Vehicle Key Positioning With Separate Interior and Exterior Ranging

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Solution Overview

Problem

Existing vehicle locking systems face inaccuracies in determining the position of a key device due to signal reflections and interruptions by the vehicle's body and surroundings, leading to incorrect distance measurements and potential unintended locking or failure to start the vehicle.

Innovation Solution

The method involves separate transit time measurements using interior and exterior transceivers, with plausibility checks and prioritization of location data based on the operating function, ensuring accurate key device positioning for reliable locking and starting operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If all transceivers (interior and exterior) are used for transit time measurements to locate the key device, then the location accuracy is improved, but measurement errors occur due to signal reflections in certain environments

Engineering Contradiction:
Improvelocation accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the transceiver system into two independent groups: interior transceivers and exterior transceivers. The control device selectively activates only the appropriate group based on the determined location of the key device. When the key device is inside the vehicle, only interior transceivers are used; when outside, only exterior transceivers are used. This segmentation prevents signal reflections from causing measurement errors while maintaining location accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic selection mechanism where the control device continuously determines the key device's location and dynamically switches between using interior transceivers, exterior transceivers, or both groups based on the current situation. This dynamic adaptation ensures that the most appropriate transceiver group is always active, optimizing both accuracy and reliability under varying conditions.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If exterior transceivers are used to locate the key device inside the vehicle, then the location can be determined, but signal reflections from the vehicle body cause incorrect distance measurements

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidsignal reflection
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful influence of exterior transceivers when the key device is located inside the vehicle. The control device determines that the key device is inside and consequently deactivates the exterior transceivers, preventing their signals from reflecting off the vehicle body and causing measurement errors. Only interior transceivers remain active during indoor location.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of signal reflections into a beneficial selection criterion. By recognizing that exterior transceivers cause reflections when the key is inside, the system uses this knowledge to selectively activate only interior transceivers during indoor operations. Similarly, when the key is outside, interior transceivers are deactivated to avoid their signal reflections. This transforms a harmful effect into a basis for intelligent transceiver selection.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If interior transceivers are used to locate the key device outside the vehicle, then the location can be determined, but signal interruptions by the vehicle body lead to incorrect measurements

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidsignal interruption
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful influence of interior transceivers when the key device is located outside the vehicle. The control device determines that the key device is outside and consequently deactivates the interior transceivers, preventing their signals from being interrupted by the vehicle body and causing measurement errors. Only exterior transceivers remain active during outdoor location.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If separate interior and exterior location systems are implemented, then measurement errors are reduced, but the device complexity increases

Engineering Contradiction:
Improvelocation reliabilityVSAvoidtransceiver system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a universal control device that manages both interior and exterior transceivers through a single integrated system. The control device performs multiple functions: determining key device location, selecting appropriate transceiver groups, and coordinating their operation. This multi-functionality reduces the need for separate control systems and minimizes overall system complexity while maintaining high reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach enhances the reliability of key device location and operation, preventing unintentional locking or engine starting by accounting for measurement errors and reflections, thus ensuring safe and accurate vehicle control.

Implementation Method 1

Transit time measurements are carried out with at least one interior transceiver and with at least one exterior transceiver

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 2

there is no direct radio measurement path between the key device and the transceivers, since, for example, with the exterior transceivers the radio signal is interrupted by the body of the vehicle and with the interior transceivers the radio signal is interrupted by seat backs or people in the vehicle. This can lead to reflections of the signal.

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3934945B1Method for operating a locking system in a vehicle with separate interior and exterior key device detecting and locking system
Publication Date: 2023.12.20 VOLKSWAGEN AG
  • EP3934945B1 patent drawingFigure 1

AI summary

The invention relates to a method for operating a locking system (2) of a vehicle (1) in which time-of-flight measurements are made using at least one interior transceiver (9), which is situated in an interior (5) of the vehicle (1), and using at least one exterior transceiver (6), which is situated outside the interior (5); the time-of-flight measurements are used to determine a position of a key device (3) relative to the vehicle (1); and an operating function of the locking system (2) is carried out depending on the relative position determined; wherein an interior locating operation, in which the relative position is determined only on the basis of the time-of-flight measurement using the at least one interior transceiver (9), and an exterior locating operation, in which the relative position is determined only on the basis of the time-of-flight measurement using the at least one exterior transceiver (6), are carried out separately, and the relative position determined during the interior locating operation and/or the exterior locating operation is selected depending on the operating function.