Layout method of RFID system in intelligent storage cabinets for hazardous chemicals based on statistical analysis method

Abstract

The present invention discloses a method for RFID system layout in hazardous chemicals intelligent storage cabinet based on statistical analysis method. First, a simulation model of hazardous chemicals intelligent storage cabinet is established in electromagnetic simulation software according to the parameters of hazardous chemicals intelligent storage cabinet; then a simulation model of read-write antenna is established inside the simulation model of hazardous chemicals intelligent storage cabinet; then the electromagnetic field distribution in the hazardous chemicals storage cabinet including the read-write antenna is calculated; the probability density function of the electric field modulus corresponding to the read-write antenna when the read-write antenna is installed at different positions in the cabinet is calculated; the probability density function of the electric field modulus is compared with the energy activation threshold of the tag antenna chip to obtain the best installation position of the read-write antenna in the storage cabinet, and determine the optimal RFID system layout plan in the storage cabinet. The present invention obtains the optimal layout of the RFID read-write antenna in the cabinet through statistical analysis method, so that the wireless communication in the cabinet can be carried out normally, and the objects in the cabinet can be automatically counted and recorded, which reduces the cost and improves the efficiency and accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless radio frequency identification, and in particular to a method for arranging an RFID system in an intelligent storage cabinet for hazardous chemicals based on a statistical analysis method. Background Art

[0002] Radio Frequency Identification (RFID) is a type of automatic identification technology that uses radio frequency to perform non-contact two-way data communication and uses radio frequency to read and write the recording medium, i.e., the tag antenna, to achieve the purpose of identifying the target and exchanging data. Radio Frequency Identification uses electromagnetic wave non-contact rapid information exchange and storage technology, wireless communication combined with data access technology, and connects to the database system to achieve non-contact two-way communication, thereby achieving the purpose of identification and data exchange. In the identification system, the reading, writing, and communication of electronic tags are achieved through electromagnetic waves.

[0003] Internet of Things technology: a network technology that connects any object to the Internet through information sensing devices such as RFID systems, infrared sensors, global positioning systems, laser scanners, etc., according to agreed protocols, to exchange information and communicate, in order to achieve intelligent identification, positioning, tracking, monitoring and management.

[0004] The storage of hazardous chemicals is usually managed by manual record keeping, and administrators are required to monitor the status of hazardous chemicals on site in real time. This not only consumes manpower and material resources, increases the cost of hazardous chemicals management, but also makes it easy for hazardous chemicals in the laboratory to be lost due to human negligence.

[0005] The hazardous chemicals intelligent storage cabinet is usually made of metal plates, and the metal environment formed by this structure will affect the RFID system arranged inside. At the same time, the complex electromagnetic environment formed in the metal cabinet by the electromagnetic field radiated by the read / write antenna and tag antenna in the RFID system when working, as well as the hazardous chemicals with different physical and electromagnetic properties placed in the cabinet, will cause significant interference to the communication between the read / write antenna and the tag antenna, thus affecting the optimized layout of the RFID system in the hazardous chemicals intelligent storage cabinet.

[0006] In the metal cabinets where hazardous chemicals are stored, the electromagnetic environment inside the cabinets is very complex due to the reflection and refraction of the electromagnetic waves emitted by the read / write antennas, as well as the influence of the hazardous chemicals in the cabinets on the distribution characteristics of the electromagnetic environment. Wireless communication is very difficult in such an environment, and electromagnetic interference problems are prone to occur.

[0007] The electromagnetic environment inside a closed metal cabinet is very complex, and it is difficult to conduct wireless communication inside it. It is necessary to reasonably layout the read / write antenna and tag antenna to avoid electromagnetic interference inside the cabinet. Summary of the invention

[0008] In view of the above problems, the purpose of the present invention is to provide a method for arranging an RFID system in a hazardous chemicals intelligent storage cabinet based on a statistical analysis method. At the same time, no human on-duty is required. You only need to enter a password to open the cabinet door. After each door is closed, it will automatically query what items are left in the cabinet and report them to the system. When we go to the system to check the access records in the cabinet, we can know what items have been taken out in a certain period of time and whether the items have been returned afterwards. The technical solution is as follows:

[0009] A method for arranging an RFID system in a hazardous chemicals intelligent storage cabinet based on a statistical analysis method comprises the following steps:

[0010] Step 1: According to the size parameters and cabinet materials of the hazardous chemicals intelligent storage cabinet, a simulation model of the hazardous chemicals intelligent storage cabinet is established in the electromagnetic simulation software;

[0011] Step 2: Establish a simulation model of a read-write antenna inside the simulation model of the hazardous chemicals intelligent storage cabinet;

[0012] Step 3: Calculate the electromagnetic field distribution inside the hazardous chemicals storage cabinet containing a single read / write antenna;

[0013] Step 4: Calculate the corresponding electric field modulus when the read / write antenna is installed at different positions in the cabinet based on the statistical analysis method The probability density function of

[0014] Step 5: Set the electric field modulus The probability density function of is compared with the energy activation threshold of the tag antenna chip;

[0015] Step 6: Obtain the best installation position of the read / write antenna in the storage cabinet and determine the optimal RFID system layout plan in the storage cabinet

[0016] Furthermore, when establishing the simulation model of the read-write antenna in step 2, the installation position of the tag antenna is selected to be attached to the side wall of the hazardous chemicals container, and the installation position of the read-write antenna is selected to be the other three side cabinet surfaces excluding the side where the cabinet door is located.

[0017] Furthermore, the step 4 is specifically as follows:

[0018] Step 4.1: Perform equal-interval sampling in three directions along the rectangular coordinate system inside the storage cabinet with a step length of one-tenth of the wavelength corresponding to the operating frequency of the RFID system to obtain the electric field modulus values ​​at all sampling points inside the storage cabinet.

[0019] Step 4.2: Calculate the electric field modulus in the storage cabinet according to the following formula: The probability density function of is:

[0020]

[0021] Among them, N is the number of samples, h is the window width, and X i is the electric field modulus at each sampling point, K() is the kernel function; x is the electric field modulus corresponding to the probability density function to be calculated.

[0022] Furthermore, when multiple read-write antennas are installed in the storage cabinet, the influence of the relative position between the read-write antennas on the electromagnetic field distribution characteristics in the storage cabinet is considered. In step 3, the electromagnetic field distribution in the hazardous chemical storage cabinet containing multiple read-write antennas needs to be calculated; before determining the optimal RFID system layout plan in the storage cabinet in step 6, determine the number and position of the installed read-write antennas.

[0023] Furthermore, in the step 1, when establishing the simulation model of the intelligent storage cabinet for hazardous chemicals, the physical properties of the hazardous chemicals themselves and the containers in which they are stored, as well as the electromagnetic properties of the hazardous chemicals are considered;

[0024] In step 3, the electric field distribution in the storage cabinet containing the hazardous chemicals and the read / write antenna is calculated;

[0025] In step 5, the electric field modulus The probability density function is compared with the energy activation threshold of the tag antenna chip and the safety threshold of hazardous chemicals.

[0026] The beneficial effect of the present invention is that the present invention obtains the optimal layout of the RFID reading and writing antenna in the cabinet through the statistical analysis method, so that the wireless communication in the cabinet can be carried out normally.

[0027] When managing items by manual recording, it is easy to lose items due to human negligence, and errors are also easy to occur in the process of counting items. The present invention can automatically count the objects in the cabinet and can automatically record the use records of the items in the cabinet, which reduces costs and improves efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Flowchart of the RFID system layout plan for hazardous chemicals intelligent storage cabinets based on statistical analysis methods

[0029] Figure 2 This is the business process diagram of the smart storage cabinet. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. The present invention is based on a statistical analysis method to solve the problem of optimizing the layout of the RFID system in the hazardous chemicals intelligent storage cabinet. The specific solution flow chart is as follows: Figure 1 shown.

[0031] 1. Analysis of intelligent storage cabinets for hazardous chemicals:

[0032] According to the size parameters of the hazardous chemicals intelligent storage cabinet (including the length, width, height, cabinet thickness, etc.), as well as the cabinet material (usually metal aluminum plate), a simulation model of the same hazardous chemicals intelligent storage cabinet is established in the electromagnetic simulation software.

[0033] 2. Read-write antenna analysis:

[0034] When laying out the RFID system in the hazardous chemicals smart storage cabinet, you can usually select the read / write antenna according to the actual situation. In the process of optimizing the layout, it is necessary not only to consider the impact of the radiation characteristics of different read / write antennas on the electromagnetic environment in the hazardous chemicals smart storage cabinet, but also the number of read / write antennas and their installation positions in the cabinet are also very important. The present invention mainly considers the number of read / write antennas and the installation position in the cabinet, according to the electric field modulus value in the storage cabinet. The probability density function distribution of is used to analyze the optimization process of the RFID system layout in the intelligent storage cabinet for hazardous chemicals.

[0035] 3. Regarding the installation of a single read / write antenna in a hazardous chemicals smart storage cabinet:

[0036] After the establishment of the simulation model of the hazardous chemicals intelligent storage cabinet, a simulation model of the read-write antenna is established inside it. When selecting the installation position of the read-write antenna, on the one hand, considering that the tag antenna is usually attached to the side wall of the hazardous chemicals container, and on the other hand, considering the stability of the installation of the read-write antenna, the other three side cabinet surfaces excluding the side where the cabinet door is located are selected as the installation position of the read-write antenna.

[0037] After the storage cabinet model and the read / write antenna model are established, the electric field modulus of the internal area of ​​the storage cabinet at the working frequency of the RFID system (including the read / write antenna and the tag antenna) is obtained through simulation calculation. Get the electric field modulus value in the storage cabinet The probability density function distribution of is mainly divided into two steps:

[0038] Step 1): In the three directions of the rectangular coordinate system inside the storage cabinet, the electric field modulus values ​​at all sampling points inside the storage cabinet are obtained by sampling at equal intervals with a step length of one tenth of the wavelength corresponding to the operating frequency of the RFID system, i.e., λ / 10.

[0039] Step 2): Calculate the electric field modulus in the storage cabinet according to formula (1) The probability density function of

[0040]

[0041] Among them, N is the number of samples, h is the window width, and X i is the electric field modulus at each sampling point, and K() is the kernel function. Electric field modulus in the storage cabinet The probability density function is a quantitative description of the electric field distribution characteristics within it.

[0042] So far, the present invention has completed the internal electric field modulus value when a single read-write antenna is installed in the hazardous chemicals intelligent storage cabinet. Obtaining statistical features.

[0043] In an RFID system composed of passive tag antennas, the tag antenna needs to obtain energy from the electromagnetic field generated by the read / write antenna to activate the chip on the tag antenna. Different tag antenna chips have different energy activation thresholds, which can be found in their product manuals.

[0044] Because the read / write antennas installed at different positions have different electromagnetic field distribution characteristics in the storage cabinet when working, that is, the electric field modulus The probability density function is different, therefore, the electric field modulus value in the hazardous chemicals intelligent storage cabinet calculated based on the statistical analysis method is The probability density function of the tag is compared with the energy activation threshold of the tag antenna chip to obtain the best installation position of the read / write antenna in the storage cabinet, thereby realizing the optimal RFID system layout plan.

[0045] In summary, for this type of situation, the steps for optimizing the layout of the RFID system in the storage cabinet are as follows:

[0046] (1) Calculate the electromagnetic field distribution inside a hazardous chemicals storage cabinet containing a single read / write antenna;

[0047] (2) Calculate the corresponding electric field modulus when the read / write antenna is installed at different positions in the cabinet based on the statistical analysis method The probability density function of

[0048] (3) The electric field modulus The probability density function of is compared with the energy activation threshold of the tag antenna chip;

[0049] (4) Find the best installation location for the read / write antenna and determine the optimal RFID system layout in the storage cabinet.

[0050] 4. Regarding the installation of multiple read-write antennas in the intelligent storage cabinet for hazardous chemicals:

[0051] When only a single read / write antenna is installed in the storage cabinet, there may be blind spots in the recognition. When the recognition efficiency of the RFID system is low, two or more read / write antennas can be installed to achieve full coverage of the recognition area in the storage cabinet. In this case, it is necessary to consider not only the layout position of each read / write antenna, but also the influence of the relative position between the read / write antennas on the electromagnetic field distribution characteristics in the storage cabinet. For such situations, the steps for optimizing the layout of the RFID system in the storage cabinet are as follows:

[0052] (1) To calculate the electromagnetic field distribution in a hazardous chemical storage cabinet containing multiple read-write antennas, it is necessary to analyze the electromagnetic field distribution in the storage cabinet when the multiple read-write antennas have different relative positions;

[0053] (2) Calculate the electric field modulus in the storage cabinet based on statistical analysis methods The probability density function of

[0054] (3) The electric field modulus The probability density function of is compared with the energy activation threshold of the tag antenna chip;

[0055] (4) Determine the number and location of installed read / write antennas to achieve the optimal RFID system layout plan.

[0056] 5. Due to the toxic, corrosive, explosive, flammable and combustion-supporting properties of hazardous chemicals, especially their explosion, combustion and combustion-supporting properties, they are sensitive to the electromagnetic energy level in the storage cabinet. At the same time, hazardous chemicals will also affect the distribution characteristics of the electromagnetic field in the storage cabinet. Therefore, when it is necessary to specially consider the requirements for explosion, combustion and combustion-supporting conditions when storing hazardous chemicals, the steps for optimizing the layout of the RFID system are as follows:

[0057] (1) To establish a simulation model of a storage cabinet containing hazardous chemicals and read / write antennas, it is necessary to consider the physical properties of the hazardous chemicals themselves and the containers in which they are stored, such as volume, solubility, state, etc.; as well as the electromagnetic properties of the hazardous chemicals, such as dielectric constant, conductivity, loss, etc.;

[0058] (2) Calculate the electric field distribution inside the storage cabinet containing hazardous chemicals and the read / write antenna;

[0059] (3) Calculate the electric field modulus in the storage cabinet based on statistical analysis methods The probability density function of

[0060] (4) The electric field modulus The probability density function of is compared with the energy activation threshold of the tag antenna chip and the safety threshold of hazardous chemicals;

[0061] (5) Determine the optimal RFID system layout plan.

[0062] In terms of smart storage, each hazardous chemical bottle in the hazardous chemical smart storage cabinet will be affixed with an RFID tag antenna. When the staff wants to know what items are in the cabinet, they can open the control software on the control end of the cabinet and enter the authorization code. After the authorization code is correct, the information of the items in the cabinet will be displayed. When it is necessary to take the hazardous chemicals in the cabinet, the staff needs to open the control software on the control end, choose to apply for door opening, and enter the password in the control software. After the password is correct, the cabinet door will automatically open, and then the staff can take the required items. After taking out the items and closing the door, the system will automatically trigger the query task of the RFID tag antenna in the cabinet. After the query, the system will report all the queried tag information and record it. If the cabinet door is not closed for a long time, the system will automatically alarm.

[0063] According to the optimized layout scheme based on the statistical analysis method proposed by the present invention, the RFID system including the read-write antenna and the tag antenna can work efficiently in the closed metal cabinet where hazardous chemicals are stored. By combining RFID technology with the Internet of Things technology, the intelligent storage cabinet can realize automatic inventory of hazardous chemicals in the cabinet, improve the safety of the hazardous chemicals storage process, and improve management efficiency. Combined with the Internet of Things technology, the intelligent management of the RFID system is realized, and the operation process is simple.

Claims

1. A method for arranging RFID systems in intelligent storage cabinets for hazardous chemicals based on statistical analysis methods, characterized in that: The following steps are involved: Step 1: According to the size parameters and cabinet materials of the hazardous chemicals intelligent storage cabinet, a simulation model of the hazardous chemicals intelligent storage cabinet is established in the electromagnetic simulation software; Step 2: Establish a simulation model of a read-write antenna inside the simulation model of the hazardous chemicals intelligent storage cabinet; Step 3: Calculate the electromagnetic field distribution inside the hazardous chemicals storage cabinet containing a single read / write antenna; Step 4: Calculate the corresponding electric field modulus when the read / write antenna is installed at different positions in the cabinet based on the statistical analysis method The probability density function of Step 5: Set the electric field modulus The probability density function of is compared with the energy activation threshold of the tag antenna chip; Step 6: Obtain the optimal installation position of the read / write antenna in the storage cabinet and determine the optimal RFID system layout plan in the storage cabinet.

2. The method for arranging RFID systems in intelligent storage cabinets for hazardous chemicals based on statistical analysis methods according to claim 1 is characterized in that: When establishing the simulation model of the read-write antenna in step 2, the installation position of the tag antenna is selected to be attached to the side wall of the hazardous chemicals container, and the installation position of the read-write antenna is selected to be the other three side cabinet surfaces excluding the side where the cabinet door is located.

3. The method for arranging RFID systems in hazardous chemicals intelligent storage cabinets based on statistical analysis methods according to claim 1 is characterized in that: The step 4 is specifically as follows: Step 4.1: Perform equal-interval sampling in three directions along the rectangular coordinate system inside the storage cabinet with a step length of one-tenth of the wavelength corresponding to the operating frequency of the RFID system to obtain the electric field modulus values ​​at all sampling points inside the storage cabinet. Step 4.2: Calculate the electric field modulus in the storage cabinet according to the following formula: The probability density function of is: Among them, N is the number of samples, h is the window width, X i is the electric field modulus at each sampling point, K() is the kernel function; x is the electric field modulus corresponding to the probability density function to be calculated.

4. The method for arranging RFID systems in hazardous chemicals intelligent storage cabinets based on statistical analysis methods according to claim 1 is characterized in that: When multiple read-write antennas are installed in the storage cabinet, the influence of the relative position between the read-write antennas on the electromagnetic field distribution characteristics in the storage cabinet is considered. In step 3, the electromagnetic field distribution in the hazardous chemical storage cabinet containing multiple read-write antennas needs to be calculated; before determining the optimal RFID system layout plan in the storage cabinet in step 6, determine the number and position of the installed read-write antennas.

5. The method for arranging RFID systems in hazardous chemicals intelligent storage cabinets based on statistical analysis methods according to claim 1 is characterized in that: In step 1, when establishing the simulation model of the intelligent storage cabinet for hazardous chemicals, the physical properties of the hazardous chemicals themselves and the containers in which they are stored, as well as the electromagnetic properties of the hazardous chemicals are considered; In step 3, the electric field distribution in the storage cabinet containing the hazardous chemicals and the read / write antenna is calculated; In step 5, the electric field modulus The probability density function is compared with the energy activation threshold of the tag antenna chip and the safety threshold of hazardous chemicals.

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