Vehicle Radio Wave Source Verification via Magnetic Field Orientation

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Solution Overview

Problem

Existing vehicle systems face challenges in accurately determining whether a radio wave received by a portable terminal is directly transmitted from an in-vehicle apparatus, especially when relayed by repeaters with multiple antennas, leading to erroneous operations.

Innovation Solution

The system employs a position detector and orientation detector to determine if the radio wave is directly received based on the characteristics of the magnetic field or electric field, position, and orientation, using multiple antennas in the in-vehicle apparatus and portable terminal to differentiate between direct and relayed signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If a repeater receives and relays radio waves from the in-vehicle apparatus, then the communication range is extended, but the portable terminal performs erroneous operation by communicating as if within predetermined distance

Engineering Contradiction:

Improvecommunication rangeVSAvoidcommunication accuracy

Core Design Contradiction:

Length of stationary objectVSReliability

Solution Approach 1:

The patent introduces a new dimension of verification by analyzing the magnetic field direction characteristics of received radio waves. Instead of relying solely on signal strength or presence, the system evaluates the spatial orientation of the magnetic field to determine whether the signal originated directly from the in-vehicle apparatus or was relayed by a repeater. This dimensional approach to signal verification resolves the contradiction by enabling accurate source identification while maintaining extended communication range.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent replaces traditional mechanical or geometric proximity detection methods with electromagnetic field characteristic analysis. By substituting physical distance measurement with magnetic field direction analysis, the system can accurately distinguish between direct and relayed signals regardless of the portable terminal's physical location, thereby maintaining communication accuracy while allowing repeaters to extend range.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If the portable terminal determines position based on signal strength alone, then the operation is simple, but erroneous communication occurs when relayed by repeater

Engineering Contradiction:

Improvedetermination simplicityVSAvoidposition determination accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the parameter used for position and authenticity determination from signal strength to magnetic field direction characteristics. This parameter change enables the system to maintain simple operational procedures while achieving high measurement precision, as the magnetic field direction provides reliable information about the signal source without requiring complex processing.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If multiple antennas are used in in-vehicle apparatus and portable terminal, then direct and relayed signals can be differentiated, but the device complexity increases

Engineering Contradiction:

Improvesignal authenticationVSAvoidantenna configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the multiple antennas serve multiple functions: they simultaneously enable signal reception, magnetic field direction measurement, and position determination. This multi-functionality reduces the need for separate authentication components, thereby maintaining signal authentication reliability while limiting the increase in device complexity.

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 allows for accurate determination of whether the radio wave is directly received from the in-vehicle apparatus, reducing erroneous operations and improving security features like door locking and vehicle starting protocols.

Implementation Method 1

whether a radio wave received by a portable terminal is a radio wave directly received from an in-vehicle apparatus is determined, based on (i) the characteristic related to the direction of a magnetic field or electric field in a radio wave received by the portable terminal

Methodology Applied

Scientific EffectMagnetic field direction detection: Magnetic Field

Data Source

PatentUS10759386B2Vehicle system, portable terminal, and in-vehicle apparatus

Publication Date: 2020.09.01 DENSO CORP

AI summary

Whether a radio wave received by a portable terminal is a radio wave directly received from an in-vehicle apparatus is determined, based on (i) the characteristic related to the direction of the magnetic field or electric field in the radio wave received by the portable terminal, (ii) the information representing the position of the portable terminal, and (iii) the information representing the orientation of the portable terminal.