CN-121995500-A - Safety detector and safety detection method

CN121995500ACN 121995500 ACN121995500 ACN 121995500ACN-121995500-A

Abstract

The application provides a safety detector and a safety detection method, wherein the safety detector comprises a magnetic detection subsystem, the magnetic detection subsystem comprises a magnetic detection front-end circuit, an instrument amplification circuit, a filtering amplification circuit and a threshold comparison circuit, the magnetic detection front-end circuit is used for sensing a first voltage corresponding to an object to be detected when the object to be detected passes through the safety detector and outputting the first voltage, the instrument amplification circuit is used for carrying out differential amplification on a second voltage corresponding to the first voltage to obtain a third voltage and outputting the third voltage, the filtering amplification circuit is used for carrying out filtering operation on the third voltage to obtain a fourth voltage and outputting the fourth voltage, the threshold comparison circuit is used for detecting whether the fourth voltage is located in a threshold interval or not, if not, a prompt signal is output, and the prompt signal indicates that the object to be detected carries a detection target. By the technical scheme of the application, the safety detector has high signal-to-noise ratio and long detection distance.

Inventors

LU XIANGYU
WANG XIAOJIANG
RAN YOUMING

Assignees

杭州睿影科技有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (10)

1. The safety detector is characterized by comprising a magnetic detection subsystem, wherein the magnetic detection subsystem comprises a magnetic detection front-end circuit, an instrument amplifying circuit, a filtering amplifying circuit and a threshold comparison circuit; The magnetism detection front-end circuit is used for sensing a first voltage corresponding to an object to be detected when the object to be detected passes through the safety detector and outputting the first voltage; the instrument amplifying circuit is used for carrying out differential amplification on a second voltage corresponding to the first voltage to obtain a third voltage and outputting the third voltage, wherein the differential amplification is used for amplifying differential signals in the second voltage and not amplifying common-mode signals in the second voltage; The filtering amplifying circuit is used for filtering the third voltage to obtain a fourth voltage and outputting the fourth voltage, wherein the filtering operation is used for filtering voltage signals smaller than the first frequency and voltage signals larger than the second frequency in the third voltage; And the threshold comparison circuit is used for detecting whether the fourth voltage is positioned in a threshold interval or not, and outputting a prompt signal if not, wherein the prompt signal indicates that the object to be detected carries a detection target.
2. The safety detector according to claim 1, wherein, The magnetic detection front-end circuit adopts a tunneling magneto-resistance effect magnetic sensor or The magnetic detection front-end circuit adopts a fluxgate sensor or The magnetic detection front-end circuit adopts a magnetic resistance sensor, or The magnetic detection front-end circuit adopts a Hall sensor, or The magnetism detection front-end circuit adopts an inductance sensor.
3. The safety detector according to claim 1, wherein, Determining the first voltage as the second voltage, or The magnetic detection subsystem further comprises a differential filter circuit, wherein the differential filter circuit is used for performing differential filter operation on the first voltage to obtain the second voltage and outputting the second voltage, and the differential filter operation is used for filtering voltage signals which are larger than a third frequency in the first voltage; Wherein the third frequency is greater than the second frequency, which is greater than the first frequency.
4. The safety detector according to claim 1, wherein, The instrument amplifying circuit comprises a first input end, a second input end and a voltage output end, wherein the first input end and the second input end are input ends of the second voltage; The instrument amplifying circuit is used for amplifying the voltage difference between the first input end and the second input end to obtain the third voltage, and outputting the third voltage through the voltage output end.
5. The safety detector according to claim 1, wherein, The filtering and amplifying circuit comprises a low-pass filtering circuit and a high-pass filtering circuit; the low-pass filter circuit is used for performing low-pass filtering operation on the third voltage to obtain a low-pass filtered voltage, outputting the low-pass filtered voltage, and the low-pass filtering operation is used for filtering voltage signals which are larger than the second frequency in the third voltage; Or the high-pass filter circuit is used for carrying out high-pass filter operation on the third voltage to obtain a high-pass filtered voltage and outputting the high-pass filtered voltage, the high-pass filter operation is used for filtering voltage signals smaller than the first frequency in the third voltage, the low-pass filter circuit is used for carrying out low-pass filter operation on the high-pass filtered voltage to obtain a fourth voltage and outputting the fourth voltage, and the low-pass filter operation is used for filtering voltage signals larger than the second frequency in the high-pass filtered voltage.
6. The safety detector according to claim 1, wherein, The magnetic detection subsystem further comprises a sliding rheostat, and the voltage value of the first end and the voltage value of the second end of the sliding rheostat are adjusted by controlling the resistance value of the sliding rheostat; The voltage value of the first end of the sliding rheostat is used as the minimum boundary voltage of the threshold interval, and the voltage value of the second end of the sliding rheostat is used as the maximum boundary voltage of the threshold interval; And if the fourth voltage is greater than the maximum boundary voltage or the fourth voltage is less than the minimum boundary voltage, the threshold comparison circuit determines that the fourth voltage is not located in a threshold interval.
7. The safety detector according to claim 1, wherein, The magnetic detection subsystem further comprises a warning circuit, wherein the warning circuit is used for outputting a warning signal to a user after receiving the prompting signal, and the warning signal comprises at least one of the following components: an alert signal based on the highlighting LED; An alert signal based on the vibration motor; Alarm signals based on the buzzer; A voice-based alert signal.
8. The safety instrumented medication of any one of claims 1-7, further comprising a power supply subsystem to power the magnetic detection subsystem; the power supply subsystem comprises a battery and a battery charging and discharging circuit, and is provided with at least one of an electric quantity indication function, a charging indication function, a charger function and a flashlight function.
9. The safety detection method is characterized by being applied to a safety detector, wherein the safety detector comprises a magnetic detection subsystem, the magnetic detection subsystem comprises a magnetic detection front-end circuit, an instrument amplification circuit, a filtering amplification circuit and a threshold comparison circuit, and the method comprises the following steps: when an object to be detected passes through the safety detector, the magnetism detection front-end circuit senses a first voltage corresponding to the object to be detected and outputs the first voltage; The instrument amplifying circuit is used for carrying out differential amplification on a second voltage corresponding to the first voltage to obtain a third voltage and outputting the third voltage, wherein the differential amplification is used for amplifying differential signals in the second voltage and not amplifying common-mode signals in the second voltage; The filtering amplifying circuit is used for filtering the voltage signals smaller than the first frequency and larger than the second frequency in the third voltage to obtain a fourth voltage and outputting the fourth voltage; And if not, outputting a prompt signal, wherein the prompt signal indicates that the object to be detected carries a detection target.
10. The method of claim 9, wherein the step of determining the position of the substrate comprises, The magnetic detection subsystem further comprises a differential filter circuit, and before the instrument amplification circuit performs differential amplification on the second voltage corresponding to the first voltage to obtain a third voltage, the method further comprises the steps of: the differential filtering circuit is used for carrying out differential filtering operation on the first voltage to obtain the second voltage and outputting the second voltage after receiving the first voltage, wherein the differential filtering operation is used for filtering voltage signals which are larger than a third frequency in the first voltage; Wherein the third frequency is greater than the second frequency, which is greater than the first frequency.

Description

Safety detector and safety detection method Technical Field The application relates to the technical field of safety inspection, in particular to a safety detector and a safety detection method. Background A Security door (Security door) is a detection device for detecting whether a person carries a metal object, and the Security door is also called a metal detection door (Metal detection door). The security gate can be applied to public places with large people flow such as airports, stations, large conference centers and the like and is used for detecting whether personnel carry metal objects. When a person passes through the security inspection door, if the person carries a metal object, the security inspection door immediately gives an alarm and displays the zone where the metal object is located, so that a manager can timely find the metal object carried by the person. Disclosure of Invention The application provides a safety detector, which comprises a magnetic detection subsystem, wherein the magnetic detection subsystem comprises a magnetic detection front-end circuit, an instrument amplifying circuit, a filtering amplifying circuit and a threshold comparison circuit; The magnetism detection front-end circuit is used for sensing a first voltage corresponding to an object to be detected when the object to be detected passes through the safety detector and outputting the first voltage; the instrument amplifying circuit is used for carrying out differential amplification on a second voltage corresponding to the first voltage to obtain a third voltage and outputting the third voltage, wherein the differential amplification is used for amplifying differential signals in the second voltage and not amplifying common-mode signals in the second voltage; The filtering amplifying circuit is used for filtering the third voltage to obtain a fourth voltage and outputting the fourth voltage, wherein the filtering operation is used for filtering voltage signals smaller than the first frequency and voltage signals larger than the second frequency in the third voltage; And the threshold comparison circuit is used for detecting whether the fourth voltage is positioned in a threshold interval or not, and outputting a prompt signal if not, wherein the prompt signal indicates that the object to be detected carries a detection target. The magnetic detection front-end circuit adopts a tunneling magneto-resistance effect magnetic sensor, or The magnetic detection front-end circuit adopts a fluxgate sensor or The magnetic detection front-end circuit adopts a magnetic resistance sensor, or The magnetic detection front-end circuit adopts a Hall sensor, or The magnetism detection front-end circuit adopts an inductance sensor. The first voltage is illustratively determined to be the second voltage, or The magnetic detection subsystem further comprises a differential filter circuit, wherein the differential filter circuit is used for performing differential filter operation on the first voltage to obtain the second voltage and outputting the second voltage, and the differential filter operation is used for filtering voltage signals which are larger than a third frequency in the first voltage; Wherein the third frequency is greater than the second frequency, which is greater than the first frequency. The meter amplification circuit comprises a first input end, a second input end and a voltage output end, wherein the first input end and the second input end are input ends of the second voltage; The instrument amplifying circuit is used for amplifying the voltage difference between the first input end and the second input end to obtain the third voltage, and outputting the third voltage through the voltage output end. Illustratively, the filter amplification circuit includes a low pass filter circuit and a high pass filter circuit; the low-pass filter circuit is used for performing low-pass filtering operation on the third voltage to obtain a low-pass filtered voltage, outputting the low-pass filtered voltage, and the low-pass filtering operation is used for filtering voltage signals which are larger than the second frequency in the third voltage; Or the high-pass filter circuit is used for carrying out high-pass filter operation on the third voltage to obtain a high-pass filtered voltage and outputting the high-pass filtered voltage, the high-pass filter operation is used for filtering voltage signals smaller than the first frequency in the third voltage, the low-pass filter circuit is used for carrying out low-pass filter operation on the high-pass filtered voltage to obtain a fourth voltage and outputting the fourth voltage, and the low-pass filter operation is used for filtering voltage signals larger than the second frequency in the high-pass filtered voltage. The magnetic detection subsystem further comprises a sliding rheostat, and the voltage value of the first end and the voltage value of the second end of the sliding rheos