Wireless Power Receiver Packet Timing for Foreign Object Detection
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Solution Overview
Problem
Existing wireless power transfer systems face issues with inaccurate foreign object detection, leading to potential heat generation or decreased power transmission efficiency due to unclear detection results, which can occur when foreign objects are present or not.
Innovation Solution
A power receiving apparatus that switches between two modes of communication with different packet transmission intervals based on the response received from a power transmission apparatus, allowing for quicker and more accurate detection of foreign objects by adjusting power reception and transmission protocols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the power receiving apparatus transmits packets with a long interval (second mode), then power transmission efficiency is maintained, but foreign object detection accuracy and speed deteriorate
Solution Approach 1:
The packet transmission interval is dynamically adjusted based on the response received from the power transmission apparatus. When a predetermined response is received, the system switches to first mode with a shorter transmission interval to improve detection accuracy. When no predetermined response is received, the system switches to second mode with a longer transmission interval to maintain power efficiency. This dynamic adaptation resolves the contradiction between detection accuracy and power efficiency.
2Measurement precision
If the power receiving apparatus transmits packets with a short interval (first mode), then foreign object detection accuracy improves, but power transmission efficiency deteriorates
Solution Approach 1:
The system dynamically switches between two transmission modes based on response feedback. The first mode (short interval) is activated only when a predetermined response is received, indicating potential foreign object presence. The second mode (long interval) is used otherwise to conserve energy. This conditional dynamic adjustment ensures short intervals are used only when necessary for detection accuracy.
Solution Approach 2:
The system employs periodic packet transmission with two different intervals depending on the operational state. The transmission interval is periodically adjusted between a short interval (first mode) for detection and a long interval (second mode) for efficiency, creating a rhythmic pattern of high and low activity that balances detection needs with energy conservation.
3Measurement precision
If foreign object detection is executed frequently, then detection accuracy improves, but detection time increases
Solution Approach 1:
The detection frequency is dynamically adjusted based on response feedback. When a predetermined response is received, the system increases detection frequency by switching to first mode with shorter intervals. When no predetermined response is received, the system decreases detection frequency by switching to second mode with longer intervals. This dynamic frequency adjustment improves detection accuracy only when necessary, reducing overall detection time.
Data Source
AI summary
A power receiving apparatus (401) includes a coil (205) that wirelessly receives electric power from a power transmission apparatus, communication means (204) for transmitting at a predetermined interval a signal for executing a detection process to detect an object, different from the power transmission apparatus or the power receiving apparatus, in accordance with a value of voltage or current at least at two time points in a predetermined period in which the power transmission apparatus restricts transmission of electric power and receives, from the power transmission apparatus, a response signal including a detection result based on the detection process executed in accordance with a signal transmitted, and control means (201) for, in a case where the detection result included in the response signal received satisfies a predetermined condition, executing control such that the signal is transmitted at an interval shorter than a predetermined interval.