Vehicle Identifier Distance Evaluation Using Dual Wireless Modules
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Solution Overview
Problem
Existing systems for evaluating the distance between a vehicle and an identifier require increasing the dimension and cost of low-frequency transmission modules to enhance range, which compromises precision.
Innovation Solution
The method estimates the distance between an identifier and a vehicle within an established wireless link without dedicated signal transmission, allowing for early detection of the user's arrival and precise distance evaluation when close, using a low-frequency transmission module with a short range and a Bluetooth Low Energy link.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the range of the low-frequency transmission module is increased to detect user arrival earlier, then the detection range is improved, but the size and cost of the transmission module increases
Solution Approach 1:
The patent divides the detection process into two distinct phases: a first phase using a low-frequency transmission module for close-proximity accurate distance measurement, and a second phase using a Bluetooth Low Energy communication module for long-range detection. This segmentation allows each module to operate in its optimal range without requiring either module to be oversized, thus resolving the contradiction between detection range and module size.
2Length of stationary object
If the range of the low-frequency transmission module is increased to detect user arrival earlier, then the detection range is improved, but the cost of the transmission module increases
Solution Approach 1:
The patent segments the detection functionality between two separate modules: a low-frequency transmission module for accurate close-range measurement and a Bluetooth Low Energy module for extended range detection. This avoids the need for a single expensive high-power low-frequency module, thereby reducing overall system cost while maintaining early detection capability.
Solution Approach 2:
The patent employs a Bluetooth Low Energy communication module that serves dual purposes: it enables long-range communication for early user detection and also provides a alternative distance estimation mechanism when the low-frequency module is not actively transmitting. This multi-functionality reduces the need for dedicated high-cost components.
3Measurement precision
If the low-frequency transmission module operates continuously to maintain detection capability, then the detection accuracy is improved, but the electrical consumption increases
Solution Approach 1:
The patent implements periodic activation of the low-frequency transmission module rather than continuous operation. The module is activated at specific intervals or triggered by proximity events, allowing the system to maintain measurement precision when needed while significantly reducing overall power consumption during idle periods.
Solution Approach 2:
The system uses the Bluetooth Low Energy module to perform preliminary detection at a distance, allowing the low-frequency transmission module to remain inactive until closer proximity is detected. This preliminary action by the low-power BLE module triggers the higher-power low-frequency module only when necessary, optimizing the balance between measurement precision and energy consumption.
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 enables early detection of the user's arrival without increasing the transmission module's dimensioning, maintaining precision in distance evaluation when the user is close, and reducing electrical consumption by adjusting the signal power based on user proximity.
Implementation Method 1
a low-frequency transmission module of the vehicle is expected to generate an electromagnetic signal (typically with a frequency below 150 kHz)
Implementation Method 2
The identifier also measures the signal strength generated by the low-frequency transmission module, allowing it to accurately assess the distance between the identifier and the vehicle (using a technique commonly known as RSSI, for 'Received Signal Strength Indication')
Data Source
Figure 1~3
Figure 2
AI summary
The invention relates to a method for evaluating the distance (d) between an identifier (20) fitted with a first wireless communication module (24) and a vehicle (10) fitted with a second wireless communication module (14), including the following steps: establishing a wireless connection (L) between the first wireless communication module (24) and the second wireless communication module (14); estimating said distance (d) on the basis of a propagation time of the electromagnetic signals involved in the wireless connection established (L); when the identifier (20) comes within the range of a signal (S) transmitted by the vehicle (10), evaluating said distance (d) by means of a measurement, by the identifier (20), of the strength of said transmitted signal (S). An associated electronic unit and identifier are also described.