimination accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from traditional single-axis or two-axis acceleration monitoring to three-dimensional acceleration measurement using multi-axis accelerometers. By adding the vertical (Z-axis) dimension to the traditional lateral (Y-axis) and longitudinal (X-axis) measurements, the system gains enhanced capability to distinguish pitch-over conditions from normal vehicle operations and false deployment scenarios.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple sensors and processing algorithms are implemented, then detection accuracy improves, but system complexity increases

Engineering Contradiction:
Improvepitch-over condition detection accuracyVSAvoidsensor assembly and processing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple accelerometer sensors are merged into a single integrated sensor assembly that processes data from all sensors centrally. The control unit combines signals from front, rear, left, and right accelerometers along with GPS and other vehicle data into a unified analysis framework, reducing the complexity that would arise from distributed independent processing systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor assembly and control unit are designed with multi-functionality to handle various detection tasks including pitch-over detection, rollover detection, collision detection, and normal operation monitoring. This universal design allows the same hardware infrastructure to serve multiple safety functions, reducing overall system complexity compared to having separate dedicated systems for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enhances the accuracy of detecting vehicle pitch-over conditions, ensuring timely and appropriate activation of occupant restraint systems, thereby improving occupant safety during such events.

Implementation Method 1

a third crash acceleration sensor, having its axis of sensitivity oriented to sense crash acceleration in a direction substantially parallel to the vehicle's Z-axis

Methodology Applied
Scientific EffectAccelerometer: Accelerometer

Data Source

PatentEP2288895B1Method and apparatus for determining a vehicle pitch-over condition
Publication Date: 2020.03.18 TRW AUTOMOTIVE US LLC
  • EP2288895B1 patent drawingFigure 1~2
  • EP2288895B1 patent drawingFigure 3
  • EP2288895B1 patent drawingFigure 4

AI summary

An apparatus for determining a pitch-over condition of a vehicle comprises a first accelerometer for sensing acceleration in a Z-axis direction substantially perpendicular to both a front-to-rear axis of the vehicle and a side-to-side axis of the vehicle and for providing a first acceleration signal indicative thereof. A second accelerometer for senses acceleration in an X-axis direction substantially parallel to said front-to-rear axis of the vehicle and provides a second acceleration signal indicative thereof. A controller determines a Z-axis velocity value from the first acceleration signal and a pitch-over condition of the vehicle in response to both the determined Z-axis velocity value and the second acceleration signal.