Pneumatic Tyre Load Estimation Using Normalized Acceleration Signals
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Solution Overview
Problem
Existing measurement methods for determining static load on a mounted assembly, such as a tire, are prone to noise interference from rotation and external forces, making it difficult to accurately extract useful information from measurement signals.
Innovation Solution
A method involving a sensor on the tire casing to generate signals sensitive to normal acceleration, normalized using a reference speed function, angularly resampled, and analyzed for energy density or spectral quantities to determine tire deformation, which is then linked to the applied load using bijective functions, accounting for inflation pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor is used to measure fine quantities on a rotating mounted assembly, then measurement sensitivity is improved, but measurement precision deteriorates due to noise from rotation and external forces
Solution Approach 1:
The patent segments the measurement signal into different frequency components using spectral analysis. By identifying and isolating the frequency component corresponding to the rotation frequency, the system can extract useful information while filtering out noise from other frequency ranges. This segmentation in the frequency domain allows selective processing of relevant signals.
Solution Approach 2:
The patent introduces an intermediary processing system that includes a processor executing specific algorithms. This intermediary system acts as a mediator between the raw sensor signals and the final measurement results, applying signal processing techniques to eliminate noise and extract meaningful data from the contaminated signals.
2Measurement precision
If signal processing is applied to remove noise and external force interference, then measurement accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent applies partial action by focusing signal processing efforts only on specific frequency components relevant to the measurement. Instead of processing the entire signal spectrum, the system identifies and processes only the frequency band containing the useful information, reducing computational load while maintaining accuracy.
Solution Approach 2:
The patent transforms the signal from the time domain to the frequency domain using spectral analysis. This parameter change in the representation domain allows for more efficient noise filtering and feature extraction, as noise and useful signals occupy different frequency regions that can be separated through spectral processing.
3Reliability
If multiple processing steps are applied to the measurement signal, then reliability of load determination is improved, but processing time increases
Solution Approach 1:
The patent performs preliminary spectral analysis and frequency identification early in the processing chain. By pre-identifying the relevant frequency components and noise characteristics, subsequent processing steps can be optimized and streamlined, reducing overall processing time while maintaining reliability.
Solution Approach 2:
The patent implements continuous signal processing where the measurement and processing operations run continuously without interruption. This continuous action allows for real-time noise filtering and load determination, maintaining reliability while minimizing delays that would occur with batch processing or repeated start-stop operations.
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 method provides accurate, precise, and efficient determination of static load on a mounted assembly by filtering out noise and external interference, reducing computational resources, and maintaining accuracy across varying conditions.
Implementation Method 1
Fixing at least one sensor on the tire casing at the top of the tire casing capable of generating at least one output signal sensitive to acceleration in the direction normal to the top experienced by said sensor in the tire casing
Data Source
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AI summary
Disclosed is a method for ascertaining the load applied to a pneumatic tyre, the method comprising the following steps: – fastening a sensor to the tyre so as to generate an acceleration relative to a line normal to the crown; – acquiring (201) a temporal signal SigTDR (101) including the amplitude of the acceleration while rolling; – determining a speed Wreference (202) associated with a portion of the signal SigTDR; – normalising (203) the portion of the signal SigTDR by a magnitude that is a function F proportional to the square of Wreference; – angularly re-sampling (204) the portion of the signal SigTDR; – defining (205) an energy density S, by means of a threshold A or a spectral magnitude ß, by spectral analysis on the basis of the resampled normalized signal SigTDR; – identifying (206) the deformation Def% as a function G of S or of ß; – identifying (207) the load Z by the function H of Def%.