阅读说明：本技术 一种无线充电系统异物检测方法、装置、系统及电子设备 (Foreign matter detection method, device and system for wireless charging system and electronic equipment ) 是由 袁李君 褚维戈 于 2020-07-17 设计创作，主要内容包括：本发明公开了一种无线充电系统异物检测方法、装置、系统及电子设备,涉及电动汽车领域,该方法包括：当所述无线充电系统工作时,获取当前目标检测时段内所述检测线圈的电磁感应值,所述电磁感应值包括电磁感应电压值和/或电磁感应电流值；将所述当前目标检测时段内所述检测线圈的电磁感应值与前一目标检测时段内所述检测线圈的电磁感应值进行比对；当比对结果满足第一异物判定条件,判定所述无线充电系统的电磁感应区域存在异物。本发明通过将无线充电系统在实际工作中的电磁感应值作为异物检测的比对值,提高了对无线充电系统异物检测的准确性。(The invention discloses a foreign matter detection method, a device and a system for a wireless charging system and electronic equipment, and relates to the field of electric automobiles, wherein the method comprises the following steps: when the wireless charging system works, acquiring an electromagnetic induction value of the detection coil in a current target detection period, wherein the electromagnetic induction value comprises an electromagnetic induction voltage value and/or an electromagnetic induction current value; comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period; and when the comparison result meets a first foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system. According to the invention, the electromagnetic induction value of the wireless charging system in actual work is used as the comparison value of foreign matter detection, so that the accuracy of foreign matter detection of the wireless charging system is improved.)

1. A foreign matter detection method for a wireless charging system, wherein an electromagnetic induction area of the wireless charging system is provided with at least one detection coil, the method is characterized by comprising the following steps:

when the wireless charging system works, acquiring an electromagnetic induction value of the detection coil in a current target detection period, wherein the electromagnetic induction value comprises an electromagnetic induction voltage value and/or an electromagnetic induction current value;

comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period;

and when the comparison result meets a first foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system.

2. The method of claim 1, further comprising: when the comparison result does not satisfy the first foreign matter determination condition, repeating the steps from obtaining the electromagnetic induction value of the detection coil in the current target detection period to comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period.

3. The method according to claim 1, wherein the acquiring the electromagnetic induction value of the detection coil in the current target detection period comprises:

and filtering a plurality of electromagnetic induction values acquired in a target detection time period, and taking the electromagnetic induction values obtained after filtering as the electromagnetic induction values of the detection coil in the target detection time period.

4. The method of claim 1, further comprising:

acquiring an electromagnetic induction value of any target detection time period or electromagnetic induction values of a plurality of target detection time periods under the condition of no foreign matters, and taking the electromagnetic induction value of any target detection time period or the average value of the electromagnetic induction values of the plurality of target detection time periods as a reference comparison value;

acquiring an electromagnetic induction value of the detection coil in a current target detection period;

comparing the electromagnetic induction value of the detection coil in the current target detection time period with the reference comparison value;

and when the comparison result meets a second foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system.

5. The method of claim 4, further comprising: and updating the reference comparison value by using the electromagnetic induction value of the latest target detection time period under the condition of no foreign matters.

6. The method according to any one of claims 1-5, further comprising:

and when the gain adjustment is carried out on the electromagnetic induction value of the detection coil, the gain adjustment reduction is carried out on the electromagnetic induction value according to the gain adjustment amplitude, and the foreign matter judgment is carried out by utilizing the reduced electromagnetic induction value.

7. The method of claim 4, further comprising:

determining whether the frequency of continuously judging whether foreign matters exist in an electromagnetic induction area of the wireless charging system is greater than a preset frequency;

and when the frequency of continuously judging that foreign matters exist in the electromagnetic induction area of the wireless charging system is greater than the preset frequency, judging that the foreign matters exist in the electromagnetic induction area of the wireless charging system.

8. A wireless charging system foreign matter detection device, the electromagnetic induction area of wireless charging system is provided with at least one detection coil, its characterized in that, the device includes:

the acquisition module is used for acquiring the electromagnetic induction value of the detection coil in the current target detection period when the wireless charging system works, wherein the electromagnetic induction value comprises an electromagnetic induction voltage value and/or an electromagnetic induction current value;

the comparison module is used for comparing the electromagnetic induction value of the detection coil in the current target detection time period with the electromagnetic induction value of the detection coil in the previous target detection time period;

and the judging module is used for judging that foreign matters exist in the electromagnetic induction area of the wireless charging system when the comparison result meets a first foreign matter judging condition.

9. A wireless charging system foreign object detection system, the system comprising:

at least one detection coil;

a controller electrically connected to the detection coil for performing the method of detecting foreign objects in the wireless charging system according to any one of claims 1 to 7.

10. An electronic device, comprising: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to cause the at least one processor to perform the steps of the wireless charging system foreign object detection method of any of claims 1-7.

11. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the wireless charging system foreign object detection method according to any one of claims 1 to 7.

Technical Field

The invention relates to the field of electric automobiles, in particular to a method, a device and a system for detecting foreign matters in a wireless charging system and electronic equipment.

Background

Wireless charging is a technology of transferring electric energy in the air between a charging device and a device to be charged by a technology such as electromagnetic induction, thereby charging a battery of the device to be charged. Because wireless charging has the advantages of being difficult to leak electricity, full-automatic operation and the like compared with wired charging, the wireless charging is widely applied to the charging technology of the electric automobile. The wireless charging mode of the existing electric automobile is that a receiving coil is installed on the electric automobile, a transmitting coil is installed on a parking space of a wireless charging system, a high-frequency magnetic field transmitted by the transmitting coil can be received by the receiving coil in an electromagnetic induction mode, and then the high-frequency magnetic field is converted into electric energy by the receiving coil, so that the wireless transmission of the electric energy is realized, and the purpose of wirelessly charging the electric automobile is achieved.

The wireless charging mode of the existing electric automobile has the problem that a transmitting coil positioned on a parking space of a wireless charging system in the wireless charging process can drop foreign matters which can generate heat in an alternating magnetic field such as coins and iron sheets. Because in the wireless charging process, very strong alternating magnetic field has between transmitting coil and the receiving coil, if there is the conductor foreign matter between transmitting coil and the receiving coil, then the conductor foreign matter can produce induced electromotive force, has not only caused great power loss, and induced electromotive force will make the temperature rise of conductor foreign matter moreover, probably triggers the conflagration when serious, causes the influence to wireless charging system's security.

Disclosure of Invention

Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor accuracy of the existing foreign object detection method for the wireless charging system during the charging process, so as to provide a method, an apparatus, a system and an electronic device for detecting a foreign object in a wireless charging system.

According to a first aspect, an embodiment of the present invention discloses a method for detecting a foreign object in a wireless charging system, where an electromagnetic induction region of the wireless charging system is provided with at least one detection coil, the method including the following steps: when the wireless charging system works, acquiring an electromagnetic induction value of the detection coil in a current target detection period, wherein the electromagnetic induction value comprises an electromagnetic induction voltage value and/or an electromagnetic induction current value; comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period; and when the comparison result meets a first foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system.

Optionally, the method further comprises: when the comparison result does not satisfy the first foreign matter determination condition, repeating the steps from obtaining the electromagnetic induction value of the detection coil in the current target detection period to comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period.

Optionally, the acquiring the electromagnetic induction value of the detection coil in the current target detection period includes: and filtering a plurality of electromagnetic induction values acquired in a target detection time period, and taking the electromagnetic induction values obtained after filtering as the electromagnetic induction values of the detection coil in the target detection time period.

Optionally, the method further comprises: acquiring an electromagnetic induction value of any target detection time period or electromagnetic induction values of a plurality of target detection time periods under the condition of no foreign matters, and taking the electromagnetic induction value of any target detection time period or the average value of the electromagnetic induction values of the plurality of target detection time periods as a reference comparison value; acquiring an electromagnetic induction value of the detection coil in a current target detection period; comparing the electromagnetic induction value of the detection coil in the current target detection time period with the reference comparison value; and when the comparison result meets a second foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system.

Optionally, the method further comprises: and updating the reference comparison value by using the electromagnetic induction value of the latest target detection time period under the condition of no foreign matters.

Optionally, the method further comprises: and when the gain adjustment is carried out on the electromagnetic induction value of the detection coil, the gain adjustment reduction is carried out on the electromagnetic induction value according to the gain adjustment amplitude, and the foreign matter judgment is carried out by utilizing the reduced electromagnetic induction value.

Optionally, the method further comprises: determining whether the frequency of continuously judging whether foreign matters exist in an electromagnetic induction area of the wireless charging system is greater than a preset frequency; and when the frequency of continuously judging that foreign matters exist in the electromagnetic induction area of the wireless charging system is greater than the preset frequency, judging that the foreign matters exist in the electromagnetic induction area of the wireless charging system.

According to a second aspect, an embodiment of the present invention further discloses a device for detecting a foreign object in a wireless charging system, where an electromagnetic induction region of the wireless charging system is provided with at least one detection coil, and the device includes: the acquisition module is used for acquiring the electromagnetic induction value of the detection coil in the current target detection period when the wireless charging system works, wherein the electromagnetic induction value comprises an electromagnetic induction voltage value and/or an electromagnetic induction current value; the comparison module is used for comparing the electromagnetic induction value of the detection coil in the current target detection time period with the electromagnetic induction value of the detection coil in the previous target detection time period; and the judging module is used for judging that foreign matters exist in the electromagnetic induction area of the wireless charging system when the comparison result meets a first foreign matter judging condition.

According to a third aspect, an embodiment of the present invention further discloses a foreign object detection system for a wireless charging system, including: at least one detection coil; and the controller is electrically connected with the detection coil and is used for executing the method for detecting the foreign matters in the wireless charging system according to the first aspect or any optional embodiment of the first aspect.

According to a fourth aspect, an embodiment of the present invention further discloses an electronic device, including: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executable by the at least one processor to cause the at least one processor to perform the steps of the method for detecting foreign objects in a wireless charging system according to the first aspect or any one of the optional embodiments of the first aspect.

According to a fifth aspect, the present invention further discloses a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the method for detecting foreign objects in a wireless charging system according to the first aspect or any optional implementation manner of the first aspect.

The technical scheme of the invention has the following advantages:

according to the foreign matter detection method/device for the wireless charging system, when the wireless charging system works, the electromagnetic induction value of the detection coil in the current target detection time period is obtained, the electromagnetic induction value of the detection coil in the current target detection time period is compared with the electromagnetic induction value of the detection coil in the previous target detection time period, and when the comparison result meets a first foreign matter judgment condition, it is judged that foreign matter exists in the electromagnetic induction area of the wireless charging system. Compared with the prior art that foreign matter detection is carried out through the preset comparison value, the foreign matter detection method and the wireless charging system have the advantages that the electromagnetic induction value of the wireless charging system in the actual work is used as the comparison value of the foreign matter detection, and the accuracy of the foreign matter detection of the wireless charging system is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic view of an application scenario of foreign object detection in a wireless charging system according to an embodiment of the present invention;

fig. 2 is a flowchart illustrating a specific example of a method for detecting a foreign object in a wireless charging system according to an embodiment of the present invention;

fig. 3 is a schematic block diagram of a specific example of a foreign object detection device of a wireless charging system according to an embodiment of the present invention;

fig. 4 is a diagram of a specific example of an electronic device in an embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The embodiment of the present application takes a specific structural schematic diagram of the wireless charging system for an electric vehicle shown in fig. 1 as an example for description. As shown in fig. 1, the wireless charging system includes a infrastructure end and a vehicle-mounted end, the infrastructure end includes a transmitting end controller 102, a transmitting coil 103, a detecting coil 101, and a detecting coil circuit 104; the vehicle-mounted terminal includes a receiving coil 107, a receiving terminal controller 106, and a vehicle-mounted battery 105. The receiving coil 107 is used for receiving the electric energy of the transmitting coil 103, converting the electric energy into the electric energy required by the battery through the control of the receiving end controller 106, and charging the vehicle-mounted battery 105.

The detection coil circuit 104 is connected to the emission end controller 102, and the detection coil circuit 104 is configured to acquire an induced voltage or current signal of the detection coil 101, and to process and send the acquired induced voltage or current signal of the detection coil 101 to the emission end controller 102 for foreign object detection and analysis. The foreign matter may be metal or the like which generates heat in the alternating magnetic field, and the type of the foreign matter is not limited in the embodiment of the present application.

The embodiment of the invention discloses a foreign matter detection method for a wireless charging system, wherein at least one detection coil is arranged in an electromagnetic induction area of the wireless charging system. As shown in fig. 2, the method comprises the steps of:

step 201, when the wireless charging system works, acquiring an electromagnetic induction value of the detection coil in a current target detection period, wherein the electromagnetic induction value includes an electromagnetic induction voltage value and/or an electromagnetic induction current value. Illustratively, the electromagnetic induction value of the detection coil can be obtained by sampling through an ADC, the target detection period may be a detection period with a fixed duration or a detection period with a variable duration, and the target detection period is not limited in the embodiment of the present application and can be determined by a person skilled in the art according to actual needs.

When the low-pass filtering is performed, the low-pass filter may not completely filter the alternating current component of the signal source, so that part of the alternating current component is still superimposed on the filtered signal, and thus, although the filtering processing is performed by a hardware circuit, the obtained electromagnetic induction signal may still be a high-frequency fluctuating signal. In order to further obtain a more stable electromagnetic induction signal, as an alternative embodiment of the present invention, step 201 includes: and filtering a plurality of electromagnetic induction values acquired in a target detection time period, and taking the electromagnetic induction values obtained after filtering as the electromagnetic induction values of the detection coil in the target detection time period.

Illustratively, the filtering process may be mean filtering, and a mean filtering period depends on a sampling period of the electromagnetic induction signal of the detection coil. According to the Shannon sampling theorem, in order to ensure the accuracy of the sampling result, the sampling frequency is not less than 2 times of the actual signal frequency, so that the sampling period of the electromagnetic induction value can be determined through the actual signal frequency, and then the average filtering period can be determined. In the embodiment of the present application, the average filtering period may be N times of 2 times of the sampling period, and a value of N may be any positive integer.

Further, besides the electromagnetic induction signal of the detection coil is susceptible to magnetic field interference, the error of the sampling precision of the ADC also brings about noise error. Therefore, due to the fluctuation of signals and the existence of measurement noise, the average filtering in a short time may cause a large difference between voltage values obtained in two periods before and after the short time, and the direct comparison of whether the voltage average values in the periods before and after the short time exceed a certain threshold range to determine whether foreign matter exists may still cause false detection. Therefore, the embodiment of the application performs Kalman filtering processing, least square processing, maximum likelihood estimation processing and other algorithm processing which can perform state estimation on dynamic behaviors according to observation data on the basis of mean filtering processing so as to filter out the change of electromagnetic induction values caused by signal fluctuation or measurement noise, thereby avoiding the false detection of foreign matters.

Step 202, comparing the electromagnetic induction value of the detection coil in the current target detection time period with the electromagnetic induction value of the detection coil in the previous target detection time period.

Step 203, when the comparison result meets the first foreign matter determination condition, determining that a foreign matter exists in an electromagnetic induction area of the wireless charging system. For example, the first foreign object determination condition may be that a difference value or a ratio of electromagnetic induction values of the detection coils in the front and rear adjacent target detection periods exceeds a preset threshold range, which is not limited by the embodiment of the present application and can be preset by a person skilled in the art according to actual needs.

According to the foreign matter detection method for the wireless charging system, when the wireless charging system works, the electromagnetic induction value of the detection coil in the current target detection time period is obtained, the electromagnetic induction value of the detection coil in the current target detection time period is compared with the electromagnetic induction value of the detection coil in the previous target detection time period, and when the comparison result meets a first foreign matter judgment condition, it is judged that foreign matter exists in the electromagnetic induction area of the wireless charging system. Compared with the prior art that foreign matter detection is carried out through the preset comparison value, the foreign matter detection method and the wireless charging system have the advantages that the electromagnetic induction value of the wireless charging system in the actual work is used as the comparison value of the foreign matter detection, and the accuracy of the foreign matter detection of the wireless charging system is improved.

As an optional embodiment of the present invention, the method further comprises: when the comparison result does not satisfy the first foreign matter determination condition, repeating the steps from obtaining the electromagnetic induction value of the detection coil in the current target detection period to comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period. When the wireless charging system works, the electromagnetic induction values of the detection coils in the front target detection period and the rear target detection period are continuously compared, so that the foreign matters in the whole wireless charging process can be accurately detected, and the safety of the wireless charging process is ensured.

In the process of detecting foreign matters in the wireless charging process, the electromagnetic induction value in the first target detection time period can be used as a comparison object and used for carrying out difference value or mean value comparison with the electromagnetic induction value in the second target detection time period, when the comparison result does not meet the first foreign matter judgment condition, the electromagnetic induction value in the third target detection time period is obtained and compared with the electromagnetic induction value in the second target detection time period, and by analogy, the foreign matter detection in the whole wireless charging process is realized. All comparison data are data generated in the actual charging process in the detection process, and compared with a mode of presetting the comparison data in the prior art, the data used in the scheme recorded in the embodiment of the application have a reference value, so that the accuracy of foreign matter detection is improved. When the target detection period is a plurality of detection periods with a certain interval duration, the interval duration may be a fixed duration or an indefinite duration, and those skilled in the art can determine the target detection period as needed.

As an optional embodiment of the present invention, the method further comprises: acquiring an electromagnetic induction value of any target detection time period or electromagnetic induction values of a plurality of target detection time periods under the condition of no foreign matters, and taking the electromagnetic induction value of any target detection time period or the average value of the electromagnetic induction values of the plurality of target detection time periods as a reference comparison value; acquiring an electromagnetic induction value of the detection coil in a current target detection period; comparing the electromagnetic induction value of the detection coil in the current target detection time period with the reference comparison value; and when the comparison result meets a second foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system.

For example, after the foreign matter enters the charging area of the wireless charging system, the electromagnetic induction value of the detection coil changes greatly only at the moment when the foreign matter enters, and the electromagnetic induction values of the front and rear target detection periods are adopted to determine the foreign matter, so that the foreign matter can be accurately detected only at the moment when the foreign matter enters the charging area, and the detection cannot be continued. In contrast, in the embodiment of the application, the electromagnetic induction value of any target detection time period or the average value of the battery induction values of a plurality of target detection time periods in the case of no foreign object is used as a reference comparison value, and the obtained electromagnetic induction value of the detection coil in the current target detection time period is compared with the reference comparison value. For example, if the difference or ratio between the electromagnetic induction value of the detection coil and the reference comparison value in the current target detection period exceeds a certain threshold range, it is determined that a foreign object exists in the electromagnetic induction area of the wireless charging system. The second foreign matter determination condition and the threshold range are not limited in the embodiments of the present application, and those skilled in the art can determine the second foreign matter determination condition and the threshold range according to actual needs.

In order to ensure the accuracy of the reference alignment value, as an optional embodiment of the present invention, the method further comprises: and updating the reference comparison value by using the electromagnetic induction value of the latest target detection time period under the condition of no foreign matters. Illustratively, as the foreign object detection is continuously performed, the foreign object detection results corresponding to a plurality of target detection time periods are continuously obtained, and under the condition that the detection results are no foreign objects, the electromagnetic induction values of one or more target detection time periods are updated recently to form a dynamic reference comparison value, so that the actual use value of the reference comparison value is improved. The reference comparison value updating mode can be periodically updated according to the target interval duration, the target interval duration is not limited in the embodiment of the application, and a person skilled in the art can determine the target interval duration according to actual needs.

As an optional embodiment of the present invention, the method further comprises: determining whether the frequency of continuously judging whether foreign matters exist in an electromagnetic induction area of the wireless charging system is greater than a preset frequency; and when the frequency of continuously judging that foreign matters exist in the electromagnetic induction area of the wireless charging system is greater than the preset frequency, judging that the foreign matters exist in the electromagnetic induction area of the wireless charging system.

For example, since the accuracy of the obtained electromagnetic induction value is susceptible to magnetic field interference and detection noise, after the electromagnetic induction value detected by any detection coil is compared with the reference comparison value to determine that a foreign object exists, in order to avoid misdetermination, the number of times of the result of continuously determining that a foreign object exists may be set, and when the number of times is greater than the preset number of times, it is determined that a foreign object exists in the electromagnetic induction area of the wireless charging system. By setting the continuous judgment times, the accuracy of the judgment result can be ensured under the condition of not adopting filtering processing. The preset times are not limited in the embodiment of the application, and can be determined by a person skilled in the art according to actual needs.

As an optional embodiment of the present invention, the method further comprises: and when the gain adjustment is carried out on the electromagnetic induction value of the detection coil, the gain adjustment reduction is carried out on the electromagnetic induction value according to the gain adjustment amplitude, and the foreign matter judgment is carried out by utilizing the reduced electromagnetic induction value. For example, when the charging power is changed during the charging process, the magnetic field of the transmitting coil may change greatly, resulting in that the electromagnetic induction signal of the detecting coil also changes in the corresponding range. In order to ensure the accuracy of the detection result, the accurate detection of a large-range signal can be realized by adjusting the gain of the detection circuit on line. When the number of the detection coils includes a plurality of coils, the gain adjustment may be performed one by one, or may be performed simultaneously with a plurality of coils as a group.

After gain adjustment is carried out on the electromagnetic induction value in the charging process, the current electromagnetic induction value is changed, so that the precision of the electromagnetic induction value obtained in the previous target detection time period and used for comparison can not meet the use requirement. In order to ensure the accuracy of foreign matter detection, the gain adjustment reduction can be performed on the electromagnetic induction value subjected to the gain adjustment, for example, the gain of the electromagnetic induction value used for comparison in the previous target detection period is 2 times, and the gain of the electromagnetic induction value in the current target detection period is 3 times, so that the electromagnetic induction value in the previous target detection period can be divided by 2, the electromagnetic induction value in the current target detection period is divided by 3, the proportional gain reduction is performed, and then the comparison between the previous target detection period and the next target detection period is performed to complete the foreign matter detection judgment.

According to the foreign matter detection method of the wireless charging system, the foreign matter detection is carried out in a mode that filtering processing and dynamic reference comparison values replace preset comparison values. The filtering processing method can effectively filter the measurement noise, the dynamic reference comparison value is calculated by adopting real-time data under the condition of no foreign matter, the influence on the foreign matter detection result under different states of magnetic field distribution and temperature can be eliminated, whether the change of the electromagnetic induction value of the detection coil is caused by the foreign matter or not is truly reflected, and the accuracy of the foreign matter detection in the wireless charging process is improved.

The embodiment of the invention also discloses a foreign matter detection device of a wireless charging system, wherein the electromagnetic induction area of the wireless charging system is provided with at least one detection coil, and as shown in figure 3, the device comprises:

an obtaining module 301, configured to obtain an electromagnetic induction value of the detection coil in a current target detection period when the wireless charging system operates, where the electromagnetic induction value includes an electromagnetic induction voltage value and/or an electromagnetic induction current value;

a comparison module 302, configured to compare the electromagnetic induction value of the detection coil in the current target detection time period with the electromagnetic induction value of the detection coil in a previous target detection time period;

the determining module 303 is configured to determine that a foreign object exists in an electromagnetic induction area of the wireless charging system when the comparison result meets a first foreign object determination condition.

When the wireless charging system works, the electromagnetic induction value of the detection coil in the current target detection time period is obtained, the electromagnetic induction value of the detection coil in the current target detection time period is compared with the electromagnetic induction value of the detection coil in the previous target detection time period, and when the comparison result meets a first foreign matter judgment condition, the foreign matter in the electromagnetic induction area of the wireless charging system is judged. Compared with the prior art that foreign matter detection is carried out through the preset comparison value, the foreign matter detection method and the wireless charging system have the advantages that the electromagnetic induction value of the wireless charging system in the actual work is used as the comparison value of the foreign matter detection, and the accuracy of the foreign matter detection of the wireless charging system is improved.

As an optional implementation manner of the present invention, the determining module 303 is further configured to repeat the steps from obtaining the electromagnetic induction value of the detection coil in the current target detection period to comparing the electromagnetic induction value of the detection coil in the current target detection period with the electromagnetic induction value of the detection coil in the previous target detection period when the comparison result does not satisfy the first foreign object determination condition.

As an optional embodiment of the present invention, the obtaining module 301 is configured to perform filtering processing on a plurality of electromagnetic induction values acquired in a target detection time period, and use the electromagnetic induction values obtained after the filtering processing as electromagnetic induction values of the detection coil in the target detection time period.

As an optional implementation manner of the present invention, the determining module 303 is further configured to obtain an electromagnetic induction value in any one target detection time period or electromagnetic induction values in multiple target detection time periods under a condition without an object, and use the electromagnetic induction value in any one target detection time period or an average value of the electromagnetic induction values in multiple target detection time periods as a reference comparison value; acquiring an electromagnetic induction value of the detection coil in a current target detection period; comparing the electromagnetic induction value of the detection coil in the current target detection time period with the reference comparison value; and when the comparison result meets a second foreign matter judgment condition, judging that foreign matters exist in an electromagnetic induction area of the wireless charging system.

As an optional embodiment of the present invention, the apparatus further comprises: and the updating module is used for updating the reference comparison value by utilizing the electromagnetic induction value of the latest target detection time period under the condition of no foreign matter.

As an optional embodiment of the present invention, the apparatus further comprises: and the adjusting module is used for adjusting the gain of the electromagnetic induction value of the detection coil, adjusting and restoring the gain of the electromagnetic induction value according to the gain adjustment amplitude, and judging the foreign matters by using the restored electromagnetic induction value.

As an optional implementation manner of the present invention, the determining module 303 is further configured to determine whether the number of times of continuously determining whether the electromagnetic induction area of the wireless charging system has the foreign object is greater than a preset number of times; and when the frequency of continuously judging that foreign matters exist in the electromagnetic induction area of the wireless charging system is greater than the preset frequency, judging that the foreign matters exist in the electromagnetic induction area of the wireless charging system.

The embodiment of the invention also provides a foreign matter detection system of the wireless charging system, which comprises:

at least one detection coil;

and the controller is electrically connected with the detection coil and is used for executing the foreign matter detection method of the wireless charging system in the embodiment. For details, reference is made to the above embodiments, which are not described herein again.

An embodiment of the present invention further provides an electronic device, as shown in fig. 4, the electronic device may include a processor 401 and a memory 402, where the processor 401 and the memory 402 may be connected by a bus or in another manner, and fig. 4 takes the connection by the bus as an example.

Processor 401 may be a Central Processing Unit (CPU). The Processor 401 may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, or combinations thereof.

The memory 402, which is a non-transitory computer-readable storage medium, may be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as program instructions/modules corresponding to the wireless charging system foreign object detection method in the embodiments of the present invention. The processor 401 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions and modules stored in the memory 402, that is, implements the wireless charging system foreign object detection method in the above method embodiment.

The memory 402 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created by the processor 401, and the like. Further, the memory 402 may include high speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, memory 402 may optionally include memory located remotely from processor 401, which may be connected to processor 401 via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The one or more modules are stored in the memory 402 and when executed by the processor 401, perform a wireless charging system foreign object detection method as in the embodiment of fig. 2.

The details of the electronic device may be understood with reference to the corresponding related description and effects in the embodiment shown in fig. 2, and are not described herein again.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD) or a Solid State Drive (SSD), etc.; the storage medium may also comprise a combination of memories of the kind described above.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.