Wireless Power Antenna Control for Accurate Foreign Object Detection
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Solution Overview
Problem
Existing methods for detecting foreign substances in wireless power transmission systems using voltage measurements are inaccurate due to interference from communication signals, leading to false positives or negatives.
Innovation Solution
A power transmission apparatus that includes a communication unit, a power transmission unit, a measurement unit, a first determination unit, a restriction unit, and a control unit. The apparatus measures voltage or current during power transmission stoppages, determines the presence of foreign substances, and restricts power transmission accordingly, while avoiding measurement interference from communication signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage measurement is performed during power transmission stoppages using the same antenna for communication, then power transmission can be controlled, but communication signals interfere with voltage measurements reducing detection accuracy
Solution Approach 1:
The patent segments the antenna usage into distinct time periods: communication periods and measurement periods. The control unit performs voltage measurements only during power transmission stoppages when communication is not occurring, thereby separating the interference sources and ensuring accurate foreign substance detection without communication signal interference.
Solution Approach 2:
The control unit schedules voltage measurements to occur during predetermined time periods when power transmission is stopped and communication is not performed. By planning and executing measurements in advance during these specific time windows, the system ensures that no communication signals are present to interfere with the voltage measurements.
2Device complexity
If communication and power transmission share the same antenna, then device complexity is reduced, but signal interference occurs during measurement periods
Solution Approach 1:
The system employs periodic action by alternating between communication periods and measurement periods in a structured sequence. During power transmission stoppages, the antenna is dedicated to voltage measurements for foreign substance detection. During other periods, the antenna is used for communication. This periodic alternation allows a single antenna to serve both functions without simultaneous interference.
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
The solution improves the accuracy of foreign substance detection by isolating measurement periods from communication activities, thereby reducing false detection rates and ensuring reliable power transmission.
Implementation Method 1
a communication unit configured to wirelessly communicate with a power reception apparatus using an antenna
Implementation Method 2
a power transmission unit configured to wirelessly transmit power to the power reception apparatus using 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.