Wireless Power Antenna Measurement for Q-Factor 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 measurement accuracy deteriorates due to signal interference
Solution Approach 1:
The patent segments the operation into distinct phases: power transmission phase, power cessation phase for measurement, and communication phase. By separating measurement operations from communication operations in time, the patent eliminates signal interference during voltage measurement while maintaining both communication functionality and measurement accuracy
Solution Approach 2:
The patent performs voltage measurement during the power cessation period before communication occurs. By completing the measurement action preliminarily before communication signals are transmitted, the patent ensures that measurement accuracy is not compromised by subsequent communication signals
2Adaptability or versatility
If foreign substance detection is performed using voltage measurement during power cessation, then detection capability is provided, but detection accuracy decreases due to communication signal interference
Solution Approach 1:
The patent segments detection operations from communication operations by performing foreign substance detection during the power cessation period when no communication signals are transmitted. This temporal separation ensures that detection accuracy is not degraded by communication signal interference while maintaining full detection capability
Solution Approach 2:
The patent uses the power cessation period as an intermediary time window that enables both accurate measurement and foreign substance detection without interference from communication signals. This intermediary period serves as a dedicated measurement window isolated from communication activities
3Reliability
If voltage measurement is performed during power transmission cessation, then foreign substance detection is enabled, but measurement reliability decreases when communication occurs simultaneously
Solution Approach 1:
The patent implements periodic cycles of power transmission followed by power cessation periods for measurement and communication. By establishing a periodic pattern where measurement occurs during dedicated cessation windows, the patent ensures both detection reliability and measurement precision are maintained through regular, interference-free measurement opportunities
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 and preventing false positives or negatives.
Implementation Method 1
a power transmission unit configured to wirelessly transmit power to the power reception apparatus using the antenna
Implementation Method 2
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.