UWB Key Position Detection for Front-Back Electronic Lock Access

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing short-range wireless communication technologies for electronic locks, such as Bluetooth Low Energy (BLE) and Ultra High Frequency (UHF), face issues with unintentional unlocking when an authorized portable key device is within range, leading to potential unauthorized access, especially when a user walks past the lock.

Innovation Solution

A method and system using ultra-wideband (UWB) technology to determine the location of a portable key device relative to an electronic lock by analyzing channel impulse responses (CIR) from multiple antennas, distinguishing between line-of-sight and non-line-of-sight conditions to differentiate between the front and back sides of the lock.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If short-range wireless communication with longer communication range (e.g., Bluetooth Low Energy, Ultra High Frequency) is used, then the portable key device can stay in a pocket or handbag and still be used for access control, but the electronic lock could unintentionally be unlocked when a person walks past the electronic lock on the inside

Engineering Contradiction:
Improveconvenience of access controlVSAvoidaccuracy of location determination
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent transitions from determining only the presence of a key device to determining its spatial dimension (front side vs. back side) by analyzing the Channel Impulse Response characteristics. This dimensional differentiation allows the system to distinguish between authorized proximity (outside the barrier) and unauthorized proximity (inside the barrier), resolving the contradiction between convenience and reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Power

If RFID is used with a relatively large antenna in the reader, then wireless communication can be established, but a large amount of energy is used and the user must actively take out the portable key device and bring it within centimetres of the lock

Engineering Contradiction:
Improvewireless communication capabilityVSAvoidenergy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent changes the communication parameters by using impulse-based UWB signals instead of continuous RFID signals. This allows for shorter transmission bursts with lower peak power requirements, reducing overall energy consumption while maintaining wireless communication capability. The impulse signal approach enables communication without requiring the key device to be actively presented within centimeters of the lock.

Inventive Principle:
Principle #35Parameter changes

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

Enhances the reliability of access control by ensuring unlocking only occurs when the key device is on the intended outside side, preventing unauthorized access due to accidental proximity detection.

Implementation Method 1

obtaining a channel impulse response, CIR, based on an impulse signal transmitted from the portable key device, the CIR being based on a plurality of samples of the impulse signal as received by an antenna

Methodology Applied
Scientific EffectElectromagnetic radiation reception: Electromagnetic Induction

Data Source

PatentEP4162293B1Determining when a portable key device is located on a front side or on a back side
Publication Date: 2025.12.31 ASSA ABLOY AB
  • EP4162293B1 patent drawingFigure 1
  • EP4162293B1 patent drawingFigure 2
  • EP4162293B1 patent drawingFigure 3A~3B

AI summary

It is provided a method for determining when a portable key device is located on a front side or on a back side in relation to a barrier secured by an electronic lock. The method is performed in a location determiner and comprises the steps of: obtaining a channel impulse response, CIR, based on an impulse signal transmitted from the portable key device, the CIR being based on a plurality of samples of the impulse signal as received by an antenna being fixedly mounted in relation to the electronic lock; and determining, based on the CIR, whether the portable key device is located on the front side or on the back side.