Wireless Charging Transmitter Foreign Object Detection Calibration
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Solution Overview
Problem
Existing wireless charging systems face interruptions and reduced sensitivity during foreign object detection calibration, which can lead to hazardous situations due to undetected objects in the charging path, as the calibration process temporarily degrades the detection system's performance.
Innovation Solution
Implementing a control circuit that operates the Foreign Object Detection (FOD) system in a high sensitivity mode concurrently with the calibration procedure and switches to standard detection mode upon completion, while the Living Object Protection (LOP) system is used to halt charging if an object is detected during calibration and resumes standard operation after clearance confirmation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the FOD system performs calibration procedure, then the detection sensitivity is improved, but the charging operations are interrupted and the detection sensitivity deteriorates during calibration
Solution Approach 1:
The patent introduces a Living Object Protection (LOP) system as an intermediary detection mechanism that operates during FOD calibration. The LOP system uses radio transmissions to detect living objects (humans, animals) in the charging area, providing a safety net while the FOD system undergoes calibration. This mediator system ensures that even though FOD sensitivity deteriorates during calibration, critical safety monitoring continues through the alternative LOP detection method.
Solution Approach 2:
The patent performs preliminary detection using the LOP system before and during the FOD calibration process. By having the LOP system ready and operational in advance, the system ensures continuous safety monitoring is established before the FOD system's sensitivity degrades during calibration. This preliminary action prevents undetected objects from remaining in the charging area while calibration is performing impedance measurements to improve FOD sensitivity.
2Measurement precision
If the FOD system is recalibrated, then the detection sensitivity is improved, but the charging time is increased due to interruptions
Solution Approach 1:
The patent maintains continuous useful action by having the LOP system operate continuously during FOD calibration. While the FOD system undergoes recalibration that interrupts charging operations, the LOP system continues to monitor the charging area without interruption. This continuity ensures that safety monitoring never stops, even when the primary FOD system is temporarily non-operational during calibration, thereby reducing the effective loss of time by preventing complete system shutdowns.
Solution Approach 2:
The patent changes the operational parameters of the detection system by switching between FOD and LOP modes. During normal operation, the FOD system using impedance measurements is the primary detection method. During calibration, the system parameter changes to rely on the LOP system using radio transmission detection. This parameter change allows the system to adapt to the calibrated state, maintaining detection functionality while FOD sensitivity is being improved, thereby reducing charging interruptions.
3Reliability
If the LOP system operates in high sensitivity mode during calibration, then the safety monitoring is improved, but the false alarm rate increases
Solution Approach 1:
The patent applies partial action by having the LOP system operate in high sensitivity mode only during the specific calibration period of the FOD system, rather than continuously. This temporary high sensitivity operation provides enhanced safety monitoring exactly when needed (during calibration when FOD is non-operational), but limits the duration of high sensitivity to minimize false alarms. The system uses excessive detection capability only when necessary, then returns to standard sensitivity mode to reduce false alarm rates during normal charging operations.
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 minimizes charging interruptions and enhances detection sensitivity, ensuring safer and more reliable wireless power transfer by maintaining continuous monitoring and alerting users to potential hazards during the calibration process.
Implementation Method 1
FOD systems utilize impedance measurements to detect metallic objects in the charging path
Implementation Method 2
LOP systems generally utilize radio transmissions to detected moving objects
Implementation Method 3
wireless charging system that is capable of transferring power in free space (e.g., via a wireless field)
Data Source
AI summary
Techniques for detecting foreign objects in a charging path of a wireless power transfer system are disclosed. An example apparatus for detecting a presence of a foreign object includes a foreign object detection (FOD) system, a living object protection (LOP) system, a control circuit operably coupled to the FOD system and the LOP system and configured to detect a change in one or more power transfer parameters, perform a calibration procedure on the FOD system based on the change in the one or more power transfer parameters, operate the LOP system in a high sensitivity mode concurrently with the calibration procedure, and operate the LOP system in a standard detection mode upon completing the calibration procedure.