Vehicle UWB Access Localization Using Transceiver Intersection
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Solution Overview
Problem
The use of ultra-wideband communication in vehicle function activation systems for hands-free access results in reduced location precision due to sensitivity to reflections and interference, leading to increased costs and potential failure in unlocking/locking functions.
Innovation Solution
A method and device utilizing at least two ultra-wideband transceivers located on either side of a vehicle opening element, capable of communicating with each other and a portable user appliance, to determine the location of the appliance by computing the intersection of a circle's perimeter and a distance from a second transceiver, thereby activating vehicle functions accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ultra-wideband communication is used for hands-free access, then the number of appliances is reduced and versatility is improved, but location precision deteriorates due to sensitivity to reflections and interference
Solution Approach 1:
The patent introduces a mediator (reference signal or intermediary transceiver) to help resolve the location determination problem. By using a reference signal transmitted between transceivers or an intermediary transceiver as a reference point, the system can distinguish between direct signals and reflected signals, thereby improving location precision while maintaining UWB compatibility with cell phones
2Measurement precision
If multiple ultra-wideband transceivers are deployed to improve location precision, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent uses a copying approach by transmitting reference signals between existing transceivers or using an intermediary transceiver as a virtual reference point. This allows the system to achieve the precision benefits of multiple transceivers without physically deploying additional hardware, thereby reducing device complexity and cost while maintaining location precision
3Adaptability or versatility
If ultra-wideband communication is used, then communication versatility is improved, but reliability deteriorates due to sensitivity to reflections and interference
Solution Approach 1:
The patent implements feedback mechanisms by having transceivers transmit reference signals and analyze received signals to detect the presence of portable appliances. The system uses the received signal strength indication (RSSI) and time of flight (ToF) measurements as feedback to reliably determine appliance presence and activate vehicle functions, thereby improving reliability while maintaining UWB versatility
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 approach enhances the precision and reliability of locating a portable appliance using ultra-wideband communication, reducing the need for multiple transceivers and associated costs, while ensuring consistent activation of vehicle functions.
Implementation Method 1
determining a time of flight of the waves
Implementation Method 2
receiving reflected waves originating from the portable appliance
Data Source
AI summary
A method for activating a vehicle function using an activation device, having at least two transceivers communicating with a portable user appliance and communicating with each other via ultra-wideband communication. The method includes: transmitting using a first transceiver; computing a radius of a circle centered around the first transceiver as a function of the time of flight of the waves reflected by the portable appliance, and determining a perimeter of the circle; comparing a profile of received reflected waves originating from the second transmitter with a predetermined received wave profile; detecting a presence as a function of the result of the comparison; computing, if a presence is detected, a distance between the second transceiver and the presence; locating the portable appliance by computing an intersection between the distance and the perimeter; and activating the vehicle function as a function of the location.