CN114706142A - Correction method of metal detection equipment and metal detection equipment - Google Patents

Correction method of metal detection equipment and metal detection equipment Download PDF

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Publication number
CN114706142A
CN114706142A CN202210346260.9A CN202210346260A CN114706142A CN 114706142 A CN114706142 A CN 114706142A CN 202210346260 A CN202210346260 A CN 202210346260A CN 114706142 A CN114706142 A CN 114706142A
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correction
value
metal
period
detection
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CN202210346260.9A
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Inventor
唐晓莉
赵瑞刚
冯雄
汪兴华
刘鹏
杨金平
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Xi'an Tianhe Defense Technology Co ltd
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Xi'an Tianhe Defense Technology Co ltd
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Priority to CN202210346260.9A priority Critical patent/CN114706142A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V13/00—Manufacturing, calibrating, cleaning, or repairing instruments or devices covered by groups G01V1/00 – G01V11/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
    • G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils

Abstract

The application provides a correction method of metal detection equipment and the metal detection equipment, wherein the correction method comprises the following steps: acquiring an induction value in a correction acquisition time period in a current correction period; judging whether the metal detection equipment detects metal in the correction acquisition time period or not according to the induction value; and if not, updating the detection reference value in the next adjacent correction period according to the induction value. The correction method provided by the application can reduce errors caused by instability of the circuit of the metal detection equipment, improve the detection rate of the metal detection equipment and reduce the false alarm rate.

Description

Correction method of metal detection equipment and metal detection equipment
Technical Field
The application belongs to the technical field of metal detection, and particularly relates to a correction method of metal detection equipment and the metal detection equipment.
Background
A metal detector is an electronic instrument for detecting metal, and has been widely used in various fields such as security inspection, mineral exploration, industrial production, and the like. The metal detector commonly used utilizes the electromagnetic induction principle to carry out metal detection, and when circular telegram, transmitting coil in the metal detector produces periodic variation's alternating magnetic field, if there is the metal object to exist in the detection range, this alternating magnetic field can be in the metal object induced eddy current, and then produces the secondary magnetic field that has the interference to former alternating magnetic field, and the metal detector is responded to the magnetic field of change and is carried out the analysis, realizes the detection of metal.
However, the metal detector is easily affected by the stability of its own circuit during the detection process, for example, the amplification circuit generates a zero drift phenomenon due to temperature, humidity, etc., which easily causes the situation of false alarm or false alarm, resulting in a low detection accuracy.
Disclosure of Invention
The application provides a correction method of metal detection equipment and the metal detection equipment, which can reduce errors caused by instability of circuits of the metal detection equipment, improve the detection rate of the metal detection equipment and reduce the false alarm rate.
In a first aspect, the present application provides a calibration method for a metal detection apparatus, the calibration method including: acquiring an induction value in a correction acquisition time period in a current correction period; judging whether the metal detection equipment detects metal in the correction acquisition time period or not according to the induction value; and if not, updating the detection reference value in the next adjacent correction period according to the induction value.
Preferably, an end time of the correction acquisition period in the current correction period is the same as an end time of the current correction period.
According to the correction method provided by the embodiment of the application, the induction value in the correction acquisition time period in the current correction period is obtained, and when the metal detection device does not detect metal in the correction acquisition time period according to the induction value, the detection reference value in the next adjacent period is updated according to the induction value. If metal detection equipment does not detect the metal in correcting the acquisition time quantum, then the change of inductive value does not receive the interference of metal, at this moment, the change of inductive value has reflected the change of components and parts in metal detection equipment self's the circuit, this application has updated the detection benchmark value in the next correction cycle according to these inductive values that have reflected self circuit change, can reduce or even eliminate the error that self circuit instability brought, make the degree of accuracy of the detection benchmark value after the renewal higher, and then metal detection equipment when carrying out the detection of target metal with the detection benchmark value after the renewal, can have higher relevance rate, lower wrong report rate. When the metal detection device executes the correction method, the steps can be periodically repeated, so that whether the detection reference value can be updated or not can be periodically judged and the detection reference value is updated when the condition is met to perform self-correction in the whole operation time period from starting to closing of the metal detection device, manual intervention is not needed, and the correction method is more intelligent.
In addition, the correction method provided by the application does not need to use new hardware, namely, a hardware circuit of the metal detection device does not need to be improved, the complexity of circuit design is low, the cost is low, and new errors cannot be introduced.
With reference to the first aspect, in a possible implementation manner, the determining, according to the sensing value, whether the metal detection device detects metal within the correction acquisition time period includes:
when the absolute value of the difference between a first average value and the detection reference value in the current correction period is smaller than a first threshold value, determining that the metal detection equipment does not detect metal in the correction acquisition time period, wherein the first average value is the arithmetic average value of the induction values;
the updating the detection reference value in the next adjacent correction period according to the induction value comprises:
and updating the detection reference value in the next adjacent correction period to be the first average value.
In this embodiment, whether the metal detection device detects metal in the correction acquisition time period may be determined by comparing the absolute value of the difference between the first average value (i.e., the arithmetic average value of the sensing values, in this case, the sensing values are multiple) and the detection reference value in the current correction period with the magnitude of the first threshold. When the absolute value of the difference between the first average value and the detection reference value in the current correction period is smaller than the first threshold, in other words, the absolute value of the difference between the first average value and the current detection reference value is smaller, the change in the sense value is caused by an error due to the instability of the circuit itself, rather than being affected by the presence of metal. Therefore, the detection reference value is updated only when the metal detection equipment is determined not to detect metal in the correction collection time period, the method is more reasonable, the accuracy of the updated detection reference value is higher, the follow-up detection process of the target metal cannot be influenced, the detection rate of the metal detector can be improved, and the false alarm rate is reduced.
With reference to the first aspect, in a possible implementation manner, if it is determined that metal is detected in each of M consecutive correction acquisition periods, where M is a positive integer greater than or equal to 2;
and updating the detection reference value in the (M + 1) th correction period according to the first average value corresponding to each correction acquisition time period in the M correction periods.
Through the arrangement, the correction method provided by the application can reduce or even eliminate the continuous interference of the external environment to the detection process (for example, a metal always exists in a longer time period, or the metal existing in the detection range of the metal detection equipment for a longer time leaves the detection range at a certain moment), and the detection reference value is updated according to the change of the metal in the environment, so that the detection rate can be improved, and the false alarm rate can be reduced.
With reference to the first aspect, in a possible implementation manner, the updating, according to the first average value corresponding to each correction acquisition time period in the M correction cycles, the detection reference value in an M +1 th correction cycle includes:
and updating the detection reference value in the M +1 th correction period according to N qualified values in the M first average values, wherein the absolute value of the difference between each qualified value and the second average value is smaller than a second threshold value, the second average value is the arithmetic average value of the M first average values, and N is a positive integer smaller than or equal to M.
With reference to the first aspect, in a possible implementation manner, the updating, according to N qualified values in the M first average values, the detection reference value in the M +1 th correction period includes:
and if the N is greater than or equal to the third threshold, updating the detection reference value in the (M + 1) th correction period to the arithmetic average of the N qualified values.
With reference to the first aspect, in a possible implementation manner, the correcting method further includes:
after the metal detection equipment is started, a plurality of measured values in a preset time period are obtained, and the arithmetic mean value of the measured values is used as a detection reference value in a first correction period.
In a second aspect, the present application provides a metal detection apparatus comprising:
the acquisition unit is used for acquiring the induction value in the correction acquisition time period in the current correction period;
the judging unit is used for judging whether the metal detecting equipment detects metal in the correction acquisition time period according to the induction value;
and the updating unit is used for updating the detection reference value in the next adjacent correction period according to the induction value if the metal detection equipment does not detect metal in the correction acquisition time period.
In a third aspect, the present application provides a metal detection apparatus comprising: a memory for storing a computer program; a processor configured to execute the computer program to implement the correction method according to the first aspect and any one of the possible implementation manners of the first aspect.
The beneficial effects of the metal detection device provided by the present application can be seen in the beneficial effects of the correction method provided by the first aspect, which are not described herein again.
In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, which, when executed by a processor, implements the correction method according to the first aspect and any one of the possible implementation manners of the first aspect.
Drawings
FIG. 1 is a schematic flow chart of a calibration method for a metal detection apparatus provided in an embodiment of the present application;
FIG. 2 is a schematic time-axis diagram of a metal detection device provided in an embodiment of the present application after being started;
FIG. 3 is a schematic flow chart diagram illustrating one embodiment of a calibration method provided by embodiments of the present application;
FIG. 4 is a schematic flow chart diagram illustrating another embodiment of a calibration method provided by an embodiment of the present application;
FIG. 5 is a schematic block diagram of a metal detection apparatus provided by an embodiment of the present application;
fig. 6 is a schematic structural diagram of a metal detection device provided in an embodiment of the present application.
Detailed Description
The technical solution of the present application is described in detail below with reference to the accompanying drawings. It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments.
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
The terms "comprises" and/or "comprising" when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.
In the description of the present application, "a plurality" means two or more.
In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.
The metal detection device is an electronic instrument for detecting metal, is mainly applied to public places with large people flow, such as airports, stations, large-scale meetings and the like, in the field of security inspection, and can detect whether detected personnel carry forbidden metal objects, such as guns, control tools and the like, so that the personal safety of people in the public places is guaranteed. The conventional metal detection device usually detects a metal object by using an electromagnetic induction effect of an oscillating coil, however, because the stability of a circuit of the metal detection device is poor, for example, a semiconductor device (such as a transistor) in the circuit is susceptible to the influence of environmental temperature, humidity and other factors to generate a zero drift phenomenon, which easily causes the metal detection device to generate false alarm and false alarm.
In order to solve the technical problem, an embodiment of the present application provides a correction method for a metal detection device and a metal detection device. According to the correction method, the induction value in the correction acquisition time period is periodically acquired, and when the metal detection device is determined not to detect metal in the correction acquisition time period, the detection reference value is updated according to the induction value, and the detection reference value is the reference value for judging whether the metal detection device has the target metal, so that errors caused by instability of a circuit of the metal detection device can be reduced, the detection rate of the metal detection device can be improved, and the false alarm rate can be reduced.
Fig. 1 is a schematic flowchart of a calibration method of a metal detection apparatus according to an embodiment of the present application. In the following, a calibration method 100 provided by an embodiment of the present application is described with reference to fig. 1, where the calibration method 100 may be applied to any type of metal detection device such as a security door, a handheld security device, and the like, and the calibration method 100 includes:
and S101, acquiring an induction value in a correction acquisition time period in the current correction period.
Specifically, the correction acquisition time period is a period of time in a correction cycle, the duration of the correction acquisition time period is less than the duration of the correction cycle, and each correction cycle has one and only one correction acquisition time period.
Fig. 2 is a schematic time line diagram of the metal detection device provided in the embodiment of the present application after being started, and as shown in fig. 2, preferably, the end time of the correction acquisition time period is the same as the end time of the correction period. Illustratively, the duration of the correction period may be 1 minute, 3 minutes, 5 minutes, 10 minutes, or the like, and the duration of the correction acquisition period may be 2 seconds, 5 seconds, 7 seconds, 10 seconds, or the like. For example, the time length of the calibration period is 5 minutes, the time length of the calibration acquisition period is 5 seconds, and assuming that the starting time of the first calibration period is 0, the ending time of the first calibration period is 5 minutes, the starting time of the calibration acquisition period in the first calibration period is 4 minutes and 55 seconds, and the ending time is also 5 minutes.
Optionally, the end time of the correction acquisition period and the end time of the correction period may also be different. For example, the start time of the correction acquisition period in the first correction cycle may be 4 minutes, and the end time may be 4 minutes and 5 seconds. In this case, the relative position of the correction acquisition time period in each correction cycle within the respective corresponding correction cycle is fixed. I.e. the start time of the calibration acquisition period in the second calibration period is 9 minutes and the end time is 9 minutes and 5 seconds. That is, regardless of the relationship between the end time of the correction acquisition period and the end time of the correction cycle, the time interval between two adjacent correction acquisition periods (the interval between the start times of the two, the duration of this interval being equal to the duration of the correction cycle) is constant. That is, when the metal detection device is started and the step S101 of the calibration method 100 is executed, the operation of acquiring the induction value in the calibration acquisition time period is performed at certain time intervals.
In the embodiment of the application, the obtained sensing value in the correction acquisition time period in the current correction period is used for updating the detection reference value in the next adjacent correction period, and the detection reference value is a reference value (or basis) for the metal detection device to determine whether a target metal exists, where the target metal refers to a metal object that needs to be detected by the metal detection device, for example, articles such as a control cutter carried by a passenger. When the end time of the correction acquisition time period is the same as the end time of the correction period, the timeliness of the induction value is better, and the detection reference value updated according to the induction value is more accurate.
It should be understood that the duration of the correction period and the duration of the correction acquisition time period can be preset according to the actual application requirements of the metal detection equipment; alternatively, the duration of the calibration period may be adjusted according to the operating state of the metal detection device, for example, when the operating intensity of the metal detection device is high (i.e. when the human flow rate is high), the duration of the calibration period is made longer (which may be 10 minutes, 20 minutes, etc.), and when the operating intensity of the metal detection device is low (i.e. when the human flow rate is low), the duration of the calibration period is made shorter (which may be 1 minute, 2 minutes, etc.).
Optionally, the induction value may be a voltage value, a current value, a frequency, an amplitude, a phase of a signal, and the like, and the induction value may be obtained based on an electromagnetic induction principle, or may be obtained based on other induction principles (for example, microwave), which is not limited in this application. The sensed value changes when a metal object is present within the detection range of the metal detection apparatus.
Optionally, in step S101, one or more sensed values may be obtained. If a plurality of induction values are obtained, the problem that the detection reference value is inaccurate due to inaccurate single data can be avoided.
Optionally, the number of the sensing values in one correction acquisition time period may be 2, 4, 8, or 10, and the like, which is not limited in this application.
And S102, judging whether the metal detection equipment detects metal in the correction acquisition time period according to the induction value.
As shown in fig. 2, taking the first calibration cycle as an example, the start time and the end time of the first calibration cycle are 0 and 5 minutes, respectively, the duration of the calibration acquisition time period is 5 seconds, and step S102 determines whether the metal detection device detects metal within a time period of 4 minutes, 55 seconds and 5 minutes.
If not, namely when it is determined that the metal detection device does not detect metal in the correction acquisition time period, step S103 is executed, and the detection reference value in the next adjacent correction period is updated according to the induction value. That is, at the end of the current calibration period, the sounding reference value is updated, and this updated sounding reference value is used in the next calibration period.
If yes, that is, when it is determined that the metal detection device detects metal in the correction acquisition time period, step S104 is executed, and the detection reference value in the next adjacent correction period is not updated, that is, the detection reference value in the next adjacent correction period is the same as the detection reference value in the current correction period.
Further, the correction method 100 provided in the embodiment of the present application further includes: acquiring an actual measurement value (the actual measurement value is the same as the sensing value, for example, both the actual measurement value and the sensing value are voltage values, and may be one or more) in the current detection period, and determining whether a target metal exists in the current detection period according to the actual measurement value and the detection reference value, if so (i.e., determining that the target metal exists), making a buzzer sound or lighting an LED to alarm; if not (namely, judging that the target metal does not exist), not alarming.
Illustratively, the duration of the detection period may be 0.5 second, 1 second, 2 seconds, etc., which is not limited in this application. Assuming that the duration of the detection period is 2 seconds, the metal detection apparatus performs the determination of whether the target metal is present or not every 2 seconds while performing the above-described steps of the correction method 100.
It should be understood that the detection period and the correction period (including the correction acquisition period) are independent from each other, that is, the determination of whether there is the target metal in the detection period and the determination of whether there is the metal in the correction acquisition period are independent from each other and do not affect each other. Specifically, the duration of one calibration period is longer than the duration of one detection period, the detection process (detection period) of the target metal can be continuously performed within one calibration period, and can be performed once, twice, or even five times, the determination processes within the detection period and the calibration period are not interfered with each other, and only the determination of the target metal performed within the detection period uses the detection reference value within the calibration period. The judgment result of whether the target metal exists or not is determined in the detection period and is used for judging whether follow-up alarm is needed or not so as to remind security personnel; and the judgment result of whether the metal exists or not determined in the correction acquisition time period is further used for judging whether the detection reference value needs to be updated or not, the judgment result is not used as the basis of whether the alarm needs to be given or not, and the updated detection reference value is used as the basis of judging whether the target metal exists or not in the detection period.
In the embodiment of the present application, for each detection period, the detection reference value in the detection period is determined according to the relationship between the end time of the detection period and the correction period. As shown in fig. 2, taking the first two calibration periods after the metal detection apparatus is started as an example, the end time of the first two detection periods is before the end time of the first calibration period, the detection reference value in the first two detection periods is the detection reference value in the first calibration period, and the end time t of the third detection period is after the end time of the first calibration period and before the end time of the second calibration period, so that the detection reference value in the third detection period is the detection reference value in the second calibration period. In other words, if the detection reference value is updated before the end time of the current detection period, the determination process of whether the target metal exists in the current detection period is determined according to the updated detection reference value.
Optionally, the correction method 100 provided in the embodiment of the present application further includes: after the metal detection device is started, a plurality of measurement values (the type of the measurement values is the same as that of the induction values, for example, the measurement values are all voltage values) in a preset time period are obtained, and the arithmetic mean value of the plurality of measurement values is used as a detection reference value in a first correction period.
As shown in fig. 2, the starting time of the preset time period is the starting time of the metal detection device, and the starting times of the first calibration cycle and the first detection cycle are the next time adjacent to the ending time of the preset time period. That is, when the metal detection apparatus applies the correction method 100, the detection of the target metal is not performed in the preset time period after the start, and the correction of the detection reference value is not started, but the detection of the target metal and the correction process of the detection reference value are started after the detection reference value in the first correction cycle, that is, the detection reference value in the first detection cycle (here, the detection reference value is also the initial detection reference value) is determined based on the plurality of measurement values obtained from the preset time period.
For example, the duration of the preset time period may be 5 seconds, 10 seconds, 20 seconds, and the like, and the number of the measured values may be 5, 10, 20, and the like, which is not limited in this application.
Through the steps, the detection reference value in the first correction period (also in the first detection period) is determined according to a plurality of measurement values in the preset time period obtained after the metal detection equipment is started, so that the interference of some non-target metals (hereinafter referred to as environment metals for short) in the environment where the metal detection equipment is located can be eliminated, for example, a security inspection X-ray machine, a liquid detector, an explosive detector and the like which are arranged beside a security inspection door are arranged, the detection of the metal detection equipment on the target metals is not influenced, the situation that the metal detection equipment misjudges the environment metals as the target metals and always gives an alarm can be avoided, and the false alarm rate can be reduced.
Optionally, the detection reference value in the first correction period may also be a preset value, that is, the first detection period and the first correction period are directly performed after the metal detection device is started.
Further, the correction method provided by the embodiment of the present application further includes: after the metal detection equipment is started and before the starting time of the preset time period, resetting operation is carried out, so that data such as induction values and detection reference values stored in the last use can be eliminated, and further the normal use of the metal detection equipment after the starting is not influenced.
The correction method 100 provided in the embodiment of the application updates the detection reference value in the next adjacent period according to the induction value when it is determined that the metal detection device does not detect metal in the correction acquisition time period according to the induction value by acquiring the induction value in the correction acquisition time period in the current correction period. If metal detection equipment does not detect the metal in correcting the acquisition time section, then the change of inductive value does not receive the interference of metal, this moment, the change of inductive value has reflected the change of components and parts in metal detection equipment self's the circuit, this application updates the detection benchmark value in the next correction cycle according to these inductive values that have reflected self circuit change, can reduce or even eliminate the error that self circuit instability brought, make the degree of accuracy of the detection benchmark value after the update higher, and then metal detection equipment can have higher relevance ratio, lower false alarm rate when carrying out the detection of target metal with the detection benchmark value after the update. When the correction method 100 is executed by the metal detection device, the foregoing steps are periodically repeated, so that the detection reference value can be periodically judged whether to be updated or not and is updated when the condition is met so as to perform self-correction in the whole operation time period from the start to the close of the metal detection device, and manual intervention is not needed, so that the metal detection device is more intelligent.
In addition, the calibration method 100 provided by the present application does not need to use new hardware, that is, does not need to improve the hardware circuit of the metal detection device, and has low complexity of circuit design, low cost, and no new error introduced.
In a possible embodiment, fig. 3 is a schematic flow chart of an embodiment of the calibration method provided in this embodiment, and as shown in fig. 3, the determining whether the metal detection device detects metal in the calibration acquisition time period according to the sensing value includes: when the absolute value of the difference between the first average value and the detection reference value in the current correction period is smaller than a first threshold value, determining that the metal detection equipment does not detect metal in the correction acquisition time period, wherein the first average value is the arithmetic average value of the induction values;
updating the detection reference value in the next adjacent correction period according to the induction value, and the method comprises the following steps: and updating the detection reference value in the next adjacent correction period to be the first average value.
Further, when the absolute value of the difference between the first average value and the detection reference value in the current correction period is greater than a first threshold, it is determined that the metal detection device detects metal in the correction acquisition time period, and the detection reference value in the next adjacent period is not updated, that is, the detection reference value remains unchanged.
It should be understood that the metal detection apparatus periodically repeats the flow steps illustrated in fig. 3 while performing the calibration method 100.
In this embodiment, whether the metal detection device detects metal in the correction acquisition time period may be determined by comparing the absolute value of the difference between the first average value (i.e., the arithmetic average value of the sensing values, in this case, the sensing values are multiple) and the detection reference value in the current correction period with the magnitude of the first threshold. When the absolute value of the difference between the first average value and the detection reference value in the current correction period is smaller than the first threshold, in other words, the absolute value of the difference between the first average value and the current detection reference value is smaller, the change in the sense value is caused by an error due to the instability of the circuit itself, rather than being affected by the presence of metal. Therefore, the detection reference value is updated only when the metal detection equipment is determined not to detect metal in the correction collection time period, the method is more reasonable, the accuracy of the updated detection reference value is higher, the follow-up detection process of the target metal cannot be influenced, the detection rate of the metal detector can be improved, and the false alarm rate is reduced.
It should be understood that the first threshold is a preset value and is a positive number, and the first threshold may be determined according to an actual usage scenario of the metal detection device.
In a possible embodiment, the determining whether the target metal exists in the current detection period according to the obtained measured value and the detection reference value in the current detection period includes: when the absolute value of the difference between the third average value and the detection reference value in the current detection period is smaller than a fourth threshold value, determining that the metal detection equipment does not detect the target metal in the current detection period; and when the absolute value of the difference between the third average value and the detection reference value in the current detection period is greater than or equal to a fourth threshold value, determining that the metal detection equipment detects the target metal in the current detection period, and further performing alarm operation. The third average value is an arithmetic average value of the plurality of measured values.
Here, the fourth threshold represents the detection sensitivity of the metal detection device, and a user can change the size of the fourth threshold by adjusting a hardware circuit when using the metal detection device, so that the sensitivity of the metal detection device can be changed, and the metal detection device can be suitable for different use scenes.
In other embodiments, when there are a plurality of sensing values, the step of determining whether the metal detection device detects metal within the correction acquisition time period according to the plurality of sensing values may be performed by using other statistical calculation methods, as long as the deviation degree of the plurality of sensing values as a whole with respect to the detection reference value within the current correction period can be measured. For example, the absolute value of the deviation between the sensing value corresponding to each sensing value and the detection reference value in the current correction period is determined, and the arithmetic mean of a plurality of absolute values of deviation is calculated, so that whether metal is detected or not is judged by comparing the arithmetic mean of the plurality of absolute values of deviation with a threshold.
Alternatively, the same judgment logic as the above embodiment may be adopted to judge whether there is the target metal in the detection period.
Alternatively, when only one sensed value is obtained, the first average value is the sensed value itself.
Further, fig. 4 is a schematic flowchart of an embodiment of a correction method provided in the embodiment of the present application, and as shown in fig. 4, the correction method 100 provided in the embodiment of the present application further includes:
if it is determined that metal is detected in each correction acquisition time period in M continuous correction periods, wherein M is a positive integer greater than or equal to 2;
and updating the detection reference value in the M +1 th correction period according to the first average value corresponding to each correction acquisition time period in the M correction periods.
It should be understood that the value of M may be set according to the actual use condition of the metal detection device. For example, M may be 10, 20, 50, even 100, etc. In practical applications, M may be taken to be larger.
As shown in fig. 2, in the continuous M correction cycles shown in fig. 2 (that is, the M correction cycles are continuous in time), that is, there are continuous M correction acquisition time periods (for a correction acquisition time period, the continuity in time is not represented), if it is determined that each of the M correction acquisition time periods detects metal, M first average values can be obtained, and then the detection reference value in the M +1 th correction cycle can be updated according to the M first average values. As shown in fig. 2, the M +1 th correction period is an adjacent next correction period to the last correction period in the M consecutive correction periods.
In M consecutive correction cycles, if one of the correction time periods is determined as not detecting metal, the first average value corresponding to the correction acquisition time period is discarded (or may be understood as deleted or not stored), so that the first average value corresponding to the correction acquisition time period cannot be obtained, and then the subsequent step of "updating the detection reference value in the M +1 th correction cycle according to the first average value corresponding to each of the M correction acquisition time periods" cannot be performed.
If it is determined that metal is detected in each correction acquisition time period in the M continuous correction periods, it is indicated that one metal always exists in the detection range of the metal detection device within the duration of the M continuous correction periods, and if the metal exists in the environment for a long time (it can be understood that the metal exists already known by the security check personnel), the metal detection device does not need to alarm the metal in each detection period, so that interference is caused to detection of other new metals, a situation of false alarm is easy to occur, and judgment by the security check personnel is not facilitated. Through the arrangement, the metal which continuously exists in the environment can be divided into the environment metal, the interference caused by the environment metal is considered when the detection reference value is updated, and then the subsequent process of detecting the target metal can be more accurate. Through the arrangement, the correction method provided by the application can reduce or even eliminate the continuous interference of the external environment to the detection process (for example, a metal always exists in a longer time period, or the metal existing in the detection range of the metal detection equipment for a longer time leaves the detection range at a certain moment), and the detection reference value is updated according to the change of the metal in the environment, so that the detection rate can be improved, and the false alarm rate can be reduced.
Optionally, the M consecutive correction periods in which metal is detected in each of the M consecutive correction acquisition time periods are within a preset time interval. For example, after the metal detection device is started, the starting time of the first calibration period is recorded as 0, and the duration of the preset time interval is recorded as T1Recording the end time of the first time interval as T1The M successive correction periods are located in their entirety in a first time interval [0-T ]1]Within, or at, a second time interval [ T ]1-2T1]Within, or at, the p-th time interval [ (p-1) T1-pT1]And if so, executing the next step of updating the detection reference value in the (M + 1) th correction period according to the first average value corresponding to each correction acquisition time period in the M correction periods.
Through the steps, the preorder condition for executing the step of updating the detection reference value is stricter, so that the interference caused by uncertain factors in the environment can be reduced as much as possible, and the accuracy of the detection reference value can be improved.
As shown in fig. 4, the updating the detection reference value in the M +1 th correction period according to the first average value corresponding to each correction acquisition time period in the M correction periods includes:
and updating the detection reference value in the M +1 th correction period according to N qualified values in the M first average values, wherein the absolute value of the difference between each qualified value and the second average value is smaller than a second threshold value, the second average value is the arithmetic average value of the M first average values, and N is a positive integer smaller than or equal to M.
Specifically, N qualified values are determined from M first average values, wherein only the first average value satisfying the condition that the absolute value of the difference from the second average value is smaller than the second threshold value can be stored and determined as a qualified value, and the first average value not satisfying the condition (which can be understood as an obvious abnormal value) is deleted, so that the fluctuation range between the N qualified values is small, and the N qualified values can be considered to represent the change caused by the same metal. Since the authenticity of the arithmetic mean is extremely susceptible to the extreme values (i.e., the aforementioned significant outliers), the accuracy of the updated detection reference value can be made higher by deleting some significant outliers and updating the detection reference value in the M +1 th correction period according to the retained qualified value.
Alternatively, the detection reference value in the M +1 th correction period may be updated to the arithmetic average of the N qualified values.
Optionally, the second threshold may be a standard deviation of the M first averages, or the second threshold may also be 2 times, 3 times, or the like of the standard deviation, or may also be any value preset according to an actual application scenario.
Specifically, the N qualified values may be all or part of M first average values, and when N is equal to M, it is stated that the M first average values all satisfy the above condition, and all of the M first average values may be qualified values.
Further, as shown in fig. 4, the updating the detection reference value in the M +1 th correction period according to the N qualified values in the M first average values includes:
and if the N is greater than or equal to the third threshold, updating the detection reference value in the (M + 1) th correction period to the arithmetic average of the N qualified values.
Here, the third threshold is a positive integer, and the third threshold may be a certain proportion of M, such as 100%, 95%, 90%, 70%, 50%, and the like. For example, M is 50, the third threshold may be 45, 40, 35, etc.; as another example, M is 100, and the third threshold may be 80, 70, etc. Illustratively, M is 100, the third threshold is 80, and the detection reference value in the M +1 th correction period is updated to the arithmetic average of the N qualified values only if the total number N of qualified values is greater than or equal to 80 (e.g., N is equal to 85, 90, 92); when N is 20, 60, 70, etc., the representativeness of the N qualified values may not be enough, and the detection reference value in the M +1 th correction period is not updated.
Through the steps, the preorder condition of updating the detection reference value in the M +1 th correction period to the arithmetic mean value of the N qualified values is stricter, so that some interference in the environment can be reduced, the accuracy of the updated detection reference value is improved, the detection rate of the metal detection equipment can be improved, and the false alarm rate is reduced.
The embodiment of the present application further provides a metal detection device 200, fig. 5 is a schematic block diagram of the metal detection device provided in the embodiment of the present application, and as shown in fig. 5, the metal detection device 200 includes an obtaining unit 210, a determining unit 220, and an updating unit 230.
The obtaining unit 210 is configured to obtain an induction value in a correction acquisition time period in a current correction cycle; the judging unit 220 is configured to judge whether the metal detection device detects metal within the correction acquisition time period according to the aforementioned induction value; the updating unit 230 is configured to update the detection reference value in the next adjacent correction period according to the aforementioned sensing value if the metal detection device does not detect metal in the correction acquisition time period.
Further, the determining unit 220 is specifically configured to: when the absolute value of the difference between a first average value and the detection reference value in the current correction period is smaller than a first threshold value, determining that the metal detection equipment does not detect metal in the correction acquisition time period, wherein the first average value is the arithmetic average value of the induction values; the updating unit 230 is specifically configured to: and updating the detection reference value in the next adjacent correction period to the first average value.
The embodiment of the present application further provides a metal detection device 300, and fig. 6 is a schematic structural diagram of the metal detection device provided in the embodiment of the present application, as shown in fig. 6, the metal detection device 300 includes a processor 310, a memory 320, and a computer program 330 stored in the memory 320 and operable on the processor. The various possible embodiments of the correction method 100 described above are implemented by the processor 310 when executing the computer program 330.
Optionally, the metal detector device 300 provided in the embodiment of the present application may be a security door, a handheld security device, or the like.
When the processor 310 in the metal detection device 300 provided in the embodiment of the present application executes the computer program 330 to implement various possible embodiments of the correction method 100, the operation speed of the processor 310 is fast, so that the speed of updating the detection reference value is fast, which is equivalent to performing correction and update in real time, and the operations of detecting, alarming, and the like of the metal detection device 300 on the target metal will not be affected.
Embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, implements various possible embodiments of the above-described correction method 100.
Alternatively, the computer-readable storage medium may be Random Access Memory (RAM), memory, Read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A method of calibrating a metal detection apparatus, comprising:
acquiring an induction value in a correction acquisition time period in a current correction period;
judging whether the metal detection equipment detects metal in the correction acquisition time period or not according to the induction value;
and if not, updating the detection reference value in the next adjacent correction period according to the induction value.
2. The calibration method according to claim 1, wherein said determining whether the metal detection device detects metal within the calibration acquisition time period according to the sensing value comprises:
when the absolute value of the difference between a first average value and the detection reference value in the current correction period is smaller than a first threshold value, determining that the metal detection equipment does not detect metal in the correction acquisition time period, wherein the first average value is the arithmetic average value of the induction values;
the updating the detection reference value in the next adjacent correction period according to the induction value comprises:
and updating the detection reference value in the next adjacent correction period to the first average value.
3. The correction method according to claim 2, characterized in that the correction method further comprises:
if it is determined that metal is detected in each correction acquisition time period in M continuous correction periods, wherein M is a positive integer greater than or equal to 2;
and updating the detection reference value in the M +1 th correction period according to the first average value corresponding to each correction acquisition time period in the M correction periods.
4. The correction method according to claim 3, wherein the updating the detection reference value in the M +1 th correction period according to the first average value corresponding to each of the M correction acquisition time periods comprises:
and updating the detection reference value in the M +1 th correction period according to N qualified values in the M first average values, wherein the absolute value of the difference between each qualified value and the second average value is smaller than a second threshold value, the second average value is the arithmetic average value of the M first average values, and N is a positive integer smaller than or equal to M.
5. The calibration method according to claim 4, wherein the updating the sounding reference value in the M +1 th calibration period according to the N qualified values in the M first average values includes:
and if the N is larger than or equal to the third threshold, updating the detection reference value in the M +1 th correction period to be the arithmetic average of the N qualified values.
6. The correction method according to any one of claims 1 to 5, characterized in that the correction method further comprises:
after the metal detection equipment is started, a plurality of measured values in a preset time period are obtained, and the arithmetic mean value of the measured values is used as a detection reference value in a first correction period.
7. The correction method according to any one of claims 1 to 5, characterized in that the end time of the correction acquisition period in the current correction cycle is the same as the end time of the current correction cycle.
8. A metal detection apparatus, comprising:
the acquisition unit is used for acquiring the induction value in the correction acquisition time period in the current correction period;
the judging unit is used for judging whether the metal detecting equipment detects metal in the correction acquisition time period according to the induction value;
and the updating unit is used for updating the detection reference value in the next adjacent correction period according to the induction value if the metal detection equipment does not detect metal in the correction acquisition time period.
9. A metal detection apparatus, comprising: a memory for storing a computer program; a processor for executing the computer program for implementing the steps of the correction method as claimed in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, carries out the steps of the correction method according to any one of claims 1-7.
CN202210346260.9A 2022-04-02 2022-04-02 Correction method of metal detection equipment and metal detection equipment Pending CN114706142A (en)

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CN202210346260.9A CN114706142A (en) 2022-04-02 2022-04-02 Correction method of metal detection equipment and metal detection equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210346260.9A CN114706142A (en) 2022-04-02 2022-04-02 Correction method of metal detection equipment and metal detection equipment

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