Inductive Charging Synchronization via Frequency Adaptation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for inductive energy transmission, particularly for charging energy stores in hand-held power tools, face challenges in achieving reliable and energy-efficient synchronization between the induction unit and the receiving unit, especially with fluctuating operating parameters and foreign object detection.

Innovation Solution

The method involves setting the transmission frequency of the synchronization signal as a function of the load operating voltage source's voltage, using a constant voltage source for synchronization, and iteratively adjusting the transmission frequency and duration to ensure secure synchronization, while recognizing the type of receiving unit for tailored signal settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the transmission frequency is set close to the resonant frequency to improve energy transmission efficiency, then the energy transmission efficiency is improved, but the receiving unit is subjected to excessively high voltage and power

Engineering Contradiction:
Improveenergy transmission efficiencyVSAvoidhigh voltage and power on receiving unit
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing synchronization at a frequency remote from resonance before initiating full energy transmission. This preliminary synchronization step establishes communication and parameter matching without subjecting the receiving unit to high voltage and power, thereby preventing harmful effects while preparing for efficient energy transfer.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action by using pulsed synchronization signals at remote frequencies interspersed between energy transmission cycles. This periodic switching between remote-frequency synchronization and resonant-frequency energy transmission allows the system to maintain efficiency while periodically preventing voltage overload on the receiving unit.

Inventive Principle:
Principle #19Periodic action

2Device complexity

If the synchronization signal uses fixed parameters to simplify control, then the control complexity is reduced, but reliable synchronization cannot be achieved with changing operating parameters

Engineering Contradiction:
Improvecontrol complexityVSAvoidsynchronization reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies dynamics by making the synchronization signal parameters variable rather than fixed. The control unit adjusts signal characteristics such as frequency, amplitude, and duration based on detected operating conditions including voltage fluctuations and load changes. This dynamic adaptation ensures reliable synchronization across varying operating parameters while maintaining manageable control through automated adjustment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using the receiving unit's response to the synchronization signal to automatically adjust subsequent signal parameters. The control unit monitors the strength and quality of the response and modifies frequency, amplitude, or timing of subsequent synchronization signals accordingly, ensuring reliable synchronization without requiring complex manual control.

Inventive Principle:
Principle #23Feedback

3Reliability

If the synchronization signal is transmitted at high power to ensure reliable detection, then the detection reliability is improved, but excessive energy is consumed during synchronization

Engineering Contradiction:
Improvesynchronization detection reliabilityVSAvoidenergy consumption during synchronization
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by transmitting synchronization signals at just sufficient power levels for reliable detection rather than continuously at high power. The system uses low-power remote-frequency signals for synchronization and only transitions to higher-power resonant-frequency signals when actual energy transmission is required, thereby reducing overall energy consumption while maintaining detection reliability.

Inventive Principle:
Principle #16Partial or excessive action

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 ensures reliable and energy-efficient synchronization, even with changing operating parameters, and effectively prevents high voltage or power imposition on the receiving unit, enhancing the charging process for hand-held power tools.

Implementation Method 1

an induction unit (12), in particular an electronic transmission unit, which is provided in particular for converting and inductively transmitting electrical energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The induction unit has at least one resonant circuit, which in particular comprises at least one coil, which is provided in particular to generate an alternating magnetic field, and at least one resonance capacitor

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3427365B1Method for inductive energy transmission
Publication Date: 2022.01.19 ROBERT BOSCH GMBH
  • EP3427365B1 patent drawingFigure 1
  • EP3427365B1 patent drawingFigure 2~3
  • EP3427365B1 patent drawingFigure 4~5

AI summary

The invention relates to a method for inductive energy transmission, in particular for charging an energy store (10), wherein an induction unit (12) emits at least one synchronization signal (14). According to the invention, at least one signal characteristic of the synchronization signal (14) is adjusted in a synchronization step.