Inductive Charging Antenna Quality Factor Metal Object Detection
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Solution Overview
Problem
Existing inductive charging systems for user devices in vehicles face challenges in accurately determining the relative position of a metal object with respect to the user device and transmitter antenna, leading to energy losses and safety risks due to predetermined power thresholds that do not account for varying configurations and internal losses.
Innovation Solution
A method and apparatus that measure and compare the quality factors of both the transmitter and receiver antennas to determine the position of a metal object, allowing for adjustments in charging power or signal transmission to mitigate energy losses and safety risks, including identifying configurations where the metal object is not aligned with either antenna.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a predetermined power threshold is used to detect metal objects, then the detection process is simple, but the detection accuracy is insufficient because it does not account for varying configurations and internal losses
Solution Approach 1:
The system measures the quality factor of the transmitter antenna and uses this feedback information to determine the position of metal objects. The quality factor measurement provides real-time information about the charging configuration, allowing the system to adapt the power threshold dynamically rather than using a fixed predetermined threshold.
Solution Approach 2:
The patent replaces complex mechanical or geometric detection systems with an electromagnetic field-based quality factor measurement approach. By measuring changes in the transmitter antenna's quality factor, the system can infer metal object positions without requiring complex physical sensors or alignment mechanisms.
2Productivity
If the transmitter antenna transmits high power charging signal, then charging efficiency is improved, but energy losses increase and metal objects heat up causing safety risks
Solution Approach 1:
The system dynamically adjusts the charging power based on the detected configuration. By continuously monitoring the quality factor and determining metal object positions, the system can vary the transmission power in real-time, transmitting high power when safe and reducing power when metal objects are detected in harmful positions.
Solution Approach 2:
The patent converts the harmful effect of metal objects (which alter the quality factor) into a useful detection mechanism. The presence and position of metal objects manifest as changes in quality factor, which the system uses to identify and respond to potential heating risks before they occur.
3Adaptability or versatility
If the predetermined threshold is based on standard configuration, then the threshold determination is simple, but it fails to account for misaligned configurations where losses may be greater
Solution Approach 1:
The system uses quality factor measurements as feedback to detect misaligned configurations. When the transmitter antenna's quality factor deviates from expected values, the system identifies that the configuration has changed (e.g., misalignment or metal object presence) and adjusts power accordingly to compensate for increased losses.
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
Effectively reduces energy losses and heating risks by accurately determining the configuration of the metal object's position relative to the antennas, enabling appropriate responses such as reducing or interrupting charging to ensure user safety and efficient charging.
Implementation Method 1
a transmitter antenna for transmitting an inductive charging signal and a support for receiving the user device, the user device comprising a battery and a receiver antenna for receiving the inductive charging signal transmitted by the transmitter antenna so as to charge the battery
Implementation Method 2
measuring a quality factor of the transmitter antenna and measuring a quality factor of the receiver antenna so as to deduce therefrom a position of the metal object in relation to the user device and to the transmitter antenna
Data Source
AI summary
A method for determining the relative position of a metal object in relation to a user device and to a transmitter antenna of an inductive charging support when charging the user device. The method includes measuring the quality factor of the transmitter antenna, measuring the quality factor of the receiver antenna, and comparing the measured quality factor of the transmitter antenna with a predetermined quality factor threshold of the transmitter antenna and comparing the measured quality factor of the receiver antenna with a predetermined quality factor threshold of the receiver antenna so as to deduce therefrom the relative position of the metal object in relation to the user device and to the transmitter antenna or the absence of an interfering metal object.