Strain-Gauge External Door Handle for Deformation-Resilient Pull Detection
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Solution Overview
Problem
Existing door lock devices in motor vehicles can lose their ability to detect pull movements due to deformation of the handle, leading to the door becoming locked and unable to be unlocked.
Innovation Solution
A vehicle door handle with a pressure sensor that maintains a prestressed condition using a U-shaped blade to ensure accurate detection of push and pull actions, utilizing strain gauges to provide reliable pressure signals for controlling the lock mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pressure sensor is prestressed to detect pull movements, then the detection capability for pull actions is improved, but the system becomes vulnerable to deformation that can cause loss of prestress and failure of detection
Solution Approach 1:
Instead of making the handle rigid to maintain sensor prestress, the patent makes the handle deformable and uses this deformation to advantage. The sensor measures deformation relative to a rest position, and the system can compensate for permanent deformation by recalibrating the rest position, thereby converting a vulnerability into a functional feature.
Solution Approach 2:
The patent changes the reference parameter from a fixed prestress value to a dynamic rest position that can be recalibrated. The control device updates the rest position based on current sensor readings, allowing the system to adapt to permanent deformations and maintain accurate detection capability throughout the handle's service life.
2Stability of the object's composition
If the handle is made rigid to maintain sensor prestress, then measurement stability is improved, but the handle becomes vulnerable to permanent deformation from shocks that prevents future pull detection
Solution Approach 1:
Rather than preventing deformation through rigidity, the patent accepts deformation as inevitable and uses it to define a new rest position. The system inverts the problem by making the rest position adaptive rather than fixed, allowing the handle to remain flexible and shock-resistant while maintaining accurate sensor measurements.
Solution Approach 2:
The patent transitions from a static prestress model to a dynamic rest position model. The rest position is no longer a fixed mechanical state but a dynamically determined reference that updates based on current sensor readings, allowing the system to adapt to changing conditions including permanent deformations from shocks.
3Ease of manufacture
If the pressure sensor detects zero pressure at rest position, then calibration is simplified, but pull movements cannot be distinguished from the rest state after handle deformation
Solution Approach 1:
The system performs preliminary calibration to establish a non-zero rest position value before normal operation begins. This preliminary action sets a reference baseline that distinguishes rest state from pull movements, and this baseline can be updated as needed to account for permanent deformations.
Solution Approach 2:
The patent changes the calibration parameter from zero pressure at rest to a non-zero reference value. This parameter change allows the system to distinguish pull movements (which increase pressure from the reference) while still maintaining simple calibration procedures that establish the reference value during initial setup or after deformations.
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 reliable detection of handle movements, allowing the door to be unlocked even after handle deformation, maintaining functionality and user access.
Implementation Method 1
the pressure sensor comprises at least one strain gauge arranged at an end region of the flexible plate along a longitudinal axis of the plate
Data Source
Figure 1A~1B
Figure 2~4
Figure 5~7
AI summary
The present disclosure relates to a vehicle door handle (20) comprising: a handle body to be fixed to a vehicle door (10), the handle body being configured to be pushed by a user for setting a lock mechanism of the vehicle door to a locked state and pulled by the user for setting the lock mechanism to an un locked state, a pressure sensor disposed in the handle body for detecting push and pull actions of the user on the handle from a rest position of the handle, wherein the pressure sensor is arranged in the handle body to provide a pressure signal representative of a pressure applied to the handle body, the pressure signal being representative of a non-zero pressure value when the handle is in the rest position, the pressure value decreasing when the handle is submitted to a push action and increasing when the handle is submitted to a pull action.