Tire Deformation Measurement Using Speed-Normalized Acceleration
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Solution Overview
Problem
Existing measurement systems for tire deformation are disturbed by external forces and noise during tire rotation, making it difficult to accurately collect clean measurement signals for deformation analysis.
Innovation Solution
A method involving fixing a sensor on the tire casing to capture acceleration signals, normalizing them using a reference speed function, angularly resampling, and defining energy densities to isolate tire deformation, while correcting for Earth's gravity and filtering noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor is fixed on the tire casing to measure acceleration during rolling, then deformation measurement capability is improved, but measurement precision deteriorates due to noise from rotation and external forces
Solution Approach 1:
The measurement signal is segmented by delimiting it over a specific number of tire revolutions (N_TDR). This segmentation allows the system to isolate deformation-related signals from noise by analyzing periodic patterns across multiple rotation cycles, thereby improving measurement precision despite the presence of rotational noise and external forces.
Solution Approach 2:
A reference speed function is introduced as an intermediary element to normalize the acceleration signal. By dividing the measured acceleration by the square of the reference speed (F(W) = W²), the system compensates for speed-dependent variations and external force influences, extracting pure deformation information from the noisy measurement signal.
2Adaptability or versatility
If acceleration signals are normalized using a reference speed function, then invariance to rotation speed is improved, but device complexity increases due to additional processing steps
Solution Approach 1:
The reference speed function transforms the acceleration signal by applying a mathematical transformation (division by W²). This parameter change approach allows the system to achieve invariance to rotation speed through a simple computational operation, avoiding the need for complex mechanical or electronic compensation mechanisms.
3Measurement precision
If the measurement signal is cleaned of disturbances, then deformation analysis accuracy is improved, but loss of information increases due to filtering out potentially useful signals
Solution Approach 1:
The signal processing steps (delimiting over N_TDR revolutions, normalizing by reference speed function, and angular resampling) are applied as preliminary actions before deformation analysis. This preliminary cleaning removes known disturbance patterns while preserving deformation information, as the processing is designed based on prior knowledge of noise characteristics and deformation signal patterns.
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, noise-free deformation measurements of the tire casing, invariant to rotation speed, enabling precise tire deformation analysis under 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
Implementation Method 2
correcting the first signal by subtracting an effect of Earth's gravity from the first signal
Data Source
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AI summary
Disclosed is a method for ascertaining the deformation of a tyre, the method comprising the following steps: – fastening an accelerometric sensor, which is capable of generating a signal representative of acceleration in a direction normal to the crown, to the tyre; – acquiring (201) a temporal wheel rotation signal SigTDR (101) comprising the amplitude of the acceleration while rolling; – determining a reference speed Wreference (202) associated with a portion of the wheel rotation signal SigTDR; – normalising (203) the portion of the wheel rotation signal SigTDR by a magnitude that is a function F proportional to the square of Wreference; – angularly resampling (204) the portion of the wheel rotation signal SigTDR; – defining an energy density S (205) on the basis of the normalised and angularly resampled wheel rotation signal SigTdR using a threshold A; – identifying the deformation of the tyre Def% (206) as a function G of the energy density S.