Wireless Charging Coil Alignment via Voltage Change Detection

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Solution Overview

Problem

Existing parking assistance systems for wireless charging systems may confuse drivers about the timing for applying brakes, leading to potential overruns or misalignment of power receiving and transmission coils due to delayed braking.

Innovation Solution

A parking assistance device that detects voltage changes in the power receiving coil and notifies the driver with specific braking instructions, including first and second braking notices based on voltage shifts, to improve alignment accuracy and prevent overruns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the system uses weak excitation to calculate distance between coils, then the positioning information is provided, but the driver is confused about when to apply brakes leading to overrun

Engineering Contradiction:
Improvepositioning information clarityVSAvoidbraking timing accuracy
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The braking process is segmented into multiple stages with distinct notifications: a first notification when the vehicle approaches the stop point (voltage change rate becomes negative), and a second notification when the vehicle is at the optimal stopping position (voltage change rate becomes positive). This segmentation provides clear, actionable information for each phase of the braking process, eliminating driver confusion about when to apply brakes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system provides preliminary notification to the driver in advance of the optimal stopping point. The first notification is issued when the voltage change rate becomes negative, giving the driver advance warning to begin braking before the vehicle reaches the exact stop position. This preliminary action allows the driver to prepare and apply brakes at the appropriate time, preventing overrun.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the driver delays applying brakes due to confusion, then the positioning accuracy deteriorates, but the braking control becomes more complex

Engineering Contradiction:
Improvecoil alignment accuracyVSAvoidbraking control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system continuously monitors the voltage change rate of the power receiving coil and provides real-time feedback to the driver through notifications. When the voltage change rate becomes negative (approaching stop point), a first notification is issued. When the voltage change rate becomes positive (reaching optimal position), a second notification is issued. This feedback mechanism guides the driver's braking action without requiring complex autonomous braking control.

Inventive Principle:
Principle #23Feedback

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

The device effectively informs drivers of precise braking times, enhancing the accuracy of positioning between the power receiving and transmission coils, thereby preventing overruns and ensuring efficient alignment.

Implementation Method 1

a power transmission coil 31 that transmits electric power to the power receiving coil 11 wirelessly through electromagnetic induction

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a voltage sensor 12 that detects a voltage of the power receiving coil 11

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3251884B1Parking assistance device
Publication Date: 2019.03.13 NISSAN MOTOR CO LTD
  • EP3251884B1 patent drawingFigure 1
  • EP3251884B1 patent drawingFigure 2(a)~2(e)
  • EP3251884B1 patent drawingFigure 3

AI summary

A parking assistance device for aligning a vehicle coil (11) mounted on a bottom surface of a vehicle (10) with a ground coil (31) installed on a ground, detects a voltage of the vehicle coil (11), detects a change in the voltage detected, notifies a driver of first braking when the change in the voltage detected shifts from an increasing direction to a decreasing direction, and notifies the driver of second braking when the change in the voltage shifts from the decreasing direction to the increasing direction.