Millimeter-Wave Tire Sensor for Inflation Height and Contact Patch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tire sensors face challenges such as low resolution, slow update rates, electronic interference, and increased manufacturing costs due to their placement inside or external to the tire, which limits their effectiveness in providing accurate data for modern vehicle control systems.
Innovation Solution
The integration of millimeter wavelength radar technology within the tire assembly to measure inflation height and contact patch, using a self-contained power source and processor to emit and receive radar waves, allowing for precise distance and velocity measurements, and communication of data to external systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are embedded in the tire casing, then the sensors can be permanently installed, but the tire manufacturing cost increases and sensor re-use is prevented
Solution Approach 1:
The sensor system is segmented into removable sensor units that can be independently installed and removed from the tire casing without permanent integration. The sensor housing with magnet assembly can be attached to the wheel assembly separately from the tire manufacturing process, allowing sensor re-use across multiple tires while maintaining stable installation during operation.
Solution Approach 2:
The sensor assembly is extracted from the tire casing interior and repositioned in the air chamber between the tire and wheel, allowing it to be mounted on the wheel rather than embedded in the tire. This extraction enables sensor removal and re-use while maintaining measurement functionality through the tire body.
2Loss of information
If optical sensors or ultrasonic sensors are used, then the sensors can detect tire conditions, but the resolution is low and update rates are slow
Solution Approach 1:
The patent replaces optical and ultrasonic sensing systems with millimeter wave radar technology. The radar system uses electromagnetic waves in the millimeter wavelength range to measure tire inflation height and contact patch dimensions, providing superior resolution and faster update rates compared to optical or ultrasonic methods while eliminating sensitivity to tire chamber environmental conditions.
3Loss of information
If ultrawideband radar sensor is used, then the sensor can sense tire conditions, but the data quality and refresh rates are deficient
Solution Approach 1:
The patent changes the radar frequency parameter from ultrawideband to millimeter wave frequencies (30-300 GHz), specifically utilizing frequencies above 100 GHz. This parameter change provides shorter wavelengths that improve measurement resolution for tire inflation height and contact patch dimensions while maintaining the ability to sense through the tire structure and providing faster data refresh rates.
4Ease of manufacture
If sensors are placed external to the tire air chamber, then the sensors can be installed without modifying the tire, but the sensing effectiveness is reduced and information quality is limited
Solution Approach 1:
The patent positions the sensor in a third spatial dimension within the air chamber between the tire and wheel, rather than embedding it in the tire or mounting it externally on the vehicle body. This dimensional placement allows the sensor to sense through the tire wall from the interior, maintaining high sensing effectiveness while enabling easy installation by simply placing the sensor in the air chamber without tire modification.
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 solution provides accurate, high-resolution data on tire inflation height and contact patch dimensions, enabling improved vehicle control systems with reduced manufacturing costs and enhanced performance.
Implementation Method 1
The radar source can be operable to emit millimeter wavelength radar waves into the annular tire chamber toward a target area along the inner surface of the tire body
Implementation Method 2
A radar receptor can be communicatively coupled with the electrical power source and operable to receive millimeter wavelength radar waves reflected off of the target area along the inner surface of the tire body
Implementation Method 3
The processor can be operable to determine a distance between the radar source and the target area based on at least one of: (i) a time of flight required for the radar waves to travel from the radar source to the target area and then to the radar receptor
Implementation Method 4
a frequency phase shift between the radar waves transmitted by the radar source and the radar waves reflected from the target area and received by the radar receptor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A tire assembly (T; T') includes a tire (TR) and a tire height and contact patch sensor (100; 100') at least partially disposed within a tire chamber (C) of the tire (TR). The sensor (100; 100) includes a radar source (160) operable to direct millimeter wave radar waves in the range of 120 to 240 gigahertz (GHz) toward an inner surface (ISF) of the tire (TR). The sensor (100; 100') also includes a radar receptor (170) operable to generate a signal upon receiving the reflected radar waves. A processor (106; 106'; 136; 136'; 112; 112') is operable to determine a distance between the radar source (160) and a target (TG) based upon at least one of: (i) a time of flight; (ii) a frequency phase shift. The sensor (100; 100') includes an antenna (104; 104') for transmitting data to a system external to the tire chamber (C). The processor (106; 106'; 136; 136'; 112; 112') optionally determines dimensions of the tire contact patch (CP; CP') and/or can generate an image of the tire contact patch (CP; CP') for image pattern matching to determine inflation and/or load state of the tire (TR).