Child Seat Tension Monitoring via Fluid Bladder and Pressure Sensor

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Solution Overview

Problem

Existing child seats lack a reliable mechanism to ensure that the seat belt webbing is tightened to a sufficient tension during installation, which can lead to undesirable rotation during sudden stops if the tension is insufficient.

Innovation Solution

A child seat equipped with a bladder filled with fluid that contacts the seat belt webbing, a pressure sensor to measure the tension, and a controller that uses LEDs and an electrical speaker to indicate when the tension is either insufficient or sufficient, providing real-time feedback on correct installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sufficient amount of tension is applied to the seat belt webbing to secure the child seat, then rotation of the child seat is restricted and child protection is improved, but the installation process becomes more difficult and users cannot verify proper tensioning

Engineering Contradiction:
Improvechild protectionVSAvoidinstallation verification
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements a feedback mechanism where a pressure sensor detects the tension force applied to the seat belt webbing during installation. The controller processes this signal and activates visual indicators (lights) to provide real-time feedback to the user about whether sufficient tension has been applied. This resolves the contradiction by enabling users to verify proper tensioning without requiring expert knowledge or complex manual assessment procedures.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces the manual mechanical assessment of seat belt tension (which requires user expertise and judgment) with an automated sensor-based system. The pressure sensor electronically detects the tension force and the controller automatically compares it against predetermined thresholds, substituting human judgment with objective mechanical measurement and electronic processing.

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

2Ease of operation

If an insufficient amount of tension is applied to the seat belt webbing when securing the child seat, then the installation process becomes easier, but the child seat may rotate more than desired during sudden stops compromising safety

Engineering Contradiction:
Improveinstallation processVSAvoidchild protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The feedback mechanism continuously monitors the tension level during installation and provides real-time guidance to the user. By displaying visual indicators that show whether tension is insufficient, adequate, or excessive, the system guides users to apply the correct amount of tension, preventing both under-tensioning (which compromises safety) and over-tensioning (which may damage components).

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary verification of tension adequacy before the child seat is considered fully installed. The pressure sensor detects tension levels during the installation process itself, allowing users to correct improper tensioning before finalizing the installation, thereby preventing safety compromises from the outset rather than detecting problems after installation is complete.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If no tension monitoring system is installed, then the device complexity remains low, but there is no way to verify if the seat belt webbing is tightened to sufficient tension

Engineering Contradiction:
Improvesystem simplicityVSAvoidtension verification
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs a pressure sensor that converts mechanical tension force into an electrical signal, which is then processed by a controller. This substitution of mechanical measurement with electronic sensing and processing enables precise tension verification while maintaining relative system simplicity through the use of standard off-the-shelf components and straightforward signal processing logic.

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

Solution Approach 2:

The patent introduces a pressure sensor as an intermediary element between the seat belt webbing and the user. This intermediary component indirectly measures the tension force by detecting the pressure exerted on it during tightening, converting this physical quantity into an electrical signal that can be easily processed and displayed, thereby enabling precise measurement without requiring direct complex measurement of the seat belt tension itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures that the child seat is securely fastened to the vehicle seat by alerting users when the seat belt webbing tension meets predetermined safety standards, thereby preventing unwanted rotation during sudden stops.

Implementation Method 1

a first pressure sensor fluidly communicating with the fluid in the first bladder. The first pressure sensor is configured to output a first signal indicative of an amount of pressure in the first bladder

Methodology Applied
Scientific EffectPressure measurement:

Data Source

PatentEP2072324B1Child seat and method for monitoring installation of the child seat
Publication Date: 2016.09.28 DELPHI TECHNOLOGIES INC
  • EP2072324B1 patent drawingFigure 1~3
  • EP2072324B1 patent drawingFigure 2~4
  • EP2072324B1 patent drawingFigure 5~7

AI summary

A child seat (20) and a method for monitoring installation of the child seat (20) are provided. The child seat (20) includes a child seat frame (40) configured to receive a child occupant. The child seat frame (40) is configured to receive a seat belt webbing (24) for securing the child seat frame (40) to a vehicle seat (22). The child seat (20) further includes a first bladder (44) configured to contact the seat belt webbing (24). The first bladder (44) has a fluid therein. The child seat (20) further includes a first pressure sensor (52) fluidly communicating with the fluid in the first bladder (44). The first pressure sensor (52) is configured to output a first signal indicative of an amount of pressure in the first bladder (44). The child seat (20) further includes a controller (56) coupled to the child seat frame (40) configured to receive the first signal and to compute a first tension value based on the first signal. The controller (56) is further configured to generate a second signal to induce a first device disposed on the child seat frame (40) to indicate when the first tension value is less than a first predetermined tension value.