TPMS Motion Detection Using Dual-Axis Acceleration Change
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tire pressure monitoring systems (TPMS) face challenges in accurately determining a vehicle's motion status to optimize power consumption, as they struggle to differentiate between motion and rest states, especially at low speeds, due to errors in accelerometer detection and the need for precise threshold settings.
Innovation Solution
A method using a dual-axis accelerometer to detect centrifugal and tangential acceleration values, determining the vehicle's motion status by comparing maximum acceleration change values in perpendicular axial directions, allowing the system to adjust power consumption based on the vehicle's state, without requiring direct correspondence to acceleration directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the TPMS operates in normal working mode to collect and send tire pressure data, then the data transmission reliability is improved, but the power consumption increases significantly
Solution Approach 1:
The TPMS alternates between normal working mode and sleep mode based on vehicle motion status. During normal operation, data is collected and transmitted reliably. When the vehicle is stationary, the system enters sleep mode to reduce power consumption, periodically waking to check acceleration values and determine whether to return to normal operation.
Solution Approach 2:
The system dynamically adjusts its operating mode based on real-time vehicle motion status detection. The controller monitors acceleration values from the accelerometer and transitions between normal and sleep modes accordingly, optimizing the balance between data transmission reliability and power consumption based on current operational conditions.
2Use of energy by moving object
If the TPMS enters sleep mode to reduce power consumption, then the power saving is improved, but the response time to detect motion status changes worsens
Solution Approach 1:
The system performs preliminary checks of acceleration values even during sleep mode to detect vehicle motion status changes. By continuously monitoring acceleration data at low power, the system can quickly transition back to normal operation when motion is detected, minimizing the response time penalty associated with sleep mode operation.
3Device complexity
If the accelerometer uses a single axial direction for motion detection, then the device complexity is reduced, but the measurement precision of motion status deteriorates
Solution Approach 1:
The system transitions from single-axis to dual-axis acceleration monitoring by incorporating both first axial direction values and second axial direction values. This dimensional expansion enables more accurate differentiation between vehicle motion and stationary states, particularly in distinguishing true motion from road surface variations, without significantly increasing overall system complexity.
4Ease of operation
If the system sets a fixed threshold for acceleration values to determine motion status, then the ease of operation is improved, but the reliability of motion status determination worsens due to accelerometer errors
Solution Approach 1:
The system dynamically adjusts the threshold for motion detection based on the vehicle's operational state. Different threshold criteria are applied depending on whether the vehicle is moving or stationary, allowing the system to maintain high reliability across different operating conditions while keeping the operation relatively simple through automated threshold selection.
Solution Approach 2:
The system changes the evaluation parameters for motion detection based on the current state. For moving vehicles, one set of acceleration criteria is used, while for stationary vehicles, a different set of criteria based on maximum acceleration change values is applied. This parameter adaptation maintains reliability across different operating conditions.
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 reduces power consumption by accurately determining vehicle motion or rest states, enabling efficient operation of TPMS, including transitioning to a sleep mode when stationary, without the need for precise accelerometer accuracy or threshold settings.
Implementation Method 1
obtaining N acceleration values in a first axial direction collected from N times sampling within a preset time period through an accelerometer mounted on a wheel
Data Source
AI summary
The present disclosure provides a method for monitoring a motion status of a vehicle, a related chip, and a system. The method includes: obtaining N acceleration values in a first axial direction collected from N times sampling and a maximum acceleration change value within a preset time period; and obtaining N acceleration values in a second axial direction collected from N times sampling and a maximum acceleration change value within the preset time period; determining whether the vehicle is in motion or in a first stationary state based on the acceleration values in the first and second axial direction; and in response to the vehicle being in the first stationary state, further determining whether the vehicle is in motion or in a second stationary state based on the maximum acceleration change values in the first and second axial direction.