Inductive Coded Lock System Using Spatially Arranged Coils
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Solution Overview
Problem
Existing inductive proximity sensors and switches lack a secure and reliable method for distinguishing between different conductive targets with varying coded sequences, which limits their ability to provide secure access control.
Innovation Solution
An inductive coded lock system utilizing multiple inductor coils spatially arranged to define non-overlapping sensing areas, combined with sensor circuitry that projects a magnetic field and measures differential inductance responses to detect a pre-defined coded key-unlock sequence, allowing for secure key-target alignment and unlock detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single inductive coil is used for proximity sensing, then the device complexity is low, but the ability to distinguish between different coded targets is insufficient
Solution Approach 1:
The sensing system is divided into multiple discrete inductor coils, each corresponding to a specific position in the coded sequence. This segmentation allows the system to detect the presence or absence of conductive material at each position independently, enabling coded target discrimination while maintaining a modular structure that manages complexity.
Solution Approach 2:
The system transitions from single-point proximity detection to multi-position spatial detection by arranging coils in a sequence along the key insertion path. This adds a spatial dimension to the sensing capability, allowing the system to read coded information distributed along the key rather than detecting a single target presence.
2Measurement precision
If multiple inductor coils are used to detect coded sequences, then the measurement precision for coded target identification is improved, but the device complexity increases
Solution Approach 1:
Multiple inductor coils are electrically connected in a differential configuration where adjacent coils are paired to compare their signals. This merging approach allows the system to process multiple sensing channels through a unified differential amplifier circuit, improving coded sequence detection while sharing common signal processing resources across all coil pairs.
Solution Approach 2:
The differential amplifier circuit is designed to process pairs of coil signals in a standardized, repeating pattern. Each adjacent pair of coils is handled by identical circuit logic, allowing the system to scale to multiple code positions using replicated circuit modules rather than requiring unique complex processing for each sensor element.
3Area of stationary object
If inductor coils are arranged with overlapping sensing areas, then the coverage area is maximized, but the ability to accurately detect coded sequences is compromised
Solution Approach 1:
Each inductor coil is designed with a specific sensing zone optimized for detecting conductive material at its corresponding position in the coded sequence. Rather than having all coils detect across the entire key insertion path, each coil has a localized sensing area that corresponds to its position, ensuring that the presence or absence of code elements at specific locations is detected by the appropriate coil without interference from adjacent coils.
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 system effectively differentiates between various coded key-target sequences, ensuring secure access by accurately detecting the pre-defined unlock condition, enhancing security and adaptability without being vulnerable to external interference.
Implementation Method 1
The sensor electronics drives the sensor coil, projecting a sensing B-Field, and then measures/acquires a sensor response, such as a change in sensor coil inductance in response to a conductive target
Implementation Method 2
each inductor coil is operable to project a magnetic field to define a key/target sensing area proximate to the inductor coil
Data Source
AI summary
An inductive coded lock system includes an inductive lock mechanism, and a conductive key/target. The inductive lock mechanism includes multiple inductor coils and sensor circuitry. Each inductor coil is operable to project a magnetic field defining a sensing area proximate to the inductor/coil, the inductor coils being spatially arranged to define a key/target sensing area incorporating each inductor coil sensing area. The sensor circuitry drives inductor coils, and measures sensor response (such as with an inductance comparator) to a key/target inserted within the key/target sensing area, including detecting an unlock condition corresponding to a pre-defined coded lock pattern. The key/target includes active and inactive areas (such as conductive/nonconductive) corresponding spatially to the sensing areas in the key target sensing area, the active and inactive areas arranged in a pre-defined coded key pattern corresponding to the pre-defined coded lock pattern. The coded lock and key patterns can be binary coded.