Wireless Power Antenna Sensing for Interference-Free Foreign Object Detection
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Solution Overview
Problem
Existing wireless power transmission systems face accuracy issues in detecting foreign substances due to interference from communication signals when measuring voltage or current during power transmission cessation, leading to incorrect detection of foreign substances.
Innovation Solution
A power transmission apparatus that measures voltage and current during power cessation, performs multiple determinations of the Q factor to accurately detect foreign substances, and adjusts power transmission based on these measurements to prevent erroneous detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If communication using an antenna for wireless power transmission is performed when voltage is measured during power cessation, then communication functionality is maintained, but the accuracy of foreign substance detection deteriorates due to signal interference
Solution Approach 1:
The patent segments the measurement process into multiple individual measurements taken at different time points during power cessation. By performing multiple measurements and evaluating their consistency, the system can distinguish between voltage changes caused by communication signals and those caused by foreign substances, thereby maintaining detection accuracy while allowing continuous communication functionality.
2Difficulty of detecting and measuring
If voltage measurement is performed during power cessation to detect foreign substances, then foreign substance detection capability is enabled, but communication signals interfere with measurement accuracy
Solution Approach 1:
The patent implements a feedback mechanism where multiple voltage measurements are taken and their results are evaluated against each other. The control unit analyzes whether the measurements are consistent with each other, and only when consistency is confirmed does it proceed with foreign substance detection. This feedback loop eliminates the interference from communication signals by ensuring measurements are taken when signal interference is minimal or absent.
3Reliability
If multiple measurements are performed to ensure detection accuracy, then measurement reliability improves, but processing time and system complexity increase
Solution Approach 1:
The patent performs preliminary actions by taking multiple voltage measurements and storing them before proceeding with the foreign substance detection decision. By preparing the measurement data in advance and evaluating their consistency, the system simplifies the subsequent detection process and reduces the need for complex real-time analysis, thereby improving reliability without excessively increasing overall system complexity.
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
Enhances the accuracy of foreign substance detection by minimizing interference from communication signals, ensuring reliable power transmission by preventing erroneous detection and reducing power transmission when foreign substances are present.
Implementation Method 1
a power transmission unit configured to wirelessly transmit power to the power reception apparatus using the antenna
Implementation Method 2
a measurement unit configured to, in a period during which the transmission of power from the power transmission unit is stopped, measure one or both of a voltage and a current output from the antenna
Data Source
AI summary
A power transmission apparatus wirelessly communicates with a power reception apparatus using an antenna, wirelessly transmits power to the power reception apparatus using the antenna, measures, in a period during which the transmission of the power is stopped, one or both of a voltage and a current output from the antenna, performs, based on a measurement result obtained by the measurement, a determination process for determining that an object different from the power reception apparatus is present, restricts, in a case where it is determined that an object different from the power reception apparatus is present as a result of the determination process performed by the first determination unit, the transmission of the power, and controls the first determination unit not to use in the determination process the measurement result obtained by the measurement in a period during which communication is performed.