Inductive Power Supply Object Detection via Coil Current
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Solution Overview
Problem
Current wireless power transmission systems face challenges with the uncertainty of object presence or absence during out-of-band communication, leading to potential mixed use and inefficiencies, particularly with the OOB communication protocol.
Innovation Solution
A method involving the use of a ping signal to detect objects by measuring coil current changes, employing an out-of-band communication protocol for object detection and pairing, and adjusting power transmission modes based on coil current measurements to ensure accurate and efficient power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If out-of-band communication protocol is used for wireless power transmission, then bandwidth and communication distance are improved, but uncertainty of object presence detection occurs leading to mixed use and inefficiencies
Solution Approach 1:
The patent introduces coil current measurement as an intermediary detection mechanism to verify object presence during OOB communication. The control unit measures coil current changes as a mediator to confirm whether a foreign object is truly present, resolving the uncertainty that arises from relying solely on OOB communication signals.
Solution Approach 2:
The system implements feedback by continuously monitoring coil current changes and using this information to adjust power transmission. When object presence is detected through coil current measurement, the system provides feedback to activate or adjust power transmission, ensuring reliable operation without mixed use.
2Measurement precision
If coil current measurement is used for object detection, then object presence detection accuracy is improved, but device complexity increases
Solution Approach 1:
The system uses the existing coil's current characteristics to detect object presence, making the coil serve dual purposes: power transmission and object detection. This self-service approach eliminates the need for separate detection hardware, maintaining simple device configuration while achieving high detection accuracy.
Solution Approach 2:
The coil is designed to perform multiple functions: generating magnetic fields for power transmission and serving as a sensor for object detection through current measurement. This multi-functionality reduces overall device complexity by eliminating dedicated detection components.
3Reliability
If ping signal is applied continuously for object detection, then object detection reliability is improved, but energy consumption increases
Solution Approach 1:
Instead of continuous ping signals, the system uses periodic coil current measurements during normal operation to detect object presence. This periodic approach maintains detection reliability while significantly reducing energy consumption compared to continuous active scanning.
Solution Approach 2:
The system performs useful object detection continuously during power transmission by monitoring coil current changes, eliminating the need for separate detection phases. This continuous useful action maintains high detection reliability without the energy overhead of dedicated detection cycles.
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 accuracy of object detection and power transfer, reduces uncertainty, and simplifies the hardware configuration, while offering advantages in bandwidth, complexity, regulation, and cost compared to traditional power line communication protocols.
Implementation Method 1
In the electromagnetic induction method, a power transmission unit generates a magnetic field through a power transmission coil (primary coil) and power is transferred to a reception coil (secondary coil) placed in a position to which a current is induced.
Implementation Method 2
power is transferred to a reception coil (secondary coil) placed in a position to which a current is induced
Implementation Method 3
In the resonance method, energy is transmitted using a resonance phenomenon between a transmission coil and a reception coil. Here, a system is configured such that a resonance frequency of the primary coil and a resonance frequency of the secondary coil are the same to use resonance mode energy coupling between the coils.
Implementation Method 4
measuring a coil current generated according to application of the ping and obtaining an envelope of the measured coil current
Data Source
AI summary
A control method for an inductive power supply (IPS), according to one embodiment of the present invention, can comprise the steps of: applying a ping for sensing an object; measuring a coil current; sensing the object on the basis of the coil current measurement result; transmitting, to the object, the minimum power for waking up a communication unit of the object, wherein the communication unit performs communication by using an out-of band communication protocol; receiving, from the object, pairing information through the out-of band communication protocol so as to perform pairing with the object; and transmitting main power to the paired object.