Tamper-Resistant Optical Encoder Wheel Sensor for Motor Vehicles
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Solution Overview
Problem
Existing devices for recording movement-dependent variables in motor vehicles lack sufficient security against manipulation, particularly susceptible to external interference and signal manipulation.
Innovation Solution
The integration of an optical sensor with an optically detectable surface structure on the encoder wheel, coupled with a lighting device for targeted illumination and a control device that manages light polarization and wavelength, utilizing a random number generator to enhance security against manipulation by comparing controlled and reflected light for error detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inductive sensors are used to detect rotational movement, then the device can measure motion-dependent parameters, but the device becomes susceptible to external magnetic field interference and manipulation
Solution Approach 1:
The patent replaces inductive sensors with optical sensors that use light beams instead of magnetic fields for detection. The optical sensor emits light that reflects off the encoder wheel's surface structure, eliminating susceptibility to magnetic field interference while maintaining rotational movement detection capability.
Solution Approach 2:
The patent changes the physical parameter used for sensing from magnetic field induction to optical reflection. By using light polarization and wavelength parameters controlled by a random number generator, the system achieves manipulation resistance while maintaining measurement precision.
2Reliability
If traditional optical sensors are used without integrated illumination, then the device structure is simpler, but the device lacks tamper protection and is susceptible to signal manipulation
Solution Approach 1:
The patent combines the illumination device and optical sensor into a single integrated motion sensor unit. The illumination device emits light that is immediately detected by the co-located optical sensor after reflecting from the encoder wheel, creating a self-contained system that is difficult to manipulate externally.
Solution Approach 2:
The patent introduces the encoder wheel's surface structure as an optical intermediary between the illumination device and sensor. The surface structure modulates the reflected light in a controlled manner, creating a verification mechanism that prevents signal manipulation while the integrated design keeps complexity manageable.
3Reliability
If the polarization and wavelength of illumination light are controlled randomly using a random number generator, then manipulation detection capability is significantly enhanced, but the control system becomes more complex
Solution Approach 1:
The patent makes the illumination parameters dynamic by using a random number generator to continuously vary polarization and wavelength. This dynamic control creates an unpredictable verification pattern that is extremely difficult to manipulate, as the control parameters change randomly over time rather than remaining fixed.
Solution Approach 2:
The patent changes multiple optical parameters (polarization, wavelength) simultaneously under random control. This multi-parameter random variation creates a complex verification signature that enhances manipulation detection while the integration with the existing optical system keeps the overall complexity increase manageable.
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
Significantly increases security against manipulation by making external interference and signal manipulation nearly impossible, ensuring reliable recording of movement-dependent variables.
Implementation Method 1
a lighting device (14) for illuminating the surface structure (12)
Implementation Method 2
the motion sensor (4) detects a rotational movement of a encoder wheel (6)
Implementation Method 3
the polarization and/or wavelength of the light is controlled depending on the random number generator (22)
Data Source
Figure 1
AI summary
The invention relates to a device 1 for recording a motion-dependent parameter of a motor vehicle, comprising a recording device 2 and a motion sensor 4 connected to the recording device 2, wherein the motion sensor 4 detects a rotational movement of a encoder wheel 6. To improve the tamper resistance of the device 1, it is proposed that a lighting device 14 be provided for illuminating a surface structure 12 of the encoder wheel 6, and that the motion sensor 4 be an optical sensor configured such that the motion sensor 4 detects a rotational movement of the encoder wheel 6 based on the light reflected from the surface structure 12 by the lighting device 14.