Magnetic Sensor for Vehicle Seat Rail Position Detection
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Solution Overview
Problem
Existing seat rail devices for vehicles lack an effective mechanism to detect the longitudinal position of the upper rail relative to the lower rail, which is crucial for preventing the deployment of airbags in certain seat positions to avoid endangerment, especially in vehicles with sliding seat bottoms.
Innovation Solution
A seat rail device with a sensor device that includes a sensor plate coupled to the lower rail and a seat position sensor on the upper rail, allowing for lateral movement to detect the sensor plate, enabling precise longitudinal position detection and preventing airbag deployment in unsafe positions through a three-point locking mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor device is added to detect the longitudinal position of the upper rail, then the safety and reliability of airbag deployment control is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces complex electronic position detection systems with a simple magnetic field-based sensor device. The sensor plate with magnetic elements interacts with a magnetic sensor to detect longitudinal position, substituting mechanical encoders or complex electronic sensors with a straightforward magnetic detection mechanism that is both reliable and relatively simple to implement
Solution Approach 2:
The sensor plate acts as an intermediary component between the upper rail and the magnetic sensor. It carries magnetic elements that generate a magnetic field detectable by the sensor, enabling indirect position detection without requiring direct mechanical connection or complex sensing infrastructure
2Measurement precision
If a sensor plate is coupled to the lower rail and sensor to the upper rail, then the measurement precision of longitudinal position is improved, but the device complexity increases
Solution Approach 1:
The sensor system is segmented into two separate components: a sensor plate mounted on the lower rail and a magnetic sensor mounted on the upper rail. This segmentation allows each component to be independently optimized and mounted, with the sensor plate providing a stable reference and the magnetic sensor providing precise position detection as the upper rail moves
Solution Approach 2:
The magnetic field pattern created by the sensor plate serves as a positional reference copy that the magnetic sensor reads to determine position. The sensor plate effectively creates a magnetic signature of its position relative to the upper rail, which the sensor detects and converts into positional information
3Ease of manufacture
If the seat position sensor moves laterally to detect the sensor plate, then the ease of manufacture and assembly is improved, but the stability under vibration may worsen
Solution Approach 1:
The sensor system is designed to accommodate lateral movement of the upper rail relative to the lower rail. The magnetic field interaction allows the sensor to detect position dynamically as the rail moves, maintaining detection capability throughout the full range of motion without requiring rigid fixed positioning
Solution Approach 2:
The magnetic sensor continuously detects the position of the sensor plate through magnetic field interaction, providing real-time feedback on the longitudinal position. This feedback mechanism maintains accuracy despite lateral movements or vibrations, as the sensor continuously adjusts its reading based on the current magnetic field configuration
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
The solution provides a secure, cost-effective, and vibration-free mounting system that ensures accurate detection of the upper rail's position, preventing airbag deployment in hazardous conditions and ensuring the stability and safety of the vehicle seat adjustment.
Implementation Method 1
a seat position sensor coupled to the upper rail and configured to move laterally in relation to the upper rail to detect the sensor plate
Data Source
AI summary
A vehicle seat adapted for use in a vehicle includes a seat rail device arranged to extend between the vehicle seat and a vehicle to mount the vehicle seat to the vehicle. The seat rail device includes a lower rail coupled to the floor of the vehicle in a fixed position, an upper rail coupled to the vehicle seat and configured to be adjustable along a longitudinal axis relative to the lower rail, and a sensor device configured to detect a least one longitudinal position of the upper rail relative to the lower rail.