Metal canning dangerous liquid detection device and control method thereof

Abstract

The invention relates to the technical field of metal detection, in particular to a metal canning dangerous liquid detection device and a control method thereof. The device comprises an inductance coil device, a heating device, a resonance circuit driving device, an alternating current signal measuring device, a temperature measuring device and a processing unit, the resonance circuit driving device is connected with the inductance coil device; the alternating current signal measuring device is connected with the inductance coil device; and the heating device is connected with the inductance coil device. And the processing unit can judge the material of the metal tank body according to the parameter change between the target alternating current signal and the initial alternating current signal. On the basis, the liquid in the inductance coil device and the metal tank body is heated, and whether the liquid in the metal tank body is dangerous liquid or not can be accurately judged by combining the detected temperature information with the material of the metal tank body. The device is simple in structural design and low in structural cost, and whether liquid in the metal tank body is dangerous liquid or not can be accurately judged.

Description

Technical Field

[0001] This application relates to the technical field of metal detection, and particularly relates to a metal canned hazardous liquid detection device and its control method. Background Art

[0002] The detection of bottled hazardous liquids is widely used in the field of public safety. For liquids in metal cans, currently, the thermal conductivity measurement method is mostly used, that is, by heating the can body and then detecting the temperature rise curve near the can to determine whether the liquid inside is water or a hazardous liquid such as gasoline. Commonly drinkable liquids are mostly water, which has a large specific heat capacity. Under the condition of the same heating power, the temperature rise of the can body is slow. For hazardous liquids such as gasoline, due to their specific heat capacity being smaller than that of water, the temperature rise is fast. By measuring the temperature rise curve, it is possible to determine whether the liquid in the can is hazardous or safe.

[0003] When the traditional method measures some irregularly shaped can bodies, errors may occur. For example, when measuring the positions of ferromagnetic and non-ferromagnetic eddy current sensors, the diameter of the can body becomes smaller, and at this time, if the sensor is too far away from the can body, it may not be able to sense. This causes the sensor to output an incorrect signal, thereby affecting the accuracy of the measurement. At the same time, the traditional measurement structure is complex in design and relatively high in cost, which affects the competitiveness of the product. Summary of the Invention

[0004] This application provides a metal canned hazardous liquid detection device and its control method to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0005] Other features and advantages of this application will become apparent through the following detailed description, or be learned in part through the practice of this application.

[0006] According to one aspect of the embodiments of this application, a metal canned hazardous liquid detection device is provided. The metal canned hazardous liquid detection device includes an inductance coil device, a heating device, a resonant circuit driving device, an alternating current signal measuring device, a temperature measuring device, and a processing unit;

[0007] The heating device, the resonant circuit driving device, the alternating current signal measuring device, and the temperature measuring device are all connected to the processing unit;

[0008] The resonant circuit driving device is connected to the inductance coil device to drive the inductance coil device to generate an initial alternating current signal;

[0009] When a metal can body appears within the preset radiation range of the inductance coil device, the parameters of the initial alternating current signal change to form a target alternating current signal;

[0010] The AC signal measuring device is connected to the inductance coil device to receive the target AC signal and transmit the target AC signal to the processing unit;

[0011] The heating device is connected to the inductance coil device to heat the inductance coil device and the liquid inside the metal tank;

[0012] The temperature measuring device is used to detect the temperature of the liquid inside the metal tank.

[0013] In an embodiment of the present application, based on the foregoing solution, the resonant circuit driving device includes a digital-to-analog converter and a first amplifier. The digital-to-analog converter is connected to the processing unit and the first amplifier, and the first amplifier is connected to the inductance coil device.

[0014] In an embodiment of the present application, based on the foregoing solution, the inductance coil device includes a first capacitor and a coil device. The first capacitor is connected to the first amplifier, the coil device, and the AC signal measuring device.

[0015] In an embodiment of the present application, based on the foregoing solution, the AC signal measuring device includes a second capacitor, a second amplifier, and a comparator. The second capacitor is connected to the first capacitor, the first amplifier, and the second amplifier. The second amplifier is connected to the comparator, and the comparator is connected to the processing unit.

[0016] In an embodiment of the present application, based on the foregoing solution, the heating device is connected to the coil device.

[0017] In an embodiment of the present application, based on the foregoing solution, the temperature measuring device includes a temperature measuring circuit and a temperature-sensitive sensor disposed within the preset radiation range. The temperature measuring circuit is connected to the temperature-sensitive sensor and the processing unit;

[0018] Wherein, when the metal tank is within the preset radiation range, the temperature-sensitive sensor abuts against the side wall of the metal tank.

[0019] According to one aspect of the embodiments of the present application, a control method for a metal canned hazardous liquid detection device is provided. The method is executed on the processing unit of the metal canned hazardous liquid detection device described above. The method includes:

[0020] Sending a driving signal to the resonant circuit driving device, so that the resonant circuit driving device sends the received driving signal into the first amplifier to generate an initial AC signal;

[0021] After receiving the target alternating current signal sent by the alternating current signal measuring device, determine the material of the metal tank according to the parameters of the target alternating current signal, where the target alternating current signal is formed by driving an inductance coil device with the initial alternating current signal;

[0022] Send a heating signal to the heating device to cause the heating device to heat the inductance coil device;

[0023] After receiving the temperature detection signal sent by the temperature measuring device, determine whether the liquid inside the metal tank is a hazardous liquid according to the temperature detection signal, where the temperature detection signal is generated after the metal tank enters the preset radiation range of the inductance coil device and the heating device heats the inductance coil device;

[0024] Wherein, the hazardous liquid is a liquid within a preset liquid classification range.

[0025] In an embodiment of the present application, based on the foregoing solution, the determining the material of the metal tank according to the parameters of the target alternating current signal includes:

[0026] Determine the phase difference between the target alternating current signal and the initial alternating current signal according to the parameters of the target alternating current signal and the parameters of the initial alternating current signal;

[0027] If the phase difference is within a first preset range, determine that the material of the metal tank is iron;

[0028] If the phase difference is within a second preset range, determine that the material of the metal tank is aluminum.

[0029] In an embodiment of the present application, based on the foregoing solution, the determining whether the liquid inside the metal tank is a hazardous liquid according to the temperature detection signal includes:

[0030] Determine the temperature change information of the liquid inside the metal tank within a target time period according to the temperature detection signal;

[0031] Determine the temperature change rate of the liquid within the target time period according to the temperature change information;

[0032] If the temperature change rate is greater than a preset change rate threshold, determine that the liquid is a hazardous liquid.

[0033] The beneficial effects of the present application are as follows: The inductance coil device is driven by a resonance circuit driving device to generate an initial alternating current signal. When a metal tank body appears within the preset radiation range of the inductance coil device, the parameters of the initial alternating current signal change to form a target alternating current signal. The alternating current signal measuring device is connected to the inductance coil device to receive the target alternating current signal and transmit the target alternating current signal to the processing unit, enabling the processing unit to determine the material of the metal tank body based on the parameter change between the target alternating current signal and the initial alternating current signal. On the basis of knowing the material of the metal tank body, the inductance coil device and the liquid inside the metal tank body are heated, and at the same time, the temperature measuring device detects the temperature of the liquid inside the metal tank body. By combining the detected temperature information with the material of the metal tank body, it is possible to accurately determine whether the liquid in the metal tank is a hazardous liquid.

[0034] The structural design of the present application is simple, and the structural cost is relatively low. While being able to distinguish the material of the metal tank body, it can accurately determine whether the liquid in the metal tank is a hazardous liquid, solving the problems and pain points existing in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly describe the drawings required for the description of the embodiments. Obviously, the described drawings are only a part of the embodiments of the present application, rather than all embodiments. Those skilled in the art can also obtain other design solutions and drawings based on these drawings without creative efforts.

[0036] Figure 1 FIG. is the overall logic block diagram of the metal canned hazardous liquid detection device shown according to the embodiment of the present application;

[0037] Figure 2 FIG. is the specific circuit diagram of the metal canned hazardous liquid detection device shown according to the embodiment of the present application;

[0038] Figure 3 FIG. is the flowchart of the control method of the metal canned hazardous liquid detection device shown according to the embodiment of the present application;

[0039] Figure 4 FIG. is the logical schematic diagram of temperature detection and analysis of the liquid shown according to the embodiment of the present application;

[0040] Figure 5 FIG. is the detection logic schematic diagram realized based on the coil-shaped heating wire shown according to the embodiment of the present application;

[0041] Figure 6 FIG. is the detection logic schematic diagram realized based on the lamination of the heating wire and the coil shown according to the embodiment of the present application. DETAILED DESCRIPTION

[0042] Example embodiments are now described more fully in conjunction with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0043] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the present application.

[0044] The block diagrams shown in the accompanying drawings are only functional entities and do not necessarily correspond to physically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or micro-control node devices.

[0045] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0046] It should be noted that the "multiple" mentioned in this article refers to two or more. "And / or" describes the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0047] The following is a detailed introduction to the background technology of this application:

[0048] The detection of bottled hazardous liquids is widely used in the field of public safety. For liquids in metal cans, the thermal conductivity measurement method is currently mostly used, that is, by heating the can body and then detecting the temperature rise curve of the nearby can body to determine whether it contains water or dangerous liquids such as gasoline. Most common drinkable liquids are water, which has a large specific heat capacity. Under the same heating power conditions, the temperature rise of the can body is slow. For dangerous liquids such as gasoline, since the specific heat capacity is smaller than that of water, the temperature rise is fast. By measuring the temperature rise curve, it is possible to determine whether the liquid in the can is dangerous or safe.

[0049] Currently, the metal cans of common beverages such as canned cola, eight-treasure porridge, and Wanglaoji are usually made of iron or aluminum. The thickness and thermal conductivity of iron and aluminum cans are different, resulting in different temperature rise curves when filling the same liquid with the same heating power. Therefore, it is necessary to detect the can body material to determine whether it is aluminum or iron, so as to use different parameters in the subsequent software algorithm for judgment to improve the measurement accuracy.

[0050] For the current mature solution, a proximity sensor is installed near the heating device and the temperature measuring device, and an eddy current sensor for measuring ferromagnetic or non-ferromagnetic materials is installed. After the proximity sensor senses that an object is approaching, the measurement is started, and at the same time, the output of the eddy current sensor is checked to determine whether it is an iron can or an aluminum can.

[0051] In summary, the traditional method has three disadvantages. First, the sensor installation and heating are not in the same position, which may cause errors when measuring some special-shaped cans. For example, when measuring the position of the ferromagnetic and non-ferromagnetic eddy current sensors, the diameter of the can body becomes smaller, and the sensor may be too far away from the can body to sense, resulting in an incorrect signal output by the sensor and affecting the measurement accuracy. The second disadvantage is that most sensors have digital outputs and can only output 1 or 0. When the can is placed and ready for measurement, it may not change. At this time, manual measurement needs to be started, which is not user-friendly. Moreover, during the heating process, the user may remove the can, and the sensor does not have a level change, which may cause the heating device to continue heating after losing the load, resulting in overheating and damage to the heating device. The third disadvantage is that the structure design is complex, and the cost of measuring ferromagnetic and non-ferromagnetic sensors is relatively high, which will increase the final cost and affect the product competitiveness.

[0052] Therefore, the present application provides a metal canned hazardous liquid detection device and its control method, which integrates the functions of heating, temperature measurement, and metal can body material judgment. By continuously monitoring the parameters of the AC signal measurement device (because the appearance of a metal can in the preset radiation range of the inductive coil device will cause a change in this parameter), the material and proximity state of the metal can are sensed, and then the heating device is started for measurement after stabilization, achieving the advantages of simple structure, low cost, fast response, and accurate measurement results for measuring hazardous liquids at a single point.

[0053] The implementation details of the technical solution of the embodiments of the present application are elaborated in detail below:

[0054] According to one aspect of the embodiments of the present application, a metal canned hazardous liquid detection device is provided, as Figure 1 and Figure 2 shown, Figure 1 is the structural block diagram of the metal canned hazardous liquid detection device.Figure 2 It is the specific circuit diagram of the detection device for dangerous liquids in metal cans.

[0055] The detection device for dangerous liquids in metal cans includes an inductance coil device, a heating device, a resonant circuit driving device, an AC signal measuring device, a temperature measuring device, and a processing unit;

[0056] The heating device, the resonant circuit driving device, the AC signal measuring device, and the temperature measuring device are all connected to the processing unit;

[0057] The resonant circuit driving device is connected to the inductance coil device to drive the inductance coil device to generate an initial AC signal;

[0058] When a metal tank body appears within the preset radiation range of the inductance coil device, the parameters of the initial AC signal change to form a target AC signal;

[0059] The AC signal measuring device is connected to the inductance coil device to receive the target AC signal and transmit the target AC signal to the processing unit;

[0060] The heating device is connected to the inductance coil device to heat the inductance coil device and the liquid inside the metal tank body;

[0061] The temperature measuring device is used to detect the temperature of the liquid inside the metal tank body.

[0062] Specifically, the inductance coil device is driven by the resonant circuit driving device to generate an initial AC signal. When a metal tank body appears within the preset radiation range of the inductance coil device, the parameters of the initial AC signal change to form a target AC signal. The AC signal measuring device is connected to the inductance coil device to receive the target AC signal and transmit the target AC signal to the processing unit, so that the processing unit can judge the material of the metal tank body according to the parameter change between the target AC signal and the initial AC signal. On the basis of knowing the material of the metal tank body, the inductance coil device and the liquid inside the metal tank body are heated, and at the same time, the temperature measuring device detects the temperature of the liquid inside the metal tank body. By combining the detected temperature information with the material of the metal tank body, it can be accurately judged whether the liquid in the metal tank is a dangerous liquid.

[0063] Further, the resonant circuit driving device includes a digital-to-analog converter and a first amplifier. The digital-to-analog converter is connected to the processing unit and the first amplifier, and the first amplifier is connected to the inductance coil device. The inductance coil device includes a first capacitor and a coil device. The first capacitor is connected to the first amplifier, the coil device, and the AC signal measuring device. The AC signal measuring device includes a second capacitor, a second amplifier, and a comparator. The second capacitor is connected to the first capacitor, the first amplifier, and the second amplifier. The second amplifier is connected to the comparator, and the comparator is connected to the processing unit.

[0064] As Figure 2 shown, the digital-to-analog converter is Figure 2 the DAC (Digital to Analog Converter) in Figure 2 , the first amplifier is Figure 2 A1 in Figure 2 , the inductance coil device is the first capacitor C1 and the coil device L in

[0065] The initial AC signal generated by the resonant circuit driving device and the first amplifier can drive the resonant circuit composed of the first capacitor C1 and the coil device L to generate a new AC signal. After passing through the second capacitor C2 and the second amplifier A2, it enters the comparator, that is, the COMP (Comparator) in The processing unit can acquire the AC signal once every certain period. If a metal tank body appears within the preset radiation range of the inductance coil device, the parameters of this AC signal will definitely change. By analyzing the parameter changes, the material of the metal tank body can be determined. In the embodiment of the present application, when the metal tank body enters the preset radiation range of the inductance coil device, the AC signal formed at this time is the target AC signal. At this time, the phase difference between the target AC signal and the initial AC signal is compared with the phase difference between the AC signal obtained when no metal tank body appears within the preset radiation range and the initial AC signal. By the change situation of the two phase differences, it can be determined whether the metal tank body is iron, aluminum, or other materials.An initial AC signal is applied to the coil device. An alternating magnetic field will be generated around the coil device. If an aluminum metal tank approaches, aluminum is a paramagnetic material and has little effect on the magnetic field change itself, but has a relatively large area passing through the magnetic lines of force. Therefore, an eddy current signal will be induced. This eddy current signal will induce a magnetic field, whose direction is opposite to that of the coil, resulting in a decrease in the total alternating magnetic field passing through the coil device. If the applied AC voltage remains unchanged, the current passing through the coil device will increase. When an iron metal tank approaches, due to ferromagnetic properties, the original magnetic field of the coil will be greatly enhanced, which is equivalent to an increase in the impedance of the coil device. If the applied AC voltage remains unchanged, then considering only the ferromagnetic properties, the current in the coil will significantly decrease. Of course, the iron tank will also have an eddy current effect, generating a magnetic field opposite to that of the coil and reducing the ferromagnetic properties.

[0066] Based on the above analysis, by analyzing the amplitude and phase changes of the AC signal on the coil device, the materials of different metal tanks can be distinguished. It should be noted that the processing unit can be a processor or a controller. Figure 2 、 Figure 5 and Figure 6 The measured tank in

[0067] is the metal tank described in the embodiments of the present invention.

[0068] The software continuously monitors the parameter Δφ. When the metal tank approaches the coil for measurement, for example, when the software detects that Δφ decreases by 2° or increases by 10° and remains stable for 10 sampling periods, the heating measurement is started. During the measurement process, the change amount of Δφ is detected. For example, if the change amount of this sampling value compared to the previous one is >0.5°, it indicates that the position of the metal tank has changed, and the heat absorption and temperature measurement of the metal tank have undergone a sudden change. It can be judged that the current measurement result is inaccurate, and the processor can immediately control the heating device to stop running to protect the heating film from damage. In summary, the circuit design of the present invention is simple, safe to use, and has a low cost, effectively improving the product competitiveness.

[0069] Further, the heating device is connected to the coil device. The temperature measurement device includes a temperature measurement circuit and a temperature-sensitive sensor disposed within the preset radiation range. The temperature measurement circuit is connected to the temperature-sensitive sensor and the processing unit. When the metal tank is within the preset radiation range, the temperature-sensitive sensor abuts against the side wall of the metal tank.

[0070] Specifically, the parameter values of the temperature-sensitive sensor are measured at regular intervals and timed. Whether a metal tank approaches is judged based on the obtained eddy current parameters. When a tank approaches, it is detected whether the eddy current parameters are stable. If they are stable, it means the metal tank has been placed stably, and the heating device is started for heating. During the heating process, it is continuously judged whether the eddy current parameters change. If a sudden change in the eddy current parameters is detected, the heating is immediately turned off and the temperature measurement is stopped. If there is no change, the heating is stopped after the set time. The processor processes the temperature change curve during this period, and finally judges whether the liquid in the metal tank is a dangerous liquid or a safe liquid based on the material characteristics of the metal tank.

[0071] In an example, when the metal tank enters the preset radiation range, it is equivalent to the metal tank being placed in a detection position. At this time, the metal tank is stable and the temperature-sensitive sensor will abut against the side wall of the metal tank. Different liquids placed in the metal tank have inconsistent temperature change curves on the side wall when heated. Therefore, the temperature change curve of the liquid in the metal tank can be indirectly analyzed by measuring the temperature of the side wall of the metal tank with the temperature-sensitive sensor, and then it can be judged whether the liquid is a dangerous liquid based on this temperature change curve.

[0072] According to one aspect of the embodiments of the present application, a control method for a detection device for dangerous liquids in metal cans is provided. Figure 3 FIG. is a flowchart of the control method for the detection device for dangerous liquids in metal cans shown according to the embodiments of the present application. The method at least includes steps S1 to S4, which are introduced in detail as follows:

[0073] In step S1, a driving signal is sent to the resonant circuit driving device, so that the resonant circuit driving device sends the received driving signal into the first amplifier to generate an initial AC signal.

[0074] Specifically, the initial AC signal is used to drive the inductive coil device to generate an alternating magnetic field. This initial AC signal is generally a sine wave signal to generate an alternating magnetic field around the inductive coil device.

[0075] In step S2, after receiving the target AC signal sent by the AC signal measuring device, the material of the metal tank body is determined according to the parameters of the target AC signal. The target AC signal is formed by driving the inductive coil device with the initial AC signal.

[0076] Specifically, the initial AC signal generated by the resonant circuit driving device and the first amplifier can drive the resonant circuit composed of the first capacitor C1 and the coil device L to generate a new AC signal. After passing through the second capacitor C2 and the second amplifier A2, it enters the comparator, that is, Figure 2 COMP (Comparator) in. The processing unit can obtain the AC signal once every certain period. If a metal tank body appears within the preset radiation range of the inductive coil device, the parameters of this AC signal will definitely change. By analyzing the parameter changes, the material of the metal tank body can be judged. In the embodiment of the present application, when the metal tank body enters the preset radiation range of the inductive coil device, the AC signal formed at this time is the target AC signal. At this time, the phase difference between the target AC signal and the initial AC signal is compared with the phase difference between the AC signal and the initial AC signal obtained when there is no metal tank body within the preset radiation range. By the change situation of the two phase differences, it can be judged whether the metal tank body is iron, aluminum, or other materials.

[0077] In an embodiment of the present application, the determining the material of the metal tank body according to the parameters of the target AC signal includes:

[0078] Determining the phase difference between the target AC signal and the initial AC signal according to the parameters of the target AC signal and the parameters of the initial AC signal;

[0079] If the phase difference is within the first preset range, it is determined that the material of the metal tank body is iron;

[0080] If the phase difference is within the second preset range, it is determined that the material of the metal tank body is aluminum.

[0081] Specifically, the first preset range and the second preset range can be set according to actual needs. In the embodiments of the present application, the first preset range is used to represent that the phase of the target AC signal moves forward, and the second preset range is used to represent that the phase of the target AC signal moves backward. Numerical limitations are not imposed on the first preset range and the second preset range herein. The first preset range and the second preset range can be explained by the following examples:

[0082] The processing unit controls the DAC to output a sine wave with a frequency of f0. After being driven by the first amplifier A1, a sine wave with an initial phase angle of φ0 is obtained, and then the LC resonant circuit composed of C1 and L is driven. Here, L is the coil device, and the coil device can be a heating coil or a coil superimposed with a heating wire. The phase detection sampling point is taken at the connection point of the first capacitor C1 and the coil device L. After being AC-coupled by the second capacitor C2, it is sent to the operational amplifier A2 for amplification, and then a rectangular wave with a frequency of f0 and a phase angle of φ1 is obtained through the comparator COMP. In this way, the phase difference Δφ = φ0 - φ1, and φ0 is fixed when the circuit parameters are determined. Under the current circuit parameters, when no metal tank is detected, Δφ0 = 6.9°. When an iron metal tank enters the preset radiation range, the phase difference becomes Δφ1 = 2.8°, and the phase of φ1 moves forward by 4.1°. When an aluminum metal tank enters the preset radiation range, the phase difference becomes Δφ2 = 17.2°, and the phase of φ1 moves backward by 10.3°. Specifically, the magnitude of the phase shift is related to the circuit parameters and also has a certain relationship with the diameter and thickness of the tank body. However, the changing trend is the same. Generally speaking, if the phase of φ1 moves forward, it means the metal tank is made of iron; if the phase of φ1 moves backward, it means the metal tank is made of aluminum.

[0083] In step S3, a heating signal is sent to the heating device so that the heating device heats the inductive coil device.

[0084] Specifically, by sending a heating signal to the heating device, the heating device can heat the inductive coil device.

[0085] In step S4, after receiving the temperature detection signal sent by the temperature measurement device, it is determined whether the liquid inside the metal tank is a dangerous liquid according to the temperature detection signal. The temperature detection signal is generated after the metal tank enters the preset radiation range of the inductive coil device and the heating device heats the inductive coil device;

[0086] Wherein, the dangerous liquid is a liquid within the preset liquid classification range.

[0087] In an embodiment of the present application, the determining whether the liquid inside the metal tank is a dangerous liquid according to the temperature detection signal includes:

[0088] Determine the temperature change information of the liquid inside the metal tank within the target period according to the temperature detection signal;

[0089] Determine the temperature change rate of the liquid within the target period according to the temperature change information;

[0090] If the temperature change rate is greater than a preset change rate threshold, determine that the liquid is a hazardous liquid.

[0091] Specifically, the preset liquid classification range can be defined according to actual needs, and the liquids within the preset liquid classification range can be hazardous liquids with flammability such as gasoline, ethylene, and diesel.

[0092] In one example, different liquids are placed in a metal tank, and the temperature change curves of its side walls are inconsistent when heated. Therefore, the temperature change curve of the liquid in the metal tank can be indirectly analyzed by measuring the temperature of the side wall of the metal tank with a temperature-sensitive sensor, and then it can be determined whether the liquid is a hazardous liquid according to this temperature change curve. The temperature detection signal is actually for the temperature change of the side wall of the metal tank, so the temperature change curve of the liquid in the metal tank (i.e., the temperature change information described in this application) can be indirectly analyzed through this temperature change.

[0093] Specifically, reference can be made to Figure 4 as shown Figure 4 is the specific logic diagram of temperature detection provided by the embodiment of the present invention. It should be noted that Figure 4The logic flow chart in it is only for the convenience of those skilled in the art to understand and is not the content protected by the present invention. The parameter values of the temperature-sensitive sensor 600 are measured every once in a while and regularly (known from the temperature detection signal described in the embodiments of the present invention). Whether there is a metal tank body approaching is judged through the obtained eddy current parameters (obtained from the temperature detection signal described in the embodiments of the present invention). When a tank body approaches, it is detected whether the eddy current parameters are stable. If they are stable, it means the metal tank body has been placed stably, and the heating device 700 is started for heating. During the heating process, it is continuously judged whether there is a change in the detected eddy current parameters. If it is detected that there is a sudden change in the eddy current parameters (the eddy current parameters here refer to the phase difference Δφ), that is, the change value of the phase difference within a period of time is greater than the preset change threshold, the heating is immediately turned off and the temperature measurement is stopped. The change threshold can be set as needed. In the present invention, the change threshold is 0.5°. If there is no change, the heating is stopped after the set time. The processor analyzes the temperature curve (i.e., the temperature change rate) during this period. Based on the material characteristics of the metal tank body, it is finally judged whether the liquid in the metal tank is a dangerous liquid or a safe liquid. Among them, the preset change rate threshold can be set according to actual needs. As long as the temperature change rate is large, it means that the liquid heats up quickly, indicating that the specific heat capacity of the liquid is small. At this time, it can be determined that the liquid is a dangerous liquid.

[0094] Further, as Figure 5 shown, the coil device of the present application can be a heating wire wound into a coil shape, having a certain inductance and resistance value. When a DC signal is applied, it can generate heat to heat the metal tank body. When an alternating current (i.e., an AC signal) is applied, an alternating magnetic field can be generated. When there is a metal tank body around, the alternating current passing through the coil-shaped heating wire will change. Through measurement and analysis, it can be judged whether the metal tank body is made of an iron tank or an aluminum tank.

[0095] As Figure 6 shown, Figure 6 is another implementation manner of the coil device of the present application. The heating wire and the coil are separated and superimposed on each other. For example, it is realized by using a double-sided FPC (Flexible Printed Circuit). A heating resistance wire is designed on the side attached to the metal tank body, and the other side of the FPC is designed as a coil, and a temperature-sensitive sensor is installed in the middle of the coil. In this way, the circuit implementation is simpler and does not require DC isolation and AC isolation.

[0096] In summary, in the present application, the inductance coil device is driven by a resonance circuit driving device to generate an initial alternating current signal. When a metal tank body appears within the preset radiation range of the inductance coil device, the parameters of the initial alternating current signal change to form a target alternating current signal. The alternating current signal measuring device is connected to the inductance coil device to receive the target alternating current signal and transmit the target alternating current signal to the processing unit, so that the processing unit can judge the material of the metal tank body according to the parameter change between the target alternating current signal and the initial alternating current signal. On the basis of knowing the material of the metal tank body, by heating the inductance coil device and the liquid inside the metal tank body, and at the same time detecting the temperature of the liquid inside the metal tank body through a temperature measuring device, it can be accurately judged whether the liquid in the metal tank is a dangerous liquid by combining the detected temperature information with the material of the metal tank body.

[0097] The structural design of the present application is simple and the structural cost is low. While being able to distinguish the material of the metal tank body, it can accurately judge whether the liquid in the metal tank is a dangerous liquid, solving the problems and pain points existing in the prior art.

[0098] In addition, the above-mentioned drawings are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present application, rather than for limiting purposes. It is easy to understand that the processes shown in the above-mentioned drawings do not indicate or limit the time sequence of these processes. Additionally, it is also easy to understand that these processes can be executed synchronously or asynchronously in multiple modules.

[0099] It should be understood that the present application is not limited to the exact structure already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A metal canned dangerous liquid detection device, characterized in that: The metal canned dangerous liquid detection device comprises an inductor coil device, a heating device, a resonant circuit driving device, an AC signal measuring device, a temperature measuring device and a processing unit; The heating device, the resonant circuit driving device, the AC signal measuring device and the temperature measuring device are all connected to the processing unit; The resonant circuit driving device is connected to the inductor device to drive the inductor device to generate an initial AC signal; When a metal can appears within the preset radiation range of the inductive coil device, the parameters of the initial AC signal change to form a target AC signal; The AC signal measuring device is connected to the inductor device to receive the target AC signal and transmit the target AC signal to the processing unit; The heating device is connected to the induction coil device to heat the induction coil device and the liquid inside the metal tank; The temperature measuring device is used to detect the temperature of the liquid inside the metal tank.

2. The metal canned dangerous liquid detection device according to claim 1, characterized in that: The resonant circuit driving device comprises a digital-to-analog converter and a first amplifier, wherein the digital-to-analog converter is connected to the processing unit and the first amplifier, and the first amplifier is connected to the inductor device.

3. The metal canned dangerous liquid detection device according to claim 2, characterized in that: The inductor coil device includes a first capacitor and a coil device, wherein the first capacitor is connected to the first amplifier, the coil device and the AC signal measuring device.

4. The metal canned dangerous liquid detection device according to claim 3, characterized in that: The AC signal measuring device includes a second capacitor, a second amplifier and a comparator. The second capacitor is connected to the first capacitor, the first amplifier and the second amplifier. The second amplifier is connected to the comparator. The comparator is connected to the processing unit.

5. The metal canned dangerous liquid detection device according to claim 4, characterized in that: The heating device is connected to the coil device.

6. The metal canned dangerous liquid detection device according to claim 1, characterized in that: The temperature measuring device comprises a temperature measuring circuit and a temperature sensitive sensor arranged in the preset radiation range, wherein the temperature measuring circuit is connected to the temperature sensitive sensor and the processing unit; Wherein, when the metal can body is within the preset radiation range, the temperature sensitive sensor abuts against the side wall of the metal can body.

7. A control method for a metal canned dangerous liquid detection device, characterized in that: The method is executed in a processing unit of the metal can dangerous liquid detection device according to any one of claims 1 to 6, and the method comprises: Sending a driving signal to the resonant circuit driving device, so that the resonant circuit driving device sends the received driving signal to the first amplifier to generate an initial AC signal; After receiving a target AC signal sent by an AC signal measuring device, determining the material of the metal can body according to parameters of the target AC signal, wherein the target AC signal is formed by driving the inductor device with the initial AC signal; sending a heating signal to a heating device so that the heating device heats the induction coil device; After receiving a temperature detection signal sent by a temperature measuring device, judging whether the liquid in the metal tank body is a dangerous liquid according to the temperature detection signal, wherein the temperature detection signal is generated after the metal tank body enters a preset radiation range of the induction coil device and the heating device heats the induction coil device; Wherein, the hazardous liquid is a liquid within a preset liquid classification range.

8. The control method according to claim 7, characterized in that: The determining the material of the metal can body according to the parameters of the target AC signal includes: Determining a phase difference between the target AC signal and the initial AC signal according to a parameter of the target AC signal and a parameter of the initial AC signal; If the phase difference is within a first preset range, it is determined that the material of the metal can body is iron; If the phase difference is within the second preset range, it is determined that the material of the metal can body is aluminum.

9. The control method according to claim 7, characterized in that: The determining whether the liquid in the metal tank body is a dangerous liquid according to the temperature detection signal includes: Determine the temperature change information of the liquid inside the metal tank within a target period of time according to the temperature detection signal; determining a temperature change rate of the liquid within the target time period according to the temperature change information; If the temperature change rate is greater than a preset change rate threshold, the liquid is determined to be a hazardous liquid.

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