TPMS Transmitter Engine Operation Detection via Low-Frequency Noise
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Solution Overview
Problem
Existing tire pressure monitoring systems (TPMS) rely on high-power consumption acceleration sensors to determine vehicle movement, which reduces battery life and increases costs and weight, and are not independent of engine operation detection.
Innovation Solution
A low-frequency stage with switchable capacitors and resistors in the TPMS transmitter, coupled with signal processing means, allows for detection of engine operation by analyzing low-frequency noise patterns, eliminating the need for an acceleration sensor and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an acceleration sensor is used to determine vehicle movement, then the vehicle movement detection accuracy is improved, but the power consumption increases and battery life decreases
Solution Approach 1:
The patent extracts and removes the acceleration sensor from the TPMS system, replacing it with an engine operation detection mechanism that uses the existing low-frequency stage and antenna to detect engine noise patterns. This eliminates the high-power component while maintaining movement detection capability through engine status monitoring.
Solution Approach 2:
The system uses the existing low-frequency stage and antenna, which were originally designed for communication purposes, to also perform engine operation detection. By repurposing these existing components to detect engine noise patterns, the system avoids adding new high-power components and leverages available hardware for multiple functions.
2Measurement precision
If an acceleration sensor is used to determine vehicle movement, then the vehicle movement detection accuracy is improved, but the system cost and weight increase
Solution Approach 1:
The low-frequency stage and antenna are designed to serve multiple functions: original communication purposes and engine operation detection. By making these components multi-functional, the patent avoids adding separate dedicated sensors, thereby reducing system weight, cost, and complexity while maintaining detection accuracy.
Solution Approach 2:
The acceleration sensor is removed from the system and replaced with a software-based engine operation detection algorithm that runs on the existing low-frequency stage processing unit. This extraction eliminates the need for additional hardware components, reducing weight and cost.
3Reliability
If the TPMS transmitter continuously transmits RF signals, then the data link reliability is improved, but the battery life decreases
Solution Approach 1:
The TPMS transmitter uses periodic RF transmission during driving mode rather than continuous transmission. The system activates periodic communication when engine operation is detected, maintaining data link reliability while significantly reducing overall power consumption and extending battery life compared to continuous transmission.
Solution Approach 2:
The system dynamically adjusts its transmission behavior based on detected engine operation status. When the engine is running, the system activates periodic RF transmission to maintain reliable data links. When the engine is off, transmission is reduced or stopped, optimizing battery life based on real-time operational conditions.
Data Source
AI summary
A system for detecting the operation of the motor or engine of a motor vehicle equipped with at least one tire-pressure-monitoring-system transmitter including: a low-frequency stage including a resonant stage connected in series with an antenna, a processing stage, a first switch and a second switch, the first switch being connected to at least two capacitors so as to control the parallel connection of at least one of the capacitors, the second switch being connected to at least two resistors so as to control the parallel connection of at least one of the resistors, outputs of the low-frequency stage being arranged to receive input from the processing stage, in order to transfer the perceived signal to a processor of the signal, which is configured to compare the level of the perceived signal to a preset threshold level.