Tire Tread Depth Estimation from TPMS Cooling Data
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Solution Overview
Problem
Existing methods for estimating tire tread depth are inadequate, particularly for fleet management, as they often require additional hardware and fail to provide real-time or accurate assessments of tire wear, leading to potential safety risks and unnecessary tire replacements due to irregular wear and improper inflation pressure.
Innovation Solution
A method utilizing thermal time constant relationships to estimate tread depth by monitoring tire pressure and temperature changes, especially during cooling periods, without requiring additional hardware, by correlating thermal mass with tire wear and using algorithms to predict tire wear and replacement times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing methods for estimating tire tread depth are used, then tire wear assessment can be provided, but additional hardware is required and real-time accurate assessment is not achieved
Solution Approach 1:
The patent enables existing tire pressure monitoring system (TPMS) sensors to perform dual functions: their original function of monitoring tire pressure and an additional function of estimating tread depth. The TPMS sensors continuously collect pressure and temperature data, and the system processes this existing data to calculate thermal time constants and estimate tread depth, eliminating the need for separate dedicated hardware for tread depth measurement.
Solution Approach 2:
The patent makes the TPMS sensors universal by enabling them to serve multiple purposes: tire pressure monitoring, temperature monitoring, and tread depth estimation. The system processes the same pressure and temperature data for multiple functions, including detecting inflation pressure anomalies, monitoring thermal patterns, and estimating remaining tread depth, thereby maximizing the utility of existing hardware infrastructure.
2Speed
If existing tread depth estimation methods are used, then wear assessment can be provided, but real-time monitoring capability is insufficient
Solution Approach 1:
The patent implements continuous monitoring by utilizing the ongoing pressure and temperature measurements already being taken by the TPMS sensors during normal tire operation. Instead of relying on periodic or offline measurements, the system continuously processes the thermal data to update tread depth estimates in real-time, providing continuous wear assessment without interrupting vehicle operation.
Solution Approach 2:
The system employs feedback mechanisms by continuously comparing measured pressure and temperature data against expected thermal patterns and models. The processed thermal time constant information feeds back into the tread depth estimation algorithm, allowing the system to adapt and refine estimates based on actual observed thermal behavior, thereby maintaining accuracy in real-time monitoring.
3Loss of information
If tire pressure and temperature monitoring is performed, then tread depth estimation can be achieved, but the system must process and analyze thermal data patterns
Solution Approach 1:
The patent extracts additional valuable information (tread depth data) from the existing pressure and temperature measurements taken by the TPMS sensors. Instead of treating the thermal data as merely auxiliary information for pressure monitoring, the system extracts the thermal time constant characteristics from this data and uses it as the basis for tread depth estimation, thereby gaining additional insights without requiring new sensors.
Solution Approach 2:
The patent transforms the existing pressure and temperature measurements into a different parameter domain by calculating thermal time constants. This parameter transformation converts raw sensor data into a new characteristic (thermal response time) that directly correlates with tread depth, enabling the system to derive tread wear information from standard TPMS data through mathematical transformation rather than direct measurement.
4Measurement precision
If thermal time constant analysis is used for tread depth estimation, then accurate wear assessment can be provided, but the system must monitor tire cooling periods specifically
Solution Approach 1:
The patent prepares for accurate tread depth estimation by continuously monitoring and storing pressure and temperature data during the tire's operational heating phase. This preliminary data collection during the heating period ensures that when the cooling phase occurs, the system already has the necessary thermal history data ready for immediate analysis, eliminating any delay in capturing the cooling curve information needed for accurate estimation.
Solution Approach 2:
The system is designed to periodically capture and analyze the thermal cooling cycles of the tire as they naturally occur during normal operation. By recognizing and analyzing each cooling period when the vehicle is stationary or decelerating, the system converts these periodic natural thermal cycles into repeated measurement opportunities, ensuring adequate data collection without requiring extended monitoring periods or artificial cooling conditions.
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
Provides accurate, real-time estimation of tire tread depth and wear, enabling timely maintenance alerts and reducing the risk of unsafe driving conditions by predicting tire replacement needs, thus optimizing fleet management and safety.
Implementation Method 1
focus on periods of time when the tire is at a standstill and is cooling down
Implementation Method 2
the thermal time constant is directly related to the mass of the tire, so that as the tire wears and loses mass, the thermal time constant will decrease
Data Source
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AI summary
Systems and methods are disclosed herein for estimating tread depth remaining on a tire mounted on a vehicle. One or more sensors are provided for detecting operational data associated with the vehicle and tire measurements corresponding to ambient temperature and contained air temperature, which may be directly measured or derived from measured tire pressure. A thermal mass of the tire is estimated based on at least the detected operational data and tire conditions, and a current tread depth of the tire is estimated based at least in part on the respective estimated thermal mass. In certain embodiments, the thermal mass estimation may be performed using heat transfer models limited to measurements captured during a cooling down phase of the tire while the vehicle is not moving, thereby simplifying calculation of a corresponding time constant.