Method, device and processor for realizing foreign object detection in wireless charging system

Abstract

The present invention relates to a method for realizing foreign object detection for a wireless charging system, wherein the method comprises collecting the working efficiency and duty cycle under different loads without offset, obtaining the working efficiency of the receiving end after the system starts working to calculate the receiving end power; and determining the inherent loss of the current system according to the working frequency, duty cycle and receiving end power of the transmitting end to calculate the power loss of the current system; judging whether there is a foreign object in the system by comparing the power loss with the power difference between the transmitting end and the receiving end under the condition of no foreign object; and the system performs corresponding work processing according to the judgment result. The present invention also relates to a corresponding device and its processor. By adopting the method, device and its processor of the present invention, the wireless charging system can accurately detect the situation in which foreign objects are present when the system is working at any position, and the system can also work normally in the presence of foreign objects without false triggering.

Description

Technical Field

[0001] The present invention relates to the field of wireless transmission technology, and in particular to the field of wireless charging technology, and specifically refers to a method, device, processor, and computer-readable storage medium thereof for implementing foreign object detection in a wireless charging system. Background Art

[0002] Wireless charging is a technology that uses electromagnetic fields or electromagnetic waves to transmit energy. It is currently widely used in the low-power range and is mainly used in smartphones, microcomputers, small portable household appliances, smart wearables, etc.

[0003] In wireless charging systems, the operating range is generally small, typically only for close distances (2-6mm) and a small offset range (0-8mm). However, for wireless charging systems with a larger operating range, the existing technology lacks the ability to detect foreign objects at a small operating distance while preventing false triggering that could cause the wireless charging system to fail at farther or more offset locations. Furthermore, the related detection methods in the existing technology rely solely on the difference between the transmitting and receiving power as the power loss to determine whether a foreign object has been detected. This testing method can easily fail to detect foreign objects at the center or false trigger at offset locations.

[0004] Based on this, in terms of existing technology, there is an urgent need for a detection method that can not only meet the normal detection of foreign objects in close distances without offset, but also avoid system false triggering in long distances with large offsets. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a method, device and processor for realizing foreign object detection for a wireless charging system, which can accurately detect and effectively avoid false triggering.

[0006] To achieve the above objectives, the present invention provides a method, device, and processor for detecting foreign objects in a wireless charging system as follows:

[0007] The method for realizing foreign object detection in a wireless charging system is characterized in that the method comprises the following steps:

[0008] (1) When the wireless charging system has no offset, collect the transmission efficiency values ​​of the current wireless charging system under different load conditions and the duty cycle corresponding to each load;

[0009] (2) Setting the offset test distance under different coordinate conditions in the current wireless charging system, and recording the operating frequency and duty cycle of the wireless charging transmitter at each preset distance by the control variable method;

[0010] (3) The wireless charging system starts working, and the wireless charging transmitter obtains the working efficiency corresponding to the wireless charging receiver under the current power according to the power packet data sent by the wireless charging receiver;

[0011] (4) Calculating the power of the wireless charging receiving end according to the power packet data and working efficiency of the wireless charging receiving end;

[0012] (5) determining the inherent loss of the wireless charging system at the current offset position based on the operating frequency and duty cycle of the wireless charging transmitter and the power of the wireless charging receiver;

[0013] (6) Calculating the power loss of the current wireless charging system using the inherent loss;

[0014] (7) Determine whether there is a foreign object in the current wireless charging system by comparing the power loss with the power difference between the wireless charging transmitter and the wireless charging receiver under the condition that there is no foreign object;

[0015] (8) Based on the judgment result, the wireless charging system performs corresponding work processing.

[0016] Preferably, the step (1) specifically includes the following steps:

[0017] (1.1) Set the rated distance of the wireless charging coil under test to D (mm);

[0018] (1.2) Under no-offset conditions, test the power under different load conditions and generate the corresponding transmission efficiency benchmark table;

[0019] (1.3) Generate a duty cycle reference table corresponding to different load conditions for subsequent comparison benchmarks.

[0020] Preferably, the step (2) specifically includes the following steps:

[0021] (2.1) Set the vertical distance of the current wireless charging system test to D+d (mm), the X-axis offset distance to x (mm), and the Y-axis offset distance to y (mm);

[0022] (2.2) Using the control variable method, fix the coordinate positions of any two directions in the above step (2.1) and move the other unfixed coordinate position;

[0023] (2.3) Record a set of test data each time the preset distance is moved until the X-axis offset reaches x (mm) and the Y-axis offset reaches y (mm).

[0024] (2.4) Record the operating frequency and duty cycle of the wireless charging transmitter at each moving distance.

[0025] Preferably, the step (3) specifically includes the following steps:

[0026] The wireless charging transmitter described in (3.1) calculates the corresponding data index number index using the following formula based on the power packet data sent by the wireless charging receiver:

[0027]

[0028] Among them, ReceivePower is the power of the wireless charging receiving end;

[0029] (3.2) Obtaining the working efficiency η corresponding to the current wireless charging receiving end power in the transmission efficiency benchmark table according to the data index number index.

[0030] Preferably, the step (4) is specifically used to calculate the wireless charging receiving end power Prx according to the following formula:

[0031]

[0032] Preferably, the step (5) specifically includes the following steps:

[0033] (5.1) Determine whether the wireless charging receiving end power Prx is less than the system preset threshold power ReceivePowerValue. If so, proceed to step (5.2); otherwise, jump to step (5.3);

[0034] (5.2) Based on the current duty cycle of the wireless charging transmitter, obtain the inherent loss fixlossvalue of the wireless charging system under the current conditions, and proceed to step (5.9);

[0035] (5.3) Based on the duty cycle corresponding to the current wireless charging receiving end power in the duty cycle reference table, assign the duty cycle to the duty cycle variable Duty under the rated distance D (mm) condition, and proceed to step (5.4);

[0036] (5.4) Determine whether the operating duty cycle NewDuty of the wireless charging system is less than 50% at this time. If so, proceed to step (5.5); otherwise, jump to step (5.6);

[0037] (5.5) Compare the current working duty cycle NewDuty with the duty cycle in the duty cycle reference table collected in step (2.4) to obtain the inherent loss fixlossvalue, and jump to step (5.9);

[0038] (5.6) Compare the current operating frequency and operating duty cycle NewDuty of the wireless charging transmitter with the frequency and duty cycle in the transmission efficiency benchmark table and the duty cycle benchmark table collected in step (2.4) to obtain the inherent loss fixlossvalue, and jump to step (5.7);

[0039] (5.7) If the operating frequency NewFre of the wireless charging system is the system maximum energy frequency Fre_Max, and the wireless charging receiving end power Prx is less than the system full load power Pmax, then directly proceed to step (5.8); otherwise, jump to step (5.9);

[0040] (5.8) Calculate the inherent loss fixlossvalue of the wireless charging system under the current conditions;

[0041] (5.9) returns the currently measured intrinsic loss fixlossvalue and goes to step (6).

[0042] Preferably, the step (5.5) specifically calculates the inherent loss fixlossvalue of the current system by the following formula:

[0043] fixlossvalue=(NewDuty–Duty)*K1;

[0044] Among them, K1 is the approximate value between the duty cycle difference and the loss difference obtained by comparing the duty cycle of the wireless charging transmitter with the corresponding duty cycle data in the duty cycle reference table under the same received power but different duty cycles and losses.

[0045] Preferably, the step (5.6) is specifically used to calculate the inherent loss fixlossvalue of the current system by the following formula:

[0046] fixlossvalue=(NewFre–Fre_Min)*K2+(50–Duty)*K2;

[0047] Among them, Fre_Min is the minimum energy frequency provided by the system, K2 is the approximate value between the frequency difference, duty cycle difference and loss difference obtained by comparing the operating frequency and duty cycle of the wireless charging transmitter with the corresponding transmission efficiency benchmark table and the operating frequency and duty cycle data in the duty cycle benchmark table under the same received power but different duty cycles and losses.

[0048] Preferably, the step (5.8) specifically calculates the inherent loss fixlossvalue of the current system by the following formula:

[0049] fixlossvalue=fixlossvalue+(Pmax–Prx).

[0050] More preferably, the step (6) is specifically used to calculate the power loss lossvalue of the wireless charging system by the following formula:

[0051] lossvalue=Ptx–ReceivePower–fixlossvalue;

[0052] Among them, Ptx is the output power of the wireless charging transmitter.

[0053] Preferably, the step (7) is specifically as follows:

[0054] Determine whether the power loss loss value is greater than the FOD threshold. If so, proceed to step (8.1); otherwise, jump to step (8.2); wherein the FOD threshold is specifically:

[0055] When there is no foreign matter in the wireless charging system, the difference between the power of the wireless charging transmitting end and the power of the wireless charging receiving end is used as the FOD threshold.

[0056] Preferably, the step (8) specifically includes the following steps:

[0057] (8.1) There is a foreign object in the wireless charging system, and wireless charging stops working;

[0058] (8.2) There is no foreign object in the current wireless charging system, and the wireless charging system continues to perform wireless charging.

[0059] The main features of the device for realizing foreign object detection in a wireless charging system are as follows:

[0060] a processor configured to execute computer-executable instructions;

[0061] The memory stores one or more computer-executable instructions, and when the computer-executable instructions are executed by the processor, the steps of the method for realizing foreign object detection in the wireless charging system are implemented.

[0062] The main feature of the processor for implementing foreign object detection for a wireless charging system is that the processor is configured to execute computer-executable instructions. When the computer-executable instructions are executed by the processor, the various steps of the above-mentioned method for implementing foreign object detection for a wireless charging system are implemented.

[0063] The method, device and processor for realizing foreign object detection in a wireless charging system of the present invention are adopted. Accurate foreign object detection can be performed under conditions of a short working distance and no offset. At the same time, even when the working distance is long and the offset position is within a large range, the technical solution first tests a set of data as a benchmark at a rated distance and no offset position, and compares the operating frequency, duty cycle of the transmitting end and the power of the receiving end at different positions with the benchmark data, thereby accurately calculating the system power loss caused by the offset position, thereby preventing the system from performing normal wireless charging in the absence of foreign objects and preventing false triggering. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Schematic diagram of the flow of the method for realizing foreign object detection in a wireless charging system according to the present invention.

[0065] Figure 2 Schematic diagram of the process of calculating inherent loss of the method for realizing foreign object detection in a wireless charging system according to the present invention. DETAILED DESCRIPTION

[0066] In order to more clearly describe the technical content of the present invention, further description is given below in conjunction with specific embodiments.

[0067] Before describing in detail embodiments according to the present invention, it should be noted that, hereinafter, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, whereby a process, method, article, or apparatus comprising a list of elements includes not only those elements, but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0068] See also Figure 1 As shown, the method for realizing foreign object detection for a wireless charging system includes the following steps:

[0069] (1) When the wireless charging system has no offset, collect the transmission efficiency values ​​of the current wireless charging system under different load conditions and the duty cycle corresponding to each load;

[0070] (2) Setting the offset test distance under different coordinate conditions in the current wireless charging system, and recording the operating frequency and duty cycle of the wireless charging transmitter at each preset distance by the control variable method;

[0071] (3) The wireless charging system starts working, and the wireless charging transmitter obtains the working efficiency corresponding to the wireless charging receiver under the current power according to the power packet data sent by the wireless charging receiver;

[0072] (4) Calculating the power of the wireless charging receiving end according to the power packet data and working efficiency of the wireless charging receiving end;

[0073] (5) determining the inherent loss of the wireless charging system at the current offset position based on the operating frequency and duty cycle of the wireless charging transmitter and the power of the wireless charging receiver;

[0074] (6) Calculating the power loss of the current wireless charging system using the inherent loss;

[0075] (7) Determine whether there is a foreign object in the current wireless charging system by comparing the power loss with the power difference between the wireless charging transmitter and the wireless charging receiver under the condition that there is no foreign object;

[0076] (8) Based on the judgment result, the wireless charging system performs corresponding work processing.

[0077] As a preferred embodiment of the present invention, the step (1) specifically includes the following steps:

[0078] (1.1) Set the rated distance of the wireless charging coil under test to D (mm);

[0079] (1.2) Under no-offset conditions, test the power under different load conditions and generate the corresponding transmission efficiency benchmark table;

[0080] (1.3) Generate a duty cycle reference table corresponding to different load conditions for subsequent comparison benchmarks.

[0081] In practical applications of the present invention, the technical solution first performs data collection. That is, the rated distance of the wireless charging coil is tested as D (mm). In the absence of offset, the power under different loads is tested, and an efficiency table is designed. At the same time, the duty cycle corresponding to the load is designed into another table. The two sets of tables tested at this time serve as a benchmark.

[0082] As a preferred embodiment of the present invention, the step (2) specifically includes the following steps:

[0083] (2.1) Set the vertical distance of the current wireless charging system test to D+d (mm), the X-axis offset distance to x (mm), and the Y-axis offset distance to y (mm);

[0084] (2.2) Using the control variable method, fix the coordinate positions of any two directions in the above step (2.1) and move the other unfixed coordinate position;

[0085] (2.3) Record a set of test data each time the preset distance is moved until the X-axis offset reaches x (mm) and the Y-axis offset reaches y (mm).

[0086] (2.4) Record the operating frequency and duty cycle of the wireless charging transmitter at each moving distance.

[0087] In a specific embodiment of the present invention, the preset distance can be adjusted accordingly according to the actual test environment. In the above test steps, the preset distance selects 2 (mm) as the optimal test distance. During the actual test process, it is not limited to selecting 2 (mm) as the preset distance. Any test distance adjusted through testing to obtain the best test data should be included in the preset distance described in the present invention.

[0088] In the practical application of the present invention, by testing the vertical distance D+d (mm), the X-axis offset distance is x (mm), the Y-axis offset distance is y (mm), fixing the position in two directions, moving the other direction, recording a set of data every 2 (mm), and recording the operating frequency and duty cycle of the transmitter.

[0089] It should be noted that the above-mentioned vertical distance refers to the distance perpendicular to the plane to which the X-axis and Y-axis belong. The X-axis is the horizontal coordinate axis in the plane rectangular coordinate system, which is located in the horizontal direction and perpendicular to the Y-axis. The Y-axis is the vertical coordinate axis in the plane rectangular coordinate system, which is located in the vertical direction and perpendicular to the X-axis.

[0090] As a preferred embodiment of the present invention, the step (3) specifically includes the following steps:

[0091] The wireless charging transmitter described in (3.1) calculates the corresponding data index number index using the following formula based on the power packet data sent by the wireless charging receiver:

[0092]

[0093] Among them, ReceivePower is the power of the wireless charging receiving end;

[0094] In the practical application of the present invention, the efficiency corresponding to the power ReceivePower of the wireless charging receiving end is stored in the array fodTableIndex[], and the data index number index=ReceivePower / 100, that is, the power value of the wireless charging receiving end is reduced by 100 times, that is, if the power of the wireless charging receiving end is 1000mW, then the data index number index=10, that is, the efficiency corresponding to the power of the wireless charging receiving end at this time is fodTableIndex

[10] . By calculating the data index number index, the power of the wireless charging receiving end can be accurately found.

[0095] (3.2) Obtaining the working efficiency η corresponding to the current wireless charging receiving end power in the transmission efficiency benchmark table according to the data index number index.

[0096] As a preferred embodiment of the present invention, the step (4) is specifically used to calculate the wireless charging receiving end power Prx according to the following formula:

[0097]

[0098] In a practical application of the present invention, the technical solution determines the inherent loss at the offset position according to the operating frequency and duty cycle of the wireless charging transmitter and the power of the wireless charging receiver.

[0099] See also Figure 2 As shown, as a preferred embodiment of the present invention, the step (5) specifically includes the following steps:

[0100] (5.1) Determine whether the wireless charging receiving end power Prx is less than the system preset threshold power ReceivePowerValue, that is, whether the current wireless charging receiving end power is under a light load condition. If so, proceed to step (5.2); otherwise, jump to step (5.3);

[0101] Since the system preset threshold power ReceivePowerValue is obtained based on test data, because the battery is charging, after the battery charging enters the constant voltage mode, the power packet will become smaller and smaller. This value can be understood as the power value when the battery charging enters the constant voltage mode from the constant current mode.

[0102] (5.2) Based on the current duty cycle of the wireless charging transmitter, obtain the inherent loss fixlossvalue of the wireless charging system under the current conditions, and proceed to step (5.9);

[0103] (5.3) Based on the duty cycle corresponding to the current wireless charging receiving end power in the duty cycle reference table, assign the duty cycle to the duty cycle variable Duty under the rated distance D (mm) condition, and proceed to step (5.4). The duty cycle variable Duty is taken from the value in the duty cycle reference table in step (1.3);

[0104] (5.4) Determine whether the operating duty cycle NewDuty of the wireless charging system is less than 50% at this time. If so, it means that the operating frequency has not changed at this time, and then go to step (5.5); otherwise, jump to step (5.6);

[0105] (5.5) Compare the data recorded in step (2) with the data in the table collected in step (1) to obtain the calculation formula for inherent loss, which is:

[0106] Compare the current working duty cycle NewDuty with the duty cycle in the duty cycle reference table collected in step (2.4) to obtain the inherent loss fixlossvalue, and jump to step (5.9);

[0107] (5.6) Compare the data recorded in step (2) with the data in the table collected in step (1) to obtain the calculation formula for inherent loss, which is:

[0108] Compare the current operating frequency and operating duty cycle NewDuty of the wireless charging transmitter with the frequency and duty cycle in the transmission efficiency benchmark table and the duty cycle benchmark table collected in step (2.4) to obtain the inherent loss fixlossvalue, and jump to step (5.7);

[0109] (5.7) If the operating frequency NewFre of the wireless charging system is the system maximum energy frequency Fre_Max, and the wireless charging receiving end power Prx is less than the system full load power Pmax, then directly proceed to step (5.8); otherwise, jump to step (5.9);

[0110] (5.8) Calculate the inherent loss fixlossvalue of the wireless charging system under the current conditions;

[0111] (5.9) returns the currently measured intrinsic loss fixlossvalue and goes to step (6).

[0112] As a preferred embodiment of the present invention, the step (5.5) specifically calculates the inherent loss fixlossvalue of the current system by the following formula:

[0113] fixlossvalue=(NewDuty–Duty)*K1;

[0114] Among them, K1 is the approximate value between the duty cycle difference and the loss difference obtained by comparing the duty cycle of the wireless charging transmitter with the corresponding duty cycle data in the duty cycle reference table under the same received power but different duty cycles and losses.

[0115] As a preferred embodiment of the present invention, the step (5.6) specifically calculates the inherent loss fixlossvalue of the current system by the following formula:

[0116] fixlossvalue=(NewFre–Fre_Min)*K2+(50–Duty)*K2;

[0117] Among them, Fre_Min is the minimum energy frequency provided by the system, K2 is the approximate value between the frequency difference, duty cycle difference and loss difference obtained by comparing the operating frequency and duty cycle of the wireless charging transmitter with the corresponding transmission efficiency benchmark table and the operating frequency and duty cycle data in the duty cycle benchmark table under the same received power but different duty cycles and losses.

[0118] In a specific embodiment of the present invention, the above K1 and K2 refer to the approximate formula of the duty cycle difference and the loss difference (i.e., the inherent loss caused by the offset) obtained by comparing the data recorded in step (2) with the data collected in step (1) under the same received power but different duty cycles. That is, K1 and K2 are approximate values ​​obtained by comparing the data in step (1) and step (2). The specific calculation steps are as follows:

[0119] Using the transmitter power PTx, receive power PRx, loss Ploss, operating frequency Freq, and duty cycle Duty at the rated distance as a benchmark, set the transmitter power PTx_x_y_z, receive power PRx_x_y_z (because the receive power is the same, PRx_x_y_z = PRx), loss Ploss_x_y_z, operating frequency Freq_x_y_z, and duty cycle Dux_x_y_z at other offset distances, where (x = 0 to 20 mm, y = 0 to 20 mm, z = 10 to 20 mm, all in 2 mm increments). The inherent loss due to offset is Pfixlossvalue_n = Ploss_x_y_z – Ploss, and the duty cycle variation is Duty_Diff_n = Duty_x_y_z – Duty, (n = 1, 2, 3, ...).

[0120] When the duty cycle Duty_x_y_z is less than 50%, a record table is made to record the duty cycle difference Duty_Diff_n and the inherent loss Pfixlossvalue_n. The relationship between the inherent loss Pfixlossvalue_n and Duty_Diff_n can be obtained, that is, Pfixlossvalue_n=Kn*Duty_Diff_n, Kn is the proportional coefficient, and K selects a minimum value from Kn (n=1,2,……n) that can satisfy the following formula, that is:

[0121] PTx_x_y_z–Pfixlossvalue–PRx_y_z <Ploss;

[0122] Because PRx_x_y_z=PRx, so PTx_x_y_z–Pfixlossvalue–PRx <Ploss。

[0123] Similarly, K2 is obtained in the same way.

[0124] In the above test environment, it can be measured that the value range of K1 and K2 is between (3, 10). It should be noted that in the actual test process, the values ​​of K1 and K2 are not constant, but will change dynamically according to the actual test environment, test tools, offset environment and other similar objective factors. What the present invention wants to protect is the method of obtaining the empirical value measured after several experiments, not a fixed value.

[0125] As a preferred embodiment of the present invention, the step (5.8) specifically calculates the inherent loss fixlossvalue of the current system by the following formula:

[0126] fixlossvalue=fixlossvalue+(Pmax–Prx).

[0127] As a preferred embodiment of the present invention, the step (6) is specifically used to calculate the power loss lossvalue of the wireless charging system by the following formula:

[0128] lossvalue=Ptx–ReceivePower–fixlossvalue;

[0129] Among them, Ptx is the output power of the wireless charging transmitter.

[0130] As a preferred embodiment of the present invention, the step (7) is specifically as follows:

[0131] Determine whether the power loss loss value is greater than the FOD threshold. If so, proceed to step (8.1); otherwise, jump to step (8.2); wherein the FOD threshold is specifically:

[0132] When there is no foreign matter in the wireless charging system, the difference between the power of the wireless charging transmitting end and the power of the wireless charging receiving end is used as the FOD threshold.

[0133] In a specific embodiment of the present invention, when there is no foreign matter in the wireless charging system, the difference between the power of the wireless charging transmitting end and the power of the wireless charging receiving end is taken as the power loss. The power loss obtained at this time is used as the FOD threshold of the system.

[0134] As a preferred embodiment of the present invention, the step (8) specifically includes the following steps:

[0135] (8.1) There is a foreign object in the wireless charging system, and wireless charging stops working;

[0136] (8.2) There is no foreign object in the current wireless charging system, and the wireless charging system continues to perform wireless charging.

[0137] The device for realizing foreign object detection in a wireless charging system comprises:

[0138] a processor configured to execute computer-executable instructions;

[0139] The memory stores one or more computer-executable instructions, and when the computer-executable instructions are executed by the processor, the steps of the method for realizing foreign object detection in the wireless charging system are implemented.

[0140] The processor for implementing foreign object detection for a wireless charging system is configured to execute computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the above-mentioned method for implementing foreign object detection for a wireless charging system are implemented.

[0141] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0142] It should be understood that each part of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution device.

[0143] Those skilled in the art will understand that all or part of the steps of the method for implementing the above-mentioned embodiment can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0144] Furthermore, the functional units in the various embodiments of the present invention may be integrated into a single processing module, each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

[0145] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0146] Throughout this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "embodiment" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0147] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0148] The method, device and processor for realizing foreign object detection in a wireless charging system of the present invention are adopted. Accurate foreign object detection can be performed under conditions of a short working distance and no offset. At the same time, even when the working distance is long and the offset position is within a large range, the technical solution first tests a set of data as a benchmark at a rated distance and no offset position, and compares the operating frequency, duty cycle of the transmitting end and the power of the receiving end at different positions with the benchmark data, thereby accurately calculating the system power loss caused by the offset position, thereby preventing the system from performing normal wireless charging in the absence of foreign objects and preventing false triggering.

[0149] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

Claims

1. A method for detecting foreign objects in a wireless charging system, characterized in that: The method comprises the following steps: (1) When the wireless charging system has no offset, collect the transmission efficiency values ​​of the current wireless charging system under different load conditions and the duty cycle corresponding to each load; (2) Setting the offset test distance under different coordinate conditions in the current wireless charging system, and recording the operating frequency and duty cycle of the wireless charging transmitter at each preset distance by the control variable method; (3) The wireless charging system starts working, and the wireless charging transmitter obtains the working efficiency corresponding to the wireless charging receiver under the current power according to the power packet data sent by the wireless charging receiver; (4) Calculating the wireless charging receiving end power Prx based on the power packet data and working efficiency of the wireless charging receiving end; (5) determining the inherent loss of the wireless charging system at the current offset position based on the operating frequency and duty cycle of the wireless charging transmitter and the power Prx of the wireless charging receiver; (6) Calculating the power loss of the current wireless charging system using the inherent loss; (7) Determine whether there is a foreign object in the current wireless charging system by comparing the power loss with the power difference between the wireless charging transmitter and the wireless charging receiver under the condition that there is no foreign object; (8) Based on the judgment result, the wireless charging system performs corresponding work processing; Wherein, the step (5) specifically includes the following steps: (5.1) Determine whether the wireless charging receiving end power Prx is less than the system preset threshold power ReceivePowerValue. If so, proceed to step (5.2); otherwise, jump to step (5.3); (5.2) Based on the current duty cycle of the wireless charging transmitter, obtain the inherent loss fixlossvalue of the wireless charging system under the current conditions, and proceed to step (5.9); (5.3) Based on the duty cycle corresponding to the duty cycle reference table generated by the wireless charging receiving end power Prx under various load conditions, the duty cycle is assigned to the duty cycle variable Duty under the condition of the rated distance of the wireless charging coil being D (mm), and the process proceeds to step (5.4); (5.4) Determine whether the operating duty cycle NewDuty of the wireless charging system is less than 50% at this time. If so, proceed to step (5.5); otherwise, jump to step (5.6); (5.5) Compare the current working duty cycle NewDuty with the duty cycle in the duty cycle reference table collected by the wireless charging transmitter at each moving distance to obtain the inherent loss fixlossvalue, and jump to step (5.9); (5.6) Compare the operating frequency and duty cycle NewDuty of the current wireless charging transmitter with the frequencies and duty cycles in the transmission efficiency benchmark table and duty cycle benchmark table generated by the power collected under different load conditions to obtain the inherent loss fixlossvalue, and jump to step (5.7); (5.7) If the operating frequency NewFre of the wireless charging system is the system maximum energy frequency Fre_Max, and the wireless charging receiving end power Prx is less than the system full load power Pmax, then directly proceed to step (5.8); otherwise, jump to step (5.9); (5.8) Calculate the inherent loss fixlossvalue of the wireless charging system under the current conditions; (5.9) returns the currently measured intrinsic loss fixlossvalue and goes to step (6).

2. The method for realizing foreign object detection in a wireless charging system according to claim 1, wherein: The step (1) specifically includes the following steps: (1.1) Set the rated distance of the wireless charging coil under test to D (mm); (1.2) Under no-offset conditions, test the power under different load conditions and generate the corresponding transmission efficiency benchmark table; (1.3) Generate a duty cycle reference table corresponding to different load conditions for subsequent comparison benchmarks.

3. The method for realizing foreign object detection in a wireless charging system according to claim 2, wherein: The step (2) specifically includes the following steps: (2.1) Set the vertical distance of the current wireless charging system test to D+d (mm), the X-axis offset distance to x (mm), and the Y-axis offset distance to y (mm); (2.2) Using the control variable method, fix the coordinate positions of any two directions in the above step (2.1) and move the other unfixed coordinate position; (2.3) Record a set of test data each time the preset distance is moved until the X-axis offset reaches x (mm) and the Y-axis offset reaches y (mm). (2.4) Record the operating frequency and duty cycle of the wireless charging transmitter at each moving distance.

4. The method for realizing foreign object detection in a wireless charging system according to claim 2, wherein: The step (3) specifically includes the following steps: The wireless charging transmitter described in (3.1) calculates the corresponding data index number index using the following formula based on the power packet data sent by the wireless charging receiver: Among them, ReceivePower is the power of the wireless charging receiving end; (3.2) Obtaining the working efficiency η corresponding to the current wireless charging receiving end power in the transmission efficiency benchmark table according to the data index number index.

5. The method for realizing foreign object detection in a wireless charging system according to claim 4, wherein: The step (4) is specifically to calculate the wireless charging receiving end power Prx according to the following formula:

6. The method for realizing foreign object detection in a wireless charging system according to claim 1, wherein: The step (5.5) specifically calculates the inherent loss fixlossvalue of the current system by the following formula: fixlossvalue=(NewDuty–Duty)*K1; Among them, K1 is the approximate value between the duty cycle difference and the loss difference obtained by comparing the duty cycle of the wireless charging transmitter with the corresponding duty cycle data in the duty cycle reference table under the same received power but different duty cycles and losses.

7. The method for realizing foreign object detection in a wireless charging system according to claim 1, wherein: The step (5.6) specifically calculates the inherent loss fixlossvalue of the current system by the following formula: fixlossvalue=(NewFre–Fre_Min)*K2+(50–Duty)*K2; Among them, Fre_Min is the minimum energy frequency provided by the system, K2 is the approximate value between the frequency difference, duty cycle difference and loss difference obtained by comparing the operating frequency and duty cycle of the wireless charging transmitter with the corresponding transmission efficiency benchmark table and the operating frequency and duty cycle data in the duty cycle benchmark table under the same received power but different duty cycles and losses.

8. The method for realizing foreign object detection in a wireless charging system according to claim 1, wherein: The step (5.8) specifically calculates the inherent loss fixlossvalue of the current system by the following formula: fixlossvalue=fixlossvalue+(Pmax–Prx).

9. The method for realizing foreign object detection in a wireless charging system according to any one of claims 6 to 8, characterized in that: The step (6) specifically calculates the power loss lossvalue of the wireless charging system by the following formula: lossvalue=Ptx–ReceivePower–fixlossvalue; Among them, Ptx is the output power of the wireless charging transmitter.

10. The method for realizing foreign object detection in a wireless charging system according to claim 9, wherein: The step (7) is specifically as follows: Determine whether the power loss loss value is greater than the FOD threshold. If so, proceed to step (8.1); otherwise, jump to step (8.2); wherein the FOD threshold is specifically: When there is no foreign matter in the wireless charging system, the difference between the power of the wireless charging transmitting end and the power of the wireless charging receiving end is used as the FOD threshold.

11. The method for realizing foreign object detection in a wireless charging system according to claim 10, wherein: The step (8) specifically includes the following steps: (8.1) There is a foreign object in the wireless charging system, and wireless charging stops working; (8.2) There is no foreign object in the current wireless charging system, and the wireless charging system continues to perform wireless charging.

12. A device for detecting foreign objects in a wireless charging system, characterized in that: The device comprises: a processor configured to execute computer-executable instructions; A memory stores one or more computer-executable instructions, and when the computer-executable instructions are executed by the processor, the steps of the method for realizing foreign object detection for a wireless charging system according to claim 11 are implemented.

13. A processor for implementing foreign object detection in a wireless charging system, characterized in that: The processor is configured to execute computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for realizing foreign object detection for a wireless charging system according to claim 11 are implemented.

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