Multi-Coil Wireless Charging With Adaptive Foreign Object Avoidance
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Solution Overview
Problem
Existing wireless charging systems face challenges in adapting to the increasing complexity of mobile devices and changing form factors, as they often enter a permanent foreign object detection (FOD) state when foreign objects are present, leading to unnecessary power loss and system noise, and fail to efficiently charge multiple devices simultaneously.
Innovation Solution
The implementation of a wireless charging device with a matrix configuration of charging cells and a controller that uses passive ping techniques for dynamic foreign object detection, allowing the system to selectively activate coils and avoid a permanent FOD state by reconfiguring the charging surface to continue charging operations around foreign objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If foreign object detection is implemented using traditional methods, then foreign objects can be detected, but the system enters a permanent FOD state causing power loss and noise
Solution Approach 1:
The system dynamically adjusts the charging configuration by selectively activating or deactivating specific coils based on real-time foreign object detection results. Instead of entering a permanent FOD state, the system adapts its operation by reconfiguring which coils are active, thereby maintaining power transfer efficiency while avoiding energy waste associated with permanent shutdown states.
Solution Approach 2:
The charging surface is divided into multiple independent coils that can be individually controlled. When a foreign object is detected in proximity to certain coils, only those specific coils are deactivated or adjusted, while other coils continue to operate normally. This segmentation allows the system to maintain charging functionality in unaffected areas rather than shutting down the entire system.
2Reliability
If traditional FOD detection is used, then foreign objects are detected, but system noise increases
Solution Approach 1:
The system uses dynamic coil selection and activation based on real-time detection data. By selectively engaging only the coils needed for current charging operations and avoiding activation of coils near detected foreign objects, the system minimizes electromagnetic interference and noise generation while maintaining effective foreign object detection capabilities.
3Adaptability or versatility
If multi-coil configuration is implemented, then charging versatility improves, but device complexity increases
Solution Approach 1:
The controller dynamically manages the multi-coil configuration by automatically selecting optimal coil combinations based on device position, size, and charging requirements. This dynamic management simplifies the user experience while maintaining the versatility benefits of multiple coils, as the system autonomously handles the complexity of coordinating multiple charging elements.
Solution Approach 2:
The multi-coil system is managed through independent control of each coil or coil group, allowing selective activation based on detection results. This segmented approach to coil management reduces overall system complexity by enabling localized control rather than requiring coordinated management of all coils simultaneously, making the system easier to control while maintaining versatility.
4Object-affected harmful factors
If coils are deactivated due to FOD, then foreign object heating is prevented, but charging efficiency decreases
Solution Approach 1:
The system segments the charging surface into independently controllable coil regions. When foreign objects are detected, only the specific coils in proximity to those objects are deactivated or adjusted, while other coils continue to provide charging power efficiently. This localized response prevents foreign object heating without sacrificing overall charging efficiency that would result from system-wide shutdown.
Solution Approach 2:
The system dynamically reconfigures active coils based on real-time foreign object detection, maintaining optimal charging efficiency by keeping unaffected coils operational. This dynamic adaptation allows the system to prevent foreign object heating through selective coil deactivation while simultaneously preserving charging efficiency by continuing power transfer through remaining active coils.
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 solution enables efficient and adaptive wireless charging by dynamically avoiding foreign objects, reducing power dissipation, and maintaining charging capabilities for multiple devices, even when foreign objects are present, thereby improving charging efficiency and versatility.
Implementation Method 1
a first plurality of switches in the charging device are configured to couple a first charging coil in the plurality of charging coils to a battery charging power source... a second plurality of switches in the charging device are configured to couple a second charging coil in the plurality of charging coils to the battery charging power source
Implementation Method 2
detecting the presence of a foreign object in proximity to at least one charging coil of a plurality of charging coils in the charging device that is selected for supplying charging energy to a receiving device
Data Source
AI summary
Systems, methods and apparatus for wireless charging are disclosed. A charging device has a plurality of charging cells provided on a charging surface, a charging circuit and a controller. The controller may be configured detect the presence of a foreign object in proximity to at least one charging coil of a plurality of charging coils in the charging device that is selected for supplying charging energy to a receiving device. Additionally, the controller may be configured to determine whether one or more other charging coils is capable of supplying charging energy to the receiving device, and determine, for each of the one or more other charging coils, whether the foreign object is in proximity thereto. Further, the controller may be configured to select at least one of the one or more other charging coils not in proximity to the foreign object for supplying charging energy to the receiving device.