Capacitive sensing for detecting battery deformation

Abstract

This document describes capacitance sensing techniques for detecting battery deformation during wireless charging of a rechargeable battery. An example system includes a processor that detects placement of a mobile device having a rechargeable battery on a wireless charger. Before or during the charging session, the processor obtains capacitance values from a plurality of capacitive sensors integrated into or on the wireless charger. The processor analyzes the capacitance values and determines whether they are indicative of a deformation of the rechargeable battery, which may be caused by an expansion or an increase. In response to determining that the capacitance value indicates a deformation of the rechargeable battery, the processor does not initiate or terminate the charging session. In this manner, the described techniques and systems may monitor battery swell and protect consumers and their mobile devices from battery swell.

Description

Background Art

[0001] Mobile devices (e.g., smartphones) with rechargeable batteries have become ubiquitous. However, batteries may swell and experience thermal runaway, especially during charging, due to the accumulation of internal gases (e.g., outgassing). Outgassing can be caused by a variety of factors, including poor manufacturing, manufacturing defects in the battery cells, overcharging, deep discharge, physical damage, exposure to excessive temperatures, or natural aging. Battery swelling may release hazardous and flammable gases, accelerate the loss of battery capacity (and device run time), or damage the mobile device. Wireless charging systems (such as Chargers and other inductive chargers) cannot detect battery deformation, putting battery cells and human safety at risk. Summary of the invention

[0002] This document describes capacitive sensing techniques for detecting battery deformation during wireless charging of a rechargeable battery in a mobile device (e.g., a smartphone). An example system includes a processor that detects placement of a mobile device having a rechargeable battery on a wireless charger. Prior to initiating a charging session or during an active charging session, the processor obtains capacitance values ​​from a plurality of capacitive sensors integrated into or on the wireless charger. The processor analyzes the capacitance values ​​and determines whether they indicate deformation of the rechargeable battery, which may be caused by swelling or growth. Swelling or growth typically results in a variable distance or air gap between the surface of the wireless charger and the mobile device. In response to determining that the capacitance values ​​indicate deformation of the rechargeable battery, the processor does not initiate or terminates the charging session. In this way, the described techniques and systems can monitor battery swelling and protect consumers and their devices.

[0003] This document also describes methods performed by the systems summarized above and other configurations set forth herein, as well as computer-executable instructions and devices for performing these methods.

[0004] This summary introduces simplified concepts related to capacitive sensing for detecting battery deformation during wireless charging of a rechargeable battery as described in the detailed description and drawings. This summary is not intended to identify essential features of the claimed subject matter, nor is it intended to determine the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Details of one or more aspects of capacitive sensing systems and techniques for detecting battery deformation are described in this document with reference to the following drawings. The same numbers are generally used throughout the drawings to reference similar features and components: Figure 1 shows an example environment in which capacitive sensing may be employed to detect battery deformation in accordance with the techniques of this disclosure; Figure 2 An example configuration of a vehicle including a capacitive sensing system for detecting battery deformation during wireless charging is shown; Figure 3-1 to Figure 3-3 An example wireless charger that performs capacitive sensing to detect battery deformation is shown; Figure 4-1 to Figure 4-4 shows an example charging session in accordance with the techniques of this disclosure, where capacitive sensing is used to detect battery deformation; Figure 5-1 and Figure 5-2 An example flow chart illustrating capacitive sensing for detecting battery deformation during wireless charging is shown; and Figure 6 An example method of capacitive sensing for detecting battery deformation during wireless charging is shown. DETAILED DESCRIPTION Overview

[0006] As described above, rechargeable batteries may swell and deform during charging. This swelling may cause the rechargeable battery to explode due to gas accumulation and thermal runaway, or cause the rechargeable battery to be punctured by other components within the consumer product, thereby releasing hazardous and flammable gases. Swelling may also accelerate capacity loss and prevent a full charge from being achieved.

[0007] Some wireless charging systems may include diagnostics based on temperature or humidity sensors. However, these wireless charging systems do not monitor or detect battery deformation during charging. Because of the incomplete warning systems that wireless chargers can provide, rechargeable batteries and consumers are at risk during wireless charging of common everyday consumer products (e.g., smartphones).

[0008] In contrast, the present document describes techniques and systems for capacitive sensing to detect battery deformation during wireless charging. As an example, a wireless charging monitor detects placement of a mobile device (e.g., a smartphone or other consumer product) with a rechargeable battery on a wireless charger. Prior to or during a charging session, the wireless charging monitor obtains capacitance values ​​from a plurality of capacitive sensors integrated into or on the wireless charger. The wireless charging monitor analyzes the capacitance values ​​and determines whether they indicate battery deformation. In response to determining that the capacitance values ​​indicate battery deformation, the wireless charging monitor does not start or stop the charging session. In this way, the described techniques and systems can monitor battery expansion and provide another layer to protect consumers and their devices from potential damage, harm, and danger that could result from further progression of battery expansion.

[0009] This example is just one example of the described capacitive sensing techniques and systems for detecting battery deformation, which can be used to control and manage the charging of a rechargeable battery or other energy storage device. This document describes other examples and implementations. Wireless charger environment

[0010] Figure 1 An example environment is shown in which capacitive sensing may be employed to detect battery deformation in accordance with the techniques of this disclosure. Figure 1 The interior of a host vehicle 102 is shown including a wireless charger 104. The wireless charger 104 includes a capacitive sensor 106 and a wireless charging monitor 108. A driver or passenger of the host vehicle 102 is charging a smartphone 110 on the wireless charger 104. The smartphone 110 includes a rechargeable battery 112.

[0011] The host vehicle 102 may be a motor vehicle (e.g., a car, automobile, motorcycle, bus, tractor, semi-trailer truck), a watercraft (e.g., a boat), or an aircraft (e.g., an airplane) that includes a wireless charger 104. In other implementations, the wireless charger 104 may be located in a home, office, or other type of building. In such an implementation, the wireless charger 104 may be a stand-alone product or integrated into another product (e.g., a desktop organizer, a nightstand). In other implementations, the smartphone 110 may be another type of mobile device or consumer product (e.g., a laptop, a smartwatch, or a tablet) with a rechargeable battery.

[0012] The rechargeable battery 112 is an energy storage device. For example, the rechargeable battery 112 may be a lithium-ion battery used in a smartphone. The rechargeable battery 112 may also be another storage device in the host vehicle 102 (e.g., a battery associated with an airbag system or a starter battery). The terms "battery" or "energy storage device" are used interchangeably in this document to refer to one or more electrochemical cells and other energy storage devices that are configured to provide electrical energy to a connected energy source or load during discharge and to accept and store electrical energy during charging from an energy source.

[0013] Rechargeable batteries and other energy storage devices are used in many personal, commercial and automotive applications. These devices come in a variety of sizes and chemistries, including, for example, zinc-carbon, alkaline, lead-acid, nickel-cadmium, nickel-zinc, nickel-metal hydride and lithium-ion. In addition, batteries often must perform under a variety of conditions, including harsh environments (e.g., extreme temperatures). Common applications include computers, medical devices, communications equipment, data centers, aircraft, hybrid vehicles and electric vehicles.

[0014] The wireless charger 104 may be, for example, A wireless charger or another inductive charger. The IEEE 802.11 standard is an interface standard for wireless power transfer using inductive charging that allows compatible consumer products (such as smartphones 110) to charge wireless power when placed on a wireless power supply. The wireless charger 104 may be configured to charge their batteries (e.g., rechargeable battery 112) when placed on a charging pad. In other implementations, the wireless charger 104 may be another type of wireless charger.

[15] The wireless charger 104 includes a plurality of capacitive sensors 106 to obtain a measurement of the capacitance between each sensor electrode and the rechargeable battery 112 or a product (e.g., smartphone 110) containing the rechargeable battery 112. The capacitive sensors 106 may be arranged in a layer of the wireless charger 104 in a horizontal array, a vertical array, or a combination thereof.

[0016] The wireless charging monitor 108 reads or obtains the measurement value from the capacitance sensor 106 and determines whether the capacitance value or the change in capacitance value over time indicates deformation of the rechargeable battery 112. For example, when the smartphone 110 without battery deformation is placed on the wireless charger 104, the capacitance measurement value across the capacitance sensor 106 is generally consistent or nearly uniform because both the smartphone surface and the array surface are flat. The capacitance measurement value may have a typical steady-state value (e.g., a saved profile) expected for a device without any battery deformation. However, if the rechargeable battery 112 is deformed, the smartphone surface becomes rounded, resulting in a much lower capacitance measurement value measured at the capacitance sensor 106 located below or near the rounding. The capacitance measurement value deviates too far from the steady-state value set when no deformation occurs. As described in more detail below, the capacitance reduction is caused by the air gap formed between the smartphone 110 and the top surface of the wireless charger 104. Air has a much lower dielectric constant than plastic, resulting in a significantly lower capacitance measurement value produced by a plastic-air-plastic dielectric stack than a plastic-to-plastic stack.

[0017] Figure 2 An example configuration 200 of a host vehicle 102 including a capacitive sensing system for detecting battery deformation during wireless charging is shown. Battery deformation is a sign of damage or failure of a rechargeable battery 112. The host vehicle 102 may include a wireless charger 104, a display 202, one or more processors 204, a computer readable storage medium (CRM) 206, and one or more communication devices 212. The host vehicle 102 also includes a wireless charging monitor 108. As shown in FIG. Figure 1 As shown, a driver may use a wireless charger 104 to charge a rechargeable battery 112 of their smartphone 110 or other mobile device.

[0018] As described in more detail below, the wireless charger 104 uses one or more arrays of capacitive sensors 106 to detect changes in the surface geometry of the smartphone 110 or rechargeable battery 112 (e.g., from flat to rounded or bowed) by measuring changes in capacitance between sensor electrodes of one or more capacitive sensors 106 and the rechargeable battery 112 (or a mobile device containing the rechargeable battery 112). Similar methods can be used with rechargeable batteries including cylindrical cells, cylindrical battery packs, or prismatic cells. The capacitive sensors 106 occasionally (e.g., periodically) collect capacitance values ​​associated with the rechargeable battery 112 before or during a charging session to detect battery deformation. The capacitance values ​​are provided to the wireless charging monitor 108.

[0019] The display 202 may output graphical information to provide the driver or passenger with information about the status of the charging session. Information including a notification of a detected potential battery deformation may be output. Additionally, the wireless charging monitor 108 may notify the driver of a previous charging error detected for a particular mobile device (e.g., a smartphone 110) and ask the user whether to start or continue the current charging session. For example, the display 202 may be integrated into a center console or dashboard of the host vehicle 102.

[0020] The processor 204 (e.g., an energy processing unit, an electronic control unit, or a microcontroller) may be a microprocessor or a system on a chip. The processor 204 executes instructions stored in the CRM 206, one or more disks, memories, or other non-transitory computer-readable storage media. For example, the processor 204 processes the measurements from the capacitance sensor 106 and executes instructions loaded from the CRM 206 that cause the processor 204 to monitor the capacitance value associated with the rechargeable battery 112 and determine whether battery deformation has occurred.

[0021] The wireless charging monitor 108 may be stored in the CRM 206. The wireless charging monitor 108 may include a capacitance comparator 208 and one or more saved profiles 210. The capacitance comparator 208 periodically analyzes the capacitance values ​​from the capacitance sensor 106 to determine whether battery deformation has occurred. As described below, battery deformation may be indicated by a large variance or standard deviation of the capacitance values, an average capacitance value below a predetermined threshold or a previous capacitance average, or an individual capacitance value (e.g., a minimum value) below a threshold.

[0022] The saved profiles 210 may also be stored in the CRM 206 or another CRM. The wireless charging monitor 108 may record or index the capacitance values ​​of individual mobile devices (e.g., smartphones 110) to assist in the analysis performed by the capacitance comparator 208. The saved profiles 210 may also include previous charging errors for a particular device so that the wireless charging monitor 108 may provide an indication or alert to the user on the display 202 or the display of the smartphone and request input from the user whether to initiate or continue a charging session. The saved profiles 210 may also include default profiles for popular models and types of mobile devices to assist in detecting battery deformation during the first charging session of a particular device on the wireless charger 104. The saved profiles 210 may also include knowledge of the age of each index or entry therein, which may be continually updated with new entries throughout the life of the battery.

[0023] The communication device 212 may include a sensor interface and a vehicle-based system interface. For example, when separate components of the wireless charger 104 and the wireless charging monitor 108 are integrated within the host vehicle 102, the sensor interface and the vehicle-based system interface transmit data (e.g., capacitance value, charging error) over a communication bus of the host vehicle 102. The communication device 212 may also facilitate the exchange of data (including charging errors and driver inputs) via a wireless link between a remote system (e.g., a consumer product) and the host vehicle 102. The communication device 212 may include a wireless communication interface via Wi-Fi, a wireless local area network (WLAN), a dedicated short-range communication, The hardware, software and / or firmware required to communicate for Vehicle-to-Everything (V2X) or cellular communications.

[0024] Figure 3-1 to Figure 3-3 An example wireless charger that performs capacitive sensing to detect battery deformation is shown. Figure 3-1 to Figure 3-3 A wireless charger can be, for example, Figure 1 and Figure 2 A wireless charger 104 is provided. Figure 3-1 A simplified diagram of the structure of the wireless charger 104 is provided, which may include Figure 3-1 Additional layers and components not shown or discussed.

[0025] The wireless charger 104 may include a top cover 302, a printed circuit board (PCB) 304, and a bottom cover 306. The top cover 302 provides a surface on which a mobile device (e.g., a smartphone 110) may be placed to initiate a charging session. A plurality of capacitive sensors 106 may be affixed to or on a bottom or underside surface of the top cover 302. The wireless charging monitor 108 utilizes the capacitive sensors 106 to detect changes in the surface geometry of a rechargeable battery 112 or a mobile device containing the rechargeable battery 112 by measuring changes in capacitance at or within the capacitive sensors 106. As described in more detail below, in the case of a deformed battery, the surface of the rechargeable battery 112 or smartphone 110 becomes rounded, resulting in much lower capacitance measured at the capacitive sensors 106 at the edge or center (depending on the direction of the deformation).

[0026] like Figure 3-1 to Figure 3-3 As shown, the capacitive sensors 106 may be arranged in different sensor arrays 308. Figure 3-1 , sensor array 308-1 includes a two-dimensional array of capacitive sensors 106 having four capacitive sensors 106 in a longitudinal or horizontal direction and nine capacitive sensors 106 in a transverse or vertical direction. In other implementations, sensor array 308-1 may include more or fewer capacitive sensors 106 along the longitudinal or transverse direction. Sensor array 308-1 may also include a sparsely populated array (e.g., in a waffle design) in which one or more capacitive sensors 106 are missing along the longitudinal or transverse direction.

[0027] exist Figure 3-2 , the sensor array 308-2 includes five capacitive sensors 106 arranged in the portrait direction. The sensor array 308-2 is ideally located near the midpoint along the landscape direction so that a capacitance value can be obtained at or near the landscape center of the sensor array 308-2 along the longitudinal axis or horizontal axis of the mobile device. In other implementations, the sensor array 308-2 may include more or fewer capacitive sensors 106. The sensor array 308-2 may also be arranged in a landscape direction opposite to the portrait direction.

[0028] exist Figure 3-3 In the embodiment, the sensor array 308-3 includes a longitudinal array (having five sensors) and a transverse array (having nine sensors) of capacitive sensors 106 forming a T-shape or a cross. The longitudinal and transverse arrays of the sensor array 308-3 are ideally located near the midpoint along the transverse direction and the longitudinal direction, respectively. In other implementations, the sensor array 308-3 may include more or fewer capacitive sensors 106 in the longitudinal array or the transverse array.

[0029] PCB 304 may include control circuitry for wireless charger 104. Additionally, charging coil 310 may be located on or secured to PCB 304. Charging coil 310 generates an oscillating magnetic field that may induce a charging current in rechargeable battery 112.

[0030] Figure 4-1 to Figure 4-4 An example charging session according to the techniques of this disclosure is shown, in which capacitive sensing is used to detect battery deformation. Figure 4-1 In the case of smartphones (e.g. Figure 1 The smart phone 110 is placed on a wireless charger (e.g., Figure 1 In this example illustration, the wireless charger 104 includes four capacitive sensors 106, including a first capacitive sensor 106-1, a second capacitive sensor 106-2, a third capacitive sensor 106-3, and a fourth capacitive sensor 106-4. The capacitive sensors 106 are fixed to the bottom surface of the top cover 302.

[0031] Many mobile devices with rechargeable batteries (e.g., smartphone 110) are designed with planar (flat) surfaces. Similarly, embedded battery packs are typically designed so that at least one surface is planar in at least one dimension. As a result, Figure 4-1 As shown, the smartphone 110 with the undeformed rechargeable battery 112 is laid flat on the top cover 302 .

[0032] exist Figure 4-2 , chart 402-1 shows the Figure 4-1 The capacitance value 404 of each capacitive sensor 106 associated with the charging session. Figure 4-1 When a smartphone 110 (with a 402-1000) is placed on the wireless charger 104, the capacitance value 404 is fairly consistent or uniform across the array of transcapacitive sensors 106 because the distance between the smartphone 110 and the capacitive sensor 106 is uniform. The output of the capacitive sensor 106 is presented in counts, which are similar to or proportional to the capacitance, but not equal to the capacitance. For example, in the graph 402-1, the capacitance values ​​404 of the capacitive sensor 106 are approximately 240, 225, 255, and 210 counts, respectively.

[0033] Capacitive sensors 106 measure the capacitance of the dielectric stack, which includes top cover 302 and smartphone 110. The stacked dielectric can be modeled as a series of capacitors, where the total capacitance C measured by each capacitive sensor 106 is represented by equation (1): Where C1 and C2 represent the capacitance of the top dielectric (e.g., smartphone 110) and the bottom dielectric (e.g., top cover 302), respectively, and are determined using equation (2): Where C0 is determined using formula (3): Where k1 and k2 represent the dielectric constants of the top dielectric and the bottom dielectric, respectively, A represents the plate area, d1 and d2 represent the thickness of the top dielectric and the bottom dielectric, respectively, and ε0 represents the dielectric constant of space (approximately 8.854 pF / m). If there are two independent parallel plate capacitors connected in series, the composite capacitance can be determined by a product-sum calculation, and the total capacitance will always be less than the smaller of the two capacitors. However, the combination of the wireless charger 104 and the smartphone 110 can be considered as a single capacitor constructed by stacking dielectrics within a shared plate set. As a result, the capacitance contributed by each dielectric (e.g., the top cover 302 and the smartphone 110) is proportional to the thickness of each dielectric and the total thickness of the dielectric stack. Figure 4-1 The capacitance of the dielectric stack shown in can be determined by rewriting equations (1) to (3) as equations (4) and (5): C=k s C0 (4) where k s is the dielectric constant of the stack, which is determined using equation (5):

[0034] exist Figure 4-3 In the embodiment of the present invention, while the smartphone 110 is charging on the wireless charger 104 (or through a series of charging sessions), venting has occurred within the rechargeable battery 112, causing the rechargeable battery 112 to expand. The expansion also deforms the smartphone 110 so that the bottom surface is no longer flat or planar. Instead, a bulge is formed along the central lateral or vertical axis of the smartphone 110, resulting in an air gap between the smartphone 110 and the top cover 302 above the first capacitive sensor 106-1 and the fourth capacitive sensor 106-4. The deformation of the smartphone 110 indicates that the rechargeable battery 112 has been damaged or failed and should be replaced.

[0035] like Figure 4-4As shown in the graph 402-2, when the rechargeable battery 112 has been deformed, the capacitance between the smartphone 110 and some of the capacitive sensors 106 (specifically, the first capacitive sensor 106-1 and the fourth capacitive sensor 106-4 in this example) changes due to the air gap formed between the top cover 302 and the smartphone. For example, in the graph 402-2, the capacitance values ​​404 of the capacitive sensors 106 are approximately 50, 190, 205, and 40 counts, respectively. When the surface of the smartphone becomes rounded, the capacitance measured at the edge capacitive sensors (e.g., the first capacitive sensor 106-1 and the fourth capacitive sensor 106-4) is much lower than the capacitance measured at the middle capacitive sensors (e.g., the second capacitive sensor 106-2 and the third capacitive sensor 106-3). Because air (e.g., about 1) has a much lower dielectric constant than plastic (e.g., about 2.7) in the smartphone 110 and the top cover 302, the resulting capacitance of the plastic-air-plastic dielectric stack is significantly lower than the capacitance of the plastic-to-plastic stack without an air gap. Similar observations can be made for cylindrical cells, cylindrical battery packs, and prismatic cells to detect battery expansion due to venting. Example Method

[0036] Figure 5-1 and Figure 5-2 An example flow chart 500 for capacitive sensing for detecting battery deformation during wireless charging is shown. The flow chart 500 is shown as operations (or actions) being performed, but is not necessarily limited to the order or combination of operations shown herein. In addition, any one or more operations may be repeated, combined, or reorganized to provide other flow charts. In the following discussion, reference may be made to Figure 1 to Figure 4-4 Entities detailed in , reference is made to them for example only. The technology is not limited to being performed by one entity or multiple entities. Although flowchart 500 provides example operations of a mobile device, the same or similar operations can be implemented to detect deformation in various systems (including embedded batteries and backup batteries in vehicles.)

[0037] At operation 502, the placement of a mobile device (e.g., smartphone 110) on a wireless charger is detected. For example, a driver may place their smartphone 110 on the wireless charger 104 during their commute. The wireless charging monitor 108 detects the presence of the smartphone 110 on the wireless charger 104.

[0038] At operation 504, it is determined whether the mobile device has been previously identified. For example, the wireless charging monitor 108 determines whether the mobile device has been previously identified as a smartphone 110. The smartphone 110 may send a data packet identifying itself and providing configuration and setup information to the wireless charger 104. The wireless charging monitor 108 may then check the saved profile 210 associated with the smartphone 110.

[0039] At operation 506 , if the mobile device has been previously identified, a saved profile of the mobile device is retrieved. For example, if the smartphone 110 has been previously identified by the wireless charge monitor 108 , the wireless charge monitor 108 retrieves the saved profile 210 associated with the smartphone 110 .

[0040] At operation 508 , it is determined whether a previous charging error is recorded. For example, the wireless charging monitor 108 determines whether the saved profile 210 or another record associated with the smartphone 110 indicates that a previous charging error is recorded for the smartphone 110 .

[0041] At operation 510, if a previous charging error has not been recorded, the capacitive sensor is read. Additionally, if the mobile device has not been previously identified at operation 504, the flowchart 500 proceeds to operation 510. For example, if a charging error has not been recorded for the smartphone 110, the wireless charging monitor 108 obtains or reads the capacitance value 404 from the capacitive sensor 106.

[0042] At operation 512, the capacitance value of the mobile device is updated. For example, the capacitance comparator 208 updates the long-term average (e.g., over multiple measurement cycles) and the short-term average (e.g., for the most recent measurement cycle) of the capacitance value. The capacitance comparator 208 may also determine the long-term and short-term standard deviation, variance, range, and / or minimum value of the capacitance value.

[0043] At operation 514, a time to capture or read the next capacitance sensor measurement is set or otherwise determined. For example, the wireless charge monitor 108 sets or reads from a predefined value the time to read or obtain the next set of capacitance measurements or values ​​from the capacitance sensor 106. The wireless charge monitor 108 may be preprogrammed to obtain or read the capacitance sensor 106 at a particular frequency (e.g., every 10 seconds).

[0044] At operation 516, device charging is initiated or resumed. For example, the wireless charger 104 initiates, resumes, or continues charging the smartphone 110. The wireless charging monitor 108 may not initiate a charging session until the capacitance comparator 208 determines that the capacitance value 404 does not indicate battery deformation.

[0045] At operation 518, a determination is made as to whether it is time to read the capacitive sensor. For example, the wireless charging monitor 108 determines whether it is time for the next measurement cycle of the capacitive sensor 106. If it is time to read the capacitive sensor 106 (e.g., for the next measurement cycle), the flowchart 500 performs an optional operation 528, which is described in more detail below, and / or returns to operation 510 (e.g., as determined by Figure 5-1 and Figure 5-2 "C" in the figure).

[0046] At operation 520 , if it is not yet time to read the capacitive sensor (again), it is determined whether the mobile device has been removed from the wireless charger. For example, the wireless charging monitor 108 determines whether the smartphone 110 has been removed from the wireless charger 104 .

[0047] If the mobile device has been removed from the wireless charger, the flowchart 500 proceeds to operation 526 and terminates charging. For example, if the wireless charging monitor 108 determines that the smartphone 110 has been removed from the wireless charger 104, the charging session or charging of the wireless charger 104 is terminated.

[0048] At operation 522, if the mobile device has not been removed, it is determined whether the capacitance value indicates deformation of the rechargeable battery or the mobile device. For example, if the smartphone 110 has not been removed from the wireless charger 104, the capacitance comparator 208 determines whether the capacitance value 404 indicates deformation or expansion of the rechargeable battery 112. If the difference between the short-term average of the capacitance value 404 and the long-term average of the capacitance value 404 (e.g., all previous measurement cycles or a set number of previous measurement cycles) is greater than a threshold, the capacitance comparator 208 can identify potential deformation of the rechargeable battery 112. Because the expansion may introduce air gaps in the surface of the smartphone 110 adjacent to the top cover 302, the short-term average will be significantly lower than the long-term average before the deformation.

[0049] Similarly, capacitance comparator 208 may identify deformation based on a short-term standard deviation, variance, or range that is greater than a corresponding threshold. Deformation may also be indicated by a difference between short-term and long-term standard deviations, variances, or ranges that is greater than another threshold. A short-term minimum or comparison to a long-term minimum may indicate that rechargeable battery 112 has swollen.

[0050] At operation 524, if the capacitance value indicates deformation, the error condition is recorded in the saved profile and the user is alerted. For example, the wireless charging monitor 108 records the error condition in the saved profile 210 associated with the smartphone 110 in response to the capacitance value 404 indicating deformation of the rechargeable battery 112 or the smartphone 110. The wireless charging monitor 108 also provides an alert of the error condition to the user (e.g., the driver). The alert can be provided on a display in the host vehicle 102 (e.g., an infotainment display in the center console), a display integrated into or on the wireless charger 104 (e.g., a small screen or LED that can indicate an error condition), or on the smartphone 110.

[0051] At operation 526 , charging is terminated. For example, the wireless charging monitor 108 causes the wireless charger 104 to terminate the charging session or stop charging the smartphone 110 .

[0052] At optional operation 528, if the capacitance value does not indicate deformation, charging may be suspended and flowchart 500 proceeds to operation 518 (eg, Figure 5-1 and Figure 5-2 4. In some embodiments, the wireless charging monitor 108 may be configured to monitor the charging session in accordance with the embodiment of the present invention. For example, the wireless charging monitor 108 may optionally pause the charging session in response to the capacitance value 404 not indicating deformation of the smart phone 110, and then continue to read the capacitance value 404 from the capacitance sensor 106. The wireless charging may be paused so that any radiated emissions from the wireless charger 104 do not affect the capacitance measurement in operation 512. In some wireless chargers or implementations, such an effect may not occur and the wireless charging may not need to be paused. In other implementations, the wireless charging monitor 108 may skip operation 528 and proceed directly to operation 510.

[0053] At operation 530, in response to a previous charging error of the mobile device recorded in the saved profile (eg, Figure 5-1 and Figure 5-2 ), indicating the previous charging error to the user and asking the user whether to continue the charging session. For example, the wireless charging monitor 108 can indicate the previous charging error on a display (e.g., in the host vehicle 102, on the wireless charger 104, or on the smartphone 110) and prompt the user to indicate whether charging should be continued or started.

[0054] At operation 532, it is determined whether the user agrees to continue or initiate charging. For example, the wireless charging monitor 108 determines whether the user indicates that the charging session of the smartphone 110 should continue or be initiated. The driver may determine to initiate the charging session because a visual inspection of the smartphone 110 indicates that it is not deformed. The driver may also know that the rechargeable battery 112 was replaced or repaired after a previous error occurred.

[0055] If the user agrees to continue or start charging, flowchart 500 performs optional operation 528 and / or proceeds to operation 510 to read the capacitive sensor (eg, Figure 5-1 and Figure 5-2 In this case, the wireless charging monitor 108 may clear or delete the previous charging error from the saved profile 210 associated with the smartphone 110. If the user does not agree to continue or start charging, the flowchart 500 proceeds to operation 526 and terminates charging.

[0056] Figure 6 An example method 600 for capacitive sensing of battery deformation during wireless charging is shown. The method 600 is shown as operations (or actions) being performed, but is not necessarily limited to the order or combination of operations shown herein. In addition, any one or more operations may be repeated, combined, or reorganized to provide other methods. In the following discussion, reference may be made to Figure 1 to Figure 5-2 The entities or operations detailed in the foregoing are referenced for example only. The technology is not limited to one or more operations being performed by one or more entities.

[0057] At step 602, placement of a mobile device with a rechargeable battery on a wireless charger is detected. For example, the wireless charging monitor 108 can detect that a mobile device with a rechargeable battery 112 (including a smartphone 110) is located on the wireless charger 104. The mobile device can also include a tablet, a computer, a smart watch, or some other type of consumer product with a rechargeable battery. The wireless charger 104 can be a stand-alone inductive charging pad or an inductive charging pad integrated into another device (e.g., a charging pad integrated into a portion of the host vehicle 102).

[0058] At optional step 604, a charging session for the rechargeable battery is initiated using the wireless charger. For example, the wireless charging monitor 108 may cause the wireless charger 104 to initiate or start a charging session for the rechargeable battery 112. In other implementations, the charging session may be initiated after confirming that the capacitance value 404 does not indicate battery deformation.

[0059] Prior to initiating a charging session, the wireless charging monitor 108 may obtain or determine an identification of a particular mobile device (e.g., a smartphone 110) and retrieve a saved profile 210 associated with the mobile device. Similarly, a default profile associated with that type of mobile device (e.g., if this is the first charging session of the smartphone 110 by the wireless charger 104) or a default profile for a popular model of mobile device of that type. The wireless charging monitor 108 may also determine whether a previous charging error has been recorded for the mobile device based on the saved profile 210 or based on the identification of the mobile device. If a previous charging error has occurred for a particular mobile device, the wireless charging monitor 108 may cause the particular mobile device to be indicated on a user interface and prompt the user to indicate whether to initiate (or continue) a charging session. Depending on the installation of the wireless charger 104, the user interface may be provided on a display 202 in the host vehicle 102, a display associated with or integrated into the wireless charger 104, or a display of the mobile device. For example, the communication device 212 may include Or other short-range communication capabilities to create a user interface for advanced charging features and display alerts.

[0060] In response to obtaining user input indicating to start or continue a charging session, the wireless charging monitor 108 causes the wireless charger 104 to start or continue a charging session. In response to obtaining user input indicating not to start or continue a charging session, the wireless charging monitor 108 causes the wireless charger 104 to terminate or not start a charging session.

[0061] At step 606, capacitance values ​​are obtained from a plurality of capacitance sensors integrated into or on the wireless charger. For example, the wireless charging monitor 108 obtains or reads the capacitance value 404 from the capacitance sensor 106. As described above, the capacitance sensor 106 can be arranged between the inductive charging circuit and the top cover 302 (e.g., the top layer), and the smartphone 110 is placed on the top cover 302 for charging. For example, the capacitance sensor 106 is fixed to the underside of the top cover 302. The capacitance sensor 106 can be arranged in a horizontal (or longitudinal) array, a vertical (or transverse) array, or a combination of a horizontal array and a vertical array. In this way, the capacitance sensor 106 is arranged to obtain the capacitance value 404 from different positions along the horizontal (or longitudinal) axis or the vertical (or transverse) axis of the smartphone 110.

[0062] In some implementations, in response to detecting or receiving notification of a vibration event (e.g., host vehicle 102 traveling on train tracks), wireless charging monitor 108 can ignore or delete capacitance values ​​404 for measurement cycles of a charging session. Vibration events can be detected using an inertial measurement unit of wireless charger 104, host vehicle 102, or smartphone 110.

[0063] At step 608, it is determined whether the capacitance values ​​indicate deformation of the rechargeable battery. For example, the capacitance comparator 208 can analyze the capacitance values ​​404 and determine whether they indicate battery deformation caused by expansion or growth of the rechargeable battery 112 resulting in a variable distance or air gap between the top surface of the wireless charger and the bottom surface of the smartphone 110. Battery deformation relative to placement on the wireless charger can result in a change in the air gap distance between the bottom surface of the smartphone 110 and the top surface of the wireless charger 104. In other words, the deformation can result in portions of the bottom surface of the smartphone 110 being separated from the top surface of the wireless charger 104 to a greater extent than other portions of the smartphone 110.

[0064] Capacitance comparator 208 may use various analytical and statistical methods to identify battery deformation. For example, battery deformation may be determined based on at least one of the following: the current (or short-term) average value of capacitance value 404 is less than the previous average value (or long-term or rolling average value) of capacitance value 404 or less than a threshold average value, which may be set for a specific device based on an initial average value or based on a device type; the standard deviation of capacitance value 404 is greater than the previous standard deviation of capacitance value 404 or a threshold standard deviation value; or at least one of capacitance value 404 (e.g., a minimum capacitance value) is below a threshold. The threshold may be determined based on a saved profile 210 or a default profile associated with smartphone 110.

[0065] In other implementations, the capacitance comparator 208 may use a machine learning model to identify battery deformation based on the capacitance value 404. The machine learning model may be trained to receive the capacitance value 404 and classify the rechargeable battery 112 as deformed or undeformed. The machine learning model 122 may perform classification, tracking, and / or other tasks related to identifying potential battery deformation during wireless charging.

[0066] For classification, supervised learning techniques can be used to train a machine learning model. For example, the wireless charging monitor 108 or an offline system can train a machine learning model with training data (e.g., valid ground truth data) that includes capacitance values ​​404 labeled as deformed or undeformed. The labels can be applied manually by an engineer or provided by other techniques (e.g., based on data from other charging systems). The training data set can include capacitance values ​​404 similar to those input to the machine learning model 122 during operation of the wireless charger 104.

[0067] The machine learning model 122 can be trained offline, for example, in a training computing system, and then provided for storage and implementation on one or more wireless chargers. For example, the training computing system can include a model trainer. The training computing system can be included in a processor that implements the machine learning model or can be separate from the processor.

[0068] In some implementations, the machine learning model can implement logistic regression, decision trees, or multi-layer perceptrons. If the processor of the wireless charger 104 has limited processing power, these machine learning models can be selected. If the processor has greater processing power, other types of models can be used. Logistic regression uses a sigmoid function to map the final output to an interval between 0 and 1, indicating the probability of the input in each category (e.g., deformed or undeformed). Features extracted from the capacitance value 404 can be used to improve the performance of logistic regression. Decision trees use white box models to show which extracted features are important in classification. A multi-layer perceptron is a feedforward neural network that uses a linear combination of features and a nonlinear activation function to generate a classification output. During the training phase, the weights of the activation function are iteratively updated or learned using a gradient-based optimization method (e.g., via back propagation).

[0069] The wireless charge monitor 108 may also periodically obtain or read the capacitance value 404. Thus, in response to the expiration of the periodic time, the wireless charge monitor 108 obtains or reads a new capacitance value 404 from the capacitance sensor 106 during the charging session. The capacitance comparator 208 determines whether the new capacitance value 404 indicates battery deformation.

[0070] At step 610, the charging session is terminated or not initiated in response to determining that the capacitance value indicates deformation of the rechargeable battery. For example, the wireless charging monitor 108 terminates or does not initiate the charging session in response to determining whether the capacitance value 404 or the analysis of the new capacitance value 404 (e.g., from a later measurement cycle) indicates battery deformation. The wireless charging monitor 108 may also record the charging error or battery deformation in a saved profile 210 associated with the smartphone 110 and alert the user of the potential battery deformation via a display or user interface. Additional Examples

[0071] In the following sections, additional examples are provided.

[0072] Example 1. A wireless charger, the wireless charger comprising: a plurality of capacitive sensors, the plurality of capacitive sensors being integrated into or on the wireless charger; and one or more processors, the one or more processors being configured to: detect placement of a mobile device having a rechargeable battery on the wireless charger; obtain capacitance values ​​from the plurality of capacitive sensors; determine whether the capacitance values ​​indicate deformation of the rechargeable battery; and in response to determining that the capacitance values ​​indicate deformation of the rechargeable battery, terminate or stop initiating a charging session performed by the wireless charger of the rechargeable battery.

[0073] Example 2. The wireless charger of Example 1, wherein a plurality of capacitive sensors are arranged between an inductive charging circuit and a top cover or top layer of the wireless charger in at least one of a horizontal array, a vertical array, or a combination of a horizontal array and a vertical array to obtain capacitance values ​​at different positions along a horizontal axis or a vertical axis of the mobile device.

[0074] Example 3. The wireless charger of Example 2, wherein a plurality of capacitive sensors are fixed to the underside of a top cover or a top layer, and a mobile device is placed on the top cover or the top layer.

[0075] Example 4. A wireless charger of any of the previous examples, wherein the one or more processors are configured to determine that the capacitance values ​​indicate deformation of the rechargeable battery using at least one of the following: determining that an average value of the capacitance values ​​is less than a previous average value of the capacitance values ​​or less than a threshold average value; determining that a standard deviation of the capacitance values ​​is greater than a previous standard deviation of the capacitance values ​​or greater than a threshold standard deviation value; or determining that at least one of the capacitance values ​​is below a threshold.

[0076] Example 5. The wireless charger of any of the previous examples, wherein the one or more processors are configured to use a machine learning model to determine whether the capacitance value indicates deformation of the rechargeable battery to identify the deformation based on the capacitance value.

[0077] Example 6. The wireless charger of any of the previous examples, wherein the one or more processors are further configured to: obtain new capacitance values ​​from the plurality of capacitance sensors during the charging session in response to expiration of a cycle time; and determine whether the new capacitance values ​​indicate deformation of the rechargeable battery.

[0078] Example 7. A wireless charger of any of the previous examples, wherein the one or more processors are further configured to: determine an identification of the mobile device; and retrieve a saved profile or a default profile associated with the identification of the mobile device, wherein the one or more processors are configured to determine whether the capacitance value indicates deformation of the rechargeable battery by comparing the capacitance value to the saved profile or the default profile.

[0079] Example 8. The wireless charger of Example 7, wherein the one or more processors are further configured to: determine whether a previous charging error of the mobile device is recorded based on a saved profile or based on an identification of the mobile device; cause the previous charging error to be indicated on a user interface and inquire the user whether to continue or start the charging session; and in response to obtaining user input indicating to continue or start charging, continue or start the charging session of the rechargeable battery; or in response to or indicating not to continue or start charging, terminate or not start the charging session of the rechargeable battery.

[0080] Example 9. The wireless charger of Example 8, wherein the user interface comprises at least one of a display in a host vehicle in which the wireless charger is installed, a display associated with the wireless charger, or a display of the mobile device.

[0081] Example 10. A wireless charger of any one of Examples 7 to 9, wherein the one or more processors are further configured to: record a charging error associated with an identification of a mobile device in response to the capacitance value indicating deformation of the rechargeable battery; and alert a user via a display of a charging error in response to the capacitance value indicating deformation of the rechargeable battery.

[0082] Example 11. The wireless charger of any of the previous examples, wherein the one or more processors are further configured to: in response to detecting a vibration event, ignore the capacitance value of the period of the charging session, and detect the vibration event using an inertial measurement unit of the wireless charger or a host vehicle on which the wireless charger is installed.

[0083] Example 12. A method comprising: detecting placement of a mobile device having a rechargeable battery on a wireless charger; obtaining capacitance values ​​from a plurality of capacitance sensors integrated into or on the wireless charger; determining whether the capacitance values ​​indicate deformation of the rechargeable battery; and terminating or not initiating a charging session for the rechargeable battery in response to determining that the capacitance values ​​indicate deformation of the rechargeable battery.

[0084] Example 13. The method of Example 12, wherein the mobile device comprises at least one of a smartphone, a tablet, a computer, or a smart watch.

[0085] Example 14. The method of Example 12 or 13, wherein the deformation is caused by expansion or growth of the rechargeable battery, the expansion or growth of the rechargeable battery causing a variable distance or air gap between the top surface of the wireless charger and the bottom surface of the mobile device.

[0086] Example 15. A non-transitory computer-readable medium storing computer-executable instructions which, when executed by a processor, cause the processor to perform the method of any one of Examples 12 to 14. Conclusion

[0087] Although various embodiments of the present disclosure are described in the foregoing description and shown in the accompanying drawings, it should be understood that the present disclosure is not limited thereto, but can be implemented in various ways within the scope of the following claims. From the foregoing description, it will be apparent that various changes can be made without departing from the scope of the present disclosure defined by the following claims.

Claims

1. A wireless charger, comprising: a plurality of capacitive sensors, wherein the plurality of capacitive sensors are integrated into or on the wireless charger; as well as One or more processors configured to: detecting placement of a mobile device having a rechargeable battery on the wireless charger; obtaining capacitance values ​​from the plurality of capacitance sensors; determining whether the capacitance value indicates deformation of the rechargeable battery; as well as In response to determining that the capacitance value indicates deformation of the rechargeable battery, a charging session by the wireless charger of the rechargeable battery is terminated or deactivated.

2. The wireless charger according to claim 1, characterized in that: The deformation is caused by expansion or growth of the rechargeable battery, which results in a variable distance or air gap between a top surface of the wireless charger and a bottom surface of the mobile device.

3. The wireless charger according to claim 1, wherein: The plurality of capacitive sensors are arranged between the inductive charging circuit of the wireless charger and the top cover or top layer in at least one of a horizontal array, a vertical array, or a combination of the horizontal array and the vertical array to obtain the capacitance values ​​at different positions along the horizontal axis or the vertical axis of the mobile device.

4. The wireless charger according to claim 3, characterized in that: The plurality of capacitive sensors are fixed to the underside of the top cover or the top layer, and the mobile device is placed on the top cover or the top layer.

5. The wireless charger according to claim 1, wherein: The one or more processors are configured to determine that the capacitance value is indicative of deformation of the rechargeable battery using at least one of: determining that the average value of the capacitance values ​​is less than a previous average value of the capacitance values ​​or less than a threshold average value; determining that a standard deviation of the capacitance values ​​is greater than a previous standard deviation of the capacitance values ​​or greater than a threshold standard deviation value; or It is determined that at least one of the capacitance values ​​is below a threshold value.

6. The wireless charger according to claim 1, wherein: The one or more processors are configured to determine whether the capacitance value indicates deformation of the rechargeable battery using a machine learning model to identify the deformation based on the capacitance value.

7. The wireless charger according to claim 1, wherein: The one or more processors are further configured to: In response to expiration of a cycle time, obtaining new capacitance values ​​from the plurality of capacitance sensors during the charging session; and A determination is made as to whether the new capacitance value indicates the deformation of the rechargeable battery.

8. The wireless charger according to claim 1, wherein: The one or more processors are further configured to: determining an identity of the mobile device; and retrieving a saved profile or a default profile associated with the identification of the mobile device, Wherein the one or more processors are configured to determine whether the capacitance value indicates deformation of the rechargeable battery by comparing the capacitance value to the saved profile or the default profile.

9. The wireless charger according to claim 8, characterized in that: The one or more processors are further configured to: determining whether a previous charging error of the mobile device is recorded according to the stored profile or based on the identification of the mobile device; causing the previous charging error to be indicated on a user interface and asking a user whether to continue or start the charging session; as well as in response to obtaining user input indicating to continue or initiate charging, continuing or initiating the charging session of the rechargeable battery; or In response to obtaining user input indicating not to continue or not to initiate charging, terminating or not initiating the charging session of the rechargeable battery.

10. The wireless charger according to claim 9, characterized in that: The user interface includes at least one of a display in a host vehicle in which the wireless charger is mounted, a display associated with the wireless charger, or a display of the mobile device.

11. The wireless charger according to claim 8, wherein: The one or more processors are further configured to: responsive to the capacitance value indicating deformation of the rechargeable battery, recording a charging error associated with the identification of the mobile device; as well as In response to the capacitance value indicating deformation of the rechargeable battery, a user is alerted via a display of the charging error.

12. The wireless charger according to claim 1, wherein: The one or more processors are further configured to: The capacitance value for a period of the charging session is ignored in response to detecting a vibration event, the vibration event being detected using an inertial measurement unit of the wireless charger or a host vehicle on which the wireless charger is installed.

13. The wireless charger according to claim 1, wherein: The wireless charger includes an inductive charging pad.

14. A method comprising: detecting placement of a mobile device having a rechargeable battery on a wireless charger; obtaining capacitance values ​​from a plurality of capacitance sensors integrated into or on the wireless charger; determining whether the capacitance value indicates deformation of the rechargeable battery; as well as In response to determining that the capacitance value indicates deformation of the rechargeable battery, a charging session for the rechargeable battery is terminated or not initiated.

15. The method according to claim 14, characterized in that Determining whether the capacitance value indicates deformation of the rechargeable battery includes at least one of: determining that the average value of the capacitance values ​​is less than a previous average value of the capacitance values ​​or less than a threshold average value; determining that a standard deviation of the capacitance values ​​is greater than a previous standard deviation of capacitance values ​​or greater than a threshold standard deviation value; or It is determined that at least one of the capacitance values ​​is below a threshold value.

16. The method according to claim 14, characterized in that A machine learning model is used to determine whether the capacitance value indicates deformation of the rechargeable battery to identify the deformation based on the capacitance value.

17. The method according to claim 14, characterized in that The method further comprises: Responsive to expiration of a cycle time, acquiring new capacitance values ​​from the plurality of capacitance sensors during the charging session; and A determination is made as to whether the new capacitance value indicates deformation of the rechargeable battery.

18. The method of claim 14, wherein: The method further comprises: determining an identity of the mobile device; and retrieving a saved profile or a default profile associated with the identification of the mobile device, Wherein, determining whether the capacitance value indicates deformation of the rechargeable battery comprises comparing the capacitance value with the saved profile or the default profile.

19. The method of claim 14, wherein: The mobile device includes at least one of a smart phone, a tablet computer, a computer, or a smart watch.

20. A non-transitory computer readable medium storing computer executable instructions which, when executed by a processor, cause the processor to: detecting placement of a mobile device having a rechargeable battery on a wireless charger; obtaining capacitance values ​​from a plurality of capacitance sensors integrated into or on the wireless charger; determining whether the capacitance value indicates deformation of the rechargeable battery; as well as In response to determining that the capacitance value indicates deformation of the rechargeable battery, a charging session of the rechargeable battery is terminated or deactivated.

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