Capacitive Occupant Sensor Testing via Variable Electrostatic Simulation
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Solution Overview
Problem
Existing methods cannot effectively test whether a capacitive occupant detection sensor operates normally, as they cannot simulate the electrostatic capacity of an occupant, making it difficult to differentiate between a person and an infant on a child restraint system.
Innovation Solution
A testing apparatus and method that includes an electrically-conductive seat ground, an electrode plate, multiple capacitors of different electrostatic capacities, and a switch mechanism to simulate occupant scenarios, determining if the sensor's signal corresponds to the selected capacitor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a weight-type sensor testing method is used, then the testing is simple and based on weight measurement, but it cannot test capacitive sensors that detect occupants based on electrostatic capacity change
Solution Approach 1:
The patent changes the testing parameter from weight to electrostatic capacity. Instead of using weight-based simulation, the invention uses capacitors with different electrostatic capacities to simulate different occupant types (adult, child, infant on CRS). This allows the testing apparatus to be adapted for capacitive sensors while maintaining a relatively simple structure through electrical parameter variation rather than physical reconstruction.
Solution Approach 2:
The patent creates electrical copies of occupant characteristics using capacitors. Rather than physically replicating human bodies or using actual occupants for testing, the invention uses capacitor elements that copy the electrostatic capacity properties of different occupant types. This enables realistic sensor testing without the complexity of physical simulation apparatus.
2Measurement precision
If actual persons or child restraint systems are used for testing, then accurate electrostatic capacity simulation is achieved, but the testing becomes complicated and difficult to operate
Solution Approach 1:
The patent extracts the essential testing function from complex physical setups. Instead of using actual persons or child restraint systems, the invention extracts only the critical parameter (electrostatic capacity) and uses simple capacitor elements to represent different occupant types. This separation allows accurate electrical measurement while eliminating the operational complexity of managing physical test subjects and restraint systems.
Solution Approach 2:
The patent introduces capacitor elements as intermediary components between the testing apparatus and the sensor being tested. These capacitors serve as mediators that provide accurate electrostatic capacity values without requiring actual occupants. The switch mechanism acts as another intermediary, enabling easy selection between different capacitor values to represent different occupant scenarios, thereby simplifying operation while maintaining measurement accuracy.
3Adaptability or versatility
If multiple capacitors with different electrostatic capacities are used, then different occupant scenarios can be simulated, but the device complexity increases
Solution Approach 1:
The patent creates a universal testing apparatus that can handle multiple occupant scenarios through a single integrated system. The switch mechanism provides multi-functionality by enabling selection among different capacitor values, allowing the same apparatus to test various sensor response conditions (adult present, child present, infant on CRS, etc.). This universal design achieves high adaptability without proportionally increasing overall device complexity, as all capacitors share common connection infrastructure.
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 simple and accurate testing of capacitive occupant detection sensors by simulating different occupant scenarios, ensuring the sensor operates correctly for both adults and infants on child restraint systems.
Implementation Method 1
a plurality of capacitors that is electrically connected between the electrode plate and the ground, and is different in electrostatic capacity from each other
Data Source
AI summary
A testing apparatus for testing whether an occupant detection sensor normally operates is disclosed. The testing apparatus includes: a ground that is an electrically-conductive structural member of the seat; an electrode plate that is electrically-conductive and is on the seat at a time of testing; multiple capacitors that are electrically connected between the electrode plate and the ground and are different in electrostatic capacity from each other; a switch mechanism that selects and switches one capacitor of the multiple capacitors; and a determination result check portion that determines, while switching the one capacitor by the switch mechanism, whether a signal outputted from the occupant detection sensor is a determination result corresponding to the switched one capacitor.