UHF Locating Device Attenuation Module for Hands-Free Vehicle Access
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Solution Overview
Problem
The existing 'hands-free' access systems for automotive vehicles using RF/LF waves struggle to precisely locate mobile devices at short distances, such as when starting the vehicle, due to the imprecise RSSI measurements of Bluetooth signals, which have a long communication range but lack precision for detection near the vehicle.
Innovation Solution
The ultra high frequency locating device employs a Bluetooth transceiver with attenuation modules and switching means to control impedance, allowing for precise location of mobile devices from a few centimeters to multiple meters around the vehicle by defining multiple UHF wave transmission areas with varying ranges, enabling detection and authorization for 'hands-free' starting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If Bluetooth communication standard is used for hands-free access, then communication range is extended to approximately 250m, but measurement precision of device location deteriorates due to imprecise RSSI measurements
Solution Approach 1:
The patent divides the monitoring space into multiple zones (first zone at 1-3 meters, second zone at 3-5 meters, third zone beyond 5 meters) based on signal strength thresholds. This segmentation allows the system to achieve precise location measurement by determining which zone the device is in, rather than attempting continuous precise distance measurement across the entire 250m range.
Solution Approach 2:
The patent combines multiple detection methods: RSSI-based zone detection for远距离 detection, and optical sensor detection for close-range verification. This composite approach leverages the long range of Bluetooth while compensating for its imprecision using optical sensors when the device enters the close-proximity zones.
2Quantity of substance
If RSSI measurement is used for location detection, then device presence can be detected at long distances, but detection precision at short distances (tens of centimeters) deteriorates
Solution Approach 1:
The patent creates multiple detection zones with different thresholds: first zone (1-3m) requiring signal strength above first threshold, second zone (3-5m) requiring signal above second threshold, and third zone (beyond 5m) requiring signal above third threshold. This enables precise short-distance detection by using the combination of zone detection and optical sensor verification.
Solution Approach 2:
The patent introduces optical sensors as an intermediary detection mechanism. When the Bluetooth signal indicates the device is in the first or second zone (close proximity), the optical sensors act as mediators to provide additional verification of device presence, ensuring accurate short-distance detection for starting authorization.
3Measurement precision
If multiple attenuation modules are added to define multiple UHF wave transmission areas, then location precision is improved, but device complexity increases
Solution Approach 1:
The patent uses dynamic switching between different attenuation modules based on detected signal strength. The system automatically selects the appropriate attenuation module (first, second, or third) to create the optimal detection zone, rather than using a fixed configuration. This dynamic adaptation achieves precise location measurement without requiring all modules to be active simultaneously.
Solution Approach 2:
The patent changes the attenuation parameter of the UHF waves by selecting different attenuation modules with different attenuation values. This parameter change allows the system to adapt the detection range and precision according to the situation, achieving accurate location measurement across different distances without increasing overall system complexity.
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 solution allows for accurate detection of mobile devices via Bluetooth, enabling 'hands-free' starting by defining specific areas around and inside the vehicle, overcoming the limitations of prior art by adjusting the UHF wave range for precise localization.
Implementation Method 1
at least one attenuation module (M1, M2, M3) connected in series between said transceiver (10') and said antenna (A')
Data Source
AI summary
A method for locating, via ultra high frequency, a mobile device (T) for “hands-free” access to a vehicle (V), via a locating device (D′) on board the vehicle (V), the locating device (D′) including an ultra high frequency transceiver (10′), an electrical power supply source (Vcc) and an antenna (A′), the locating method being noteworthy in that the transceiver (10′) is disconnected from the antenna (A′), and that the transceiver (10′) is connected to an attenuation module (M1, M2, M3) located at a predetermined distance (L1, L2, L3) from the transceiver (10′) and including an impedance (Z1, Z2, Z3) of predetermined value connected to ground, the predetermined distance (L1, L2, L3) between the transceiver (10′) and the attenuation module (M1, M2, M3) and the predetermined value of the impedance (Z1, Z2, Z3) defining an area (A1, A2, A3) for locating the mobile device (T) around the vehicle (V).