Vehicle Distance Estimation Using Offset Signal Phase Detection
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Solution Overview
Problem
Existing methods for estimating the distance between a vehicle and an identifier using electromagnetic signals are inefficient due to anisotropy problems and the need to reconfigure phase-locked loops for frequency changes, which is time-consuming.
Innovation Solution
A method that generates and transmits signals with distinct frequencies by combining a base signal with an offset signal, allowing for quick determination of reception phases and frequencies without reconfiguring the phase-locked loop, enabling rapid refinement of distance estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional distance evaluation techniques using high-frequency electromagnetic signals are used, then distance estimation can be performed, but measurement accuracy deteriorates due to anisotropy problems and reflected signals
Solution Approach 1:
The patent changes the frequency parameter of the electromagnetic signals used for distance estimation. By using lower frequency signals instead of conventional high-frequency signals (such as 2400 MHz Bluetooth), the method avoids anisotropy problems and reflected signal interference that plague high-frequency measurements, thereby improving measurement accuracy without requiring hardware reconfiguration
2Measurement precision
If phase-locked loop is reconfigured for frequency changes to measure signal phases, then distance estimation can be performed, but implementation time increases significantly
Solution Approach 1:
The patent performs preliminary action by pre-configuring the phase-locked loop to operate at the lower frequency before distance measurement begins. This eliminates the need for time-consuming reconfiguration when frequency changes are needed for different measurement conditions, allowing rapid successive measurements to be performed without the hundred-microsecond setup delay that plagues conventional approaches
Solution Approach 2:
The patent changes the operating frequency parameter of the phase-locked loop from conventional high frequencies to lower frequencies, and maintains this configuration. This parameter change allows the loop to operate more quickly and eliminates the need for frequent reconfiguration, thereby reducing implementation time while maintaining measurement accuracy
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 allows for quick and precise estimation of the distance between a vehicle and an identifier, reducing implementation time and improving measurement accuracy.
Implementation Method 1
a) elaboration and transmission, by a first of the wireless communication modules, of a first signal and of a second signal having respectively first and second distinct frequencies
Implementation Method 2
To implement this solution, it is possible to use a phase-locked loop (commonly called "PLL loop") in order to successively generate two signals of different frequencies
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a method for estimating a distance (d) separating a motor vehicle (10) equipped with a first wireless communication module (12) and an identifier (20) equipped with a second wireless communication module (22), comprising the following steps: a) development and transmission, by a first of the wireless communication modules, of a first signal and a second signal having respectively distinct first and second frequencies, b) reception, by at least the other of the wireless communication modules, of said first and second signals, c) determination of a first phase of reception of the first signal and a second phase of reception of the second signal, and d) estimation of said distance as a function of the first and second phases and of the first and second frequencies.According to the invention, in step a), said second signal is obtained on the basis of said first signal and a first offset signal, and, in step c), the second phase is determined on the basis of said second received signal and a second offset signal whose frequency is identical to that of said first offset signal.