NFC Hubodometer With Hall Sensor for Tamper-Proof Mileage
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Solution Overview
Problem
Existing hubodometers are prone to intentional or inadvertent data alteration, lack confidentiality, and are fragile, with reed switches having a limited lifespan and being sensitive to road irregularities and vibrations.
Innovation Solution
A hubodometer with a NFC-based bi-directional communication link, a bipolar Hall sensor, and an anti-rotation pendulum device using permanent magnets, which differentiates between forward and backward travel and ensures secure data transmission using a commercially available NFC-equipped device like a cellphone or tablet, and provides robust mechanical design with an opaque cover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reed switches are used to detect wheel rotation, then the device can record distance information, but the reed switches are subject to wear and have a limited life span
Solution Approach 1:
The patent replaces the mechanical reed switch system with a magnetic field-based detection system using a permanent magnet and magnetic sensor. This eliminates mechanical contact and wear, allowing the device to endure the entire vehicle lifecycle without component degradation from friction or impact.
2Ease of operation
If the display window is made visible, then the distance information can be read, but the display window is fragile
Solution Approach 1:
The patent replaces the fragile visual display window with an electronic display system that shows distance information through digital readouts. This eliminates the fragile glass or plastic window while maintaining full accessibility to the recorded information.
3Measurement precision
If the hubodometer is attached to the wheel hub, then it can measure distance traveled, but it is sensitive to road irregularities and vibrations that may be interpreted as wheel rotation
Solution Approach 1:
The patent employs a pendulous element with a counterweight that remains oriented vertically due to gravity. This gravitational reference provides a stable baseline that distinguishes true wheel rotation from vibrations and road irregularities, allowing the magnetic sensor to accurately detect only genuine rotational movement.
Solution Approach 2:
Instead of trying to eliminate vibrations, the patent inverts the approach by using gravity as a reference frame. The pendulous element's vertical orientation under gravitational influence creates a stable reference that filters out horizontal vibrations and road irregularities, allowing accurate rotation detection despite harsh operating conditions.
4Loss of information
If the hubodometer records distance information, then it provides mileage data, but the information is vulnerable to intentional or inadvertent alteration
Solution Approach 1:
The patent creates a secure copy of the distance information through NFC technology, allowing data to be transferred to external devices for verification without exposing the original recording mechanism to tampering. This enables confidential yet accessible information management.
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
The solution provides reliable, secure, and confidential distance recording, immune to shock and vibrations, with automatic data transfer and cloning capabilities, ensuring accurate and tamper-proof mileage tracking.
Implementation Method 1
an assembly rotating with the hub and comprising a pendulous element provided with two permanent magnets oriented in a bipolar fashion
Implementation Method 2
a bipolar Hall sensor which generates, upon rotation of the hub, an asymmetric square wave when traversing the magnetic fields of said two permanent magnets
Implementation Method 3
a pendulous element provided with an anti-rotation weight
Data Source
AI summary
A hubodometer for attachment to a wheel hub comprising an outer housing enclosing equipment for measuring distance travelled based on the wheel hub's number of revolutions, and a NFC-based communications link for transmitting to an external unit data related to the measured distance and for receiving operational data such as the diameter of the vehicle's wheel, and the position of the hub to which the hubodometer is attached. The equipment comprises a first electronic assembly conjoined with the outer housing and a second assembly comprising an anti-rotation pendulum provided with two permanent magnets of opposing polarities, the positions of which subtend an angle smaller than 180 degrees. The first electronic assembly comprises a bipolar Hall sensor moving in a circular path that traverses North and South fields of the magnets, whose output signal is a rectangular wave in which different mark-to-space ratios are associated with forward or reverse travel direction.