Tire Pressure Monitoring Device Position Assignment via Signal Strength
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Solution Overview
Problem
Existing tire pressure monitoring systems struggle to accurately assign wheel-mounted devices to their respective positions on a vehicle independently of other vehicle systems, particularly due to reliance on safety-critical systems like ABS and complex data correlation methods.
Innovation Solution
A method utilizing wheel-mounted tire pressure monitoring devices with position sensors and unique identifiers, transmitting pressure information and rotational angle data to a central unit, which compares received signal strength and angle information patterns to determine wheel positions, using characteristic signal profiles unique to each position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tire pressure monitoring devices are fixed to wheels and wheels are removed for repair or seasonal changes, then the monitoring devices must be removed together with the wheels, but the central unit cannot readily obtain information on the mounting position of a wheel with its tire pressure monitoring device
Solution Approach 1:
The system performs preliminary measurement and storage of characteristic reception level profiles for each wheel position during a teaching phase. These profiles are stored in the central unit for later comparison, enabling automatic position assignment when wheels are remounted without needing to relearn the positions.
Solution Approach 2:
The system creates a copy of the characteristic reception level pattern for each wheel position and stores it in the central unit. This stored pattern serves as a reference template that can be compared against newly received signals to determine wheel positions, effectively copying the spatial signature of each position.
2Extent of automation
If rotational information from tire pressure monitoring devices is correlated with ABS sensor values to determine wheel position, then position assignment can be made, but the system becomes dependent on the anti-lock braking system which has different priorities and requires continuous monitoring
Solution Approach 1:
The invention extracts the position determination function from the safety-critical ABS system by using a separate, dedicated reception level measurement approach. The tire pressure monitoring devices and central unit independently measure and compare reception levels without needing to access or process ABS sensor data, thereby separating the automation function from the safety system.
Solution Approach 2:
The reception level of radio signals serves as an intermediary parameter that indirectly indicates wheel position without requiring direct access to ABS system data. By measuring signal strength variations as wheels rotate and are positioned, the system uses this intermediary metric to assign positions independently of the ABS system.
3Measurement precision
If wheel angle information is used to determine tire pressure monitoring device positions, then position can be identified, but the method requires complex compensation signals and transmission only within specific angular ranges
Solution Approach 1:
The system changes the measurement parameter from wheel angle (which requires complex compensation) to reception level of radio signals. By measuring signal strength variations that occur naturally as wheels rotate and are positioned, the system achieves position identification through a simpler parameter that directly reflects spatial position without requiring angular range constraints or compensation signals.
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
Enables accurate and independent assignment of tire pressure monitoring devices to wheel positions without relying on other vehicle systems, reducing complexity and detection time, and ensuring correct pressure information display across varying assembly configurations.
Implementation Method 1
Each tire pressure monitoring device has a transmitting device for radio signals and can transmit pressure information to the receiving unit with its transmitting device
Implementation Method 2
A position sensor can be an acceleration sensor, for example, which can derive the rotational angle information from acceleration data
Data Source
Figure 1
Figure 2a~2e
Figure 3a~3d
AI summary
The invention relates to a method for assigning tire pressure control devices (3a, 3b, 3c, 3d) mounted on a wheel to wheel positions of a motor vehicle (1). A respective tire pressure control device (3a, 3b, 3c, 3d) is assigned to multiple wheels (2a, 2b, 2c, 2d) of the motor vehicle. Each tire pressure control device has at least one position sensor for ascertaining rotational angle information and a unique identifier. The identifier is repeatedly transmitted by the tire pressure control devices (3a, 3b, 3c, 3d) together with at least one piece of rotational angle information of the respective corresponding position sensor. In response to the transmissions, a respective reception level is detected and stored in the central unit (4). The received rotational angle information and the corresponding reception levels are compared with stored pattern value assignments of rotational angle information to comparison reception levels for each identifier. Each identifier is assigned to a wheel position using the comparisons.