Wireless Power Transfer Control for Accurate Foreign Object Detection
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Solution Overview
Problem
Existing wireless power transfer systems face reduced accuracy in foreign object detection due to changes in power transmission and reception environments, leading to potential errors in charging and temperature increases.
Innovation Solution
A power transmission apparatus that includes a processing unit to detect objects using power loss, obtains reference value information from a power reception apparatus, and controls power output based on elapsed time to prevent increases in transmission power, ensuring accurate foreign object detection and preventing erroneous charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If foreign object detection is performed using past received power information, then detection function is provided, but detection accuracy deteriorates due to environmental changes over time
Solution Approach 1:
The system performs preliminary calibration to establish the relationship between transmission power and received power before actual power transmission begins. This preliminary action creates a baseline model that accounts for environmental conditions at the time of calibration, enabling accurate foreign object detection during subsequent operation without being affected by temporal environmental changes.
Solution Approach 2:
The system continuously monitors received power during power transmission and compares it against the calibrated relationship model. When a foreign object is detected, the system provides feedback by adjusting or stopping power transmission. This closed-loop feedback mechanism maintains detection accuracy by constantly validating the calibration model against actual operating conditions.
2Productivity
If transmission power is increased to improve charging speed, then productivity increases, but foreign object detection accuracy deteriorates
Solution Approach 1:
The system performs preliminary calibration at low power levels to establish the transmission-received power relationship before high-power charging begins. This preliminary action creates an accurate baseline model that enables foreign object detection even during subsequent high-power transmission, allowing the system to maintain both high charging speed and detection accuracy.
Solution Approach 2:
The system uses the calibrated model to continuously monitor received power during high-power transmission and detect foreign objects. When a foreign object is detected, feedback control stops or reduces power transmission, preventing safety issues while allowing high-speed charging to proceed when no foreign objects are present.
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 enhances the convenience of wireless power transfer by preventing erroneous detections and temperature increases, ensuring stable and accurate power transmission.
Implementation Method 1
a power transmission unit configured to wirelessly transmit power to a power reception apparatus
Data Source
AI summary
A power transmission apparatus configured to wirelessly transmit power to a power reception apparatus executes, when wirelessly transmitting power, detection processing for detecting an object different from the power reception apparatus, using a power loss, obtains, from the power reception apparatus, reference value information regarding a reference value of received power used to obtain the power loss, and performs a specific control after the power loss has been obtained and in a case where a predetermined time has elapsed since a predetermined timing associated with a timing at which information is obtained from the power reception apparatus, without obtaining the reference value information that is valid, the specific control being a control to prevent a power transmission output from being increased, regardless of received power in the power reception apparatus.