Tire Sensor Auto-Location Using Footprint Length Comparison
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Solution Overview
Problem
Existing tire monitoring systems face challenges in accurately and economically identifying the location of a tire on a vehicle, particularly due to tire replacement, rotation, and changes between summer and winter tires, which alter the tire positions and complicate signal auto-location or localization.
Innovation Solution
The system employs tire sensor units with footprint length measurement sensors to determine the position of each tire by measuring the footprint length and using a processor to calculate mean footprint lengths, compare them, and determine the tire positions based on load distribution principles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If prior art techniques (low frequency transmitters, two-axis acceleration sensors, RF signal strength methods) are used for tire location identification, then tire position can be determined, but the system becomes expensive, inaccurate, complex, and/or difficult to execute
Solution Approach 1:
The patent extracts and utilizes only the necessary functional components from complex prior art systems. Instead of implementing full acceleration sensors or RF signal strength analysis systems, it extracts the essential measurement need (tire position identification) and solves it through a simpler footprint length measurement approach that requires minimal additional hardware beyond the basic pressure sensor.
Solution Approach 2:
The patent employs inexpensive footprint length measurement capabilities that are already integrated into standard TPMS sensors, rather than deploying expensive specialized equipment like low frequency transmitters or complex acceleration sensor arrays. This approach uses readily available, cost-effective measurement functions to achieve location identification.
2Measurement precision
If frequent sensor communications and auto-location are implemented, then tire position identification improves, but power consumption increases making it impractical
Solution Approach 1:
The patent implements auto-location functionality that operates periodically or on-demand rather than continuously. The system determines tire positions by comparing footprint lengths at appropriate intervals, allowing the sensor to remain in low-power mode between measurements and transmissions, thus reducing overall power consumption while maintaining location identification capability.
Solution Approach 2:
The system uses existing sensor data (footprint length measurements already being taken for pressure monitoring) to simultaneously determine tire position without requiring separate dedicated measurement systems. This self-service approach leverages available data to achieve location identification without additional power expenditure on specialized sensors or continuous transmission.
3Adaptability or versatility
If tire replacement, rotation, and seasonal changes are accommodated, then system adaptability improves, but location identification accuracy deteriorates
Solution Approach 1:
The patent implements a dynamic reference system where the mean footprint length is continuously updated based on measurements from all tires. When tires are replaced, rotated, or changed seasonally, the system adapts by recalculating the reference mean from the new set of tires, allowing it to maintain accurate location identification despite changes in the tire population.
Solution Approach 2:
The system changes its reference parameter (mean footprint length) based on the current tire population. By dynamically adjusting the reference mean footprint length to match the actual tires installed on the vehicle, the system maintains accurate location identification even when tires are replaced, rotated, or changed between summer and winter sets.
Data Source
AI summary
An auto-location system includes a first tire sensor unit that measures a footprint length of a first tire. A second tire sensor unit measures a footprint length of a second tire. A vehicle status determination module receives the measured footprint lengths and determines when the vehicle is in a static or cruising state. A mean calculation module receives the measured footprint lengths when the vehicle is in a static or cruising state, and determines a first mean footprint length corresponding to the first sensor unit and a second mean footprint length corresponding to the second sensor unit. A comparison module receives the mean footprint lengths and determines a longest and a shortest of the mean footprint lengths. A position determination module generates a position determination of the first sensor unit and the second sensor unit based on the longest and the shortest of the mean footprint lengths.