Metal article detection method and device, detection equipment and storage medium

Abstract

The embodiment of the invention provides a metal article detection method and device, detection equipment and a storage medium, the method can be applied to a controller in the detection equipment, the detection equipment further comprises a transmitting circuit and a receiving circuit, and the method comprises the following steps: in the process of detecting an article to be detected, detecting the article to be detected; the controller can adjust the transmitting power of the transmitting circuit according to a preset transmitting power adjustment strategy, so that the transmitting circuit transmits a signal at target power, and the preset transmitting power adjustment strategy comprises that in a plurality of time periods, target power corresponding to at least two time periods is different. And determining the metal type of the to-be-detected article based on the receiving signal of the receiving circuit in each time period. According to the embodiment of the invention, the transmitting power of the transmitting circuit can be adjusted according to the preset transmitting power adjustment strategy, so that the transmitting circuit transmits the signal at the non-constant power instead of the constant transmitting power, and the detection accuracy of the metal article can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of object detection, and in particular to a method, device, detection equipment and storage medium for detecting metal objects. Background Art

[0002] The metal classification door is a detection device that detects whether a person is carrying metal objects. The metal classification door based on eddy current induction technology has a constant transmission power and can detect different metals.

[0003] Specifically, according to the basic principle of eddy current induction technology, the controller can control the transmitting control circuit to transmit a single-frequency or multi-frequency sine wave. The transmitting circuit is connected to the transmitting coil, which can make the transmitting coil generate a changing electromagnetic field. When a metal object enters the changing electromagnetic field, an induced eddy current will be generated on the surface of the metal object. The induced eddy current will cause the electromagnetic field of the receiving coil to change, thereby affecting the impedance of the receiving coil. The signals of the receiving coil and the transmitting coil are converted into digital signals through an analog-to-digital conversion circuit, and then the real and imaginary parts of the impedance of the receiving coil are obtained through digital orthogonal demodulation technology, and then different metals are classified according to the characteristics of the impedance.

[0004] However, the transmitting power of the transmitting circuit of the existing metal classification gate is constant, which has the problem of low accuracy in detecting metal objects. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a metal object detection method, device, detection equipment and storage medium to improve the accuracy of metal object detection. The specific technical solution is as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for detecting metal objects, which is applied to a controller in a detection device, wherein the detection device further includes a transmitting coil, a receiving coil, a transmitting circuit, and a receiving circuit, wherein the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, and the controller is connected to the transmitting circuit and the receiving circuit, respectively, wherein the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, and the receiving coil is used to generate an induction signal when the electromagnetic field changes due to a to-be-detected object passing through the detection device, and the induction signal is sent to the receiving circuit; the method includes:

[0007] During the inspection of the object to be inspected, adjusting the transmission power of the transmission circuit according to a preset transmission power adjustment strategy so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods;

[0008] The metal type of the object to be detected is determined based on the reception signal of the receiving circuit in each time period.

[0009] Optionally, the detection device further includes a variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively;

[0010] The step of adjusting the transmit power of the transmit circuit according to a preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power includes:

[0011] According to a preset transmission power adjustment strategy, the gain of the variable gain amplifier circuit is adjusted so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

[0012] Optionally, the step of adjusting the transmit power of the transmit circuit according to a preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power includes:

[0013] According to the preset duration and target power of each time period, control the transmitting circuit to transmit a signal according to the duration and the target power; or,

[0014] Based on the received signal of the receiving circuit in the previous time period, determine the target power corresponding to the current time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period.

[0015] Optionally, the detection device further includes an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected to the transmitting circuit and the receiving circuit respectively;

[0016] The step of determining the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period includes:

[0017] Determine an envelope change value between a received signal of the receiving circuit and a transmitted signal of the transmitting circuit based on a digital signal output by the analog-to-digital conversion circuit;

[0018] Determining the power change value to be adjusted according to the magnitude relationship between the envelope change value and a preset threshold;

[0019] Based on the power change value and the transmit power of the transmit circuit in the previous time period, a target power corresponding to the current time period is determined.

[0020] Optionally, the step of determining the power change value to be adjusted according to the magnitude relationship between the envelope change value and a preset threshold value includes at least one of the following:

[0021] If the envelope change value is less than a preset lower threshold value, based on a difference between the envelope change value and the preset lower threshold value, determining that the power change value to be adjusted is to increase the first value;

[0022] If the envelope change value is greater than a preset high threshold value, based on a difference between the envelope change value and the preset high threshold value, determining that the power change value to be adjusted is to reduce a second value;

[0023] If the envelope variation value is not less than the preset lower threshold value, and the envelope variation value is not greater than the preset upper threshold value, it is determined that the power variation value to be adjusted is zero.

[0024] Optionally, the step of controlling the transmitting circuit to transmit a signal according to a target power and duration corresponding to a current time period includes:

[0025] Control the transmitting circuit to transmit a signal according to the target power and preset duration corresponding to the current time period; or,

[0026] Based on the movement speed characteristics of the object to be detected, the duration corresponding to the current time period is determined; and the transmitting circuit is controlled to transmit a signal according to the target power corresponding to the current time period and the determined duration.

[0027] Optionally, the detection device further includes a speed sensor;

[0028] The step of determining the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected includes:

[0029] The movement speed of the object to be detected before entering the detection process detected by the speed sensor is obtained, and the duration corresponding to each time period is determined based on the movement speed and the ratio relationship between the durations of the preset time periods.

[0030] Optionally, the detection device further includes a position sensor;

[0031] The step of determining the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected includes:

[0032] Acquire the position of the object to be detected during the detection process collected by the position sensor;

[0033] Determining a positional relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device;

[0034] When the position relationship satisfies a preset condition, the current moment is determined as the end moment of the current time period, wherein the position relationship corresponding to the preset condition indicates that the detection device should change the transmission power to detect the object to be detected.

[0035] In a second aspect, an embodiment of the present application provides a metal object detection device, which is applied to a controller in a detection device, wherein the detection device further includes a transmitting coil, a receiving coil, a transmitting circuit, and a receiving circuit, wherein the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, and the controller is connected to the transmitting circuit and the receiving circuit respectively, wherein the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, and the receiving coil is used to generate an induction signal when the electromagnetic field changes due to a to-be-detected object passing through the detection device, and the induction signal is sent to the receiving circuit; the device includes:

[0036] A transmission power adjustment module, used to adjust the transmission power of the transmission circuit according to a preset transmission power adjustment strategy during the detection of the object to be detected, so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods;

[0037] The metal type determination module is used to determine the metal type of the object to be detected based on the received signal of the receiving circuit in each time period.

[0038] Optionally, the detection device further includes a variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively;

[0039] The transmission power adjustment module comprises:

[0040] The gain adjustment submodule is used to adjust the gain of the variable gain amplifier circuit according to a preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

[0041] Optionally, the transmit power adjustment module includes:

[0042] A signal transmission submodule, configured to control the transmission circuit to transmit a signal according to the preset duration and target power of each time period; or,

[0043] Used to determine the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period.

[0044] Optionally, the detection device further includes an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected to the transmitting circuit and the receiving circuit respectively;

[0045] The signal transmission submodule comprises:

[0046] an envelope variation value determining unit, configured to determine an envelope variation value between a received signal of the receiving circuit and a transmitted signal of the transmitting circuit based on a digital signal output by the analog-to-digital conversion circuit;

[0047] A power change value determining unit, used to determine the power change value to be adjusted according to the magnitude relationship between the envelope change value and a preset threshold;

[0048] The target power determination unit is used to determine the target power corresponding to the current time period based on the power change value and the transmission power of the transmission circuit in the previous time period.

[0049] Optionally, the power change value determining unit includes at least one of the following:

[0050] A first determining subunit is configured to determine, if the envelope variation value is less than a preset lower threshold value, based on a difference between the envelope variation value and the preset lower threshold value, that the power variation value to be adjusted is increased by a first value;

[0051] A second determining subunit is configured to determine, if the envelope variation value is greater than a preset high threshold value, based on a difference between the envelope variation value and the preset high threshold value, that the power variation value to be adjusted is to be reduced by a second value;

[0052] The third determining subunit is configured to determine that the power change value to be adjusted is zero if the envelope change value is not less than the preset lower threshold value and the envelope change value is not greater than the preset upper threshold value.

[0053] Optionally, the signal transmission submodule includes:

[0054] a signal transmitting unit, used to control the transmitting circuit to transmit a signal according to a target power and a preset duration corresponding to a current time period; or,

[0055] It is used to determine the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected; and control the transmitting circuit to transmit a signal according to the target power corresponding to the current time period and the determined duration.

[0056] Optionally, the detection device further includes a speed sensor;

[0057] The signal transmitting unit comprises:

[0058] The duration determination subunit is used to obtain the movement speed of the object to be detected before entering the detection process detected by the speed sensor, and determine the duration corresponding to each time period based on the movement speed and the preset duration ratio of each time period.

[0059] Optionally, the detection device further includes a position sensor;

[0060] The second transmitting unit comprises:

[0061] A position acquisition subunit, used to acquire the position of the object to be detected during the detection process collected by the position sensor;

[0062] A position relationship determination subunit, used to determine the position relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device;

[0063] The end time determination subunit is used to determine the current time as the end time of the current time period when the position relationship meets the preset conditions, wherein the position relationship corresponding to the preset conditions indicates that the detection device should change the transmission power to detect the object to be detected.

[0064] In a third aspect, an embodiment of the present application provides a detection device, the detection device comprising a controller, a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes due to an object to be inspected passing through the detection device, and the induction signal is sent to the receiving circuit, wherein:

[0065] The controller is used to adjust the transmission power of the transmission circuit according to a preset transmission power adjustment strategy during the detection of the object to be detected, so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods;

[0066] The receiving circuit is used to receive a receiving signal in each time period;

[0067] The controller is further used to determine the metal type of the object to be detected based on the received signal.

[0068] Optionally, the detection device further includes a variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively;

[0069] The controller is specifically used to adjust the gain of the variable gain amplifier circuit according to a preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

[0070] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any method described in the first aspect is implemented.

[0071] Beneficial effects of the embodiments of the present application:

[0072] The solution provided in the embodiment of the present application is applied to a controller in a detection device, and the detection device also includes a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit. The transmitting coil is connected to the transmitting circuit, and the receiving coil is connected to the receiving circuit. The controller is connected to the transmitting circuit and the receiving circuit respectively. The transmitting coil is used to generate an electromagnetic field based on the transmitting signal generated by the transmitting circuit, and the receiving coil is used to generate an induction signal when the electromagnetic field changes when the object to be detected passes through the detection device, and the induction signal is sent to the receiving circuit. In the process of detecting the object to be detected, the controller can adjust the transmission power of the transmitting circuit according to the preset transmission power adjustment strategy, so that the transmitting circuit transmits the signal with the target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers, and the metal type of the object to be detected is determined based on the received signal of the receiving circuit in each time period. Since the preset transmission power adjustment strategy includes that at least two time periods have different target powers, the transmission power of the transmitting circuit is adjusted according to the preset transmission power adjustment strategy, so that the transmitting circuit can transmit the signal with non-constant power instead of detecting the metal with constant transmission power, which can improve the accuracy of metal object detection. Of course, it is not necessary to achieve all the advantages described above at the same time to implement any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0074] Figure 1 A flowchart of a method for detecting metal objects provided in an embodiment of the present application;

[0075] FIG. 2( a ) is a schematic diagram of envelope changes provided in an embodiment of the present application;

[0076] FIG2( b ) is another schematic diagram of envelope variation provided in an embodiment of the present application;

[0077] Figure 3A schematic diagram of different target powers provided in an embodiment of the present application;

[0078] Figure 4 A schematic diagram of metal object detection provided in an embodiment of the present application;

[0079] Figure 5 Another schematic diagram of metal object detection provided by an embodiment of the present application;

[0080] Figure 6 A specific flow chart for determining target power provided in an embodiment of the present application;

[0081] Figure 7 A specific flow chart for determining the duration corresponding to a time period provided in an embodiment of the present application;

[0082] Figure 8 A schematic diagram of the structure of a metal object detection device provided in an embodiment of the present application;

[0083] Fig. 9 A schematic diagram of the structure of a detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0084] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0085] In order to improve the accuracy of metal object detection, the embodiments of the present application provide a metal object detection method, device, detection equipment, computer readable storage medium and computer program product. The following first introduces a metal object detection method provided by the embodiments of the present application.

[0086] A method for detecting metal objects provided in an embodiment of the present application can be applied to a controller in a detection device. The detection device may further include a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit. The transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, and the controller is connected to the transmitting circuit and the receiving circuit, respectively. The transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, and the receiving coil is used to generate an induction signal when the electromagnetic field changes due to the object to be inspected passing through the detection device, and the induction signal is sent to the receiving circuit.

[0087] like Figure 1 As shown, a method for detecting metal objects is applied to a controller in a detection device, and the method comprises:

[0088] S101, in the process of detecting the object to be detected, adjusting the transmission power of the transmitting circuit according to a preset transmission power adjustment strategy, so that the transmitting circuit transmits a signal at a target power;

[0089] The preset transmission power adjustment strategy includes that, within a plurality of time periods, at least two time periods have different target powers corresponding to them.

[0090] S102, determining the metal type of the object to be detected based on the reception signal of the receiving circuit in each time period.

[0091] It can be seen that in the solution provided in the embodiment of the present application, the controller is applied to the detection device, the detection device also includes a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on the transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes when the object to be detected passes through the detection device, and the induction signal is sent to the receiving circuit. In the process of detecting the object to be detected, the controller can adjust the transmission power of the transmitting circuit according to the preset transmission power adjustment strategy, so that the transmitting circuit transmits the signal with the target power, wherein the preset transmission power adjustment strategy includes that in multiple time periods, at least two time periods correspond to different target powers, and based on the receiving signal of the receiving circuit in each time period, the metal type of the object to be detected is determined. Since the preset transmission power adjustment strategy includes that in multiple time periods, at least two time periods correspond to different target powers, therefore, according to the preset transmission power adjustment strategy, the transmission power of the transmitting circuit is adjusted, so that the transmitting circuit can transmit the signal with non-constant power, instead of detecting the metal with constant transmission power, which can improve the accuracy of metal object detection.

[0092] Currently, in the process of detecting metal objects, the transmission power of the metal classification gate based on eddy current induction technology is constant and is not compatible with the simultaneous detection of small and large metal objects.

[0093] For example, as shown in FIG2(a), within the detection time t, the transmission power of the metal classification gate is too high, and the metal sensing signal is too large, resulting in an envelope value overflow; as shown in FIG2(b), within the detection time t, the transmission power of the metal classification gate is too low, and the metal sensing signal is too small, resulting in almost no change in the envelope value, so that the accuracy of metal detection is low. Therefore, the embodiment of the present application provides a method for detecting metal objects using non-constant power.

[0094] In step S101, during the process of detecting the object to be detected, the controller can adjust the transmission power of the transmission circuit according to the preset transmission power adjustment strategy, so that the transmission circuit transmits the signal at the target power. The object to be detected can be a metal object carried by a person, such as a belt, a key, a mobile phone, etc. When a person passes through the metal classification door, the metal classification door detects the metal object carried by the person. The object to be detected can also be a metal object stored in a package carried by a person.

[0095] The preset transmission power adjustment strategy includes that at least two time periods have different target powers in a plurality of time periods. That is to say, the preset transmission power adjustment strategy is a strategy that corresponds to different transmission powers in different time periods, so that the controller can adjust the transmission power in different time periods to the target power corresponding to the time period, thereby enabling the transmission circuit to transmit signals at the target power instead of at a constant power. The duration of each time period can be the same or different.

[0096] In one embodiment, for the same detection of the object to be detected, the detection time can be divided into a preset number of time periods based on actual experience, and each time period corresponds to a target power. In multiple time periods, there may be a situation where the target powers corresponding to the time periods are the same, but in multiple time periods, there are at least two time periods corresponding to different target powers. Among them, the preset number can be 2, 3, 4, 5, etc., which is not specifically limited here. The detection time is generally not more than 2s, and the length of each time period can be between 100ms and 1000ms. Of course, for different application scenarios, it can be set according to the actual situation.

[0097] When there is no object to be detected, the transmission power of the transmission circuit can be set according to the actual situation. As an implementation method, in order to have a certain buffer time when adjusting the transmission power, the transmission power of the transmission circuit when there is no object to be detected can be set to be the same as the target power corresponding to the first time period. When the controller adjusts the transmission frequency of the transmission circuit to the target power, it can adjust from the previous transmission frequency to the current target power, or it can adjust from the transmission power of the transmission circuit when there is no object to be detected to the current target power, which is reasonable.

[0098] For example, Figure 3As shown in the figure, for the same detection, the detection time from the tester entering the metal classification door to walking out of the metal classification door is T, and T can be divided into 4 time periods, and the target power corresponding to each time period is P0, P1, P2 and P3. Among them, when no tester enters, the transmitting circuit transmits the signal at the transmitting power P0. In other words, the transmitting power of the metal classification door in the idle stage is P0, which is the same as the target power corresponding to the first time period in the detection process.

[0099] Then, when the tester enters the metal classification door, that is, when the tester enters the door, the controller can determine that there is no need to adjust the transmit power in the first time period of the detection process according to the preset transmit power adjustment strategy, until the duration of the transmit signal reaches the duration of the first time period. At this time, the controller needs to adjust the transmit power of the transmit circuit to the target power P1 corresponding to the second time period according to the preset transmit power adjustment strategy.

[0100] By analogy, in the third time period, the controller adjusts the transmit power of the transmit circuit to the target power P2 corresponding to the third time period. In the fourth time period, the controller adjusts the transmit power of the transmit circuit to the target power P3 corresponding to the fourth time period, until the current test ends, that is, when the tester goes out, the transmit power is adjusted to the transmit power P0 of the idle stage.

[0101] In one embodiment, the controller adjusts the transmission power of the transmission circuit, and a variable gain amplifier circuit can be added to the detection device, and then the transmission power is adjusted by adjusting the gain of the variable gain amplifier circuit. In another embodiment, the controller adjusts the transmission power of the transmission circuit by adjusting the current of the transmission circuit.

[0102] For different types of metal objects, the signals received by the receiving circuit are different. In step S102, the controller can determine the metal type of the object to be detected based on the received signal of the receiving circuit in each time period.

[0103] For example, Figure 4 As shown, during the process of the detection device detecting metal objects, the controller can determine the target power of the transmitting circuit according to the preset transmission power adjustment strategy, and then the controller can control the transmission control circuit to transmit the corresponding sine wave at the target power. The transmitting circuit is electrically connected to the transmitting coil, and the transmitting coil can generate a changing electromagnetic field.

[0104] When a metal object enters a changing electromagnetic field, an induced eddy current will be generated on the surface of the metal object, which will cause the electromagnetic field of the receiving coil connected to the receiving circuit to change, thereby affecting the impedance of the receiving coil. The signals of the receiving coil and the transmitting coil are converted into digital signals through an AD (Analog Digital) conversion circuit, and band-pass filtered. The real and imaginary parts of the impedance of the receiving coil are obtained through Hilbert transform and digital orthogonal demodulation technology, and then low-pass filtered. Finally, different metals are classified according to the characteristics of the impedance to determine the metal type of the object to be detected.

[0105] Among them, bandpass filtering refers to filtering out low-frequency and high-frequency signal components and retaining the passband components. Low-pass filtering refers to retaining low-frequency signal components and filtering out high-frequency signal components. Orthogonal demodulation refers to demodulating the carrier signal and the orthogonal carrier signal with the intermediate frequency signal to obtain the real and imaginary parts of the baseband signal.

[0106] In the solution of this embodiment, since the preset transmission power adjustment strategy includes multiple time periods, there are at least two time periods corresponding to different target powers. Therefore, according to the preset transmission power adjustment strategy, the transmission power of the transmission circuit is adjusted, so that the transmission circuit transmits signals with non-constant power instead of detecting metal with constant transmission power, which can improve the accuracy of metal object detection. At the same time, the complexity of transmission power adjustment can be reduced, and the versatility can be improved.

[0107] As an implementation of the embodiment of the present application, the detection device may further include a variable gain amplifier circuit, which is electrically connected to the controller and the transmitting circuit respectively. The controller adjusts the transmission power of the transmitting circuit by adjusting the gain of the variable gain amplifier circuit.

[0108] The step of adjusting the transmit power of the transmit circuit according to the preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power may include:

[0109] According to a preset transmission power adjustment strategy, the gain of the variable gain amplifier circuit is adjusted so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

[0110] Since at least two of the multiple time periods included in the preset transmit power adjustment strategy have different target powers, the controller needs to adjust the transmit power of the transmit circuit at least once. If there are multiple time periods with different target powers included in the preset transmit power adjustment strategy, the controller needs to adjust the transmit frequency of the transmit circuit multiple times. If the transmit power of the transmit circuit is adjusted by changing the current, the operation is more complicated.

[0111] In one embodiment, the detection device includes a variable gain amplifier circuit, and the controller can determine the target power corresponding to each time period according to a preset transmission power adjustment strategy, and obtain the gain for adjusting the transmission power to the target power, and then adjust the gain of the variable gain amplifier circuit so that the transmission circuit generates an electromagnetic field with the target power based on the gain of the variable gain amplifier circuit.

[0112] For example, Figure 5 As shown, the detection device includes a variable gain amplifier, and the controller can generate a DA (Digital Analog) transmission waveform. After configuring the gain of the variable gain amplifier in real time according to the target power through a preset transmission power adjustment strategy, the controller can enable the transmission circuit to adjust the transmission power to the target power based on the gain of the variable gain amplifier circuit, and the transmission control circuit transmits the corresponding sine wave, thereby enabling the transmitting coil to generate an electromagnetic field with the target power.

[0113] The controller can collect the digital signals converted by the attenuator and AD conversion circuit and the digital signals converted by the receiving coil by the AD conversion circuit, and can perform signal processing such as bandpass filtering, orthogonal demodulation, and low-pass filtering on the digital signals converted by the AD conversion circuit to obtain the real and imaginary parts of the impedance of the receiving coil, and classify different metals according to the characteristics of the impedance to determine the metal type of the object to be detected.

[0114] It can be seen that in this embodiment, the controller can adjust the gain of the variable gain amplifier circuit according to the preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit. In this way, according to the preset transmission power adjustment strategy, by adjusting the gain of the variable gain amplifier circuit, the transmission circuit generates an electromagnetic field with a non-constant power, which can improve the accuracy of metal object detection, and at the same time reduce the complexity of transmission power adjustment and improve versatility.

[0115] As an implementation manner of an embodiment of the present application, the step of adjusting the transmit power of the transmit circuit according to a preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power may include:

[0116] According to the preset duration and target power of each time period, control the transmitting circuit to transmit a signal according to the duration and the target power; or,

[0117] Based on the received signal of the receiving circuit in the previous time period, determine the target power corresponding to the current time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period.

[0118] Since the purpose of pre-setting the transmission power adjustment strategy is to prevent the transmission circuit from transmitting signals at a constant power during the detection of the object to be detected, the pre-set transmission power adjustment strategy includes multiple time periods, and the target powers of at least two time periods are different. This means that in the same detection, the transmission circuit transmits signals at a non-constant transmission power, and different methods can be used to determine the duration of the time period and the target power. Therefore, the preset transmission power adjustment strategy can include multiple strategies.

[0119] In one embodiment, the preset transmission power adjustment strategy can be a timing fixed power strategy, that is, the duration of each time period and the target power corresponding to each time period are preset, so that the controller can control the transmission circuit to transmit the signal according to the duration and target power according to the preset duration and target power of each time period. Among them, the target power corresponding to the first preset time period can be the same as the transmission power of the detection device in the idle stage, or it can be different from the transmission power in the idle stage.

[0120] The length of each time period can be set according to the specific application scenario. The main influencing factor is the shortest time required for a single detection. Generally, the time of a single detection can be divided into 2 to 5 time periods. Then, the shortest time of a single detection can be divided by the number of time periods to set each time period to the same length. Alternatively, the length of each time period can be set as required based on the shortest time required for a single detection and the number of time periods.

[0121] Generally, the duration of each time period is between 100ms and 1000ms. If the duration is less than 100ms, the detection waveform may be discontinuous. If the duration is greater than 1000ms, the duration of the two time periods exceeds 2s. Generally, the single detection time is not greater than 2s. If the duration is greater than 1000ms, the number of time periods in a single detection process can only be 1, which does not meet the requirement of being greater than or equal to 2.

[0122] The target power corresponding to each time period also needs to be set according to the specific application scenario. For example, in an application scenario where the main detected objects are small metal objects, the target power corresponding to most of the multiple time periods should be set to high transmission power; in an application scenario where the main detected objects are objects with large induction signals such as mobile phones, the target power corresponding to most of the multiple time periods can be set to medium transmission power.

[0123] As an implementation mode, the detection device includes a variable gain amplifier circuit, so for the target power corresponding to each preset time period, the gain corresponding to the target power can be preset, so that at the initial moment of each time period, the controller can set the gain corresponding to the time period, and according to the preset duration and gain of each time period, control the transmitting circuit to transmit the signal based on the duration and gain.

[0124] For example, Figure 3 As shown, four time periods are preset, and the duration of each time period is t0, t1, t2 and t3 respectively, and the target powers corresponding to each time period are P0, P1, P2 and P3 respectively. If the transmission power of the detection device in the idle phase is P0, then in the first time period, the controller does not need to adjust the transmission power, that is, when the tester enters the door, the controller can control the transmission circuit to transmit the signal according to the preset duration t0 and transmission power P0. In the second time period, the controller can control the transmission circuit to transmit the signal according to the preset duration t1 and target power P1 according to the preset duration t1 and target power P1.

[0125] By analogy, in the third time period, the controller can control the transmitting circuit to transmit the signal according to the preset duration t2 and target power P2; in the fourth time period, the controller can control the transmitting circuit to transmit the signal according to the preset duration t3 and target power P3.

[0126] If the transmission power of the detection equipment in the idle phase is P, then in the first time period, the controller needs to adjust the transmission power P to the target power P0 of the first time period, that is, when the tester enters the door, the controller can control the transmission circuit to transmit the signal according to the preset duration t0 and target power P0.

[0127] If the detection device includes a variable gain amplifier circuit, the controller can set the gain corresponding to each time period. When the tester enters the door, the controller can adjust the transmission power to the target power P0 according to the gain K0, and control the transmission circuit to transmit the signal according to the duration t0 and the target power P0. Similarly, in each subsequent time period, the controller can control the transmission circuit to transmit the signal based on the duration and gain according to the duration and gain of each time period.

[0128] In another embodiment, the preset transmission power adjustment strategy may be an adaptive power strategy. The controller may determine the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period, so that the target power corresponding to each time period can be more adapted to the actual power required by the detected object. Then the controller may control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period. Among them, the target power corresponding to the first time period is a preset value. The preset value may be the same as the transmission power of the detection device in the idle phase, or it may be different from the transmission power in the idle phase.

[0129] The duration of each time period can be set in advance or can be adjusted adaptively. Therefore, the adaptive power strategy can include a timed adaptive power strategy and a time-varying adaptive power strategy.

[0130] For example, the target power corresponding to the first time period is P0. When the transmitting circuit transmits a signal with the target power P0, the controller can determine that the target power corresponding to the second time period is P1 based on the received signal of the receiving circuit in the first time period. Then, in the second time period, the controller can transmit a signal according to the preset length of the second time period and the determined target power P1 corresponding to the time period.

[0131] It can be seen that in this embodiment, the controller can control the transmitting circuit to transmit signals according to the duration and target power of each preset time period, so that the transmission power adjustment is relatively simple, which can reduce the complexity of the transmission power adjustment and improve the versatility. The controller can determine the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period, wherein the target power corresponding to the first time period is a preset value, and can control the transmitting circuit to transmit signals according to the target power and duration corresponding to the current time period. In this way, the complexity of the transmission power adjustment can be reduced, the versatility is improved to a great extent, and the objects to be detected can be detected with the optimal transmission power, thereby improving the accuracy of the detection.

[0132] As an implementation of the embodiment of the present application, the detection device may further include an analog-to-digital conversion circuit, which is electrically connected to the transmitting circuit and the receiving circuit, respectively. In this way, the controller may receive digital signals converted by the receiving circuit and the transmitting circuit through the analog-to-digital conversion circuit.

[0133] like Figure 6 As shown, the step of determining the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period may include:

[0134] S601, determining an envelope change value between a received signal of the receiving circuit and a transmitted signal of the transmitting circuit based on a digital signal output by the analog-to-digital conversion circuit;

[0135] S602, determining a power change value to be adjusted according to a magnitude relationship between the envelope change value and a preset threshold;

[0136] In order to determine the target power corresponding to the current time period, the difference between the received signal of the receiving circuit and the transmitted signal of the transmitting circuit in the previous time period can be determined, and then based on the difference, the target power corresponding to the previous time period is adjusted to determine the target power corresponding to the current time period.

[0137] In one implementation, the controller may determine the envelope change value between the received signal of the receiving circuit and the transmitted signal of the transmitting circuit based on the digital signal output by the analog-to-digital conversion circuit, and then compare the envelope change value with a preset threshold value, and determine the power change value to be adjusted according to the magnitude relationship between the envelope change value and the preset threshold value.

[0138] If the envelope change value is too large compared to the preset threshold, the transmit power can be reduced to a certain extent, and the controller can determine the power change value to be reduced based on the size relationship between the envelope change value and the preset threshold. If the envelope change value is too small compared to the preset threshold, the transmit power can be increased to a certain extent, and the controller can determine the power change value to be increased based on the size relationship between the envelope change value and the preset threshold.

[0139] Since the impact on metal object detection is small when the envelope change value changes within a certain range, there is no need to adjust the transmission signal of the transmission circuit. Therefore, the low threshold value and high threshold value of the envelope change can be preset. When the envelope change value is less than the preset low threshold value, the controller can determine the power change value to be increased based on the difference between the envelope change value and the preset low threshold value; when the envelope change value is greater than the preset high threshold value, the controller can determine the power change value to be reduced based on the difference between the envelope change value and the preset high threshold value.

[0140] For example, the preset threshold low value is THRESH_LOW, and the preset threshold high value is THRESH_HIGH. The controller can count the envelope change value corresponding to the AD data of the receiving coil in the receiving circuit in real time. When the envelope change value is less than THRESH_LOW within a certain period of time, the controller can determine the power change value to be increased based on the difference between the envelope change value and THRESH_LOW. When the envelope change value is greater than THRESH_HIGH within a certain period of time, the controller can determine the power change value to be reduced based on the difference between the envelope change value and THRESH_HIGH.

[0141] S603: Determine a target power corresponding to a current time period based on the power change value and the transmit power of the transmit circuit in the previous time period.

[0142] After the controller determines the power change value to be adjusted, the target power corresponding to the current time period can be determined based on the power change value and the transmit power of the transmit circuit in the previous time period. Specifically, if the controller determines that the power change value to be adjusted is an increased power change value, then the transmit power of the transmit circuit in the previous time period needs to be increased; if the controller determines that the power change value to be adjusted is a decreased power change value, then the transmit power of the transmit circuit in the previous time period needs to be decreased, and then the adjusted transmit power is determined as the target power corresponding to the current time period.

[0143] If the detection device includes a variable gain amplifier circuit, the controller can adjust the gain of the variable gain amplifier circuit based on the power conversion value to be adjusted, and then determine the target power corresponding to the current time period based on the adjusted gain and the transmission power of the transmitting circuit in the previous time period.

[0144] For example, the controller determines that the power change value to be adjusted is an increased power change value ΔP, so the gain of the variable gain amplifier circuit can be adjusted, and then based on the adjusted gain and the transmit power P of the transmit circuit in the previous time period, the transmit power of the transmit circuit in the previous time period is increased by the power change value ΔP to determine that the target power corresponding to the current time period is P+ΔP.

[0145] It can be seen that in this embodiment, the controller can determine the envelope change value between the received signal of the receiving circuit and the transmitted signal of the transmitting circuit based on the digital signal output by the analog-to-digital conversion circuit, determine the power change value to be adjusted based on the size relationship between the envelope change value and the preset threshold, and determine the target power corresponding to the current time period based on the power change value and the transmission power of the transmitting circuit in the previous time period. This can reduce the complexity of the transmission power adjustment, greatly improve the versatility, and can detect the object to be detected with the optimal transmission power, thereby improving the accuracy of the detection.

[0146] As an implementation manner of an embodiment of the present application, the step of determining the power change value to be adjusted according to the magnitude relationship between the envelope change value and the preset threshold value may include at least one of the following:

[0147] If the envelope change value is less than a preset lower threshold value, based on a difference between the envelope change value and the preset lower threshold value, determining that the power change value to be adjusted is to increase the first value;

[0148] If the envelope change value is greater than a preset high threshold value, based on a difference between the envelope change value and the preset high threshold value, determining that the power change value to be adjusted is to reduce a second value;

[0149] If the envelope variation value is not less than the preset lower threshold value, and the envelope variation value is not greater than the preset upper threshold value, it is determined that the power variation value to be adjusted is zero.

[0150] The controller can determine the power change value to be adjusted based on the relationship between the envelope change value and the preset envelope change threshold low value or threshold high value. If the envelope change value is much smaller than the preset threshold low value, it can be determined that the power change value to be increased is larger, and if the envelope change value is close to the preset threshold low value, it can be determined that the power change value to be increased is smaller. Similarly, if the envelope change value is much larger than the preset threshold high value, it can be determined that the power change value to be reduced is larger, and if the envelope change value is close to the preset threshold high value, it can be determined that the power change value to be reduced is smaller. Therefore, multiple power change value adjustment gears can be pre-set so that the controller can reasonably determine the power change value based on the difference between the envelope change value and the preset threshold low value or the difference between the envelope change value and the preset threshold high value.

[0151] In this way, if the envelope change value is less than the preset threshold lower value, the controller can determine the difference between the envelope change value and the preset threshold lower value based on the difference between the envelope change value and the preset threshold lower value. When the difference is less than the first preset difference, the difference between the envelope change value and the preset threshold lower value is small, and the power change value required to be increased is determined to be the preset smaller power change value; when the difference is not less than the first preset difference, the difference between the envelope change value and the preset threshold lower value is large, and the power change value required to be increased is determined to be the preset larger power change value.

[0152] Similarly, if the envelope change value is greater than the preset threshold high value, the controller can determine the difference between the envelope change value and the preset threshold high value based on the difference between the envelope change value and the preset threshold high value. When the difference is less than the second preset difference, the difference between the envelope change value and the preset threshold low value is small, and the power change value to be reduced is determined to be the preset smaller power change value; when the difference is not less than the second preset difference, the difference between the envelope change value and the preset threshold low value is large, and the power change value to be reduced is determined to be the preset larger power change value.

[0153] If the envelope change value is not less than the preset threshold lower value and the envelope change value is not greater than the preset threshold upper value, the controller can determine that the power change value to be adjusted is zero, that is, the transmission power corresponding to the previous time period can be determined as the target power corresponding to the current time period.

[0154] For example, five power change values ​​are preset, the first level is a 10dB increase in transmit power; the second level is a 3dB increase in transmit power; the third level is a constant transmit power; the fourth level is a 3dB decrease in transmit power; the fifth level is a 10dB decrease in transmit power, and the first preset difference is 10db. The transmit power corresponding to the previous time period is P0. If the envelope change value corresponding to the previous time period is less than the preset threshold lower value of 12db according to real-time statistics, the controller can determine that the difference between the envelope change value and the preset threshold lower value is greater than the first preset difference of 10db, and then it can be determined that the required power change value is 10dB.

[0155] The controller may determine that the power value corresponding to the current time period is P0+10dB based on the required increased power change value and the transmit power P0 corresponding to the previous time period.

[0156] It can be seen that in this embodiment, if the envelope change value is less than the preset threshold low value, the controller can determine that the power change value to be adjusted is to increase the first value based on the difference between the envelope change value and the preset threshold low value, if the envelope change value is greater than the preset threshold high value, based on the difference between the envelope change value and the preset threshold high value, determine that the power change value to be adjusted is to decrease the second value, if the envelope change value is not less than the preset threshold low value, and the envelope change value is not greater than the preset threshold high value, determine that the power change value to be adjusted is zero. In this way, the transmission power corresponding to the previous time period can be reasonably adjusted to determine the target power corresponding to the current time period, and then the object to be detected is detected with the optimal transmission power, thereby improving the accuracy of detection.

[0157] As an implementation manner of an embodiment of the present application, the step of controlling the transmitting circuit to transmit a signal according to the target power and duration corresponding to the current time period may include:

[0158] Control the transmitting circuit to transmit a signal according to the target power and preset duration corresponding to the current time period; or,

[0159] Based on the movement speed characteristics of the object to be detected, the duration corresponding to the current time period is determined; and the transmitting circuit is controlled to transmit a signal according to the target power corresponding to the current time period and the determined duration.

[0160] During the inspection of the objects to be inspected, the controller can determine the duration of each time period and the target power corresponding to the time period in real time, or it can pre-set the duration of each time period and determine the corresponding target power in real time within each time period. That is, when the preset transmission power adjustment strategy is an adaptive power strategy, it can include a time-varying adaptive strategy and a timing adaptive strategy.

[0161] In one implementation, the controller can control the transmitting circuit to transmit a signal according to the target power and preset duration corresponding to the current time period, that is, the transmitting power is adjusted using a timing adaptive strategy. The single detection time can be set according to the specific application scenario, and the duration of each time period can be set according to actual experience.

[0162] Generally, the duration of the first time period can be set shorter, for example, 100ms, so that the transmit power can be adjusted quickly. The duration of the second time period can be set longer to fine-tune the transmit power. The duration of the third time period can be set to the longest, so that the best transmit power state can be maintained for the longest time. The duration of the last time period can be set shorter, because when the detection is about to end, the envelope value of the received signal of the receiving circuit changes less, so that it can also transition more smoothly from the target power corresponding to the time period to the transmit power of the idle stage.

[0163] In another embodiment, the controller can determine the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected, and control the transmitting circuit to transmit the signal according to the target power corresponding to the current time period and the determined duration. That is, the transmission power is adjusted using a time-varying adaptive strategy. In other words, the controller can not only adaptively adjust the target power corresponding to each time period according to the change value of the received signal envelope, but also adaptively adjust the duration of each time period.

[0164] Exemplarily, the controller can determine the length of the time period in real time according to the speed of the object to be detected before detection or the position change of the object to be detected during the detection process, and then control the transmitting circuit to transmit the signal according to the target power corresponding to the current time period and the determined duration.

[0165] It can be seen that in this embodiment, the controller can control the transmitting circuit to transmit a signal according to the target power and preset duration corresponding to the current time period, or, based on the movement speed characteristics of the object to be detected, determine the duration corresponding to the current time period, and control the transmitting circuit to transmit a signal according to the target power and the determined duration corresponding to the current time period. This greatly improves the versatility of the transmission power adjustment, and can detect the object to be detected with the optimal transmission power, thereby improving the accuracy of the detection.

[0166] As an implementation method of the embodiment of the present application, the above-mentioned detection device may further include a speed sensor;

[0167] The step of determining the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected may include:

[0168] The movement speed of the object to be detected before entering the detection process detected by the speed sensor is obtained, and the duration corresponding to each time period is determined based on the movement speed and the ratio relationship between the durations of the preset time periods.

[0169] In order to make the duration of the transmitting circuit transmitting the signal at the target power more reasonable, the controller can determine the duration corresponding to each time period according to the movement speed of the object to be detected, that is, it can reasonably determine the duration corresponding to the current time period.

[0170] In one embodiment, the detection device includes a speed sensor, and the controller can obtain the movement speed of the object to be detected detected by the speed sensor before entering the detection process, and then determine the duration corresponding to each time period based on the movement speed and the preset duration ratio of each time period. The speed sensor can be an infrared sensor, a photoelectric sensor, etc., which is not specifically limited here. The single detection time does not need to be set according to the specific application scenario.

[0171] For example, a speed sensor is set on the metal classification door, and the number of time periods is preset to 3 and the ratio of the duration of each time period is 1:2:1. Before the inspector enters the metal classification door, the controller can obtain the walking speed of the person detected by the speed sensor, that is, the movement speed of the items to be inspected carried by the person can be determined. Then, based on the movement speed and the preset ratio of the duration of each time period of 1:2:1, the controller can determine that the duration corresponding to each time period is 500ms, 1000ms and 500ms respectively, and then based on the real-time nature of time, the duration corresponding to the current time period can be determined.

[0172] It can be seen that in this embodiment, the controller can obtain the movement speed of the object to be detected detected by the speed sensor before entering the detection process, and determine the duration corresponding to each time period based on the movement speed and the preset duration ratio of each time period. In this way, the duration of the time period can be determined in real time, so that the duration of the transmitting circuit transmitting the signal at the target power is more reasonable, and the object to be detected can be detected more effectively, thereby improving the accuracy of metal object detection. And the duration of each time period can be adaptively adjusted to adapt to the detection scenarios under different door speeds.

[0173] As an implementation method of the embodiment of the present application, the above-mentioned detection device may further include a position sensor;

[0174] like Figure 7 As shown, the step of determining the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected may include:

[0175] S701, obtaining the position of the object to be detected during the detection process collected by the position sensor;

[0176] S702, determining a positional relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device;

[0177] In one embodiment, the detection device includes a position sensor, and the controller can obtain the position of the object to be detected during the detection process collected by the position sensor, and then determine the positional relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device. The position sensor can be a camera, an infrared sensor, etc., which is not specifically limited here. The single detection time does not need to be set according to the specific application scenario.

[0178] For example, a camera is installed on the metal classification door to capture the position of the inspector, that is, to obtain the position of the object to be inspected carried by the inspector. Then, based on the position of the inspector and the position of the metal classification door, the positional relationship between the object to be inspected and the metal classification door can be determined. For example, the object to be inspected is at the half position of the metal classification door.

[0179] S703: When the position relationship satisfies a preset condition, determine the current time as the end time of the current time period.

[0180] The positional relationship corresponding to the preset condition indicates that the detection device should change the transmission power to detect the object to be detected.

[0181] If the position relationship meets the preset conditions, the controller can determine the current moment as the end moment of the current time period. The position relationship identification detection device corresponding to the preset conditions should change the transmission power to detect the object to be detected. In other words, based on the position relationship and the preset conditions, the controller can determine whether the duration of the current transmitting circuit transmitting the signal has met the detection duration. If so, it can enter the next time period and adjust the transmission power to the target power corresponding to the time period.

[0182] For example, when the controller determines that the positional relationship between the object to be detected and the detection device is that the object to be detected is at one-third of the metal classification door, the controller can determine the current moment as the end moment of the first time period, and then enter the second time period. When it is determined that the positional relationship between the object to be detected and the detection device is that the object to be detected is in the middle position of the metal classification door, the controller can determine the current moment as the end moment of the second time period, and then enter the third time period, until the positional relationship between the object to be detected and the detection device is that the object to be detected is no longer in the metal classification gate.

[0183] It can be seen that in this embodiment, the controller can obtain the position of the object to be detected during the detection process collected by the position sensor, determine the positional relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device, and when the positional relationship meets the preset conditions, determine the current moment as the end moment of the current time period, wherein the positional relationship corresponding to the preset conditions indicates that the detection device should change the transmission power to detect the object to be detected. In this way, the duration of transmitting the signal at the target power can be determined in real time, so that the duration of the transmitting circuit transmitting the signal at the target power is more reasonable, and the object to be detected can be detected more effectively, thereby improving the accuracy of metal object detection. And the duration of each time period can be adaptively adjusted to adapt to the detection scenarios under different door speeds. At the same time, it can be realized that the transmission power of the transmitting circuit can be adaptively adjusted according to the different positions of the object to be detected in the detection channel.

[0184] Corresponding to the above-mentioned method for detecting a metal object, the embodiment of the present application further provides a device for detecting a metal object. The following is an introduction to the device for detecting a metal object provided in the embodiment of the present application.

[0185] like Figure 8 As shown, a metal object detection device is applied to a controller in a detection device, the detection device also includes a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes due to the object to be detected passing through the detection device, and the induction signal is sent to the receiving circuit; the device includes:

[0186] The transmission power adjustment module 810 is used to adjust the transmission power of the transmission circuit according to a preset transmission power adjustment strategy during the detection of the object to be detected, so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods;

[0187] The metal type determination module 820 is used to determine the metal type of the object to be detected based on the received signal of the receiving circuit in each time period.

[0188] It can be seen that in the solution provided in the embodiment of the present application, the controller is applied to the detection device, the detection device also includes a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on the transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes when the object to be detected passes through the detection device, and the induction signal is sent to the receiving circuit. In the process of detecting the object to be detected, the controller can adjust the transmission power of the transmitting circuit according to the preset transmission power adjustment strategy, so that the transmitting circuit transmits the signal with the target power, wherein the preset transmission power adjustment strategy includes that in multiple time periods, at least two time periods correspond to different target powers, and based on the receiving signal of the receiving circuit in each time period, the metal type of the object to be detected is determined. Since the preset transmission power adjustment strategy includes that in multiple time periods, at least two time periods correspond to different target powers, therefore, according to the preset transmission power adjustment strategy, the transmission power of the transmitting circuit is adjusted, so that the transmitting circuit can transmit the signal with non-constant power, instead of detecting the metal with constant transmission power, which can improve the accuracy of metal object detection.

[0189] As an implementation of the embodiment of the present application, the above-mentioned detection device may further include a variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively;

[0190] The transmit power adjustment module 810 may include:

[0191] The gain adjustment submodule is used to adjust the gain of the variable gain amplifier circuit according to a preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

[0192] As an implementation of the embodiment of the present application, the transmit power adjustment module 810 may include:

[0193] A signal transmission submodule, configured to control the transmission circuit to transmit a signal according to the preset duration and target power of each time period; or,

[0194] Used to determine the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period.

[0195] As an implementation manner of the embodiment of the present application, the above-mentioned detection device further includes an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected to the transmitting circuit and the receiving circuit respectively;

[0196] The above-mentioned signal transmission submodule may include:

[0197] an envelope variation value determining unit, configured to determine an envelope variation value between a received signal of the receiving circuit and a transmitted signal of the transmitting circuit based on a digital signal output by the analog-to-digital conversion circuit;

[0198] A power change value determining unit, used to determine the power change value to be adjusted according to the magnitude relationship between the envelope change value and a preset threshold;

[0199] The target power determination unit is used to determine the target power corresponding to the current time period based on the power change value and the transmission power of the transmission circuit in the previous time period.

[0200] As an implementation manner of an embodiment of the present application, the power change value determining unit may include at least one of the following:

[0201] A first determining subunit is configured to determine, if the envelope variation value is less than a preset lower threshold value, based on a difference between the envelope variation value and the preset lower threshold value, that the power variation value to be adjusted is increased by a first value;

[0202] A second determining subunit is configured to determine, if the envelope variation value is greater than a preset high threshold value, based on a difference between the envelope variation value and the preset high threshold value, that the power variation value to be adjusted is to be reduced by a second value;

[0203] The third determining subunit is configured to determine that the power change value to be adjusted is zero if the envelope change value is not less than the preset lower threshold value and the envelope change value is not greater than the preset upper threshold value.

[0204] As an implementation of the embodiment of the present application, the signal transmission submodule may include:

[0205] a signal transmitting unit, used to control the transmitting circuit to transmit a signal according to a target power and a preset duration corresponding to a current time period; or,

[0206] It is used to determine the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected; and control the transmitting circuit to transmit a signal according to the target power corresponding to the current time period and the determined duration.

[0207] As an implementation method of the embodiment of the present application, the above-mentioned detection device may further include a speed sensor;

[0208] The signal transmitting unit may include:

[0209] The duration determination subunit is used to obtain the movement speed of the object to be detected before entering the detection process detected by the speed sensor, and determine the duration corresponding to each time period based on the movement speed and the preset duration ratio of each time period.

[0210] As an implementation method of the embodiment of the present application, the above-mentioned detection device may further include a position sensor;

[0211] The second transmitting unit may include:

[0212] A position acquisition subunit, used to acquire the position of the object to be detected during the detection process collected by the position sensor;

[0213] A position relationship determination subunit, used to determine the position relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device;

[0214] The end time determination subunit is used to determine the current time as the end time of the current time period when the position relationship meets the preset conditions, wherein the position relationship corresponding to the preset conditions indicates that the detection device should change the transmission power to detect the object to be detected.

[0215] The present application also provides a detection device, such as Fig. 9 As shown, the detection device includes a controller 901, a transmitting coil 904, a receiving coil 905, a transmitting circuit 902 and a receiving circuit 903, wherein the transmitting coil 904 is connected to the transmitting circuit 902, the receiving coil 905 is connected to the receiving circuit 903, the controller 901 is connected to the transmitting circuit 902 and the receiving circuit 903 respectively, the transmitting coil 904 is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit 902, and the receiving coil 905 is used to generate an induction signal when the electromagnetic field changes due to the object to be detected passing through the detection device, and send the induction signal to the receiving circuit 903, wherein:

[0216] The controller 901 is used to adjust the transmission power of the transmission circuit according to a preset transmission power adjustment strategy during the detection of the object to be detected, so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods;

[0217] The receiving circuit 903 is used to receive a receiving signal in each time period;

[0218] The controller 901 is further configured to determine the metal type of the object to be detected based on the received signal.

[0219] It can be seen that in the solution provided in the embodiment of the present application, the controller is applied to the detection device, the detection device also includes a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on the transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes when the object to be detected passes through the detection device, and the induction signal is sent to the receiving circuit. In the process of detecting the object to be detected, the controller can adjust the transmission power of the transmitting circuit according to the preset transmission power adjustment strategy, so that the transmitting circuit transmits the signal with the target power, wherein the preset transmission power adjustment strategy includes that in multiple time periods, at least two time periods correspond to different target powers, and based on the receiving signal of the receiving circuit in each time period, the metal type of the object to be detected is determined. Since the preset transmission power adjustment strategy includes that in multiple time periods, at least two time periods correspond to different target powers, therefore, according to the preset transmission power adjustment strategy, the transmission power of the transmitting circuit is adjusted, so that the transmitting circuit can transmit the signal with non-constant power, instead of detecting the metal with constant transmission power, which can improve the accuracy of metal object detection.

[0220] As an implementation of the embodiment of the present application, the above-mentioned detection device may further include a variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively;

[0221] The controller 901 may be specifically configured to adjust the gain of the variable gain amplifier circuit according to a preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field at a target power based on the gain of the variable gain amplifier circuit.

[0222] As an implementation mode of an embodiment of the present application, the controller 901 can be specifically used to control the transmitting circuit to transmit a signal according to the preset duration and target power of each time period; or, based on the received signal of the receiving circuit in the previous time period, determine the target power corresponding to the current time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit a signal according to the target power and duration corresponding to the current time period.

[0223] As an implementation manner of the embodiment of the present application, the above-mentioned detection device may further include an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected to the transmitting circuit and the receiving circuit respectively;

[0224] The controller 901 can be specifically used to determine the envelope change value between the received signal of the receiving circuit and the transmitted signal of the transmitting circuit based on the digital signal output by the analog-to-digital conversion circuit; determine the power change value that needs to be adjusted according to the size relationship between the envelope change value and a preset threshold; and determine the target power corresponding to the current time period based on the power change value and the transmission power of the transmitting circuit in the previous time period.

[0225] As an implementation manner of an embodiment of the present application, the controller 901 can be specifically used to determine that the power change value to be adjusted is to increase the first value based on the difference between the envelope change value and the preset threshold low value if the envelope change value is less than the preset threshold low value; if the envelope change value is greater than the preset threshold high value, based on the difference between the envelope change value and the preset threshold high value, determine that the power change value to be adjusted is to decrease the second value; if the envelope change value is not less than the preset threshold low value, and the envelope change value is not greater than the preset threshold high value, determine that the power change value to be adjusted is zero.

[0226] As an implementation mode of an embodiment of the present application, the controller 901 can be specifically used to control the transmitting circuit to transmit a signal according to a target power and a preset duration corresponding to a current time period; or, based on the movement speed characteristics of the object to be detected, determine the duration corresponding to the current time period; and control the transmitting circuit to transmit a signal according to the target power corresponding to the current time period and the determined duration.

[0227] As an implementation method of the embodiment of the present application, the above-mentioned detection device may further include a speed sensor;

[0228] The controller 901 can be specifically used to obtain the movement speed of the object to be detected detected by the speed sensor before entering the detection process, and determine the duration corresponding to each time period based on the movement speed and the ratio between the durations of the preset time periods.

[0229] As an implementation method of the embodiment of the present application, the above-mentioned detection device may further include a position sensor;

[0230] The controller 901 can be specifically used to obtain the position of the object to be detected during the detection process collected by the position sensor; determine the positional relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device; when the positional relationship meets a preset condition, determine the current moment as the end moment of the current time period, wherein the positional relationship corresponding to the preset condition indicates that the detection device should change the transmission power to detect the object to be detected.

[0231] In another embodiment provided in the present application, a computer-readable storage medium is provided, in which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned metal object detection methods are implemented.

[0232] In another embodiment provided in the present application, a computer program product including instructions is also provided, which, when executed on a computer, enables the computer to execute any of the metal object detection methods in the above embodiments.

[0233] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that contains one or more available media integrated. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), etc.

[0234] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0235] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, detection equipment, computer-readable storage medium, and computer program product embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0236] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A method for detecting metal objects, characterized in that: A controller applied to a detection device, wherein the detection device further comprises a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, wherein the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes due to a to-be-detected object passing through the detection device, and the induction signal is sent to the receiving circuit; the method comprises: During the process of detecting the object to be detected, adjusting the transmit power of the transmit circuit according to a preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power, wherein the preset transmit power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods; The metal type of the object to be detected is determined based on the reception signal of the receiving circuit in each time period.

2. The method according to claim 1, characterized in that The detection device further comprises a variable gain amplifier circuit, wherein the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively; The step of adjusting the transmit power of the transmit circuit according to a preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power includes: According to a preset transmission power adjustment strategy, the gain of the variable gain amplifier circuit is adjusted so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

3. The method according to claim 1, characterized in that The step of adjusting the transmit power of the transmit circuit according to a preset transmit power adjustment strategy so that the transmit circuit transmits a signal at a target power includes: According to the preset duration and target power of each time period, control the transmitting circuit to transmit a signal according to the duration and the target power; or, Based on the received signal of the receiving circuit in the previous time period, determine the target power corresponding to the current time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period.

4. The method according to claim 3, characterized in that The detection device further comprises an analog-to-digital conversion circuit, wherein the analog-to-digital conversion circuit is electrically connected to the transmitting circuit and the receiving circuit respectively; The step of determining the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period includes: Determine an envelope change value between a received signal of the receiving circuit and a transmitted signal of the transmitting circuit based on a digital signal output by the analog-to-digital conversion circuit; Determining the power change value to be adjusted according to the magnitude relationship between the envelope change value and a preset threshold; Based on the power change value and the transmit power of the transmit circuit in the previous time period, a target power corresponding to the current time period is determined.

5. The method according to claim 4, characterized in that The step of determining the power change value to be adjusted according to the magnitude relationship between the envelope change value and the preset threshold value comprises at least one of the following: If the envelope change value is less than a preset lower threshold value, based on a difference between the envelope change value and the preset lower threshold value, determining that the power change value to be adjusted is to increase the first value; If the envelope change value is greater than a preset high threshold value, based on a difference between the envelope change value and the preset high threshold value, determining that the power change value to be adjusted is to reduce a second value; If the envelope variation value is not less than the preset lower threshold value, and the envelope variation value is not greater than the preset upper threshold value, it is determined that the power variation value to be adjusted is zero.

6. The method according to claim 3, characterized in that The step of controlling the transmitting circuit to transmit a signal according to the target power and duration corresponding to the current time period includes: Control the transmitting circuit to transmit a signal according to the target power and preset duration corresponding to the current time period; or, Based on the movement speed characteristics of the object to be detected, the duration corresponding to the current time period is determined; and the transmitting circuit is controlled to transmit a signal according to the target power corresponding to the current time period and the determined duration.

7. The method according to claim 6, characterized in that The detection device also includes a speed sensor; The step of determining the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected includes: The movement speed of the object to be detected before entering the detection process detected by the speed sensor is obtained, and the duration corresponding to each time period is determined based on the movement speed and the ratio relationship between the durations of the preset time periods.

8. The method according to claim 6, characterized in that The detection device also includes a position sensor; The step of determining the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected includes: Acquire the position of the object to be detected during the detection process collected by the position sensor; Determining a positional relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device; When the position relationship satisfies a preset condition, the current moment is determined as the end moment of the current time period, wherein the position relationship corresponding to the preset condition indicates that the detection device should change the transmission power to detect the object to be detected.

9. A metal object detection device, characterized in that: A controller used in a detection device, wherein the detection device further comprises a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, wherein the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, the receiving coil is used to generate an induction signal when the electromagnetic field changes due to a to-be-detected object passing through the detection device, and the induction signal is sent to the receiving circuit; the device comprises: A transmission power adjustment module, used to adjust the transmission power of the transmission circuit according to a preset transmission power adjustment strategy during the detection of the object to be detected, so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods; The metal type determination module is used to determine the metal type of the object to be detected based on the received signal of the receiving circuit in each time period.

10. The device according to claim 9, characterized in that The detection device further comprises a variable gain amplifier circuit, wherein the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively; The transmission power adjustment module comprises: A gain adjustment submodule, configured to adjust the gain of the variable gain amplifier circuit according to a preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field at a target power based on the gain of the variable gain amplifier circuit; The transmission power adjustment module comprises: A signal transmission submodule, configured to control the transmission circuit to transmit a signal according to the preset duration and target power of each time period; or, Used to determine the target power corresponding to the current time period based on the received signal of the receiving circuit in the previous time period, wherein the target power corresponding to the first time period is a preset value; and control the transmitting circuit to transmit the signal according to the target power and duration corresponding to the current time period; The detection device further comprises an analog-to-digital conversion circuit, wherein the analog-to-digital conversion circuit is electrically connected to the transmitting circuit and the receiving circuit respectively; The signal transmission submodule comprises: an envelope variation value determining unit, configured to determine an envelope variation value between a received signal of the receiving circuit and a transmitted signal of the transmitting circuit based on a digital signal output by the analog-to-digital conversion circuit; A power change value determining unit, used to determine the power change value to be adjusted according to the magnitude relationship between the envelope change value and a preset threshold; a target power determination unit, configured to determine a target power corresponding to a current time period based on the power change value and the transmit power of the transmit circuit in the previous time period; The power change value determining unit includes at least one of the following: A first determining subunit is configured to determine, if the envelope variation value is less than a preset lower threshold value, based on a difference between the envelope variation value and the preset lower threshold value, that the power variation value to be adjusted is increased by a first value; A second determining subunit is configured to determine, if the envelope variation value is greater than a preset high threshold value, based on a difference between the envelope variation value and the preset high threshold value, that the power variation value to be adjusted is to be reduced by a second value; A third determining subunit, configured to determine that the power change value to be adjusted is zero if the envelope change value is not less than the preset low threshold value and the envelope change value is not greater than the preset high threshold value; The signal transmission submodule comprises: a signal transmitting unit, used to control the transmitting circuit to transmit a signal according to a target power and a preset duration corresponding to a current time period; or, Used to determine the duration corresponding to the current time period based on the movement speed characteristics of the object to be detected; and control the transmitting circuit to transmit a signal according to the target power corresponding to the current time period and the determined duration; The detection device also includes a speed sensor; The signal transmitting unit comprises: A duration determination subunit, configured to obtain the movement speed of the object to be detected detected by the speed sensor before entering the detection process, and determine the duration corresponding to each time period based on the movement speed and the preset duration ratio of each time period; The detection device also includes a position sensor; The second transmitting unit comprises: A position acquisition subunit, used to acquire the position of the object to be detected during the detection process collected by the position sensor; A position relationship determination subunit, configured to determine a position relationship between the object to be detected and the detection device based on the position of the object to be detected and the position of the detection device; The end time determination subunit is used to determine the current time as the end time of the current time period when the position relationship meets the preset conditions, wherein the position relationship corresponding to the preset conditions indicates that the detection device should change the transmission power to detect the object to be detected.

11. A detection device, characterized in that: The detection device includes a controller, a transmitting coil, a receiving coil, a transmitting circuit and a receiving circuit, wherein the transmitting coil is connected to the transmitting circuit, the receiving coil is connected to the receiving circuit, the controller is connected to the transmitting circuit and the receiving circuit respectively, the transmitting coil is used to generate an electromagnetic field based on a transmitting signal generated by the transmitting circuit, and the receiving coil is used to generate an induction signal when the electromagnetic field changes due to the object to be detected passing through the detection device, and send the induction signal to the receiving circuit, wherein: The controller is used to adjust the transmission power of the transmission circuit according to a preset transmission power adjustment strategy during the detection of the object to be detected, so that the transmission circuit transmits a signal at a target power, wherein the preset transmission power adjustment strategy includes that at least two time periods have different target powers in the multiple time periods; The receiving circuit is used to receive a receiving signal in each time period; The controller is further used to determine the metal type of the object to be detected based on the received signal.

12. The detection device according to claim 11, characterized in that: The detection device further comprises a variable gain amplifier circuit, wherein the variable gain amplifier circuit is electrically connected to the controller and the transmitting circuit respectively; The controller is specifically used to adjust the gain of the variable gain amplifier circuit according to a preset transmission power adjustment strategy, so that the transmission circuit generates an electromagnetic field with a target power based on the gain of the variable gain amplifier circuit.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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