Foreign matter detection device and method

Abstract

The embodiment of the present application relates to a foreign object detection device and method thereof, wherein the foreign object detection device comprises: an antenna group, comprising a plurality of detection antennas, wherein the detection antennas are used to detect foreign objects to be detected during movement and generate induction signals; a detection circuit, respectively connected to the plurality of detection antennas, for receiving the induction signals and generating alternating detection signals, wherein the amplitude or frequency of the generated alternating detection signals corresponds to the amplitude of the induction signals; and a processor, connected to the detection circuit, for receiving the alternating detection signals, and obtaining the relative position relationship between the antenna group and the foreign objects to be detected according to the alternating detection signals. By setting a plurality of detection antennas, the relative position relationship between the plurality of detection antennas and the foreign objects can be obtained according to the detection results of different detection antennas, and the foreign objects can be more accurately located through the plurality of relative position relationships, thereby improving the detection accuracy of the foreign object detection device.

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, renovating or maintaining a building, it is often necessary to cut or drill holes in the walls and floors. In the current house structure, the load-bearing structures such as walls and floors need to be built with steel bars or wooden beams to strengthen the structural strength. In addition, foreign objects such as water pipes and wires are usually buried in the walls to ensure the appearance. When facing maintenance and renovation work, it is usually impossible to know the exact location of objects such as steel bars, wooden beams, and wires hidden in the building. Therefore, how to avoid harming foreign objects hidden inside the building has become a major pain point for current building upgrade and maintenance construction personnel. If the above-mentioned hidden foreign objects cannot be effectively avoided during construction, it will cause the building's reinforced structure to fail or life safety accidents.

[0003] The existing identification of charged foreign objects usually uses a wire or a piece of copper foil as an antenna, the detection circuit amplifies the detection antenna signal, the processor (MCU) module samples the amplified signal and extracts the effective amplitude and frequency of the signal after digital processing to determine whether there is alternating current; the existing traditional metal detection scheme usually uses an excitation coil to excite the metal to be tested, and uses an induction coil antenna to receive the induced magnetic field generated by the induced eddy current in the metal to be tested, the detection circuit amplifies the induced signal, and the processor (MCU) module samples the amplified signal and extracts the effective amplitude of the specific frequency signal after digital processing to determine whether there is metal; and the existing traditional non-metal detection scheme usually uses a piece of copper foil or multiple pieces of copper foil as an antenna to detect the changes in the dielectric constant and capacitance value in the medium to be tested to determine whether there is a foreign object. However, the accuracy of the above detection methods can no longer meet the current detection needs. 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 foreign objects in a wall.

[0005] A foreign body detection device, comprising:

[0006] An antenna group, comprising a plurality of detection antennas, wherein the detection antennas are used to detect foreign objects to be detected during movement and generate induction signals;

[0007] a detection circuit, connected to the plurality of detection antennas respectively, for receiving the induction signal and generating an alternating detection signal, wherein the amplitude or frequency of the generated alternating detection signal corresponds to the amplitude of the induction signal;

[0008] The processor is connected to the detection circuit and is used to receive the alternating detection signal and obtain the relative position relationship between the antenna group and the foreign object according to the alternating detection signal.

[0009] In one embodiment, the detection circuit includes a plurality of detection subcircuits, each of which is used to receive a different induction signal and generate a corresponding alternating detection signal, and the detection device further includes:

[0010] A selection switch is configured with a plurality of first ends and a plurality of second ends, wherein the plurality of first ends of the selection switch are respectively connected to the plurality of detection antennas in a one-to-one correspondence, and the plurality of second ends of the selection switch are respectively connected to the plurality of detection sub-circuits in a one-to-one correspondence;

[0011] The processor is further used to control the selection switch to select and conduct a signal transmission path between any first end and any second end.

[0012] In one embodiment, when the detection antenna detects a charged foreign object, the alternating detection signal generated by the detection subcircuit is a sinusoidal signal. In one embodiment, the detection subcircuit includes an operational amplifier, a reference voltage generation unit, a first capacitor, and a first resistor; wherein,

[0013] 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 second end of the selection switch via the first capacitor, the output terminal of the operational amplifier is used to output the alternating detection 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.

[0014] In one of the embodiments, when the detection antenna detects a non-charged foreign object, the alternating detection signal generated by the detection subcircuit is approximately a triangular wave signal or a square wave signal or other alternating signals.

[0015] In one embodiment, the selection switch is one of a mechanical switch, a relay, a contactor, a triode, a field effect transistor and an analog switch; and / or

[0016] The detection antenna is a copper foil or a conductive coil; and / or

[0017] The plurality of detection antennas are arranged on the same circuit board, or are connected to the same circuit board through wires and / or connectors. The circuit board is one of a printed circuit board, a conductive metal plate or a flexible circuit board.

[0018] A foreign body detection method, comprising:

[0019] Acquire an alternating detection signal generated by a detection circuit according to a sensing signal, wherein the sensing signal is a signal generated by a detection antenna when detecting a foreign object to be detected, and the amplitude or frequency of the alternating detection signal corresponds to the amplitude of the sensing signal;

[0020] The relative position relationship between the antenna group and the foreign object is obtained according to the alternating detection signal.

[0021] In one embodiment, the detection circuit includes a plurality of detection subcircuits, each of which is used to receive a different sensing signal and generate a corresponding alternating detection signal, and the acquisition of the alternating detection signal generated by the detection circuit according to the sensing signal includes:

[0022] Switching the selection switch to conduct the signal transmission path between the initial detection antenna and the initial detection subcircuit, wherein the initial detection antenna is one of the plurality of detection antennas, and the initial detection subcircuit is one of the plurality of detection subcircuits;

[0023] Acquiring an initial alternating detection signal output by the initial detection subcircuit;

[0024] When the amplitude corresponding to the initial alternating detection signal is greater than or equal to the amplitude threshold, switching the selection switch to conduct the signal transmission paths between the plurality of detection antennas and the plurality of detection sub-circuits one by one;

[0025] The alternating detection signals generated by the detection sub-circuits connected to the detection antenna are respectively acquired.

[0026] In one embodiment, the acquiring of the alternating detection signal generated by the detection circuit according to the sensing signal further includes:

[0027] When the amplitude corresponding to the initial alternating detection signal is less than the amplitude threshold, switching the selection switch to conduct the signal transmission path between the plurality of detection antennas and the same detection sub-circuit;

[0028] The alternating detection signal generated by the detection subcircuit connected to the detection antenna during the movement of the antenna group is obtained until the amplitude corresponding to the initial alternating detection signal is greater than or equal to an amplitude threshold.

[0029] In one embodiment, before acquiring the alternating detection signal generated by the detection circuit according to the sensing signal, the method further includes:

[0030] When the user holds the antenna group and is away from the foreign object to be detected, the signal output by each detection sub-circuit is respectively obtained as a calibration signal;

[0031] The obtaining the relative position relationship between the antenna group and the foreign object according to the alternating detection signal includes:

[0032] Calibrate each of the alternating detection signals respectively according to the calibration signal;

[0033] The relative position relationship between the antenna group and the foreign object is obtained according to the calibrated alternating detection signal.

[0034] The above-mentioned foreign object detection device and method, the foreign object detection device includes: an antenna group, including multiple detection antennas, the detection antennas are used to detect the foreign objects to be detected during movement and generate induction signals; a detection circuit, respectively connected to the multiple detection antennas, for receiving the induction signals and generating alternating detection signals, the amplitude or frequency of the generated alternating detection signals corresponding to the amplitude of the induction signals; a processor, connected to the detection circuit, for receiving the alternating detection signals, and obtaining the relative position relationship between the antenna group and the foreign objects according to the alternating detection signals. By setting multiple detection antennas, the relative position relationship between the multiple detection antennas and the foreign objects can be obtained according to the detection results of different detection antennas, and the foreign objects can be more accurately located through multiple relative position relationships, thereby improving the detection accuracy of the foreign object detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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.

[0036] Figure 1 This is one of the structural block diagrams of a foreign body detection device according to an embodiment of the present application;

[0037] Figure 2 is a distribution curve of antenna signal strength and wire position of an embodiment;

[0038] Figure 3 is a strength curve diagram of the induction signals of the two detection antennas in the above example;

[0039] Figure 4 for Figure 3 A graph showing the superposition of the strengths of the induction signals of the two detection antennas;

[0040] Figure 5 This is a second structural block diagram of a foreign body detection device according to an embodiment;

[0041] Figure 6is a circuit diagram of a detection subcircuit of an embodiment;

[0042] Figure 7 is a dielectric constant ε distribution curve of an embodiment;

[0043] Figure 8 FIG. 4 is a flow chart of a foreign body detection method according to an embodiment of the present invention.

[0044] Component number description:

[0045] Antenna group: 100; detection antenna: 110; detection circuit: 200; detection subcircuit: 210; reference voltage generating unit: 211; processor: 300; selection switch: 400. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Figure 1 This is one of the structural block diagrams of a foreign body detection device according to an embodiment of the present application, refer to Figure 1 In this embodiment, the foreign object detection device includes an antenna group 100, a detection circuit 200 and a processor 300.

[0050] The antenna group 100 includes a plurality of detection antennas 110, which are used to detect foreign objects to be detected and generate induction signals during movement. The detection antenna 110 may be, for example, a capacitive plate detection antenna 110. Further, the number of the detection antennas 110 may be greater than or equal to three, for example, four. For example, one of the detection antennas 110 detects a charged foreign object (such as an AC wire). Figure 2 The antenna signal strength and wire position distribution curve of an embodiment is shown in FIG. Figure 2 , when the AC power line is far away from the detection antenna 110, the induction signal is very small; when the AC power line gradually approaches the detection antenna 110, the induction signal gradually increases. Among them, when the distance between the AC power line and the detection antenna 110 is the shortest, that is, when it is directly below the detection antenna 110, the induction signal reaches the maximum value, and then when the AC power line gradually moves away from the detection antenna 110, the induction signal gradually decreases. It can be understood that this is only an exemplary description of charged foreign objects, and it does not limit the foreign object detection device of the present application to only detect charged foreign objects. The foreign object detection device of the embodiment of the present application can also detect non-charged foreign objects, such as non-ferrous foreign objects such as plastic water pipes and wooden beams, and metal objects such as steel bars and steel plates.

[0051] The detection circuit 200 is respectively connected to the plurality of detection antennas 110, and is used to receive the induction signal and generate an alternating detection signal, and the amplitude or frequency of the generated alternating detection signal corresponds to the amplitude of the induction signal. That is, the detection circuit 200 is used to convert the signal output by the detection antenna 110 into an alternating detection signal that is easy to detect. The processor 300 is connected to the detection circuit 200, and is used to receive the alternating detection signal, and obtain the relative position relationship between the antenna group 100 and the foreign object according to the alternating detection signal. Specifically, the processor 300 is used to obtain the relative position relationship between the antenna group 100 and the foreign object according to the waveform of the alternating detection signal corresponding to each detection antenna 110.

[0052] For example, Figure 1 For the two detection antennas 110 located on the left and right sides of the antenna group 100, assume that the AC power line moves from left to right under the antenna. When the AC power line approaches directly under one of the detection antennas 110 (for example, the left side), the sensing signal corresponding to the left antenna reaches the maximum value, but the sensing signal of the other detection antenna 110 (for example, the right side) has not yet reached the maximum value. When the AC power line gradually approaches the other detection antenna 110, the sensing signal of the original antenna that reaches the maximum value will gradually decrease, while the sensing signal of the other detection antenna 110 will gradually increase. When the AC power line approaches directly under the other detection antenna 110, the antenna sensing signal reaches the maximum value, and as the AC power line gradually moves away from the two detection antennas 110, the sensing signals of the two detection antennas 110 gradually decrease. Figure 3 is a graph showing the strength of the induction signals of the two detection antennas 110 in the above example, Figure 4 for Figure 3 The curve diagram of the superposition of the induction signal strengths of the two detection antennas 110 is shown in FIG. Figure 3 and Figure 4 The superimposed signal of the two sensing signals is like a hump signal, and the trough position in the middle of the hump curve can be determined as the position when the AC power line is between the two detection antennas 110.

[0053] In one embodiment, when three detection antennas 110 are selected, if the center of the middle detection antenna 110 is distributed near the central axis of the left and right detection antennas 110, the one-dimensional spatial position can be distinguished, but it is not conducive to distinguishing the two-dimensional spatial position. Therefore, in an actual embodiment, the center of the middle detection antenna 110 should be as far away from the central axis of the left and right antennas as possible to improve the resolution of the two-dimensional spatial position.

[0054] Figure 5 This is a second structural block diagram of a foreign body detection device according to an embodiment, referring to Figure 5 In one embodiment, the detection circuit 200 includes a plurality of detection subcircuits 210, each of which is used to receive different induction signals and generate corresponding alternating detection signals. The detection device also includes a selection switch 400. The selection switch 400 is configured with a plurality of first ends and a plurality of second ends, the plurality of first ends of the selection switch 400 are respectively connected to a plurality of the detection antennas 110 in a one-to-one correspondence, and the plurality of second ends of the selection switch 400 are respectively connected to a plurality of the detection subcircuits 210 in a one-to-one correspondence. Optionally, the selection switch 400 is one of a mechanical switch, a relay, a contactor, a triode, a field effect transistor, and an analog switch.

[0055] The processor 300 is further used to control the selection switch 400 to select and conduct the signal transmission path between any first end and any second end. In this embodiment, by setting the selection switch 400, different numbers of detection antennas 110 can be connected to the detection circuit 200 according to different detection scenarios, thereby improving the flexibility of the foreign object detection device.

[0056] Figure 6 is a circuit diagram of the detection subcircuit 210 of an embodiment, refer to Figure 6In one embodiment, the detection subcircuit 210 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 second terminal of the selection switch 400 via the first capacitor, the output terminal of the operational amplifier is used to output the alternating detection signal, and the two ends of the first resistor R1 are respectively connected to the inverting input terminal of the operational amplifier and the output terminal of the operational amplifier. Specifically, taking the foreign matter as a charged foreign matter as an example, when the detection antenna detects a charged foreign matter, the alternating detection signal generated by the detection subcircuit is a sinusoidal signal. The induction signal is connected to the inverting input terminal of the operational amplifier of the detection circuit 200 by AC coupling, and a 50Hz to 60Hz sinusoidal signal is obtained after amplification (the specific frequency of the sinusoidal signal is determined by the frequency of the signal in the detected charged wire), so the signal amplitude is related to the distance between the center of the detection antenna 110 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 alternating detection signal, it can extract the frequency and effective amplitude of the signal and determine whether there is a charged foreign object with alternating current. In this embodiment, through the above structure, the induction signal can be accurately converted into an alternating detection signal with a corresponding amplitude, and the noise in the induction signal can be filtered out to a certain extent, thereby outputting an alternating detection signal that is easier to detect.

[0057] Continue to refer Figure 6 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.

[0058] In one embodiment, when the detection antenna detects a non-charged foreign object, the alternating detection signal generated by the detection subcircuit is approximately a triangular wave signal or a square wave signal or other alternating signal, wherein, based on the charging and discharging principle of the RC circuit, the frequency of the approximate triangular wave signal is related to the distributed capacitance value of the antenna, and then to the dielectric constant of the building, and the non-charged foreign object in the building will affect the dielectric constant of the building. Specifically, for a capacitive plate antenna, the dielectric constant of the sensing area will affect the capacitance value sensed by the antenna. That is, when detecting a non-charged foreign object hidden outside the AC power line, the foreign object in the measured medium with a dielectric constant different from that of the measured medium will produce a change in dielectric constant, and the capacitance value sensed by the detection antenna 110 will also change accordingly. Therefore, when the foreign object is far away from the detection antenna 110, the capacitance value detected by the detection antenna 110 changes less. When the foreign object gradually approaches the detection antenna 110, the capacitance value detected by the detection antenna 110 changes gradually. When the foreign object is close to the bottom of the detection antenna 110, the capacitance value detected by the detection antenna 110 changes the most. The dielectric constant change sensed by the detection antenna 110 and the corresponding capacitance value change are as follows: Figure 7 shown.

[0059] Exemplarily, when considering the two detection antennas 110 on the left and right, assuming that the detection antenna 110 moves from right to left over the foreign object, when the foreign object approaches one of the detection antennas 110 (for example, the left side) directly below, the capacitance change sensed by the detection antenna 110 reaches the maximum value, but the capacitance change sensed by the other detection antenna 110 (for example, the right side) has not yet reached the maximum value. When the foreign object gradually approaches the other detection antenna 110, the sensing signal of the original detection antenna 110 sensing capacitance change reaching the maximum value will gradually decrease, while the sensing signal of the other detection antenna 110 will gradually increase. When the foreign object approaches the other detection antenna 110 directly below, the capacitance change sensed by the detection antenna 110 reaches the maximum value, and as the foreign object gradually moves away from the two detection antennas 110, the sensing signals of the two detection antennas 110 gradually decrease. The superposition of the sensing signals of the two detection antennas 110 is like a hump curve, and the trough position in the middle of the hump curve can be judged as the position when the foreign object is in the middle of the two detection antennas 110. It can be understood that the relationship between the capacitance change curve sensed by the detection antenna 110 and the distance between the detection antenna 110 and the foreign object is similar to Figure 3 and Figure 4 .

[0060] In one embodiment, the detection antenna 110 is a copper foil or a conductive coil.

[0061] In one embodiment, a plurality of the detection antennas 110 may be arranged on the same circuit board, or may be connected to the same circuit board through wires and connectors. The circuit board is one of a printed circuit board, a conductive metal plate, or a flexible circuit board. Preferably, four copper foil conductors printed on the PCB circuit board may be selected as four capacitive plate-type detection antennas 110, respectively. The shapes and sizes of these detection antennas 110 are not required to be the same, and may be flexibly arranged according to the internal space and outer surface of the detection device to make full use of the space. It is understandable that other conductors (such as LDS laser direct molding plastic parts) may also achieve similar detection effects, which is not limited in this embodiment.

[0062] Figure 8 is a flow chart of a foreign body detection method according to an embodiment, Figure 8 In one embodiment, the foreign matter detection method includes steps S100 to S200.

[0063] S100, obtaining an alternating detection signal generated by the detection circuit 200 according to the sensing signal. Figure 1 The sensing signal is a signal generated by the detection antenna 110 when detecting a foreign object to be detected, and the amplitude or frequency of the alternating detection signal corresponds to the amplitude of the sensing signal.

[0064] S200, obtaining a relative position relationship between the antenna group 100 and the foreign object to be detected according to the alternating detection signal.

[0065] In this embodiment, the relative position relationship between multiple detection antennas 110 and foreign objects can be obtained according to the detection results of different detection antennas 110, and the foreign objects can be more accurately located through multiple relative position relationships, thereby improving the detection accuracy of the foreign object detection method.

[0066] In one embodiment, in conjunction with reference Figure 5 The detection circuit 200 includes a plurality of detection subcircuits 210, each of which is used to receive different sensing signals and generate corresponding alternating detection signals. The acquisition of the alternating detection signal generated by the detection circuit 200 according to the sensing signal includes steps S110 to S140.

[0067] S110 , switching the selection switch 400 to conduct the signal transmission path between the initial detection antenna 110 and the initial detection sub-circuit 210 , wherein the initial detection antenna 110 is one of the multiple detection antennas 110 , and the initial detection sub-circuit 210 is one of the multiple detection sub-circuits 210 .

[0068] S120 , obtaining an initial alternating detection signal output by the initial detection subcircuit 210 .

[0069] S130 , when the amplitude corresponding to the initial alternating detection signal is greater than or equal to the amplitude threshold, switching the selection switch 400 to connect the signal transmission paths between the plurality of detection antennas 110 and the plurality of detection sub-circuits 210 in a one-to-one correspondence.

[0070] S140 , respectively acquiring the alternating detection signals generated by the detection sub-circuits 210 connected to the detection antenna 110 .

[0071] In this embodiment, the initial detection antenna 110 is used to detect whether there is a foreign object near the current detection position. If the amplitude corresponding to the initial alternating detection signal is greater than or equal to the amplitude threshold, it means that there is a foreign object near the current detection position, and each detection antenna 110 can be used to detect it respectively, thereby improving the positioning accuracy of the foreign object.

[0072] In one embodiment, the acquisition detection circuit 200 generates an alternating detection signal according to the sensing signal, further comprising steps S150 to S160, wherein steps S150 to S160 are provided before step S140.

[0073] S150 , when the amplitude corresponding to the initial alternating detection signal is less than the amplitude threshold, switching the selection switch 400 to conduct the signal transmission path between the plurality of detection antennas 110 and the same detection sub-circuit 210 .

[0074] S160, acquiring the alternating detection signal generated by the detection subcircuit 210 connected to the detection antenna 110 during the movement of the antenna group 100, until the amplitude corresponding to the initial alternating detection signal is greater than or equal to an amplitude threshold.

[0075] In this embodiment, if the amplitude corresponding to the initial alternating detection signal is less than the amplitude threshold, multiple detection antennas 110 can be connected to the same detection circuit 200, so that multiple sensing signals can be directly accumulated to improve the sensitivity of foreign object detection. If the detected signal amplitude is still less than the amplitude threshold, it means that there is no foreign object near the current detection position. In addition, by connecting multiple detection antennas 110 to the same detection circuit 200, while improving the sensitivity of foreign object detection, the preliminary position of the foreign object can be determined more quickly during the process of the user moving the antenna group 100, thereby improving the detection speed.

[0076] In one of the embodiments, before acquiring the alternating detection signal generated by the detection circuit 200 according to the induction signal, it also includes: when the user holds the antenna group 100 and is away from the foreign object to be detected, respectively acquiring the signal output by each detection subcircuit 210 as a calibration signal. Among them, the calibration signal is a signal when it is not affected by the foreign object to be detected, that is, the calibration signal is only related to the user holding the antenna group 100. The acquisition of the relative position relationship between the antenna group 100 and the foreign object to be detected according to the alternating detection signal includes: calibrating each of the alternating detection signals according to the calibration signal; acquiring the relative position relationship between the antenna group 100 and the foreign object to be detected according to the calibrated alternating detection signal. It can be understood that in actual use, handheld devices are easily affected by human body induction and produce misjudgment. Moreover, when held by a person's hand, the signals sensed by multiple detection antennas 110 will increase (or decrease) at the same time. Therefore, the processor 300 can determine this change and suppress or eliminate it by measuring the sensing signals of these detection antennas 110 separately during the calibration or measurement process, thereby avoiding misjudgment and improving the reliability of detection.

[0077] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flow chart may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0078] 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.

[0079] In one embodiment, the foreign body detection device includes an alternating detection signal acquisition module and a position analysis module. The alternating detection signal acquisition module is used to acquire an alternating detection signal generated by the detection circuit 200 according to the sensing signal. The sensing signal is a signal generated by the detection antenna 110 when detecting the foreign body to be detected, and the amplitude or frequency of the alternating detection signal corresponds to the amplitude of the sensing signal. The position analysis module is used to acquire the relative position relationship between the antenna group 100 and the foreign body to be detected according to the alternating detection signal.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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: An antenna group, comprising a plurality of detection antennas, wherein the detection antennas are used to detect foreign objects to be detected during movement and generate induction signals; a detection circuit, connected to the plurality of detection antennas respectively, the detection circuit comprising a plurality of detection subcircuits, each of the detection subcircuits being used to receive a different sensing signal and generate a corresponding alternating detection signal, the amplitude or frequency of the generated alternating detection signal corresponding to the amplitude of the sensing signal; A selection switch is configured with a plurality of first ends and a plurality of second ends, wherein the plurality of first ends of the selection switch are respectively connected to the plurality of detection antennas in a one-to-one correspondence, and the plurality of second ends of the selection switch are respectively connected to the plurality of detection sub-circuits in a one-to-one correspondence; a processor connected to the detection circuit, and used to control the selection switch to select and conduct a signal transmission path between an initial detection antenna and an initial detection subcircuit, wherein the initial detection antenna is one of the plurality of detection antennas, and the initial detection subcircuit is one of the plurality of detection subcircuits; Acquire an initial alternating detection signal output by the initial detection subcircuit; when the amplitude corresponding to the initial alternating detection signal is less than an amplitude threshold, switch the selection switch to conduct a signal transmission path between the plurality of detection antennas and the same detection subcircuit; The alternating detection signal generated by the detection subcircuit connected to the detection antenna during the movement of the antenna group is obtained until the amplitude corresponding to the initial alternating detection signal is greater than or equal to an amplitude threshold; and the relative position relationship between the antenna group and the foreign object to be detected is obtained according to the alternating detection signal.

2. The foreign matter detection device according to claim 1, characterized in that: When the detection antenna detects a charged foreign object, the alternating detection signal generated by the detection subcircuit is a sinusoidal signal.

3. The foreign matter detection device according to claim 1, characterized in that: The detection subcircuit 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 second end of the selection switch via the first capacitor, the output terminal of the operational amplifier is used to output the alternating detection 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.

4. The foreign matter detection device according to any one of claims 1 to 3, characterized in that: The selection switch is one of a mechanical switch, a relay, a contactor, a triode, a field effect transistor and an analog switch.

5. The foreign matter detection device according to any one of claims 1 to 3, characterized in that: The detection antenna is a copper foil or a conductive coil; and / or The plurality of detection antennas are arranged on the same circuit board, or are connected to the same circuit board through wires and / or connectors. The circuit board is one of a printed circuit board, a conductive metal plate or a flexible circuit board.

6. A foreign body detection method, characterized in that: include: Acquire an alternating detection signal generated by a detection circuit according to an induction signal, wherein the induction signal is a signal generated by a detection antenna when detecting a foreign object to be detected, and the amplitude or frequency of the alternating detection signal corresponds to the amplitude of the induction signal; the detection circuit comprises a plurality of detection subcircuits, each of which is used to receive a different induction signal and generate a corresponding alternating detection signal; Acquire the relative position relationship between the antenna group and the foreign object to be detected according to the alternating detection signal; The acquisition of the alternating detection signal generated by the detection circuit according to the induction signal comprises: Switching the selection switch to conduct the signal transmission path between the initial detection antenna and the initial detection subcircuit, wherein the initial detection antenna is one of the plurality of detection antennas, and the initial detection subcircuit is one of the plurality of detection subcircuits; Acquiring an initial alternating detection signal output by the initial detection subcircuit; When the amplitude corresponding to the initial alternating detection signal is less than the amplitude threshold, switching the selection switch to conduct the signal transmission path between the plurality of detection antennas and the same detection sub-circuit; The alternating detection signal generated by the detection subcircuit connected to the detection antenna during the movement of the antenna group is obtained until the amplitude corresponding to the initial alternating detection signal is greater than or equal to an amplitude threshold.

7. The foreign matter detection method according to claim 6, characterized in that: The acquisition detection circuit generates an alternating detection signal according to the induction signal, and further comprises: When the amplitude corresponding to the initial alternating detection signal is greater than or equal to the amplitude threshold, switching the selection switch to conduct the signal transmission paths between the plurality of detection antennas and the plurality of detection sub-circuits one by one; The alternating detection signals generated by the detection sub-circuits connected to the detection antenna are respectively acquired.

8. The foreign matter detection method according to claim 7, characterized in that: Before acquiring the alternating detection signal generated by the detection circuit according to the induction signal, the method further includes: When the user holds the antenna group and is away from the foreign object to be detected, the signal output by each detection sub-circuit is respectively obtained as a calibration signal; The obtaining the relative position relationship between the antenna group and the foreign object according to the alternating detection signal includes: Calibrate each of the alternating detection signals respectively according to the calibration signal; The relative position relationship between the antenna group and the foreign object is obtained according to the calibrated alternating detection signal.

9. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the computer program is executed by the processor, the processor is caused to perform the steps of the foreign matter detection method according to any one of claims 6 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the foreign matter detection method according to any one of claims 6 to 8 are implemented.

11. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the foreign matter detection method according to any one of claims 6 to 8 are implemented.

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