Tyre Pressure Estimation Using Wheel Speed and Slip Compensation
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Solution Overview
Problem
Existing direct-type tyre pressure monitoring systems are expensive and unsuitable for frequent tyre changes, while current indirect and hybrid systems may not accurately detect abnormal deflation conditions within the required time frame.
Innovation Solution
A method for estimating tyre pressure using an indirect or hybrid system that measures the angular velocity of wheels during rectilinear travel and accounts for slippage of drive wheels, allowing for reliable pressure estimation by calculating pressure ratios between tyres.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct measurement systems with pressure sensors on each tyre are used, then measurement precision and reliability are improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces direct mechanical pressure sensing with an indirect measurement approach using wheel angular velocity data from existing sensors. The system substitutes complex pressure measurement hardware with a computational model that infers pressure from rotational dynamics, thereby reducing device complexity while maintaining monitoring capability
Solution Approach 2:
The patent creates a virtual model of tyre pressure by copying and analyzing wheel rotation characteristics. Instead of directly measuring pressure, the system replicates the physical effects of pressure on wheel rotation and uses this copied behavior to estimate actual pressure values through comparison with reference models
2Device complexity
If indirect measurement systems using angular velocity are used, then device complexity is reduced, but measurement precision and reliability deteriorate
Solution Approach 1:
The patent implements feedback mechanisms where the estimated pressure values are continuously compared with reference models and adjustment factors are applied. The system uses feedback from wheel slip detection, road gradient information, and vehicle acceleration data to refine pressure estimates and compensate for sources of error in the indirect measurement approach
Solution Approach 2:
The patent dynamically changes multiple parameters including reference angular velocities, correction factors, and threshold values based on operating conditions such as vehicle speed, acceleration, and road gradient. By adapting these parameters in real-time, the system maintains measurement precision across varying operational contexts despite using indirect measurement
3Ease of manufacture
If hybrid systems with limited pressure sensors are used, then cost is reduced, but reliability in detecting abnormal deflation conditions deteriorates
Solution Approach 1:
The patent segments the vehicle's wheel set into monitored and unmonitored groups, applying different measurement strategies to each. Wheels with pressure sensors provide direct reference data, while wheels without sensors use indirect estimation enhanced by comparative analysis against the segmented reference group, improving overall system reliability
Solution Approach 2:
The patent performs preliminary calibration and establishes reference angular velocity profiles for each wheel under known pressure conditions before normal operation. This preliminary action creates a baseline that enables more reliable detection of abnormal deflation during actual vehicle operation, compensating for the limited number of active sensors
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 provides a cost-effective and efficient means of tyre pressure estimation, capable of detecting deflation conditions accurately and reliably, even in varying grip conditions and vehicle speeds.
Implementation Method 1
measuring a value representing an indirect index of the inflation pressure of a tyre of the vehicle, in this case the angular velocity of the wheels
Implementation Method 2
measuring a value representing an indirect index of the inflation pressure of a tyre of the vehicle, in this case the angular velocity of the wheels, and/or a quantity indicative of the slippage of the pair of tyres of the drive wheels on the ground
Data Source
AI summary
A method estimates tire pressure of vehicle. For each tire, signals or data indicative of angular velocity of the wheel with which the tire is associated are acquired. A subset of detected signals or data acquired in rectilinear vehicle travel condition is selected. Pressure relationship between tires of each pair of wheels of the same axle is determined by comparing the rolling radius of the wheel on which a first tire is mounted and the rolling radius of the wheel on which a second tire is mounted. A pressure relationship between tire pairs is determined for comparison between the mean value of the rolling radii of wheels of a first axle and the mean value of the rolling radii of wheels of a second axle. Ratios are calculated based on signals or data indicative of angular velocity of the wheels and on slippage of the drive wheels.