Tire Pressure Monitoring Wear Load Detection via Centrifugal Acceleration
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Solution Overview
Problem
Existing tire pressure monitoring devices face significant energy challenges in accurately determining wheel rotation frequency and wear-relevant load due to the need for frequent high-frequency measurements, which is particularly problematic for battery-operated units.
Innovation Solution
The method involves determining the proportionality factor linking centrifugal acceleration to rotation frequency once and using it to calculate rotation frequency at longer intervals, reducing energy consumption by measuring centrifugal acceleration at intervals where it remains constant, allowing for significant energy savings while maintaining accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-frequency measurements (more than 100 measured values per second) are performed to accurately capture the sinusoidal signal component for rotational frequency determination, then measurement precision is improved, but energy consumption increases
Solution Approach 1:
The patent applies preliminary action by determining the proportionality factor between centrifugal acceleration and rotational frequency in advance during a calibration phase. This pre-determined factor is then used to calculate rotational frequency from single low-frequency acceleration measurements during normal operation, eliminating the need for continuous high-frequency measurements while maintaining accuracy.
Solution Approach 2:
The patent changes the measurement parameter from high-frequency acceleration sampling (required for direct sinusoidal analysis) to low-frequency centrifugal acceleration measurement combined with a pre-determined proportionality factor. This parameter transformation allows accurate rotational frequency determination at much lower measurement frequencies, significantly reducing energy consumption.
2Reliability
If continuous high-frequency measurement of centrifugal acceleration is performed to determine rotational frequency throughout the entire journey, then reliability of wear-relevant load detection is improved, but energy expenditure increases
Solution Approach 1:
The patent implements periodic action by performing high-frequency measurements only during brief calibration intervals to determine the proportionality factor, then switching to low-frequency periodic measurements using the stored factor for rotational frequency calculation. This dramatically reduces the duty cycle of high-power operations while maintaining detection reliability.
Solution Approach 2:
The calibration phase performs preliminary action by pre-determining the proportionality factor that relates centrifugal acceleration to rotational frequency. This pre-computed factor enables subsequent low-energy measurements to reliably determine rotational frequency and accumulate wear-relevant load data without continuous high-frequency sampling.
3Use of energy by moving object
If measurements are taken at longer intervals to reduce energy consumption, then energy efficiency is improved, but measurement precision may deteriorate
Solution Approach 1:
The patent transforms the measurement approach by changing from direct high-frequency sinusoidal signal analysis to low-frequency centrifugal acceleration measurement combined with a pre-determined proportionality factor. This parameter substitution allows accurate rotational frequency determination even at long measurement intervals, as the proportionality factor compensates for the reduced sampling rate.
Solution Approach 2:
The patent creates a copy of the relationship between centrifugal acceleration and rotational frequency in the form of a stored proportionality factor. This copied relationship allows the system to accurately determine rotational frequency from low-frequency acceleration measurements without needing to capture the full high-frequency sinusoidal signal, enabling long measurement intervals while maintaining precision.
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 efficient and accurate determination of wear-relevant load with reduced energy expenditure, allowing for longer measurement intervals and improved battery life in tire pressure monitoring systems.
Implementation Method 1
measuring the centrifugal acceleration at second time intervals Δt2 that are greater than the first time intervals Δt1
Implementation Method 2
The signal from an acceleration sensor in a tire pressure monitoring system mounted on a wheel has a sinusoidal component due to the acceleration due to gravity
Data Source
Figure 1
AI summary
A method is described for detecting a wear-relevant load on a vehicle wheel using a tire pressure monitoring unit mounted on the vehicle wheel, which contains at least one acceleration sensor, wherein a rotational frequency of the vehicle wheel is determined for a time interval from a series of measured values of the acceleration sensor at first time intervals, a centrifugal acceleration value is determined for the time interval, a proportionality factor is determined from the rotational frequency and the centrifugal acceleration value, which links the square of the rotational frequency to the centrifugal acceleration, then a rotational frequency of the wheel is continuously calculated from measured values of the centrifugal acceleration, which were determined at second time intervals that are larger than the first time intervals, and the proportionality factor.and a load value is calculated from the rotational frequency and the second time intervals, and these load values are continuously added together to form a total load.