Tire Pressure Sensor Correction via Acceleration Compensation
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Solution Overview
Problem
Pressure sensors in tire pressure monitoring systems (TPMS) are sensitive to acceleration, leading to measurement errors due to variations caused by vehicle speed, which affect the accuracy of tire pressure readings during driving.
Innovation Solution
A method that generates a library of ratios between pressure sensor and temperature sensor measurements at different speeds, defines a variation law to account for acceleration, and corrects pressure measurements using this law to minimize errors caused by sensor sensitivity to acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure sensors are used in tire pressure monitoring systems, then tire pressure can be measured directly in the cavity, but measurement errors occur due to sensor sensitivity to acceleration during vehicle operation
Solution Approach 1:
The patent introduces an intermediary correction method that uses temperature sensor data and acceleration compensation algorithms to mediate between the raw pressure sensor output and the actual tire pressure. The correction term K(Tp, v) acts as a mediator that accounts for acceleration effects based on temperature and vehicle speed, thereby isolating the true pressure measurement from acceleration-induced errors.
Solution Approach 2:
The patent changes the parameters used for pressure measurement by introducing a correction term that depends on temperature (Tp) and vehicle speed (v) parameters. Instead of using raw pressure sensor output directly, the system transforms the measurement by applying a correction factor Pcor = K(Tp, v) × Pm, where the correction term varies based on temperature and speed parameters to compensate for acceleration effects.
2Reliability
If pressure sensors have high sensitivity to acceleration, then they can detect pressure changes, but this same sensitivity causes measurement errors during vehicle motion
Solution Approach 1:
The patent converts the harmful acceleration sensitivity into a beneficial feature by using it to detect wheel rotation and vehicle speed. The same acceleration sensitivity that causes measurement errors is repurposed to determine wheel rotational speed, which then becomes a parameter for applying the appropriate correction factor. The acceleration signal is transformed from a source of error into a useful diagnostic parameter for speed-based compensation.
Solution Approach 2:
The patent implements a feedback mechanism where the measured acceleration (converted to speed information) is fed back into the pressure measurement system to generate a correction term. The correction factor K(Tp, v) is continuously updated based on feedback from temperature and speed sensors, creating a closed-loop system that dynamically compensates for acceleration effects and maintains accurate pressure readings during vehicle operation.
3Measurement precision
If a correction method using temperature and speed parameters is implemented, then measurement errors are reduced, but system complexity increases
Solution Approach 1:
The patent makes the temperature sensor serve multiple functions: it monitors tire temperature for thermal management and simultaneously provides a parameter for the acceleration correction calculation. The vehicle speed parameter also serves dual purposes by being used for speed monitoring and as a correction factor input. This multi-functionality reduces the need for additional dedicated sensors and simplifies the overall system architecture.
Solution Approach 2:
The system uses its own existing sensors (temperature sensor and speed information from the vehicle's communication bus) to generate the correction term, rather than requiring external or additional dedicated correction sensors. The pressure monitoring system serves itself by utilizing data already available within the vehicle's sensor network, thereby avoiding increased hardware complexity while achieving improved measurement accuracy.
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
The method effectively reduces measurement errors by accurately estimating and correcting for acceleration-induced variations, improving the precision of tire pressure readings during vehicle operation.
Implementation Method 1
Pressure sensors generally have a sensitivity that is dependent on acceleration, i.e. the signal output from the sensor is representative of both of two variables: the pressure in the cavity of the tire and the acceleration of the pressure sensor.
Implementation Method 2
The system incorporated into the cavity of the tire may comprise other sensors, such as a temperature sensor and/or an accelerometer.
Implementation Method 3
The acceleration of the pressure sensor is obtained in step c) with an accelerometer arranged in the tire.
Data Source
AI summary
A method for determining the pressure of a tire of a vehicle being driven at a speed, the tire comprising, arranged in the tire, a pressure sensor and a temperature sensor. The method includes generating a library of ratios between a measurement of the output of the pressure sensor and a measurement of the output of the temperature sensor, the one or more ratios being calculated at different speeds and one ratio being measured at a speed of zero, defining a variation law representative of the variation in the ratios with respect to the acceleration experienced by the pressure sensor, measuring the output of the pressure sensor and the output of the temperature sensor, and obtaining the value of the acceleration experienced by the pressure sensor, and determining the pressure by correcting this measurement with the variation law.