LC Circuit Variable Capacitor Vehicle Positioning Wireless Charging

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Solution Overview

Problem

Current wireless charging systems for vehicles lack standardization, leading to interoperability issues and inefficient power transfer due to assumptions about the optimal positioning of the receiver coil over the charging station, which can be affected by environmental conditions and coil aging.

Innovation Solution

A driving assist system utilizing an LC circuit with a variable capacitor to determine the optimal impedance and frequency matching, generating control signals to guide the vehicle to the correct position for maximum power transfer efficiency, eliminating the need for short-range geolocation assistants and allowing for optimal positioning regardless of environmental factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If GPS and short-range wireless geolocation assistants are used for vehicle positioning, then the vehicle can be guided to the charging station, but the system lacks standardization and interoperability between different systems

Engineering Contradiction:
Improvevehicle positioning capabilityVSAvoidinteroperability between systems
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent replaces mechanical/geolocation-based positioning systems (GPS, Bluetooth, WLAN, ZigBee) with an electromagnetic field-based detection system. The receiver coil detects the electromagnetic field generated by the transmission coil to determine optimal positioning, eliminating the need for multiple proprietary short-range communication protocols and achieving universal interoperability across different wireless charging systems.

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

Solution Approach 2:

The patent introduces an electromagnetic field as an intermediary between the charging station and the vehicle's positioning system. The receiver coil detects the electromagnetic field characteristics to determine optimal positioning, serving as a universal intermediary that works across different charging station implementations without requiring system-specific geolocation protocols.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the receiver coil is positioned at the center of the ground pad, then alignment is simplified, but the optimum power transfer location may not be at the center due to environmental conditions and coil aging

Engineering Contradiction:
Improvealignment simplicityVSAvoidpower transfer efficiency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the receiver coil continuously detects the electromagnetic field characteristics and the system adjusts the vehicle's position based on the detected signal strength and phase. This feedback loop allows the system to dynamically find and maintain the optimal positioning for maximum power transfer, compensating for environmental changes and coil aging without requiring manual realignment.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from a static positioning approach (fixed center alignment) to a dynamic positioning system that continuously adjusts the vehicle's position based on real-time electromagnetic field detection. The system can adapt to changing conditions such as environmental factors and coil degradation by dynamically finding the optimal receiver-coil alignment for maximum power transfer efficiency.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If standard geolocation methods are used, then vehicle positioning can be achieved, but the positioning accuracy is insufficient for optimal wireless power transfer

Engineering Contradiction:
Improvevehicle location determinationVSAvoidcoil alignment precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent replaces coarse geolocation methods with an electromagnetic field-based detection system that provides fine-grained positioning information. The receiver coil detects the electromagnetic field characteristics to determine the precise relative position between the transmission and receiver coils, enabling alignment precision far beyond what GPS or other geolocation systems can achieve.

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

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

Enables efficient and standardized power transfer across different wireless charging stations by optimizing the vehicle's position for maximum coupling, ensuring high efficiency and interoperability without relying on specific short-range geolocation services.

Implementation Method 1

The receiver coil of the LC circuit is configured to convert the electromagnetic field generated by the charging station into an electrical signal

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The variable capacitor is configured to match the LC circuit, in particular impedance and frequency of the LC circuit

Methodology Applied
Scientific EffectImpedance matching: Capacitance

Data Source

PatentEP3511194B1A driving assist system and a method for positioning a vehicle over a charging station
Publication Date: 2020.12.23 BAYERISCHE MOTOREN WERKE AG
  • EP3511194B1 patent drawingFigure 1~2
  • EP3511194B1 patent drawingFigure 3~4

AI summary

The application concerns a driving assist system for positioning a vehicle over a charging station which is configured to generate an electromagnetic field for wirelessly transmitting electrical energy to the vehicle, comprising: an LC circuit comprising a receiver coil which is configured to convert the electromagnetic field into an electrical signal and a variable capacitor which is configured to match the LC circuit; a determination unit which is configured to determine the capacitor value of the variable capacitor after matching the LC circuit; a control unit which is configured to receive the determined capacitor value from the determination unit and to generate a first control signal that depends on a comparison of a predetermined capacitor value and the determined capacitor value; and a guidance unit which is configured to receive the first control signal from the control unit and to guide the vehicle or a driver of the vehicle for positioning the vehicle over the charging station by means of the first control signal.