Torque Control for Contactless Charging Coil Alignment

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Solution Overview

Problem

The challenge in contactless charging systems is accurately positioning the power receiving coil of a vehicle relative to the power transmitting coil during parking, which affects the efficiency of power transfer and makes it difficult to align the coils correctly.

Innovation Solution

A torque control apparatus that adjusts the vehicle's torque based on the relative position between the predetermined parking position and the vehicle's position, using a correction coefficient to facilitate precise alignment and improve power supply efficiency by correcting the torque as the vehicle approaches the parking position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the vehicle uses conventional torque control during parking, then the vehicle can be driven to the parking position, but fine movement control for precise coil alignment is difficult

Engineering Contradiction:
Improvepositioning precisionVSAvoidfine movement control
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The torque control is made dynamic by adjusting the torque map based on the vehicle's position relative to the parking position. When the vehicle is far from the parking position, normal torque control is applied for efficient movement. When the vehicle approaches the parking position, the torque map is corrected to provide finer control, enabling precise coil alignment. This dynamic adjustment resolves the contradiction between achieving positioning precision and maintaining ease of operation for fine movement control.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the vehicle approaches the parking position with normal torque control, then the vehicle can reach the parking area, but accurate alignment between power receiving coil and power transmitting coil is difficult

Engineering Contradiction:
Improvecoil alignment accuracyVSAvoidcharging efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system uses feedback from the position detection unit to continuously monitor the vehicle's position relative to the parking position. Based on this feedback, the torque control unit corrects the torque map when the vehicle approaches the parking position, enabling accurate coil alignment. This feedback mechanism ensures that the coils are properly aligned, thereby maximizing charging efficiency and resolving the contradiction between alignment accuracy and charging productivity.

Inventive Principle:
Principle #23Feedback

3Productivity

If the vehicle is positioned accurately for charging, then power supply efficiency is improved, but the positioning process becomes more complex

Engineering Contradiction:
Improvepower supply efficiencyVSAvoidtorque control system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system changes the torque parameter dynamically based on the vehicle's position. By correcting the torque map when the vehicle approaches the parking position, the system achieves accurate coil alignment and improves power supply efficiency. This parameter change approach is implemented through software control rather than hardware modifications, minimizing the increase in device complexity while achieving the desired positioning precision and charging efficiency.

Inventive Principle:
Principle #35Parameter changes

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 enhances the operability of the vehicle during parking, reduces positional deviation between the coils, and increases power supply efficiency by ensuring accurate alignment, thereby shortening charging time and improving the overall charging process.

Implementation Method 1

In a contactless power supply apparatus having a power transmitting coil and a power receiving coil, these coils being mutually opposed to each other via a gap formed with a predetermined distance

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2700530B1Torque control apparatus and contactless charging system
Publication Date: 2018.05.02 NISSAN MOTOR CO LTD
  • EP2700530B1 patent drawingFigure 1
  • EP2700530B1 patent drawingFigure 2a~2ac
  • EP2700530B1 patent drawingFigure 2b~2bc

AI summary

A torque control apparatus is provided which facilitates a positioning between a position of the vehicle and a predetermined parking position when the vehicle is parked. The torque control apparatus according to the present invention includes: accelerator opening angle detecting means for detecting an accelerator opening angle; torque setting means for setting a torque to drive the vehicle (100) on a basis of an accelerator opening angle detected by the accelerator opening angle detecting means; and torque control means for correcting the torque set by the torque setting means in accordance with the relative position between the predetermined parking position and the position of vehicle (100), and driving the vehicle (100) according to the corrected torque.