Foreign matter detection device and method thereof

Abstract

An embodiment of the present application relates to a foreign object detection device and a method thereof. The detection device includes a detection antenna, including a first detection unit and a second detection unit. The first detection unit is used to generate a first induced electromotive force under the action of a magnetic field of a charged foreign object, and the second detection unit is used to generate a second induced electromotive force under the action of the magnetic field of the charged foreign object. The detection antenna is used to output the sum of the first induced electromotive force and the second induced electromotive force; a detection circuit is connected to the detection antenna, used to receive the sum of the electromotive forces and generate a sinusoidal signal, and the amplitude of the generated sinusoidal signal corresponds to the sum of the electromotive forces; a processor is connected to the detection circuit, used to receive the sinusoidal signal, and obtain the relative position relationship between the detection antenna and the charged foreign object according to the sinusoidal signal.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of metal detection, and in particular, to a foreign body detection device and method thereof. Background Art

[0002] At present, during the process of upgrading or maintaining a building, it is often necessary to cut or drill holes in the walls and floors, and usually bury charged foreign objects such as wires in the walls to ensure aesthetics. When facing maintenance and renovation work, it is usually impossible to know the exact location of wires and other objects hidden in the building. Therefore, how to avoid damaging the cables hidden in the building has become a major pain point for current building upgrading and maintenance construction personnel. If the above cables cannot be effectively avoided during construction, it will cause the building function to fail or cause incidents that harm life safety.

[0003] Existing methods for identifying charged foreign objects often use a wire or a piece of copper foil as an antenna to detect the electric field signal of the charged foreign object. The detection circuit amplifies the detection antenna signal, and the microprocessor (MCU) module samples and digitally filters the amplified signal to extract the effective amplitude of the signal to determine whether there is AC and determine the location information. These detection methods have low sensitivity to AC induction and are not accurate enough in determining the location of AC wires. Summary of the invention

[0004] The embodiments of the present application provide a foreign object detection device and method thereof, which can optimize the detection accuracy of charged foreign objects in the wall by detecting the near-field magnetic field of the charged foreign objects in the wall.

[0005] A foreign body detection device, comprising:

[0006] A detection antenna, comprising a first detection unit and a second detection unit, wherein the first detection unit is used to generate a first induced electromotive force under the action of a magnetic field of a charged foreign object, and the second detection unit is used to generate a second induced electromotive force under the action of the magnetic field of the charged foreign object, and the detection antenna is used to output the sum of the first induced electromotive force and the second induced electromotive force;

[0007] A detection circuit connected to the detection antenna, configured to receive the sum of the electromotive forces and generate a sinusoidal signal, wherein the amplitude of the generated sinusoidal signal corresponds to the sum of the electromotive forces;

[0008] A processor is connected to the detection circuit, and is used to receive the sinusoidal signal and obtain the relative position relationship between the detection antenna and the charged foreign object according to the sinusoidal signal.

[0009] In one of the embodiments, the first detection unit is connected to the second detection unit, one of the first detection unit and the second detection unit is connected to a reference voltage terminal, and the other of the first detection unit and the second detection unit is connected to the detection circuit.

[0010] In one embodiment, the first detection unit includes a first sensing portion and a second sensing portion connected to each other, the second detection unit includes a third sensing portion and a fourth sensing portion connected to each other, the third sensing portion is close to the first detection unit, the fourth sensing portion is far away from the first detection unit, and the second sensing portion is close to the second detection unit, and the first sensing portion is far away from the second detection unit;

[0011] The length of the first sensing portion is greater than the length of the second sensing portion, and the length of the third sensing portion is greater than the length of the fourth sensing portion.

[0012] In one embodiment, the length of the first sensing portion is equal to the length of the third sensing portion, and the length of the second sensing portion is equal to the length of the fourth sensing portion.

[0013] In one embodiment, the foreign object detection device includes a plurality of connected first sensing units and a plurality of connected second sensing units, the plurality of first sensing units are used to jointly output a first induced electromotive force, and the plurality of second sensing units are used to jointly output a second induced electromotive force.

[0014] In one embodiment, the number of the first sensing units is equal to the number of the second sensing units.

[0015] In one embodiment, the detection circuit includes an operational amplifier, a reference voltage generating unit, a first capacitor and a first resistor; wherein,

[0016] The non-inverting input terminal of the operational amplifier is connected to the reference voltage generating unit, the inverting input terminal of the operational amplifier is connected to the detection antenna via the first capacitor, the output terminal of the operational amplifier is used to output the sinusoidal signal, and the two ends of the first resistor are respectively connected to the inverting input terminal of the operational amplifier and the output terminal of the operational amplifier.

[0017] In one of the embodiments, the reference voltage generating unit includes:

[0018] A second resistor is connected to the power supply voltage terminal and the non-inverting input terminal of the operational amplifier respectively;

[0019] The third resistor is connected to the ground terminal and the non-inverting input terminal of the operational amplifier respectively.

[0020] In one embodiment, the sensing antenna is a printed antenna or a wound antenna.

[0021] A foreign body detection method, comprising:

[0022] Acquire a sinusoidal signal generated by a detection circuit in response to the sum of electromotive forces output by a detection antenna, wherein the amplitude of the sinusoidal signal corresponds to the sum of the electromotive forces, wherein the detection antenna comprises a first detection unit and a second detection unit, wherein the first detection unit is used to generate a first induced electromotive force under the action of a magnetic field of a charged foreign object, and the second detection unit is used to generate a second induced electromotive force under the action of a magnetic field of the charged foreign object, and the sum of the electromotive forces is the sum of the first induced electromotive force and the second induced electromotive force;

[0023] The relative position relationship between the detection antenna and the charged foreign object is acquired according to the sinusoidal signal.

[0024] The above-mentioned foreign body detection device and method, the detection device includes a detection antenna, including a first detection unit and a second detection unit, the first detection unit is used to generate a first induced electromotive force under the magnetic field of the charged foreign body, the second detection unit is used to generate a second induced electromotive force under the magnetic field of the charged foreign body, and the detection antenna is used to output the sum of the first induced electromotive force and the second induced electromotive force; the detection circuit is connected to the detection antenna, and is used to receive the sum of the electromotive force and generate a sinusoidal signal, and the amplitude of the generated sinusoidal signal corresponds to the sum of the electromotive force; the processor is connected to the detection circuit, and is used to receive the sinusoidal signal, and obtain the relative position relationship between the detection antenna and the charged foreign body according to the sinusoidal signal. Among them, since the relative position relationship between the first detection unit and the second detection unit and the charged foreign body is different, the first induced electromotive force generated by the first detection unit and the second induced electromotive force generated by the second detection unit are not completely the same, and the direction of the induced electromotive force will also change accordingly. Therefore, the sum of the electromotive force can not only reflect the amplitude of the two induced electromotive forces, but also reflect the direction of the induced electromotive force. That is, the correspondingly generated sinusoidal signal can also reflect the above situation, and the relative position relationship between the detection antenna and the charged foreign object can be accurately obtained by analyzing the sinusoidal signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 is a structural block diagram of a foreign body detection device according to an embodiment;

[0027] Figure 2 A schematic diagram of the structure of a detection antenna according to an embodiment;

[0028] Figure 3 A schematic diagram of the induced electromotive force corresponding to different relative positional relationships between the detection antenna and the charged object;

[0029] Figure 4 is a distribution curve of antenna signal strength and wire position of an embodiment;

[0030] Figure 5 FIG. 4 is a circuit diagram of a detection circuit according to an embodiment.

[0031] Component number description:

[0032] Detection antenna: 100; first detection unit: 110; second detection unit: 120; detection circuit: 200; reference voltage generation unit: 211; processor: 300. DETAILED DESCRIPTION

[0033] In order to facilitate understanding of the embodiments of the present application, the embodiments of the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the embodiments of the present application are given in the drawings. However, the embodiments of the present application can be implemented in many different forms and are not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the embodiments of the present application more thorough and comprehensive.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the technical field of the embodiments of the present application. The terms used herein in the specification of the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of the present application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0036] Figure 1 is a structural block diagram of a foreign body detection device according to an embodiment, Figure 1 The foreign object detection device includes a detection antenna 100, a detection circuit 200 and a processor 300.

[0037] The detection antenna 100 includes a first detection unit 110 and a second detection unit 120, wherein the first detection unit 110 is used to generate a first induced electromotive force under the magnetic field of a charged foreign object, and the second detection unit 120 is used to generate a second induced electromotive force under the magnetic field of the charged foreign object, and the detection antenna 100 is used to output the sum of the first induced electromotive force and the second induced electromotive force. The detection circuit 200 is connected to the detection antenna 100, and is used to receive the sum of the electromotive forces and generate a sinusoidal signal, and the amplitude of the generated sinusoidal signal corresponds to the sum of the electromotive forces. The processor 300 is connected to the detection circuit 200, and is used to receive the sinusoidal signal, and obtain the relative position relationship between the detection antenna 100 and the charged foreign object according to the sinusoidal signal.

[0038] In this embodiment, since the relative positional relationship between the first detection unit 110 and the second detection unit 120 and the charged foreign object is different, the first induced electromotive force generated by the first detection unit 110 and the second induced electromotive force generated by the second detection unit 120 are not completely the same, and the direction of the induced electromotive force will also change accordingly. Therefore, the sum of the electromotive forces can not only reflect the amplitude of the two induced electromotive forces, but also reflect the direction of the induced electromotive forces. That is, the correspondingly generated sinusoidal signal can also reflect the above situation. By analyzing the sinusoidal signal, the relative positional relationship between the detection antenna 100 and the charged foreign object can be accurately obtained.

[0039] In one embodiment, the first detection unit 110 is connected to the second detection unit 120, one of the first detection unit 110 and the second detection unit 120 is connected to the reference voltage terminal, and the other of the first detection unit 110 and the second detection unit 120 is connected to the detection circuit 200. Exemplarily, the first detection unit 110 may be connected to the reference voltage terminal, and the second detection unit 120 may be connected to the detection circuit 200. Taking the reference voltage terminal as the ground terminal as an example, if the sum of the electromotive force is a positive value, the second detection unit 120 outputs a positive induced electromotive force to the detection circuit 200; if the sum of the electromotive force is a negative value, the second detection unit 120 outputs a negative induced electromotive force to the detection circuit 200. The processor 300 can obtain the relative position relationship between the first detection unit 110, the second detection unit 120 and the charged foreign object based on the voltage value of the reference voltage terminal and the sum of the received electromotive force.

[0040] Figure 2 FIG. 1 is a schematic diagram of the structure of a detection antenna 100 according to an embodiment of the present invention. Figure 2, which provides 8 structures of the detection antenna 100, wherein the first detection unit 110 includes a first sensing portion (i.e., the A'" to A"" segment in each figure) and a second sensing portion (i.e., the A' to A" segment in each figure), and the second detection unit 120 includes a third sensing portion (i.e., the B'" to B"" segment in each figure) and a fourth sensing portion (i.e., the B' to B" segment in each figure) connected to each other. The third sensing portion is close to the first detection unit 110, the fourth sensing portion is far away from the first detection unit 110, and the second sensing portion is close to the second detection unit 120, and the first sensing portion is far away from the second detection unit 120. The length of the first sensing portion is greater than the length of the second sensing portion, and the length of the third sensing portion is greater than the length of the fourth sensing portion. Correspondingly, the area of ​​the figure enclosed by A-A'-A"-A'" is smaller than the area of ​​the figure enclosed by A"-A'"-A""-A'"", and the area enclosed by B-B'-B"-B'" is smaller than the area of ​​the figure enclosed by B"-B'"-B""-B'"". It can be understood that the lines in the figure are horizontal or vertical only for the convenience of description. The actual lines can be in any other direction or can be arcs, and the turning angles are not limited to right angles and can be any angles. The detection antenna 100 has two lead-out ports, which are respectively connected to the reference voltage terminal and the detection circuit 200, one of which is led out from one of A, A', A", or A'", and the other is led out from one of B, B', B", or B'".

[0041] For example, Figure 2 The detection antenna 100 in (f) is taken as an example for description. Figure 3 Schematic diagram of detecting the induced electromotive force corresponding to different relative positional relationships between the antenna 100 and the charged object. Figure 3 The charged object in the detection antenna 100 is the wire. When the AC wire is far away from the detection antenna 100, it is assumed that the current flowing through the AC wire is from bottom to top at a certain moment and the current increases. If the AC wire is located on the left side of the detection antenna 100, such as Figure 3 As shown in (a), the total electromotive force of A-A'-A"-A'"-A""-A'"" is negative at the top and positive at the bottom, and the total electromotive force of B-B'-B"-B'"-B""-B'"" is also negative at the top and positive at the bottom. Because B-B'-B"-B'"-B""-B'"" is farther away from the AC power line than A-A'-A"-A""-A""-A'"" and has a smaller magnetic induction intensity, the induced electromotive force of B-B'-B"-B'"-B""-B"""-……-A'""-A""-A""-A"-A'-A in series is also B positive and A negative. When the AC power line gradually approaches the detection antenna 100, the magnetic induction intensity in the area where the antenna is located gradually increases, and the signal amplitude detected by the detection antenna 100 gradually increases. As shown Figure 3As shown in (b), when the AC power line is close to the axis of the detection antenna 100, the signals detected on the left and right sides of the detection antenna 100 are not canceled out but enhanced. At this time, the total electromotive force of A-A'-A”-A’”-A””-A’”” is positive at the top and negative at the bottom, and the total electromotive force of B-B'-B”-B’”-B””-B’”” is negative at the top and positive at the bottom (because the directions of the magnetic lines of force on the left and right sides of the axis are opposite), and the induced electromotive force of B-B'-B”-B’”-B””-B’””-…-A’””-A””-A’”-A’”-A’-A connected in series is enhanced, B is negative and A is positive, and the signal amplitude detected by the detection antenna 100 reaches the maximum. If the AC power line is located on the right side of the detection antenna 100, as shown in FIG. Figure 3 As shown in (c), there is an enhanced magnetic field on the left side of the AC wire, generating an induced electromotive force with a negative top and a positive bottom on A-A'-A”-A'” and B-B'-B”-B’”, and a positive top and a negative bottom on A”-A’”-A””-A’”” and B”-B’”-B””-B’””. Because the area of ​​the figure enclosed by A-A'-A”-A'”(B-B'-B”-B’”) is smaller than the area of ​​the figure enclosed by A”-A’”-A””-A’””(B”-B’”-B””-B’””), the total electromotive force of A-A'-A”-A’”-A””-A’”” is positive at the top and negative at the bottom, and the total electromotive force of B-B'-B”-B’”-B””-B’”” is also positive at the top and negative at the bottom. And because B-B'-B”-B’”-B””-B’”” is closer to the AC power wire than A-A'-A”-A’”-A””-A’””, the magnetic induction intensity is greater. Therefore, the induced electromotive force of B-B'-B”-B’”-B””-B’””-……-A’””-A””-A””-A”-A’-A in series is B positive and A negative.

[0042] Moreover, when the AC power line is far away from the detection antenna 100, the signals detected on the left and right sides of the detection antenna 100 are substantially offset, and the absolute value of the signal amplitude is small. Figure 4 Based on the structure of the detection antenna 100, the exact position of the AC power line can be accurately determined, that is, the position with the maximum signal strength is the position of the charged foreign object.

[0043] In one embodiment, continue to refer to Figure 2 The foreign object detection device includes a plurality of connected first sensing units and a plurality of connected second sensing units. Figure 2Each detection antenna 100 includes two or three first sensing units, and two or three second sensing units. A plurality of the first sensing units are used to jointly output a first induced electromotive force, and a plurality of the second sensing units are used to jointly output a second induced electromotive force. It is understandable that when the processor 300 performs calculations and analyses, the number of sensing units is also added to the calculations as a basic parameter. In this embodiment, by setting a plurality of the first sensing units connected to each other and a plurality of the second sensing units connected to each other, the amplitudes of the first induced electromotive force and the second induced electromotive force can be increased, thereby avoiding the situation where the insufficient sensitivity of the detection circuit 200 leads to erroneous detection results. In one embodiment, the number of the first sensing units is equal to the number of the second sensing units.

[0044] Figure 5 is a circuit diagram of a detection circuit 200 according to an embodiment, Figure 5 In one embodiment, the detection circuit 200 includes an operational amplifier, a reference voltage generating unit 211, a first capacitor and a first resistor R1. The in-phase input terminal of the operational amplifier is connected to the reference voltage generating unit 211, the inverting input terminal of the operational amplifier is connected to the detection antenna via the first capacitor, the output terminal of the operational amplifier is used to output the sinusoidal signal, and the two ends of the first resistor are respectively connected to the inverting input terminal of the operational amplifier and the output terminal of the operational amplifier. Specifically, the induction signal is connected to the inverting input terminal of the operational amplifier of the detection circuit 200 by AC coupling, and a sinusoidal signal of a specific frequency (usually 50Hz to 60Hz, the specific frequency is determined by the frequency of the signal in the detected live wire) is obtained after amplification. Therefore, the signal amplitude is related to the distance between the center of the detection antenna 100 and the AC wire. That is, the closer the distance, the larger the signal, and the farther the distance, the smaller the signal. After the processor 300 samples, digitally filters, and processes the digital signal of the sinusoidal signal, the frequency and effective amplitude of the signal can be extracted and it can be determined whether there is a charged foreign object with AC. In this embodiment, through the above structure, the sensing signal can be accurately converted into a sinusoidal signal with a corresponding amplitude, and the noise in the sensing signal can be filtered out to a certain extent, so as to output a sinusoidal signal that is easier to detect.

[0045] Continue to refer Figure 5 In one embodiment, the reference voltage generating unit 211 includes a second resistor R2 and a third resistor R3. The second resistor R2 is connected to the power supply voltage terminal and the non-inverting input terminal of the operational amplifier, respectively. The third resistor R3 is connected to the ground terminal and the non-inverting input terminal of the operational amplifier, respectively. In this embodiment, based on the above circuit structure, the required reference voltage can be accurately provided.

[0046] In one embodiment, the sensing antenna is a printed antenna.

[0047] In one embodiment, the sensing antenna is a wound antenna.

[0048] An embodiment of the present application also provides a foreign object detection method, which includes: obtaining a sinusoidal signal generated by the detection circuit 200 in response to the sum of the electromotive forces output by the detection antenna 100, the amplitude of the sinusoidal signal corresponding to the sum of the electromotive forces, the detection antenna 100 including a first detection unit 110 and a second detection unit 120, the first detection unit 110 is used to generate a first induced electromotive force under the action of the magnetic field of the charged foreign object, the second detection unit 120 is used to generate a second induced electromotive force under the action of the magnetic field of the charged foreign object, the sum of the electromotive forces is the sum of the first induced electromotive force and the second induced electromotive force; the relative position relationship between the detection antenna 100 and the charged foreign object is obtained according to the sinusoidal signal.

[0049] Based on the same inventive concept, the embodiment of the present application also provides a foreign body detection device for implementing the foreign body detection method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more foreign body detection device embodiments provided below can refer to the limitations of the foreign body detection method above, and will not be repeated here.

[0050] In one of the embodiments, as shown in the foreign body detection figure, a foreign body detection device is provided, including: a sinusoidal signal acquisition module and a position analysis module. Among them, the sinusoidal signal acquisition module is used to obtain the sinusoidal signal generated by the detection circuit 200 in response to the sum of the electromotive forces output by the detection antenna 100. The amplitude of the sinusoidal signal corresponds to the sum of the electromotive forces. The detection antenna 100 includes a first detection unit 110 and a second detection unit 120. The first detection unit 110 is used to generate a first induced electromotive force under the magnetic field of the charged foreign body, and the second detection unit 120 is used to generate a second induced electromotive force under the magnetic field of the charged foreign body. The sum of the electromotive forces is the sum of the first induced electromotive force and the second induced electromotive force. The position analysis module is used to obtain the relative position relationship between the detection antenna 100 and the charged foreign body according to the sinusoidal signal.

[0051] Each module in the above-mentioned foreign body detection device can be implemented in whole or in part by software, hardware or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor 300 in the electronic device in the form of hardware, or can be stored in the memory in the electronic device in the form of software, so that the processor 300 can call and execute the operations corresponding to each of the above modules.

[0052] In one embodiment, an electronic device is provided, which may be a terminal. The electronic device includes a processor 300, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor 300 of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the electronic device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through BT (Bluetooth), WIFI / WLAN (wireless local area network), mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor 300, a foreign body detection method is implemented. The display screen of the electronic device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the electronic device may be a touch layer covered on the display screen, or a key, trackball or touchpad provided on the housing of the electronic device, or an external keyboard, touchpad or mouse, etc.

[0053] Those skilled in the art will understand that the above structure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0054] In one embodiment, an electronic device is provided, including a memory and a processor 300, wherein a computer program is stored in the memory, and the processor 300 implements the steps in the above-mentioned method embodiments when executing the computer program.

[0055] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor 300, the steps in the above method embodiments are implemented.

[0056] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by the processor 300.

[0057] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited thereto. The processor 300 involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited thereto.

[0058] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments only express several implementation methods of the embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the embodiments of the present application, and these all belong to the protection scope of the embodiments of the present application. Therefore, the protection scope of the patent of the embodiments of the present application shall be subject to the attached claims.

Claims

1. A foreign body detection device, characterized in that: include: A detection antenna, comprising a first detection unit and a second detection unit, wherein the first detection unit is used to generate a first induced electromotive force under the action of a magnetic field of a charged foreign object, and the second detection unit is used to generate a second induced electromotive force under the action of the magnetic field of the charged foreign object, and the detection antenna is used to output the sum of the first induced electromotive force and the second induced electromotive force; the first detection unit comprises a first sensing part and a second sensing part connected to each other, and the second detection unit comprises a third sensing part and a fourth sensing part connected to each other, the third sensing part is close to the first detection unit, the fourth sensing part is far away from the first detection unit, and the second sensing part is close to the second detection unit, and the first sensing part is far away from the second detection unit; the length of the first sensing part is greater than the length of the second sensing part, and the length of the third sensing part is greater than the length of the fourth sensing part; A detection circuit connected to the detection antenna, configured to receive the sum of the electromotive forces and generate a sinusoidal signal, wherein the amplitude of the generated sinusoidal signal corresponds to the sum of the electromotive forces; A processor is connected to the detection circuit, and is used to receive the sinusoidal signal and obtain the relative position relationship between the detection antenna and the charged foreign object according to the sinusoidal signal.

2. The foreign matter detection device according to claim 1, characterized in that: The first detection unit is connected to the second detection unit, one of the first detection unit and the second detection unit is connected to a reference voltage terminal, and the other of the first detection unit and the second detection unit is connected to the detection circuit.

3. The foreign matter detection device according to claim 1, characterized in that: The length of the first sensing portion is equal to the length of the third sensing portion, and the length of the second sensing portion is equal to the length of the fourth sensing portion.

4. The foreign matter detection device according to claim 1, characterized in that: The foreign object detection device includes a plurality of connected first sensing units and a plurality of connected second sensing units, wherein the plurality of first sensing units are used to jointly output a first induced electromotive force, and the plurality of second sensing units are used to jointly output a second induced electromotive force.

5. The foreign matter detection device according to claim 4, characterized in that: The number of the first sensing units is equal to the number of the second sensing units.

6. The foreign matter detection device according to claim 1, characterized in that: The detection circuit includes an operational amplifier, a reference voltage generating unit, a first capacitor and a first resistor; wherein, The non-inverting input terminal of the operational amplifier is connected to the reference voltage generating unit, the inverting input terminal of the operational amplifier is connected to the detection antenna via the first capacitor, the output terminal of the operational amplifier is used to output the sinusoidal signal, and the two ends of the first resistor are respectively connected to the inverting input terminal of the operational amplifier and the output terminal of the operational amplifier.

7. The foreign matter detection device according to claim 6, characterized in that: The reference voltage generating unit comprises: A second resistor is connected to the power supply voltage terminal and the non-inverting input terminal of the operational amplifier respectively; The third resistor is connected to the ground terminal and the non-inverting input terminal of the operational amplifier respectively.

8. The foreign matter detection device according to any one of claims 1 to 7, characterized in that: The inductive antenna is a printed antenna or a wound antenna.

9. A foreign body detection method, characterized in that: include: Acquire a sinusoidal signal generated by a detection circuit in response to the sum of electromotive forces output by a detection antenna, wherein the amplitude of the sinusoidal signal corresponds to the sum of the electromotive forces, wherein the detection antenna comprises a first detection unit and a second detection unit, wherein the first detection unit is used to generate a first induced electromotive force under the action of a magnetic field of a charged foreign object, and the second detection unit is used to generate a second induced electromotive force under the action of a magnetic field of the charged foreign object, and the sum of the electromotive forces is the sum of the first induced electromotive force and the second induced electromotive force; Acquire the relative position relationship between the detection antenna and the charged foreign object according to the sinusoidal signal; Wherein, the first detection unit includes a first sensing part and a second sensing part connected to each other, the second detection unit includes a third sensing part and a fourth sensing part connected to each other, the third sensing part is close to the first detection unit, the fourth sensing part is far away from the first detection unit, and the second sensing part is close to the second detection unit, and the first sensing part is far away from the second detection unit; the length of the first sensing part is greater than the length of the second sensing part, and the length of the third sensing part is greater than the length of the fourth sensing part.

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