EV Inductive Charging Transponder Positioning

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Solution Overview

Problem

Existing inductive charging systems for electric vehicles face challenges in precise positioning due to the hidden coil system under the road surface and the lack of intuitive recognition of the vehicle's coil system, making it difficult for drivers to align the vehicle without skilled intervention or markings.

Innovation Solution

The system employs a transponder unit in the electric vehicle and the charging station to exchange wireless messages, using triangulation and transit time differences to determine the precise positioning of the vehicle on the charging station, enabling accurate alignment without requiring driver skill or floor markings, and includes a navigation unit for guiding the vehicle using GPS data or alternative positioning methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the coil system is installed underneath the road surface for inductive charging, then the charging station can be integrated into the infrastructure, but the exact position becomes invisible and difficult to locate for the driver

Engineering Contradiction:
Improveintegration of charging stationVSAvoidvisibility of coil position
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The patent employs optical markings or visual indicators on or near the road surface that change color or illuminate to indicate the precise position and status of the hidden coil system, making the invisible charging area visible to drivers

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent introduces an intermediary signaling system (optical markers, LEDs, or visual indicators) that mediates between the hidden coil system and the driver, translating the invisible electromagnetic field position into visible guidance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If manual positioning by skilled drivers is required for precise coil alignment, then positioning accuracy can be achieved, but the ease of operation deteriorates and requires specialized skill

Engineering Contradiction:
Improvecoil alignment accuracyVSAvoiddriver skill requirement
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent implements a self-positioning system where the vehicle automatically determines its position relative to the charging station using sensors and navigation data, eliminating the need for skilled manual positioning by the driver

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical positioning with an automated electronic positioning system using GPS, inertial sensors, and optical recognition to achieve precise alignment without driver intervention

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If floor markings are used to guide vehicle positioning, then the ease of operation improves, but the device complexity and cost increase

Engineering Contradiction:
Improvepositioning guidanceVSAvoidpositioning aid infrastructure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into the existing vehicle navigation system, using the same sensors and processors for both navigation and charging position alignment, avoiding dedicated positioning infrastructure

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

Solution Approach 2:

The patent uses virtual representations of the charging station position in the vehicle's navigation system, creating a digital map overlay that guides positioning without physical markings on the ground

Inventive Principle:
Principle #26Copying

4Ease of operation

If transponders are used for wireless communication and positioning, then the ease of operation improves and no markings are needed, but the measurement precision of position determination must be sufficient

Engineering Contradiction:
Improvecontactless positioningVSAvoidposition determination accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent combines multiple positioning methods (GPS coordinates, inertial sensor data, transit time measurement of transponder signals) into an integrated positioning system that achieves high precision through data fusion

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent measures position not only through spatial coordinates but also through the time dimension by measuring the transit time of transponder signals, adding a temporal dimension to position determination for enhanced accuracy

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

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 solution allows for precise and conflict-free positioning of electric vehicles on inductive charging stations, even in complex environments like multi-story car parks, using mature RFID technology, reducing the need for costly optical systems and enabling autonomous alignment.

Implementation Method 1

a first transponder unit for sending a wireless query message and for receiving a wireless response message answering the query message sent by a second transponder unit assigned to the charging station

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

Energy is inductively transferred from the charging station to the vehicle via an alternating magnetic field that penetrates this coil system

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2838753B1Electric vehicle, inductive charging station, and method
Publication Date: 2020.06.10 SIEMENS AG
  • EP2838753B1 patent drawingFigure 1

AI summary

In the method according to the invention for positioning an electric vehicle on an inductive charging station, a wireless request message is transmitted by a first transponder unit paired with the electric vehicle. The request message is then received by a second transponder unit paired with the inductive charging station. A wireless response message which answers the request message is subsequently generated by a control unit paired with the inductive charging station. The response message contains position data of the inductive charging station. The response message is then transmitted at least once by the second transponder unit. On the electric vehicle side, the response message is received by the first transponder unit, and the position data contained in the response message is transferred to a navigation unit paired with the electric vehicle. Finally, a trajectory for positioning the electric vehicle on the inductive charging station is determined by comparing the position data of the inductive charging station with a current electric vehicle position ascertained by the navigation unit. The trajectory for positioning the electric vehicle is alternatively or additionally carried out by determining a transit time difference of the response message between the first transponder unit and the second transponder unit, at least two transponders which are arranged at a specified distance from one another being provided in at least one of the first or second transponder units.