A method for optimizing RFID coverage capacity

Abstract

The application discloses an RFID coverage capacity optimization method, comprising the following steps: step 1, constructing a theoretical model of the coverage capacity of an RFID system, and performing actual scene measurement calibration to form a coverage capacity calculation scheme facing the actual scene; step 2, constructing an RFID system optimization deployment scheme; step 3, implementing system deployment according to the optimization deployment scheme, and designing experimental verification deployment effect according to the coverage capacity calculated according to the actual scene. The application determines the maximum number of tags that can be effectively covered by a single RFID reader by calculating the coverage capacity, and optimizes the system deployment according to the same, so that the scheme can not only significantly improve the tag coverage capacity of the RFID reader, but also ensure efficient and stable reading performance, and has good compatibility, is compatible with the existing standard, and can be directly applied to a commercial RFID system.

Description

Technical Field

[0001] This invention belongs to the field of RFID system deployment, and specifically relates to a method for optimizing RFID coverage capacity. Background Technology

[0002] Radio Frequency Identification (RFID), as a key sensing technology in the Internet of Things (IoT), is an important carrier for realizing the "Internet of Everything" and has been widely used in retail, logistics, healthcare, security, and other fields. With the continuous maturation of RFID technology and the deepening of industry applications, the demand for large-scale RFID system deployment is increasing daily. Against this backdrop, accurately measuring the maximum number of tags that a single reader can effectively cover (i.e., "coverage capacity") has become a critical issue in ensuring system stability and efficiency. On the one hand, it helps maximize the utilization of reader resources, reduce hardware costs and power consumption, and improve the system's economy and operational efficiency. On the other hand, clearly defining the coverage capacity helps improve the scalability of the RFID system, ensuring stable operation even as business scale and the number of tags increase. Furthermore, a system deployment scheme based on coverage capacity can ensure that every tag within the system is within the effective reading range, reducing the risk of missed reads and improving system reliability.

[0003] Existing RFID system deployment schemes have the following limitations in terms of coverage capacity assessment and optimized deployment: 1) Lack of coverage capacity assessment methods – There is currently a lack of research on reader coverage capacity assessment, which limits the utilization rate of readers and affects system scalability; 2) Local parameter tuning – Most existing schemes focus on optimizing antenna positions and parameter tuning, ignoring the synergistic effect of various system components in overall deployment (such as tag deployment, distance between tags and readers, etc.); 3) Stringent deployment conditions – Existing deployment guidelines rely on precise calibration between multiple antennas, which is difficult to implement in engineering, lacks scalability and adaptability, and restricts its large-scale application. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for optimizing RFID coverage capacity in order to address the shortcomings of the existing technology.

[0005] To address the aforementioned technical problems, this invention discloses a method for optimizing RFID coverage capacity, comprising the following steps:

[0006] Step 1: Construct a theoretical model of the coverage capacity of the RFID system and perform actual measurement and calibration in real-world scenarios to form a coverage capacity calculation scheme for real-world scenarios;

[0007] Step 2: Construct an optimized deployment plan for the RFID system;

[0008] Step 3: Implement system deployment according to the optimized deployment plan, and design experiments to verify the deployment effect based on the coverage capacity calculated according to the actual scenario.

[0009] 2. The method for optimizing RFID coverage capacity according to claim 1, wherein in step 1, the RFID system includes a reader, an antenna, and a tag;

[0010] The theoretical model for the coverage capacity of the RFID system is as follows:

[0011]

[0012] in, Indicates the reader's transmission power. This represents the minimum power threshold required for tag activation. This indicates the tag's power transmission efficiency.

[0013] The specific steps for performing on-site calibration in real-world scenarios to develop a coverage capacity calculation scheme tailored to real-world applications are as follows:

[0014] Step 1-1 addresses the difficulty in obtaining tag transmission efficiency in real-world scenarios. Measure a single label at a reference distance Cutoff power at This is the minimum transmission power required for the reader to activate the tag;

[0015] Steps 1-2: Considering that actual deployment environments are mostly two-dimensional planes, the main lobe width of the antenna at a distance is calculated using the radiation pattern of the antenna connected to the reader. The projected area of ​​the plane is ;

[0016] Steps 1-3: Calculate the effective aperture area of ​​the label. :

[0017]

[0018] in, For tag antenna gain, The wavelength of the electromagnetic waves emitted by the reader;

[0019] Steps 1-4, actual coverage capacity for:

[0020] .

[0021] Step 1-1 specifically involves: adjusting the reader's transmission power. Set the value to the maximum value, start the reader, and gradually reduce the reader's transmission power in steps until the tag stops responding. Record the transmission power at this point as the cutoff power.

[0022] Step 2 describes the construction of an optimized RFID system deployment scheme, which includes:

[0023] Step 2-1: Based on the shadow effect caused by occlusion between tags and in combination with the feasibility of actual deployment, clarify the tag layout strategy of single-layer and uniform deployment;

[0024] Step 2-2: Based on the physical size of the tags and their electromagnetic coupling characteristics, analyze the adverse effects of excessively small tag spacing on reading, and thus determine the minimum spacing for tag deployment.

[0025] Steps 2-3: Based on the theoretical modeling of the effective aperture of the tag, understand the actual absorption process of electromagnetic waves by the tag and determine the maximum spacing for tag deployment;

[0026] Step 2-4, combining steps 2-1 to 2-3, establishes a functional relationship between the deployment distance between the RFID reader and the tag and the tag deployment spacing, forming a coverage capacity-oriented optimized deployment scheme.

[0027] The minimum spacing for tag deployment described in step 2-2 should meet the following requirements:

[0028] ,

[0029] The physical dimensions of the label are: , , These refer to the horizontal and vertical spacing between labels, where the spacing is the distance between the geometric centers of adjacent labels. A minimum threshold for tag spacing is introduced to suppress interference caused by coupling effects.

[0030] Deployment distances mentioned in steps 2-4 The functional relationship between the tag deployment spacing and the tag spacing is as follows:

[0031]

[0032] The effective pore area of ​​the label is modeled as follows: Upper bound of tag deployment distance .

[0033] The maximum spacing of the tags deployed in steps 2-3 satisfies:

[0034] ,

[0035] The upper bound of the tag deployment distance for:

[0036]

[0037] in, For reference distance The cutoff power at that point.

[0038] The method for designing experiments to verify the deployment effect described in step 3 includes:

[0039] Step 3-1: Inventory the deployed tags and evaluate the reading performance of the RFID system by comparing the actual number of tags read with the coverage capacity.

[0040] Step 3-2: In the experiment, multiple scenarios with different label spacings are pre-set, and reading tests are conducted under the conditions of satisfying the optimized deployment scheme and deviating from the optimized deployment scheme.

[0041] Step 3-3: Analyze the reading performance in each scenario in Step 3-2. If the system is deployed according to the optimization deployment plan in Step 2, the reading performance evaluation of the system described in Step 3-1 is optimal, then the accuracy and effectiveness of the proposed plan can be verified.

[0042] Beneficial effects:

[0043] This invention calculates the coverage capacity to determine the maximum number of tags that a single RFID reader can effectively cover, and optimizes system deployment accordingly. This solution not only significantly improves the tag coverage capability of RFID readers, but also ensures efficient and stable reading performance, and has good compatibility with existing standards, making it directly applicable to commercial RFID systems. Attached Figure Description

[0044] Figure 1 A flowchart of an RFID coverage capacity optimization method provided by the present invention.

[0045] Figure 2 The flowchart shows the coverage capacity calculation scheme for real-world scenarios provided by this invention.

[0046] Figure 3 The present invention provides a flowchart for constructing an optimized deployment scheme for an RFID system.

[0047] Figure 4 A flowchart illustrating the method for designing experiments to verify the deployment effect provided by this invention.

[0048] Figure 5 This is a schematic diagram of the RFID tag deployment method provided by the present invention.

[0049] Figure 6This is a schematic diagram of the effective aperture model of the RFID tag provided by the present invention.

[0050] Figure 7 This diagram illustrates the verification results of the optimized deployment scheme with different label spacings provided by this invention.

[0051] Figure 8 This is a schematic diagram illustrating the verification results of the correspondence between tag spacing and deployment distance provided by the present invention. Detailed Implementation

[0052] In real-world warehousing scenarios, shelves are typically piled high with a large number of items awaiting management, each tagged with an RFID tag. To achieve efficient inventory checks, a large number of tags need to be read at once within a designated area. However, traditional, experience-based deployments often fail to fully utilize the coverage capacity of RFID readers, resulting in low resource utilization. Furthermore, when tag distribution is unreasonable or deployment distances are improperly set, some tags may fail to read, impacting overall inventory efficiency and system stability. To address these issues, this invention proposes an optimization method for RFID coverage capacity. This method determines the maximum number of tags a single reader can cover in a given scenario through a coverage capacity calculation scheme, and uses the optimized deployment scheme to guide system deployment, thereby achieving efficient and stable tag reading within the coverage capacity to meet inventory targets. This method has significant practical value and application prospects.

[0053] This invention proposes a method for optimizing RFID coverage capacity, such as... Figure 1 As shown, the method includes:

[0054] Step 1: Construct a theoretical model of the coverage capacity of the RFID system and perform actual measurement and calibration in real-world scenarios to form a coverage capacity calculation scheme for real-world scenarios;

[0055] Step 2: Construct an optimized deployment plan for the RFID system;

[0056] Step 3: Implement system deployment according to the optimized deployment plan, and design experiments to verify the deployment effect based on the coverage capacity calculated according to the actual scenario.

[0057] This invention proposes a method for optimizing RFID coverage capacity. The basic idea is to calculate the coverage capacity to determine the maximum number of tags that a single RFID reader can effectively cover, and then combine theoretical analysis with experimental verification to optimize system deployment. This invention constructs a systematic deployment guideline to ensure the economy, reliability, and scalability of the RFID system.

[0058] This method first performs step 1 to construct a theoretical model of the coverage capacity of the RFID system, and then, in combination with actual hardware conditions, performs actual measurement and calibration of key parameters to form a coverage capacity calculation scheme for actual scenarios.

[0059] like Figure 2 As shown, the coverage capacity calculation scheme for real-world scenarios in step 1 includes:

[0060] Step 1-1 addresses the difficulty in obtaining tag transmission efficiency in real-world scenarios. Measure a single label at a reference distance Cutoff power at This is the minimum transmission power required for the reader to activate the tag;

[0061] Steps 1-2: Considering that actual deployment environments are mostly two-dimensional planes, the main lobe width of the antenna at a distance is calculated using the radiation pattern of the antenna connected to the reader. The projected area of ​​the plane is ;

[0062] Steps 1-3: Calculate the effective aperture area of ​​the label. :

[0063]

[0064] in, For tag antenna gain, The wavelength of the electromagnetic waves emitted by the reader;

[0065] Steps 1-4, actual coverage capacity for:

[0066] .

[0067] For example, we can choose an Impinj R420 reader, a Laird S9028PCL antenna, and an Alien 9640 tag. First, we construct a theoretical model of the coverage capacity of the RFID system, assuming the reader's transmission power is... The power received by the tag is This received power is used for both tag power supply and backscatter communication. For successful tag activation, Must be greater than or equal to ,in The power transmission efficiency of the tag. This represents the minimum power threshold required for tag activation. Based on the principle of energy conservation, this represents the coverage capacity of an RFID system. It can be represented as This indicates that under ideal conditions, a single reader can activate at most [number missing]. A tag.

[0068] However, in practical applications, the power transmission efficiency of tags... This data is typically difficult to obtain, and considering that deployment environments are mostly two-dimensional planes, it is necessary to re-estimate the coverage capacity under actual deployment conditions through actual measurement and calibration of key parameters. Therefore, step 1-1 is performed first. In the experiment, an Alien 9640 tag is deployed 1 meter directly in front of the reader antenna. m, to ensure the tag is in the maximum gain region of the antenna main lobe. Next, the reader's transmit power... Set to maximum value The reader is started at dBm, and its transmit power is gradually reduced in steps of 0.25 dBm until the tag stops responding. The transmit power at this point is recorded as the cutoff power. The measured value is [value missing]. dBm.

[0069] After obtaining the tag's cutoff power at the reference distance, the next step is to perform steps 1-2 to calculate the projected area of ​​the antenna's main lobe width. For the Laird S9028PCL antenna, according to the manufacturer's parameter table, the horizontal and vertical beam angles of the antenna's main lobe are both 70 degrees, i.e. Considering that the projection of the antenna main lobe width onto the plane can be approximated as an ellipse, the major and minor axes of the ellipse are respectively... and Therefore, in The projected area of ​​the antenna main lobe width at point m is: m 2 .

[0070] Then, steps 1-3 are performed. Since the Alien 9640 tag uses a typical half-wave dipole antenna with an operating frequency of approximately 920MHz, its effective aperture... cm 2 ,in, dBi is the gain of the dipole antenna. m is the wavelength.

[0071] Through steps 1-1 to 1-3, the actual coverage capacity can be further calculated. In steps 1-4, the antenna's transmit power was set to 30 dBm, while the Alien 9640 tag's cutoff power at 1 meter was measured to be 12.5 dBm. Based on the conversion formula between dBm and watts (W)... The transmit power can be calculated to be 1W, and the cutoff power (the minimum transmit power required for the reader to activate the tag) is approximately 17.8mW. Then, substituting the actual parameters, the formula is applied... Therefore, the coverage capacity under this hardware configuration can be calculated to be approximately 1900.

[0072] Calculate actual coverage capacity The physical meaning of the formula is as follows: When measuring the cutoff power of a single RFID tag, the tag faces the antenna directly, in the direction of the antenna's maximum radiation gain, at which point the received signal is strongest. However, within the projection area of ​​the antenna's main lobe beam angle, the electromagnetic energy distribution is not uniform, exhibiting the highest energy density at the center of the ellipse and gradually attenuating towards the edges. According to the definition of beam angle, the power density at the beam edge is half that at the center. Therefore, when calculating coverage capacity, the power density at the edge is selected as a reference, i.e. While this approach sacrifices some energy in the central area, it greatly simplifies system deployment while ensuring reliable reading, making it highly practical in real-world scenarios. Meanwhile, in the absence of interference from other tags, the effective energy-receiving area of ​​a single RFID tag is equal to its effective aperture. Therefore, when calculating coverage capacity, it is necessary to consider the projected area of ​​the antenna main lobe width and the effective receiving area of ​​a single tag. The ratio is reflected as This item. Taking all the above factors into account, the final coverage capacity calculation formula... Taking into full account the spatial coverage characteristics of the antenna and the energy absorption characteristics of the tag, this allows for the maximum number of tags that a single RFID reader can cover.

[0073] like Figure 3 As shown, step 2, constructing an optimized deployment scheme for an RFID system, includes:

[0074] Step 2-1: Based on the shadow effect caused by occlusion between tags and in combination with the feasibility of actual deployment, clarify the tag layout strategy of single-layer and uniform deployment;

[0075] Step 2-2: Based on the physical size of the tags and their electromagnetic coupling characteristics, analyze the adverse effects of excessively small tag spacing on reading, and thus determine the minimum spacing for tag deployment.

[0076] Steps 2-3: Based on the theoretical modeling of the effective aperture of the tag, understand the actual absorption process of electromagnetic waves by the tag and determine the maximum spacing for tag deployment;

[0077] Step 2-4, combining steps 2-1 to 2-3, establishes a functional relationship between the deployment distance between the RFID reader and the tag and the tag deployment spacing, forming a coverage capacity-oriented optimized deployment scheme.

[0078] To develop an optimized RFID system deployment plan, the key lies in two core dimensions: the deployment distance between the RFID reader and the tag, and the deployment spacing between tags. If the distance between the reader and the tag is too close, the projected area of ​​the antenna main lobe beam angle on the target plane is too small, limiting the number of tags that can be deployed in that area and making it difficult to meet the coverage capacity requirements. Conversely, if the distance between the reader and the tag is too far, the tag may not be able to acquire enough energy for activation, thus affecting reading performance. Without loss of generality, let's assume the tag deployment method is as follows... Figure 5 As shown, the physical size of the label is... The horizontal and vertical spacing between labels are respectively , This spacing represents the distance between the geometric centers of adjacent labels.

[0079] Step 2-1 first determined the strategy of single-layer, uniform tag deployment. When tags are deployed in multiple stacked layers, tags in different layers will create a shadowing effect due to mutual occlusion, interfering with signal propagation and hindering normal reading. Therefore, a single-layer deployment strategy is necessary. Secondly, in calculating coverage capacity... Since the energy non-uniformity within the main lobe beam angle projection area has been fully considered, and the edge power density is used as the calculation benchmark, tags can be uniformly deployed within the projection area during actual deployment. This maximizes overall readout efficiency and ensures that each tag receives sufficient energy for activation. Furthermore, the uniform deployment strategy also depends on the energy competition mechanism generated when tags are densely deployed. In high-density situations, although the effective apertures of multiple tags may overlap, the uniform arrangement of tags throughout the area reasonably assumes that each tag faces a similar level of energy competition, thus ensuring that each tag can be stably activated.

[0080] Step 2-2 determines the minimum spacing for tag deployment based on the physical dimensions of the tags and their electromagnetic coupling characteristics. First, to avoid shading effects caused by tag occlusion, basic constraints must be met, namely… , Secondly, if the tags are arranged closely according to their physical dimensions, it will lead to a strong coupling effect between them. According to Faraday's law of electromagnetic induction, when there is an alternating current in the RFID tag loop, a time-varying magnetic field will be generated. This magnetic field will induce a current in neighboring tags, thereby causing signal interference or missed reads. The intensity of this induced current decreases rapidly as the tag spacing increases, and becomes negligible after exceeding a certain threshold. Therefore, to suppress the interference caused by the coupling effect, another minimum threshold for tag spacing should be introduced. This ensures that coupling between tags is reduced to a negligible level. In summary, the minimum spacing for tag deployment should satisfy:

[0081] , .

[0082] Steps 2-3, based on theoretical modeling of the effective aperture of the tag, determine the maximum spacing for tag deployment. For example... Figure 6 As shown, the effective aperture of the label This represents the area that effectively receives energy; by definition, this area can typically be modeled as... This physical characteristic implicitly determines the upper bound of the tag deployment spacing, namely:

[0083] , .

[0084] Once the tag spacing exceeds this threshold, further increasing the spacing will not benefit the tag's energy absorption; instead, it will waste some of the energy emitted by the reader.

[0085] Steps 2-4 require establishing a functional relationship between the deployment distance between the reader and the tag and the tag deployment spacing to form a coverage capacity-oriented optimized deployment scheme. Intuitively, when the deployment distance between the reader and the tag is short, the projected area of ​​the reader antenna is small, and the electromagnetic energy density per unit area is high, thus enabling denser tag deployment. Conversely, as the distance between the reader and the tag gradually increases, the projected area increases but the energy density decreases; therefore, tag deployment should be more sparse to avoid insufficient energy for activation. This is based on the Friis transmission equation. It can be seen that the strength of the signal received by the RFID tag Deployment distance It is inversely proportional to the square of, that is When the label is known to be at the reference distance The cutoff power at that point is To ensure that the tag can still obtain activation energy at the edge of the antenna main lobe projection, a compensation factor is still introduced. Then the upper bound of the deployment distance can be given by the formula Confirmed. At this point, the tag spacing should reach its maximum value, consistent with the effective aperture model. Otherwise, energy competition between tags will lead to missed reads in this critical state, affecting system performance. If the deployment distance decreases, the tag spacing... , Adjustments should also be made proportionally to maintain a reasonable energy distribution, the corresponding relationship of which can be described by the following formula:

[0086] ,

[0087] in , Should meet:

[0088] , .

[0089] when , When taking the minimum value, the lower bound of the deployment distance can be further derived. Ultimately, this deployment scheme characterizes the two-way correspondence between the deployment distance between the reader and the tag and the tag deployment spacing, ensuring the system can operate at any deployment distance. At all times, it can maintain stable read performance and coverage capability.

[0090] For example, an Impinj R420 reader, a Laird S9028PCL antenna, and an Alien 9640 tag were selected for the experiment, and a single-layer, uniform deployment strategy was determined according to step 2-1. Subsequently, the minimum spacing needs to be determined based on the tag's physical size and the electromagnetic coupling characteristics between tags, where the physical size of the Alien 9640 tag is... To determine the minimum spacing threshold introduced for the coupling effect, In the experiment, two Alien 9640 tags were placed 1.5 meters away from the reader antenna, with an initial horizontal spacing between the two tags. The vertical spacing is 0.5 cm. It can be considered as infinity. Then it is gradually increased in increments of 0.5 cm. The difference in cutoff power between the two tags was observed. The reason for focusing on this difference is that when the tag spacing is small, the coupling effect between adjacent tags is significant, generating additional induced current in the antenna loop, causing a shift in their cutoff power. As the tag spacing increases, the coupling effect gradually weakens, and the difference in cutoff power between the two tags decreases. Experimental results show that when... At that time, the cutoff power of the two tags was almost identical. Furthermore, actual measurements showed that when the vertical spacing... When the distance is cm, the vertical coupling effect is negligible. In summary, let... , and thus , .

[0091] Next, the effective aperture of the Alien 9640 tag needs to be determined. Modeling is performed to determine the maximum spacing, which is known through formula calculation. To more intuitively describe the geometric distribution of this area, a feasible modeling approach is to model this aperture as a square with sides of 15cm, that is, let... cm, therefore, the upper limit for the label deployment spacing is: .

[0092] Increase the reader's transmission power It is 30dBm, and at the reference distance The cutoff power was measured at time m. dBm, substitute these parameter values ​​into the formula From this, we can obtain m. Therefore, at any deployment distance Below, there is a corresponding relationship:

[0093] (m),

[0094] in:

[0095] , .

[0096] Will , Substituting into the above formula, we can obtain the minimum deployment distance. Therefore, under the current configuration, the deployment distance must meet the following requirements:

[0097] ,

[0098] That is, for any deployment distance Within this range, as long as an appropriate tag spacing is selected, the system can maintain stable reading performance. Similarly, for any suitable tag spacing... , (in , Alternatively, the optimal deployment distance can be derived through corresponding calculations.

[0099] Step 3 will involve deploying the system according to the optimization plan and designing experiments to verify the deployment effect.

[0100] like Figure 4 As shown, the method for designing experiments to verify the deployment effect in step 3 includes:

[0101] Step 3-1: Use the C1G2 protocol to inventory the deployed tags and evaluate the reading performance of the RFID system by comparing the actual number of tags read with the coverage capacity.

[0102] Step 3-2: In the experiment, multiple scenarios with different label spacings are pre-set, and reading tests are conducted under the conditions of satisfying the optimized deployment scheme and deviating from the optimized deployment scheme.

[0103] Step 3-3: Analyze the reading performance in each scenario in Step 3-2. If the system is deployed according to the optimization deployment plan in Step 2, the reading performance evaluation of the system described in Step 3-1 is optimal, then the accuracy and effectiveness of the proposed plan can be verified.

[0104] Taking the previous hardware configuration as an example, the theoretical coverage capacity Furthermore, the relationship between deployment distance and tag spacing is known. First, step 3-1 is performed to inventory the deployed tags using the C1G2 protocol. Considering the large coverage capacity of a single reader, directly deploying all tags is very complex. To address this issue, a more operational strategy was adopted in the experiment. Specifically, a scaling factor was selected in the experiment. In the projected area Deployment within sub-regions The number of labels will be reduced proportionally to the experimental scale. Assume the number of labels successfully read in this region is... The system's read performance can be assessed by the ratio. An evaluation was conducted. This strategy ensured the feasibility of the experiment while avoiding biases caused by scaling down the experimental scale.

[0105] When performing step 3-2, the experiment is conducted according to... Figure 5 The method shown deploys five different label spacings, namely... , , , and Based on model calculations, the optimal deployment distances for each spacing type are 1.1m, 1.9m, 2.5m, 3.5m, and 7m, respectively. Each experiment was conducted at the corresponding deployment distance, and the results are as follows: Figure 7 As shown. Subsequently, to further verify the effectiveness of the proposed optimized deployment scheme, three label spacings were selected for the experiment: (Dense) (Medium) and (Sparse), and based on its optimal deployment distance, different offsets were applied with a step size of 0.5m, and the reading effect was repeatedly tested. The relevant results are as follows: Figure 8 As shown.

[0106] Finally, the accuracy and effectiveness of the proposed solution are verified according to step 3-3. Figure 7 As can be seen, with the 1.1m and 7m configurations, the deployment distances are below or exceed the recommended range, respectively. This results in a read count far lower than the coverage capacity; conversely, within the recommended deployment range (i.e., 1.9m, 2.5m, and 3.5m), the actual read count can reach over 90% of the coverage capacity, with the remaining approximately 10% of tag read misses primarily due to signal blind spots caused by factors such as multipath effects. Furthermore, Figure 8 The display shows that system read performance significantly degrades when the actual deployment distance deviates from the optimal value. For example, when the offset is... At a distance of 0.5m, the actual coverage capability of the model decreased by 25.4%. In summary, the experimental results fully verify the feasibility and accuracy of the proposed RFID system optimization deployment scheme, demonstrating that under reasonable deployment conditions, this scheme can effectively optimize the reader's coverage capability and ensure the stable and efficient operation of the system.

[0107] This invention provides a method for optimizing RFID coverage capacity. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A method for optimizing RFID coverage capacity, characterized in that, Includes the following steps: Step 1: Construct a theoretical model of the coverage capacity of the RFID system and perform actual measurement and calibration in real-world scenarios to form a coverage capacity calculation scheme for real-world scenarios; Step 2: Construct an optimized deployment plan for the RFID system; Step 3: Implement system deployment according to the optimized deployment plan, and design experiments to verify the deployment effect based on the coverage capacity calculated according to the actual scenario; Step 2 describes the construction of an optimized RFID system deployment scheme, which includes: Step 2-1: Define the label layout strategy for single-layer, uniform deployment; Step 2-2: Based on the physical size of the tags and their electromagnetic coupling characteristics, analyze the adverse effects of excessively small tag spacing on reading, and thus determine the minimum spacing for tag deployment. Steps 2-3: Based on the theoretical modeling of the effective aperture of the tag, understand the actual absorption process of electromagnetic waves by the tag and determine the maximum spacing for tag deployment; Step 2-4, combining steps 2-1 to 2-3, establishes a functional relationship between the deployment distance between the RFID reader and the tag and the tag deployment spacing, forming a coverage capacity-oriented optimized deployment scheme; Deployment distances mentioned in steps 2-4 The functional relationship between the tag deployment spacing and the tag spacing is as follows: The effective pore area of ​​the label is modeled as follows: , Modeling the effective pore size of the label The long and short sides, and the upper bound of the label deployment distance. , For reader transmission power, reference distance This is the distance that ensures the tag is within the maximum gain region of the antenna's main lobe, and the tag is at the reference distance. Cutoff power at The minimum transmission power required for the reader to activate the tag. , These are the horizontal and vertical spacing between labels, where the spacing is the distance between the geometric centers of adjacent labels.

2. The method for optimizing RFID coverage capacity according to claim 1, characterized in that, In step 1, the RFID system includes a reader, an antenna, and tags; The theoretical model for the coverage capacity of the RFID system is as follows: in, Indicates the reader's transmission power. This represents the minimum power threshold required for tag activation. This indicates the tag's power transmission efficiency.

3. The method for optimizing RFID coverage capacity according to claim 2, characterized in that, The specific steps for performing on-site calibration in real-world scenarios to develop a coverage capacity calculation scheme tailored to real-world applications are as follows: Step 1-1, Measure the distance of a single tag to the reference distance. Cutoff power at ; Steps 1-2: Using the radiation pattern of the antenna connected to the reader, calculate the main lobe width of the antenna at a distance... The projected area of ​​the plane is ; Steps 1-3: Calculate the effective aperture area of ​​the label. : in, For tag antenna gain, The wavelength of the electromagnetic waves emitted by the reader; Steps 1-4, actual coverage capacity for: 。 4. The method for optimizing RFID coverage capacity according to claim 3, characterized in that, Step 1-1 specifically involves: adjusting the reader's transmission power. Set the value to the maximum value, start the reader, and gradually reduce the reader's transmission power in steps until the tag stops responding. Record the transmission power at this point as the cutoff power.

5. The method for optimizing RFID coverage capacity according to claim 4, characterized in that, The minimum spacing for tag deployment described in step 2-2 should meet the following requirements: ， The physical dimensions of the label are: , and These are the long and short sides of the label, respectively. A minimum threshold for tag spacing is introduced to suppress interference caused by coupling effects.

6. The method for optimizing RFID coverage capacity according to claim 5, characterized in that, The maximum spacing of the tags deployed in steps 2-3 satisfies: ， 。 7. The method for optimizing RFID coverage capacity according to claim 1, characterized in that, The method for designing experiments to verify the deployment effect described in step 3 includes: Step 3-1: Inventory the deployed tags and evaluate the reading performance of the RFID system by comparing the actual number of tags read with the coverage capacity. Step 3-2: In the experiment, multiple scenarios with different label spacings are set up in advance, and reading tests are carried out under the conditions of satisfying the optimized deployment scheme and deviating from the optimized deployment scheme. Step 3-3: Analyze the reading performance in each scenario in Step 3-2. If the system is deployed according to the optimization deployment plan in Step 2, the reading performance evaluation of the system described in Step 3-1 is optimal, then the accuracy and effectiveness of the proposed plan can be verified.

Images