Occupant Displacement-Based Supplemental Restraint Deployment Immunity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing vehicle supplemental restraint systems face challenges in distinguishing between deployment and non-deployment crash events, particularly due to acceleration disturbances from rough road surfaces, leading to potential false deployments.

Innovation Solution

The method uses occupant displacement to determine whether to enable or disable restraint deployment, employing two calibrated thresholds to differentiate between crash events and non-crash events, ensuring timely and reliable deployment decisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If acceleration-based deployment detection is used, then deployment response time is improved, but false deployment due to rough road surfaces occurs

Engineering Contradiction:

Improvedeployment response timeVSAvoidfalse deployment rate

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The patent introduces an intermediary variable (displacement) between the acceleration sensor and the deployment decision. Instead of directly using acceleration signals to trigger deployment, the system integrates acceleration to obtain velocity, then integrates velocity to obtain displacement. This intermediary displacement measurement filters out high-frequency noise from rough roads while preserving the low-frequency signature of actual crash events, thereby reducing false deployments without compromising response time.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/threshold-based acceleration detection system with a physics-based integration system. Instead of comparing acceleration against fixed thresholds, the system performs mathematical integration (acceleration → velocity → displacement) to transform the detection mechanism. This substitution leverages the physical relationship between motion parameters to inherently filter disturbances and improve reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If ΔV-based crash severity assessment is used, then deployment decision speed is improved, but inability to distinguish non-deployment crash events occurs

Engineering Contradiction:

Improvedeployment decision speedVSAvoidcrash event discrimination accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent adds another dimension to crash severity assessment by introducing displacement as a complementary metric to ΔV. While ΔV provides information about the intensity and duration of the crash, displacement provides information about the cumulative effect and severity classification. By evaluating both dimensions together, the system can quickly assess crash severity while accurately distinguishing between deployment-worthy and non-deployment-worthy events, even when ΔV values are similar.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If multiple procedures and rules are implemented to overcome false deployment, then deployment reliability is improved, but system complexity increases

Engineering Contradiction:

Improvedeployment accuracyVSAvoidcontrol logic complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the fundamental parameter used for deployment assessment from acceleration to displacement. This single parameter change inherently provides immunity from rough road surfaces and simplifies the control logic. Instead of implementing multiple complex procedures and rules to filter false signals, the displacement parameter naturally distinguishes between true crash events and road disturbances, achieving high reliability with simpler logic.

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 provides a physics-based, time-independent immunity gate that effectively discriminates between crash and non-crash events, preventing unnecessary deployments and ensuring timely deployment of restraints based on crash severity.

Implementation Method 1

the acceleration signal is monitored to detect the onset of a crash event (as indicated by acceleration in excess of a reference value, for example), and then filtered or integrated over the course of the crash event to determine the change in velocity due to the crash

Methodology Applied

Scientific EffectIntegration of acceleration signal:

Implementation Method 2

occupant displacement due to a crash event is determined and used to enable and disable deployment of supplemental restraints based on crash severity. The determined occupant displacement is compared to a first threshold calibrated to discriminate against disturbances due to rough roads and other non-crash events

Methodology Applied

Scientific EffectDisplacement measurement: Displacement

Data Source

PatentUS7660655B2Supplemental restraint deployment method with displacement-based deployment immunity

Publication Date: 2010.02.09 APTIV TECHNOLOGIES AG

AI summary

Occupant displacement corresponding to sensed acceleration in a crash event is determined and used to enable and disable deployment of supplemental restraints based on crash severity. The determined occupant displacement is compared to a first threshold calibrated to discriminate against disturbances due to rough roads and other non-crash events, and a second threshold calibrated to discriminate against non-deployment crash events. Deployment of supplemental restraints based on crash severity is enabled only when the determined displacement is between the first and second thresholds.