UHF RFID robot real-time state evaluation method based on dynamic scene and related system

Abstract

The invention belongs to the technical field of RFID robots, and discloses a UHF RFID robot real-time state evaluation method based on a dynamic scene and a related system, and the method comprises the steps: building an MAC layer system state evaluation model and a physical layer link quality evaluation model through the performance indexes of an MAC layer and a physical layer; and integrating the MAC layer system state and the physical layer link quality evaluation to construct a UHF RFID robot system real-time state evaluation model, and obtaining the RFID system real-time state grade. According to the method, the state of the UHF RFID robot can be monitored in real time by acquiring the multiple characteristic values and the time slot information in the unit time, and problems can be found in time and adjusted. By evaluating the performance indexes of the MAC layer and the physical layer at the same time, comprehensive system state evaluation is provided, and the working state of the whole RFID system can be reflected more accurately.

Description

Technical Field

[0001] The invention belongs to the technical field of RFID robots, and in particular relates to a real-time state evaluation method of a UHF RFID robot based on dynamic scenes and a related system. Background Art

[0002] The real-time status assessment of UHF RFID robot based on dynamic scene is to use the reader-writer carried by RFID robot to transmit electromagnetic signal to activate electronic tag in mobile scene, collect the multi-feature value returned to the reader-writer by the activated electronic tag in unit time and the time slot information in unit time obtained by the spectrum analyzer, analyze the system status in depth from MAC layer (Media Access Control Layer) and physical layer, and build MAC layer system status assessment model and physical layer link quality assessment model. Combining the evaluation results of the above two models, a real-time status assessment method and system of UHF RFID robot based on dynamic scene are proposed.

[0003] In recent years, the application and deployment of RFID is no longer limited to fixed static positions. Tags can be placed on mobile devices such as conveyor belts and assembly lines, and readers can be mounted on mobile devices such as robots, drones, and AGVs, forming a mobile RFID reading system based on dynamic scenes. Because the reader and the tag are in relative motion in dynamic scenes, mobility can lead to problems such as reduced system recognition rate and tag misses, which reduces the reading performance of the RFID mobile system. By deeply analyzing the system status from the MAC layer and the physical layer, the system status of RFID in dynamic scenes can be observed in real time, and targeted adaptive adjustment strategies for the RFID system can be proposed.

[0004] In the prior art, the invention patent application "A UHF RFID tag performance grading evaluation method and evaluation system" (application number: 202111223856.1) evaluates the performance of radio frequency identification tags from four aspects: static performance, environmental adaptability, sensitivity degradation, and multi-tag performance. It only evaluates the performance of tags in static scenes, lacks the evaluation of the overall reading status of the RFID system, and this method cannot be applied in dynamic scenes. The invention patent application "A self-test method for the transceiver link based on a UHF frequency band passive RFID reader" (application number: 201610950974.5) realizes the evaluation of the connectivity of the reader's transmission link and receiving link and the functionality of the reader by analyzing and processing the signals of the RF transmission link and receiving link in the claims. It only uses the physical characteristics of the reader in the RFID system hardware device for system evaluation, does not use the signal characteristic value returned by the tag backscattering, and lacks the evaluation of the overall reading status of the RFID system. The invention patent application "A wireless communication system and method between direct devices" (application number: 202410417410.X) uses the electromagnetic interference level in the area where the RFID reader is located, the signal attenuation between the reader and the tag, and the stability information of the activated tag in the claims to evaluate the RFID wireless communication system and achieve comprehensive monitoring and early warning of wireless communication. It requires the use of professional electromagnetic field strength measuring instruments to measure the electromagnetic field strength in the area where the RFID reader is located, which increases the complexity and cost of the system; and different application scenarios require re-measurement of the electromagnetic field strength, resulting in poor adaptability to the application scenarios; the electromagnetic impact threshold is set by the technicians themselves, which will affect the reliability of the system evaluation results.

[0005] The invention patent application "A Performance Evaluation Method for RFID Reader Anti-collision Protocol" (application number: 201910757057.9) studies the anti-collision protocol of the MAC layer in the claims, and performs performance evaluation on a variety of RFID reader anti-collision protocols based on graph theory principles and RFID system characteristics. It only evaluates the performance of the anti-collision protocol of the MAC layer in the RFID system, without considering the performance indicators of the physical layer. The evaluation method is relatively simple, and it is impossible to evaluate the status of the RFID system in real time.

[0006] In conclusion, many existing methods are limited to evaluation in static scenarios, lack the evaluation of RFID system performance in dynamic application scenarios (such as reader movement, tag movement or environmental changes), and are difficult to adapt to the complex and changing environment in actual applications. Some technologies only evaluate the performance of a certain layer (such as the physical layer or MAC layer), ignoring other important layers (such as the backscatter signal characteristics of the RFID tag or the performance of the physical layer), resulting in a single evaluation method. Summary of the invention

[0007] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a UHF RFID robot real-time status evaluation method based on dynamic scenes and a related system.

[0008] In order to achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a UHF RFID robot real-time state assessment method based on a dynamic scene, comprising the following steps: In dynamic scenarios, the fixed-frequency electromagnetic waves emitted and received by the UHF RFID robot are obtained, and the multi-feature values ​​of the returned RFID tag per unit time are obtained; According to the fixed frequency electromagnetic waves transmitted and received by the UHF RFID robot, the time slot information of the RFID tag in a unit time is obtained, and the MAC layer performance index is calculated according to the time slot information of the RFID tag in a unit time; Calculate the physical layer performance index according to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time; According to the MAC layer performance indicators and physical layer performance indicators, the system status of the MAC layer and the link quality of the physical layer are evaluated per unit time; According to the system status of the MAC layer and the link quality of the physical layer at all times, the real-time status of the UHFRFID robot based on dynamic scenarios is evaluated.

[0009] A further improvement of the present invention is that, in a dynamic scenario, a specific method for obtaining fixed-frequency electromagnetic waves emitted and received by a UHF RFID robot and obtaining multiple characteristic values ​​of the returned RFID tag per unit time is as follows: The reader / writer mounted on the UHF RFID robot sends electromagnetic waves to the tag at a fixed frequency through a single antenna. After the tag receives the fixed-frequency electromagnetic waves, it uses the reader / writer to obtain multiple feature values ​​of the tag per unit time based on the relative distance and relative angle between the tag and the reader / writer antenna and the physical characteristics of the tag itself.

[0010] A further improvement of the present invention is that the specific method for calculating the MAC layer performance index according to the RFID tag time slot information within a unit time is as follows: Use a spectrum analyzer to capture the transmission waveform between the reader and the tag, analyze the transmission waveform according to the command interaction process between the reader and the tag, determine the type of time slot in each frame per unit time, and obtain the number and duration of successful time slots, collision time slots, and idle time slots; According to the type of time slots in each frame within a unit time and the number and duration of successful time slots, collision time slots, and idle time slots, the time efficiency, recognition efficiency, and throughput are calculated as MAC layer performance indicators.

[0011] A further improvement of the present invention is that the time efficiency is the statistical average of the ratio of the time occupied by the successful time slots in each frame to the total time within a unit time; The recognition efficiency is the total number of tags successfully recognized by the reader per unit time; Throughput is the ratio of the number of successful time slots to the total number of time slots per unit time.

[0012] A further improvement of the present invention is that, according to the returned multiple characteristic values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time, a specific method for calculating the physical layer performance index is as follows: According to the returned multi-feature values ​​of the RFID tag per unit time, the number of inventory counts and the tag recognition rate per unit time are calculated; According to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time, the mean signal strength value within a unit time, the link quality fluctuation indication and the bit error rate are calculated; The obtained inventory count times per unit time, tag recognition rate, signal strength mean, link quality fluctuation indication and bit error rate are used as physical layer performance indicators.

[0013] A further improvement of the present invention is that, according to the MAC layer performance index and the physical layer performance index, a specific method for evaluating the system status of the MAC layer and the link quality of the physical layer within a unit time is as follows: The MAC layer performance index is assigned a weight value, and the MAC layer system status score per unit time is calculated using the approximate ideal solution sorting method as the MAC layer system status; The data set composed of physical layer performance indicators is subjected to data dimension reduction and clustering to obtain the physical layer link quality classification result per unit time.

[0014] A further improvement of the present invention is that, according to the system status of the MAC layer and the link quality of the physical layer at all times, a specific method for evaluating the real-time status of a UHF RFID robot based on a dynamic scene is as follows: The proximity analysis method is used to map the link quality of the physical layer to the link quality score of the physical layer; The physical layer link quality score is combined with the MAC layer system status to evaluate the real-time status of the UHF RFID robot system and obtain the grading result of the real-time status of the UHF RFID robot system.

[0015] In a second aspect, the present invention provides a UHF RFID robot real-time status assessment system based on dynamic scenes, comprising: The multi-feature value acquisition module is used to acquire the fixed-frequency electromagnetic waves emitted and received by the UHF RFID robot and obtain the multi-feature values ​​of the RFID tag returned per unit time; The MAC layer performance index acquisition module is used to obtain the RFID tag time slot information within a unit time according to the fixed frequency electromagnetic waves transmitted and received by the UHF RFID robot, and calculate the MAC layer performance index according to the RFID tag time slot information within a unit time; A physical layer performance index acquisition module is used to calculate the physical layer performance index according to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time; A state quality evaluation module, used to evaluate the system state of the MAC layer and the link quality of the physical layer within a unit time according to the MAC layer performance index and the physical layer performance index; The real-time status evaluation module is used to evaluate the level of the real-time status of the UHF RFID robot based on dynamic scenarios according to the system status of the MAC layer and the link quality of the physical layer at all times.

[0016] In a third aspect, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of a real-time status assessment method of a UHF RFID robot based on dynamic scenarios when executing the computer program.

[0017] In a fourth aspect, the present invention provides a storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of a real-time status assessment method of a UHF RFID robot based on a dynamic scene are implemented.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses MAC layer and physical layer performance indicators to construct a MAC layer system state evaluation model and a physical layer link quality evaluation model, and comprehensively constructs a UHF RFID robot system real-time state evaluation model based on the MAC layer system state and physical layer link quality evaluation to obtain the real-time state level of the RFID robot system. The present invention can monitor the state of the UHF RFID robot in real time by acquiring multiple characteristic values ​​and time slot information within a unit time, and timely discover problems and make adjustments. By simultaneously evaluating the performance indicators of the MAC layer and the physical layer, a comprehensive system state evaluation is provided, which can more accurately reflect the working state of the entire RFID system, and focuses on performance evaluation in dynamic scenarios, which can adapt to reader movement, tag movement and environmental changes, and improve the application flexibility of the system. The present invention uses multiple characteristic values ​​of RFID tags for analysis, which can deeply understand the performance of tags under different conditions, thereby optimizing system performance. By evaluating the link quality of the physical layer, the present invention can effectively identify problems such as signal attenuation and interference, and ensure the reliability of data transmission. This method can be adjusted and expanded according to different application requirements and environments, and has good flexibility and adaptability. In summary, this method not only improves the real-time and accuracy of the state assessment of the UHFRFID robot, but also enhances its applicability in dynamic environments, providing a good foundation for the further development of related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of the present invention; Figure 2 is a system diagram of the present invention; Figure 3 A schematic diagram of the command interaction process between the reader and the tag provided in the embodiment; Figure 4A graph showing the relationship between the received signal strength and the relative distance between the tag and the antenna provided in the embodiment; Figure 5 A graph showing the relationship between received signal strength and the relative angle between the tag and the antenna provided in the embodiment; Figure 6 A schematic diagram of the relative angle between the tag and the antenna provided in the embodiment; Figure 7 A schematic diagram of a real-time status assessment scenario of a UHF RFID robot system provided in an embodiment; Figure 8 A schematic diagram of a MAC layer system status evaluation result provided in an embodiment; Fig. 9 A schematic diagram of a physical layer link quality assessment result provided by an embodiment; Fig.10 A schematic diagram of real-time status classification of a UHF RFID robot system provided in an embodiment; Fig.11 A schematic diagram of the real-time status evaluation results of the UHF RFID robot system provided in the embodiment; Fig.12 A system diagram is provided in real time. DETAILED DESCRIPTION

[0020] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0021] See also Figure 1 ,The real-time state evaluation method of UHF RFID robot based on dynamic scenes includes the following steps: S101, in a dynamic scene, using a reader / writer mounted on a UHF RFID robot to transmit fixed-frequency electromagnetic waves to the tag, and obtaining multiple characteristic values ​​of the returned RFID tag per unit time.

[0022] S102, using a spectrum analyzer to obtain RFID tag time slot information within a unit time, and calculating a MAC layer performance indicator according to the RFID tag time slot information within the unit time.

[0023] S103, calculating a physical layer performance index according to the returned multiple feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time.

[0024] S104, evaluating the system status of the MAC layer and the link quality of the physical layer within a unit time according to the MAC layer performance index and the physical layer performance index.

[0025] S105, evaluating the real-time status of the UHF RFID robot based on the dynamic scene according to the system status of the MAC layer and the link quality of the physical layer at all times.

[0026] See also Figure 2 , a UHF RFID robot real-time status assessment system based on dynamic scenes, which includes: The multi-feature value acquisition module is used to obtain the multi-feature values ​​of the RFID tag returned per unit time based on the tag return signal received by the single antenna of the reader in a dynamic scene.

[0027] The MAC layer performance index acquisition module is used to obtain the RFID tag time slot information within a unit time by using a spectrum analyzer, and calculate the MAC layer performance index according to the RFID tag time slot information within a unit time.

[0028] The physical layer performance index acquisition module is used to calculate the physical layer performance index according to the returned multiple feature values ​​of the RFID tag within a unit time and the RFID tag time slot information within a unit time.

[0029] The state quality evaluation module is used to evaluate the system state of the MAC layer and the link quality of the physical layer within a unit time according to the MAC layer performance index and the physical layer performance index.

[0030] The real-time status evaluation module is used to evaluate the level of the real-time status of the UHF RFID robot based on dynamic scenarios according to the system status of the MAC layer and the link quality of the physical layer at all times.

[0031] Embodiment 1: This embodiment further defines step S101. In a dynamic scenario, a reader / writer mounted on a UHF RFID robot transmits fixed-frequency electromagnetic waves to a tag, and a specific method for obtaining multiple characteristic values ​​of the returned RFID tag per unit time is as follows: S1011, the reader / writer mounted on the UHF RFID robot sends electromagnetic waves to the tag at a fixed frequency through a single antenna; S1012, after the tag receives the fixed frequency electromagnetic wave emitted by the reader, the tag uses the reader to obtain multiple feature values ​​of the tag per unit time according to the relative distance and relative angle between the tag and the reader antenna and the physical characteristics of the tag itself.

[0032] The movement of the RFID robot equipped with a reader and a single antenna causes the relative distance and angle between the tag and the reader antenna to change, causing the tag to reflect different eigenvalue characteristics, and the reader obtains multiple eigenvalues ​​of the tag per unit time.

[0033] Embodiment 2: This embodiment further limits step S102, and uses a spectrum analyzer to obtain the RFID tag time slot information within a unit time. The specific method for calculating the MAC layer performance index according to the RFID tag time slot information within a unit time is as follows: S1021, using a spectrum analyzer to capture the transmission waveform of the transmission waveform between the reader and the tag, analyzing the command interaction process between the reader and the tag, determining the type of time slots in each frame within a unit time, and the number and duration of successful time slots, collision time slots, and idle time slots; S1022, according to the type of time slots in each frame within a unit time and the number and duration of successful time slots, collision time slots, and idle time slots, time efficiency, recognition efficiency, and throughput are calculated as MAC layer performance indicators.

[0034] Assumptions , and Respectively represent i frame The number of idle slots, successful slots and collision slots in , and Respectively represent i frame The duration of idle slots, successful slots and collision slots, k Indicates the number of frames per unit time.

[0035] Time efficiency is the statistical average of the ratio of the time occupied by successful time slots in each frame to the total time per unit time, and its formula is:

[0036] in, Indicates that The time efficiency in the frame is:

[0037] The recognition efficiency is the total number of tags successfully recognized by the reader per unit time, and its formula is:

[0038] Throughput is the ratio of the number of successful time slots to the total number of time slots per unit time, and its formula is: .

[0039] Embodiment 3: This embodiment further defines step S103. The specific method for calculating the physical layer performance index according to the returned multiple feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time is as follows: S1031, by counting the number of tags that return characteristic value information obtained by the reader within a unit time, the number of inventory counts and the tag recognition rate within a unit time are calculated. The tag recognition rate is defined as the ratio of the number of tags successfully recognized by the reader within a unit time to the total number of tags within the recognition range of the reader.

[0040] S1032, according to the returned multi-feature values ​​of the RFID tag in the unit time and the RFID tag time slot information in the unit time, the mean signal strength, link quality fluctuation indication and bit error rate in the unit time are calculated; the mean signal strength is the average value of the tag signal strength in the unit time; LQVI is the weighted value of the variance, skewness and kurtosis of the tag signal strength in the unit time. Among them, the weights of the variance, skewness and kurtosis of the signal strength are calculated by the entropy weight method; the bit error rate is the ratio of the number of error time slots in the unit time to the total number of time slots, among which, the reader is considered to have successfully read after sending the ACK command and then the QueryRepeat command, otherwise the time slot is an error time slot.

[0041] S1033, taking the obtained number of inventory counts per unit time, tag recognition rate, signal strength average, link quality fluctuation indication and bit error rate as physical layer performance indicators.

[0042] Embodiment 4: This embodiment further defines step S104. The specific method for evaluating the system status of the MAC layer and the link quality of the physical layer within a unit time according to the MAC layer performance index and the physical layer performance index is as follows: S1041, using a combined weighting method to assign weight values ​​to the time efficiency, recognition efficiency and throughput in the MAC layer performance indicators, and using the approximate ideal solution sorting method to calculate the MAC layer system status score per unit time as the MAC layer system status; wherein, using the analytic hierarchy process (AHP) and the entropy weight method (EW) to assign weights to the time efficiency, recognition efficiency and throughput, and using the Kendall's W and the critical weighting method (CRITIC) to combine the two weights, and using the TOPSIS method to calculate the MAC layer system status score per unit time.

[0043] S1042, perform data dimension reduction and clustering on the data set consisting of the number of inventory counts, label recognition rate, signal strength mean, LQVI and bit error rate in the physical layer performance indicators to obtain the physical layer link quality grading result per unit time. The unified manifold approximation and projection method (UMAP) is used to perform data dimension reduction on the data set consisting of the number of inventory counts, label recognition rate, signal strength mean, LQVI and bit error rate, and the K-means clustering algorithm (K-Means) is used to cluster the first three principal components obtained by the dimension reduction to obtain the physical layer link quality grading result per unit time.

[0044] Embodiment 5: This embodiment further defines step S105. The specific method for evaluating the real-time status of the UHF RFID robot based on the dynamic scene according to the system status of the MAC layer and the link quality of the physical layer at all times is as follows: S1051, using proximity analysis method to map the link quality of the physical layer to the physical layer link quality score; wherein, using the K-Means clustering algorithm to obtain the range of each performance indicator at each link quality level, and combining the mapping relationship between the link level and the score, using the proximity analysis method to accurately map the physical layer link quality level to the physical layer link quality score.

[0045] S1052, combining the physical layer link quality score with the MAC layer system status, using a classification algorithm to evaluate the real-time status of the UHF RFID robot system, and obtaining a grading result of the real-time status of the UHF RFID robot system. Among them, the MAC layer system status score and the physical layer link quality score are comprehensively utilized, and the classification and regression tree (CART) is used to evaluate the real-time status of the UHF RFID robot system to obtain a grading result of the real-time status of the UHF RFID robot system.

[0046] Embodiment 6: The reader / writer mounted on the UHF RFID robot of the present invention transmits fixed frequency electromagnetic waves to the tag through a single antenna, and uses the reader / writer and the spectrum analyzer to obtain the tag's multiple characteristic values ​​and time slot information respectively. For example, assuming that the reader / writer frequency is The reader receives multiple characteristic values ​​of the tag, including signal strength per unit time, inventory times and number of identified tags. The spectrum analyzer obtains the tag time slot information, including the time slot type per unit time and the number and duration of successful time slots, collision time slots and idle time slots.

[0047] According to step S102, the MAC layer performance index is calculated. Exemplarily, the command interaction process between the reader and the tag is as follows: Figure 3 As shown. It can be seen that the interactive commands between the reader and the tag are different in different types of time slots. The time slot type is analyzed and determined, and the number and duration of successful time slots, collision time slots, and idle time slots in each frame per unit time are counted. Among them, there is a tag response in the successful time slot and the EPC information is successfully transmitted, there are multiple tags responding in the collision time slot, and there is no tag response in the idle time slot. The MAC layer performance indicators are calculated using the time slot information. The MAC layer performance indicators include time efficiency, recognition efficiency, and throughput.

[0048] For example, assuming , and Respectively represent i frame The number of idle slots, successful slots and collision slots in , and Respectively represent i frame The duration of idle slots, successful slots and collision slots, k Indicates the number of frames per unit time.

[0049] Time efficiency It is defined as the statistical average of the ratio of the time occupied by the successful time slots in each frame to the total time per unit time. The calculation formula is:

[0050] in, Indicates that The time efficiency in the frame is calculated as:

[0051] Recognition efficiency It is defined as the total number of tags successfully identified by the reader per unit time, and its calculation formula is:

[0052] Throughput It is defined as the ratio of the number of successful time slots to the total number of time slots per unit time. The calculation formula is:

[0053] In summary, the MAC layer performance index is calculated based on the label time slot information.

[0054] According to step S103, the physical layer performance index is calculated. For example, the relationship between the signal strength and the relative distance between the tag and the antenna is as follows: Figure 4 As shown, the relationship between signal strength and the relative angle between the tag and the antenna is as follows Figure 5 As shown, the relative angle diagram between the tag and the antenna is as follows Figure 6 As shown in the figure, it can be seen that the signal strength value changes as the relative distance and relative angle between the tag and the antenna change.

[0055] For example, Figure 7 The figure shows a schematic diagram of the real-time status assessment scenario of the UHF RFID robot system. The labels are evenly distributed on a length of l , the number of layers is c , the floor height is h On the file rack, a robot equipped with a reader and a single antenna v (m / s) and move at a constant speed in front of the file rack. Use the reader to obtain the tMultiple tag feature values ​​within seconds including signal strength , Inventory times n , the number of tags successfully identified , use the spectrum analyzer to count the number of time slots with bit errors per unit time .

[0056] Tag recognition rate RoI It is defined as the ratio of the number of tags successfully identified by the reader per unit time to the total number of tags within the reader's identification range. The calculation formula is:

[0057] in, Indicates t The total number of tags within the reader's recognition range within one second is calculated as follows:

[0058] Signal strength mean It is defined as the average value of the tag signal strength per unit time, and its calculation formula is:

[0059] LQVI is defined as the weighted value of the variance, skewness, and kurtosis of the tag signal intensity per unit time, and its calculation formula is:

[0060] Among them, the variance , skewness Skewness and Kurtosis Kurtosis It is defined as the variance of the tag signal strength per unit time, the standard third-order central moment, and the standard fourth-order central moment. The calculation formula is:

[0061]

[0062]

[0063] The weights of the variance, kurtosis and skewness of the signal strength are calculated by the entropy weight method, and the weight distribution is shown in Table 1: Table 1 Weight distribution results

[0064] Bit Error Rate BER It is defined as the ratio of the number of error time slots to the total number of time slots per unit time. The calculation formula is:

[0065] Among them, the reader sends the ACK command and then sends QueryRepeatThe command is considered to be read successfully, otherwise the time slot is an error time slot.

[0066] In summary, the physical layer performance index is calculated based on the tag's multiple feature values ​​and time slot information.

[0067] According to the evaluation of the MAC layer system status and the physical layer link quality in step S104, exemplary, based on the MAC layer performance index obtained in step S102, the index weights are calculated using the AHP method and the EW method respectively, and the obtained weight distribution results are shown in Table 2: Table 2 Weight distribution results

[0068] The Kendall synergy coefficient is used to test the consistency of the indicator weights calculated by the AHP method and the EW method. If the test passes, it means that the weights calculated by the AHP method and the EW method are not much different, so the combined weights The calculation formula is:

[0069] in, The index weights calculated by AHP and EW methods.

[0070] If the test fails, it means that the weights calculated by the AHP method and the EW method are quite different. The CRITIC method is used to calculate the combined weight of the indicator weights calculated by the AHP method and the EW method. The calculation formula is:

[0071] in, , , Representation weight i With weight j The correlation coefficient between Representation weight j The standard deviation of .

[0072] In summary, the combined weight distribution results of AHP method and EW method are shown in Table 3: Table 3 Combination weight allocation results

[0073] Based on the combined weight , construct a weighted decision matrix ,in , To standardize the data, we can get the optimal solution matrix in the TOPSIS method. and the worst solution matrix They are:

[0074]

[0075] The comprehensive score of the evaluation object is calculated based on the best solution matrix and the worst solution matrix. The calculation formula is:

[0076] in, and Respectively represent i The evaluation object and the best solution matrix and i The distance between an evaluation object and the worst solution matrix is ​​calculated as follows:

[0077]

[0078] In summary, the combined weighting and TOPSIS method are used to evaluate the MAC layer system status. Figure 8 The figure shows the MAC layer system status evaluation results during the RFID robot's horizontal movement for 60 seconds.

[0079] Exemplarily, based on the physical layer performance indicators obtained in step S103, UMAP is used to perform data dimensionality reduction analysis to obtain three link characteristic parameters. The K-Means algorithm sets the number of clusters K=5 to cluster the link characteristic parameters, and uses the entropy weight method to calculate the weight of each indicator, and weighted sorts the clusters to divide the link quality into levels I~V, where level I is the best and level V is the worst. The weights of each indicator are shown in Table 4, and the clustering results are shown in Table 4. Fig. 9 As shown, the cluster average silhouette coefficient is 0.70184.

[0080] Table 4 Index weights

[0081] According to the comprehensive evaluation of the real-time status of the RFID robot system in step S105, the range of each performance indicator at each link quality level obtained based on the K-Means clustering algorithm is shown in Table 5, and the mapping relationship between the link level and the score is shown in Table 6.

[0082] Table 5 Link level and parameter range

[0083] Table 6 Relationship between link level and score

[0084] The proximity analysis method is used to accurately map the physical layer link quality level to the physical layer link quality score, and the calculation formula is:

[0085] C is the comprehensive closeness, and its calculation formula is: , n is the total number of indicators, is the minimum value of comprehensive closeness, usually 0. is the maximum value of the comprehensive closeness, usually 1. The current rating range.

[0086] Link quality i The closeness of the performance indicators is calculated as follows:

[0087] in, are performance indicators of link quality, including the number of inventory counts, tag recognition rate, signal strength mean, LQVI, and bit error rate. and The indicators are respectively j The lower and upper limits of the indicator range under the level.

[0088] Comprehensive MAC layer system status score and physical layer link quality score, based on Fig.10 The real-time status classification of the UHF RFID robot system uses the CART decision tree to evaluate the real-time status of the UHF RFID robot system. The evaluation results are as follows: Fig.11 The classification algorithm performance is shown in Table 7: Table 7 Classification algorithm evaluation

[0089] In summary, the real-time status of the UHF RFID robot system is comprehensively evaluated by combining the MAC layer system status and the physical layer link quality, and the classification results of the real-time status of the RFID system are obtained.

[0090] The present invention evaluates the real-time status of a UHF RFID robot system by utilizing multiple characteristic values ​​of a tag. First, a MAC layer performance index is calculated through the tag time slot information within a unit time obtained by a spectrum analyzer. Then, a physical layer performance index is calculated through multiple characteristic values ​​of the tag within a unit time obtained by a reader and the time slot information obtained by the spectrum analyzer. Next, an algorithm is designed based on the performance indicators of the MAC layer and the physical layer to respectively evaluate the MAC layer system status and the physical layer link quality. Finally, a classification algorithm is used to comprehensively utilize the MAC layer system status and the physical layer link quality to evaluate the real-time status of the UHF RFID robot system, and a classification result of the real-time status of the RFID system is obtained.

[0091] The present invention can enable the UHF RFID robot system to perform real-time evaluation on the overall reading status of the RFID system in a dynamic scenario. At the same time, in order to improve the accuracy of the system reading status evaluation, the present invention uses MAC layer performance indicators - recognition efficiency, time efficiency, throughput and physical layer performance indicators - signal strength mean, inventory count times, recognition rate, link quality fluctuation indication (LQVI), bit error rate, to construct a MAC layer system status evaluation model and a physical layer link quality evaluation model, further obtain the real-time status evaluation classification result of the UHF RFID robot system, and can also propose a targeted RFID system adaptive adjustment strategy.

[0092] Embodiment 7: See also Fig.12 As shown, the present invention also provides an electronic device 100 for a UHF RFID robot real-time status assessment method based on dynamic scenarios; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on the at least one processor 102, and at least one communication bus 104.

[0093] The memory 101 can be used to store the computer program 103, and the processor 102 implements the steps of the UHF RFID robot real-time state assessment method based on dynamic scenes described in Example 1 by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101. The memory 101 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data (such as audio data) created according to the use of the electronic device 100, etc. In addition, the memory 101 can include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0094] The at least one processor 102 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor, etc. The processor 102 is the control center of the electronic device 100, and uses various interfaces and lines to connect various parts of the entire electronic device 100.

[0095] The memory 101 in the electronic device 100 stores a plurality of instructions to implement a UHF RFID robot real-time status assessment method based on a dynamic scene, and the processor 102 can execute the plurality of instructions to implement: In dynamic scenarios, the reader / writer mounted on the UHF RFID robot transmits fixed-frequency electromagnetic waves to the tag to obtain the multiple characteristic values ​​of the RFID tag in the returned unit time; Use a spectrum analyzer to obtain the RFID tag time slot information within a unit time, and calculate the MAC layer performance index based on the RFID tag time slot information within a unit time; Calculate the physical layer performance index according to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time; According to the MAC layer performance indicators and physical layer performance indicators, the system status of the MAC layer and the link quality of the physical layer are evaluated per unit time; According to the system status of the MAC layer and the link quality of the physical layer at all times, the real-time status of the UHFRFID robot based on dynamic scenarios is evaluated.

[0096] Embodiment 8: If the module / unit integrated in the electronic device 100 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory and read-only memory (ROM, Read-Only Memory).

[0097] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0098] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0099] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A real-time status assessment method for UHF RFID robots based on dynamic scenarios, characterized in that: The following steps are involved: In dynamic scenarios, the fixed-frequency electromagnetic waves emitted and received by the UHF RFID robot are obtained, and the multi-feature values ​​of the returned RFID tag per unit time are obtained; According to the fixed frequency electromagnetic waves transmitted and received by the UHF RFID robot, the time slot information of the RFID tag in a unit time is obtained, and the MAC layer performance index is calculated according to the time slot information of the RFID tag in a unit time; Calculate the physical layer performance index according to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time; According to the MAC layer performance indicators and physical layer performance indicators, the system status of the MAC layer and the link quality of the physical layer are evaluated per unit time; According to the system status of the MAC layer and the link quality of the physical layer at all times, the real-time status of the UHFRFID robot based on dynamic scenarios is evaluated.

2. The UHF RFID robot real-time state assessment method based on dynamic scenes according to claim 1 is characterized in that: In a dynamic scenario, the specific method of obtaining the fixed frequency electromagnetic waves emitted and received by the UHF RFID robot and obtaining the multiple characteristic values ​​of the RFID tag returned per unit time is as follows: The reader / writer mounted on the UHF RFID robot sends electromagnetic waves to the tag at a fixed frequency through a single antenna. After the tag receives the fixed-frequency electromagnetic waves, it uses the reader / writer to obtain multiple feature values ​​of the tag per unit time based on the relative distance and relative angle between the tag and the reader / writer antenna and the physical characteristics of the tag itself.

3. The UHF RFID robot real-time status assessment method based on dynamic scenes according to claim 1 is characterized in that: The specific method for calculating the MAC layer performance index based on the RFID tag time slot information within a unit time is as follows: Use a spectrum analyzer to capture the transmission waveform between the reader and the tag, analyze the transmission waveform according to the command interaction process between the reader and the tag, determine the type of time slot in each frame per unit time, and obtain the number and duration of successful time slots, collision time slots, and idle time slots; According to the type of time slots in each frame within a unit time and the number and duration of successful time slots, collision time slots, and idle time slots, the time efficiency, recognition efficiency, and throughput are calculated as MAC layer performance indicators.

4. The method for real-time status assessment of a UHF RFID robot based on dynamic scenarios according to claim 1 is characterized in that: Time efficiency is the statistical average of the ratio of the time occupied by successful time slots in each frame to the total time per unit time; The recognition efficiency is the total number of tags successfully recognized by the reader per unit time; Throughput is the ratio of the number of successful time slots to the total number of time slots per unit time.

5. The method for real-time status assessment of a UHF RFID robot based on dynamic scenarios according to claim 1 is characterized in that: According to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time, the specific method for calculating the physical layer performance index is as follows: According to the returned multi-feature values ​​of the RFID tag per unit time, the number of inventory counts and the tag recognition rate per unit time are calculated; According to the returned multi-feature values ​​of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time, the mean signal strength value within a unit time, the link quality fluctuation indication and the bit error rate are calculated; The obtained inventory count times per unit time, tag recognition rate, signal strength mean, link quality fluctuation indication and bit error rate are used as physical layer performance indicators.

6. The method for real-time status assessment of a UHF RFID robot based on dynamic scenarios according to claim 1 is characterized in that: Based on the MAC layer performance indicators and the physical layer performance indicators, the specific method for evaluating the system status of the MAC layer and the link quality of the physical layer per unit time is as follows: The MAC layer performance index is assigned a weight value, and the MAC layer system status score per unit time is calculated using the approximate ideal solution sorting method as the MAC layer system status; The data set composed of physical layer performance indicators is subjected to data dimension reduction and clustering to obtain the physical layer link quality classification result per unit time.

7. The method for real-time status assessment of a UHF RFID robot based on dynamic scenarios according to claim 1 is characterized in that: According to the system status of the MAC layer and the link quality of the physical layer at all times, the specific method for evaluating the real-time status of the UHFRFID robot based on dynamic scenarios is as follows: The proximity analysis method is used to map the link quality of the physical layer to the link quality score of the physical layer; The physical layer link quality score is combined with the MAC layer system status to evaluate the real-time status of the UHF RFID robot system and obtain the grading result of the real-time status of the UHF RFID robot system.

8. UHF RFID robot real-time status assessment system based on dynamic scenes, characterized by: include: The multi-feature value acquisition module is used to acquire the fixed-frequency electromagnetic waves emitted and received by the UHF RFID robot and obtain the multi-feature values ​​of the RFID tag returned per unit time; The MAC layer performance index acquisition module is used to obtain the RFID tag time slot information within a unit time according to the fixed frequency electromagnetic waves transmitted and received by the UHF RFID robot, and calculate the MAC layer performance index according to the RFID tag time slot information within a unit time; A physical layer performance index acquisition module is used to calculate the physical layer performance index according to the returned multi-feature value of the RFID tag within a unit time and the time slot information of the RFID tag within a unit time; A state quality evaluation module, used to evaluate the system state of the MAC layer and the link quality of the physical layer within a unit time according to the MAC layer performance index and the physical layer performance index; The real-time status evaluation module is used to evaluate the real-time status of the UHF RFID robot based on dynamic scenarios according to the system status of the MAC layer and the link quality of the physical layer at all times.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the UHF RFID robot real-time state assessment method based on dynamic scenes described in any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the real-time state assessment method of a UHF RFID robot based on a dynamic scene according to any one of claims 1 to 7 are implemented.

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