UWB Tire Position Learning for Reliable TPMS at High Speed
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Solution Overview
Problem
Conventional tire pressure monitoring systems (TPMS) face challenges in accurately learning tire positions due to issues such as signal reflection and fading, and existing methods like LF initiator and Loc on Sync are either costly, complex, or prone to errors at high speeds.
Innovation Solution
The use of ultra-wide band (UWB) technology to learn tire positions in a TPMS, where tire module units transmit pressure information via UWB signals and vehicle module units calculate tire positions using distance information measured by UWB communication units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RF signals are used for wireless communication between TPMS WU and ECU, then wireless communication can be achieved, but signal reflection and fading occur causing communication reliability to deteriorate
Solution Approach 1:
The patent changes the communication parameter from traditional RF frequency to UWB (Ultra-Wideband) frequency range. UWB signals operate at extremely wide bandwidth with very low power spectral density, which allows them to penetrate obstacles and resist multipath fading effects that plague traditional RF communications. This parameter change in frequency spectrum utilization directly resolves the signal reflection and fading problems while maintaining wireless communication reliability.
2Measurement precision
If LF initiators are installed in four places in tire adjacent spaces to learn tire positions, then tire position learning can be achieved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes the LF initiator components from the system. Instead of requiring four separate LF initiators installed in tire adjacent spaces, the invention uses the existing UWB communication capability of the tire module units themselves to determine position. The tire module units transmit UWB signals that are received by multiple vehicle-mounted UWB communication units, eliminating the need for additional LF initiator hardware and simplifying the overall system architecture.
Solution Approach 2:
The patent makes the tire module units multi-functional by enabling them to perform both tire pressure monitoring and position determination using the same UWB transceiver. The tire module unit that originally only monitored pressure now also serves as a position beacon by transmitting UWB signals. This universality eliminates the need for separate LF initiators and reduces system complexity while maintaining position learning capability.
3Measurement precision
If Loc on Sync method is used for tire position learning, then tire position can be learned by phase information, but position learning mistakes occur at high speeds above 130 km/h
Solution Approach 1:
The patent replaces the mechanical/kinematic-based Loc on Sync method (which relies on wheel rotation phase and speed sensor data) with a wireless signal-based UWB time-of-flight measurement system. Instead of calculating position from wheel phase information that becomes inaccurate at high speeds, the system uses electromagnetic signal propagation time measurements which are not affected by vehicle speed. This substitution of measurement methodology eliminates speed-related position learning errors.
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 allows for accurate and efficient learning of tire positions, reducing errors and costs associated with conventional methods, while maintaining reliability even at high vehicle speeds.
Implementation Method 1
a plurality of tire module units mounted on a tire of the vehicle respectively so as to detect pressure information and transmit same via an ultra-wide band (UWB) signal
Implementation Method 2
a vehicle module unit operable to communicate with the plurality of tire module units via UWB signals so as to detect the individual tire pressures and any tire in a position where low pressure has occurred
Data Source
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AI summary
The present invention relates to a tire position learning apparatus for a tire pressure monitoring system, comprising: a plurality of tire module units each of which is respectively mounted on a tire of the vehicle so as to detect pressure information and transmit same via an ultra-wide band (UWB) signal; and a vehicle module unit which communicates with the plurality of tire module units via UWB signals so as to detect the individual tire pressures and any tire in a position where low pressure has occurred and notifies the user of same.