An oil and gas maintenance site explosion-proof monitoring instrument full life cycle tracing method and system

Abstract

The application provides a kind of oil and gas maintenance site's explosion-proof monitor whole life cycle tracing method and system, including RFID reader passes through the analysis mixed baseband signal constellation chart distortion degree in collision time slot, according to the preset mapping relationship estimation collision label quantity;Combining the success and idle time slot number of MAC layer statistics, the total number of to be identified label is calculated, to set the frame length of next frame, and get collision density index by the ratio of collision time slot number and frame length;Based on the index, adjust the transmission power of reader;For each successfully identified explosion-proof monitor label, the label ID, maintenance record, time stamp, reader position and collision density index are encoded into data block, the current abstract is generated by hash operation combined with the hash value of the previous data block and stored, to build a complete whole life cycle tracing chain.

Description

Technical Field

[0001] This application belongs to the field of traceability, and in particular relates to a method and system for tracing the entire life cycle of an explosion-proof monitoring instrument at an oil and gas maintenance and emergency repair site. Background Technology

[0002] Radio Frequency Identification (RFID) technology is a non-contact identification technology. In practical applications, when multiple electronic tags respond simultaneously within the same time slot of a reader's command, the returned signals can overlap and interfere with each other, preventing the reader from successfully decoding the information of any single tag. The Dynamic Frame Slotted ALOHA algorithm based on Time Division Multiple Access (TDMA) disperses tag responses by adjusting the number of time slots in the communication frame. However, it typically only identifies time slot collisions but cannot determine the number of tags involved, impacting real-time identification. In terms of data management and traceability, RFID asset management systems usually record the collected tag IDs, time, and location information in a centralized database. Centralized data storage structures face the risks of single points of failure and malicious attacks, making it difficult to guarantee data integrity and security. There is a lack of an inherent, verifiable correlation mechanism between different operation records, making it difficult to form a full lifecycle traceability chain. The recorded information is also limited in scope, lacking information about the environmental conditions at the time of data collection, resulting in a lack of objective assessment of the situation during troubleshooting or process auditing. Therefore, how to design a technical solution that can both improve the identification efficiency in dense scenarios and ensure that the traceability data is tamper-proof is a problem that RFID technology urgently needs to solve in the field of critical equipment management. Summary of the Invention

[0003] This invention proposes a full lifecycle traceability method for explosion-proof monitoring instruments at oil and gas maintenance and repair sites, addressing the problems of low identification efficiency and inability to guarantee the immutability of traceability data in existing technologies in dense environments. The method includes:

[0004] Within a communication frame, the RFID reader analyzes the degree of in-phase orthogonal constellation diagram distortion of the mixed baseband signal in the identified collision time slot, and estimates the number of tags in the collision time slot based on the preset mapping relationship between the degree of constellation diagram distortion and the number of tags.

[0005] The number of successful time slots and idle time slots are obtained from the MAC layer statistics. Combined with the estimated number of tags from all collision time slots, the total number of tags to be identified is calculated, and the frame length of the next communication frame is set according to the total number. At the same time, the collision density index is calculated based on the ratio of the number of collision time slots to the current frame length, and the reader's transmission power is controlled based on the collision density index.

[0006] For each successfully identified explosion-proof monitoring device tag, the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and the collision density index are encoded into a data block. Through hash operation, the hash value of the current data block is combined with that of the previous data block to generate a summary of the current data block and store it, forming a full life cycle traceability chain for the explosion-proof monitoring device.

[0007] On another front, this invention provides a full lifecycle traceability system for explosion-proof monitoring instruments at oil and gas maintenance and repair sites, comprising the following modules:

[0008] The estimation module is used by the RFID reader to analyze the degree of in-phase orthogonal constellation diagram distortion of the mixed baseband signal in the identified collision time slot within a communication frame, and to estimate the number of tags in the collision time slot according to the preset mapping relationship between the degree of constellation diagram distortion and the number of tags.

[0009] The control module is used to obtain the number of successful time slots and the number of idle time slots counted by the MAC layer, combine the estimated number of tags with all collision time slots, calculate the total number of tags to be identified, and set the frame length of the next communication frame according to the total number; at the same time, it calculates the collision density index according to the ratio of the number of collision time slots to the current frame length, and controls the reader's transmission power based on the collision density index.

[0010] The generation module is used to encode the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index into a data block for each successfully identified explosion-proof monitoring device tag; through hash operation, the current data block is generated and stored by combining the hash value of the data block with the hash value of the previous data block, thus forming a full life cycle traceability chain for the explosion-proof monitoring device.

[0011] This invention estimates the number of tags within a collision time slot by analyzing constellation diagram distortion, enabling the calculation of the total number of tags to be identified and setting an appropriate communication frame length accordingly. This improves identification efficiency and system throughput in high-density tag environments. Simultaneously, it controls the reader's transmission power using a collision density index. When tags are densely packed and collisions are severe, it actively shrinks the identification range, reducing communication conflicts and interference between tags and ensuring identification stability at maintenance and repair sites. Furthermore, by encoding the collision density index as an environmental parameter into the traceability data block and constructing a traceability chain using hash operations, it not only ensures the integrity of the explosion-proof monitoring device's data throughout its entire lifecycle but also enhances the reliability of the entire traceability information. Attached Figure Description

[0012] Figure 1 A flowchart of the first embodiment;

[0013] Figure 2 This is a constellation diagram for single-tag signals;

[0014] Figure 3 A schematic diagram of communication frame time slot allocation and tag estimation;

[0015] Figure 4 This is a schematic diagram of power regulation decision based on collision density. Detailed Implementation

[0016] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0017] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0018] In the first embodiment, the present invention proposes a method for tracing the entire lifecycle of an explosion-proof monitoring instrument at an oil and gas maintenance and repair site, such as... Figure 1 ,include:

[0019] S1, Within a communication frame, the RFID reader analyzes the degree of in-phase orthogonal constellation diagram distortion of the mixed baseband signal in the identified collision time slot, and estimates the number of tags in the collision time slot based on the preset mapping relationship between the degree of constellation diagram distortion and the number of tags.

[0020] RFID tags are affixed to the explosion-proof monitoring device, optionally to the nameplate area of ​​the device. If the reader receives superimposed signals from multiple tags in a certain time slot, making decoding impossible, it is determined to be a collision time slot. The digital signal processor within the reader performs analog-to-digital conversion on the analog baseband signal of that time slot, obtaining two digital signal streams: in-phase I and quadrature Q. The I and Q data pairs are then plotted as coordinate points on a two-dimensional coordinate system to form a constellation diagram, such as... Figure 2 The process involves calculating the dispersion of all coordinate points relative to the origin of the constellation diagram, i.e., calculating the statistical variance. By consulting a pre-established table of variance and tag count (e.g., a variance of 0.1 corresponds to 2 tags, and a variance of 0.3 corresponds to 3 tags), the calculated variance value is mapped to an estimate of the number of tags present in the collision time slot. In the in-phase orthogonal constellation diagram, the horizontal axis represents the in-phase components, and the vertical axis represents the orthogonal components. The position of each sampling point in the diagram reflects the vector state of the signal at that moment. In ideal single-tag communication, sampling points cluster into several clear and fixed constellation points. By observing the positional shift, fuzzy diffusion, or shape distortion (aberration) of the sampling points caused by the superposition of multiple tag signal vectors, the degree of collision interference within the channel can be quantified, thereby inferring the number of concurrent tags.

[0021] In an optional embodiment, analyzing the degree of in-phase quadrature constellation diagram distortion of the mixed baseband signal within the collision time slot includes:

[0022] Calculate the N received baseband signal sampling points within the collision time slot. and the corresponding ideal constellation point The average Euclidean distance D between them is used as an indicator of the degree of distortion, and the calculation formula is as follows: .

[0023] Specifically, within the time slot where the collision occurs, the mixed baseband signal is sampled by the reader's analog-to-digital converter (ADC) to obtain a complex sequence of N in-phase quadrature components, for example, 128 points are collected, each point being represented as... Based on the modulation scheme used, such as quadrature phase shift keying (QPSK), determine the positions of the four standard constellation points in the ideal constellation diagram, for example, the normalized (1,0), (0,1), (-1,0), (0,-1). For each received sampling point... The nearest ideal constellation point is determined by the minimum distance decision principle. .

[0024] Calculate the Euclidean distance between each received sampling point and its corresponding ideal constellation point, representing the degree of signal offset. Preferably, the ideal constellation point is a reference constellation point after carrier synchronization and amplitude normalization. For example, if an ideal point is... The actual received point is Then the distance between them is The average Euclidean distance D is obtained by summing the distance values ​​calculated from all N sampling points within a time slot and dividing by the total number of sampling points N. For example, if N is 128, the resulting D is an indicator of the degree of constellation diagram distortion for that collision time slot.

[0025] In an optional embodiment, analyzing the distortion degree of the in-phase orthogonal constellation diagram of the mixed baseband signal within the collision time slot includes: the digital signal processor of the reader performing analog-to-digital conversion and orthogonal down-conversion on the mixed baseband signal within the collision time slot to obtain N complex sampling point sequences composed of in-phase component I and orthogonal component Q. ,in M standard ideal constellation points are determined based on the modulation scheme used in the communication protocol. For example, when using QPSK modulation, M=4; for each sampling point Calculate its distance to all standard ideal constellation points. The Euclidean distances between them are taken as the minimum value. Calculate the arithmetic mean of the minimum distances between all sampling points within the collision time slot to obtain an index of the degree of constellation diagram distortion. .

[0026] In an optional embodiment, estimating the number of tags within the collision time slot based on a preset mapping relationship between constellation diagram distortion and tag number includes:

[0027] The distortion level indicator is compared with multiple preset threshold intervals, and the corresponding number of tags is determined according to the interval in which it is located.

[0028] A mapping model is established through offline experiments or simulations, defining the correspondence between the constellation diagram distortion index and the number of collision labels. For example, a set of threshold intervals can be set, such as a distortion index between 0 and 0.15 corresponding to 2 labels, between 0.15 and 0.35 corresponding to 3 labels, between 0.35 and 0.6 corresponding to 4 labels, and greater than 0.6 corresponding to 5 or more labels. The thresholds and intervals are determined based on statistical analysis of distortion data under scenarios with a known number of label collisions.

[0029] In actual operation, the distortion index D calculated in the previous step, for example, D=0.28, is compared one by one with the preset threshold range. Since 0.28 falls within the range of 0.15 to 0.35, it is determined that the number of tags participating in the collision in the current collision time slot is 3. The segmented mapping method discretizes the continuous distortion index into specific tag count values, realizing a rapid estimation of the collision scale.

[0030] In another embodiment, the preamble of the communication frame is subjected to carrier frequency offset estimation and phase de-rotation processing, and the sampling points are multiplied by a correction complex exponential factor. This process eliminates random phase rotation caused by the channel, allowing constellation points to return to the standard I / Q axis. Density-based clustering methods, such as DBSCAN, are used to cluster the corrected N sampling points, identifying the number of effective high-density clusters K in the constellation diagram and the normalized variance within each cluster. Since the increased number of label signals causes the superimposed signal to tend towards a Gaussian distribution, the kurtosis approaches 0. The kurtosis of the signal amplitude is further calculated, and the extracted cluster number, intra-cluster variance, and signal kurtosis are combined to form a multi-dimensional feature vector. This vector is then input into a pre-trained K-nearest neighbor classifier or lookup table to obtain the estimated number of labels.

[0031] S2, obtain the number of successful time slots and idle time slots counted by the MAC layer, combine the estimated number of tags with all collision time slots, calculate the total number of tags to be identified, and set the frame length of the next communication frame according to the total number; at the same time, calculate the collision density index according to the ratio of the number of collision time slots to the current frame length, and control the reader's transmission power based on the collision density index.

[0032] After a communication frame with a frame length of 128 ends, the reader's MAC layer firmware records 50 successfully identified time slots and 60 idle time slots with no response received, resulting in 18 collision time slots. The physical layer estimates the total number of tags in these 18 collision time slots to be 40. Based on this, the total number of tags to be identified on-site is calculated to be the 50 successfully identified tags plus the 40 tags in the collision time slots, totaling 90. Figure 3 According to the dynamic frame length adjustment algorithm, the frame length of the next communication frame is set to 128; simultaneously, the current collision density index is calculated to be approximately 0.14. The total number of tags to be identified is an estimate of the number of tags that have not yet been successfully identified in the current communication cycle.

[0033] Set a congestion threshold of 0.25; compare the collision density index of 0.14 calculated in the previous step with 0.25; since 0.14 is lower than 0.25, it indicates that the tag density is not high. The reader controls the power amplifier of the radio frequency front end to increase the transmission power by one step, for example, from 28dBm to 29dBm, to try to identify tags at a greater distance; if the calculated collision density index is 0.3, which is higher than 0.25, it means that the tags are too densely packed, causing serious collisions. The reader then reduces the transmission power by one step, for example, from 28dBm to 27dBm, narrowing the energy field range and temporarily communicating only with nearby tags to reduce the number of tags responding at the same time.

[0034] In an optional embodiment, setting the frame length of the next communication frame based on the total number includes:

[0035] Frame length of the next communication frame ,in, This represents the total number of tags to be identified.

[0036] Specifically, the total number of tags to be identified is obtained by summarizing the tag number estimates for all time slots within the current communication frame. For example, a communication frame contains 64 time slots, of which 10 successful time slots are identified, each counted as 1 tag; and 3 collision time slots are analyzed, estimated to contain 3, 4, and 2 tags respectively, with the remainder being idle time slots. What is the total number of tags to be identified? That is, 19.

[0037] Get the total Then, the formula is used to determine the length of the next frame. Taking the above example as an example, =19. Calculate the logarithm of 19 to the base 2. Approximately 4.25. Rounding up gives 5. Calculating 2 to the power of 5, we get 32. Therefore, the frame length of the next communication frame is... Setting it to 32 provides sufficient communication time slots, optimizes recognition efficiency, and reduces the probability of collisions.

[0038] In an optional embodiment, controlling the reader's transmission power based on the collision density index includes:

[0039] Update the reader transmit power according to the following rules. :

[0040]

[0041] in, As a collision density index, To preset the congestion threshold, To preset the power adjustment step size, and These are the preset minimum and maximum transmit power.

[0042] Several control parameters are preset, such as congestion threshold. Setting it to 0.25 indicates that congestion is defined as the percentage of collision slots exceeding 25%; power adjustment step size. Set to 1dBm; minimum and maximum transmit power and The values ​​were set to 20dBm and 30dBm respectively. Simultaneously, a collision density index was calculated after each frame. That is, the number of collision time slots divided by the total number of frame time slots.

[0043] Assuming the current transmission power It is 25dBm, calculated as follows If the value is 0.5, network congestion is detected, and a power reduction operation is performed. The transmit power at the next moment is... It will be updated to 24dBm. Conversely, if the calculation yields... If the value is 0.2, which is less than 0.25, the network is considered idle, and a power increase operation is performed. The transmit power will be updated to 26dBm in the next moment. The power adjustment is always limited to... and This ensures operational stability and safety, such as... Figure 4 .

[0044] In order to naturally isolate remote interference with low power while maximizing coverage, in some embodiments, the reading cycle is divided into several power levels. After identifying the near-end tag in the low-power stage, an instruction is immediately sent to put the identified tag into a silent state, and the power is gradually increased to activate the remote or blocked weak signal tags.

[0045] S3, for each successfully identified explosion-proof monitoring device tag, the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and the collision density index are encoded into a data block; through hash operation, the hash value of the current data block is combined with the hash value of the previous data block to generate a summary of the current data block and store it, forming a full life cycle traceability chain for the explosion-proof monitoring device.

[0046] After successfully reading a tag, the EPC code is obtained as E20011223344556677889900; the maintenance personnel input the operation record as "replacing the sealing gasket" through the handheld terminal; the reader obtains the current time as 15:30:05 on October 26, 2023; the reader's built-in GPS module obtains the current geographical coordinates as 118.79 degrees east longitude and 32.04 degrees north latitude; the collision density index obtained from the MAC layer is 0.14; the five data items are concatenated into a string; the hash value of the previous record is retrieved from the database, for example, a 64-bit hexadecimal string starting with 5A; this hash value is appended to the end of the current data string; the SHA-256 hash algorithm is executed on the concatenated new string to generate a new 64-bit hexadecimal hash value; the data block containing the five original data items and the newly generated hash value are stored as a new record in the database, and this new hash value will be used for linking the next data block.

[0047] In an optional embodiment, encoding the tag ID, maintenance and repair operation record, timestamp, reader geographic location, and collision density index into a single data block includes:

[0048] The tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index are formatted according to a predetermined data structure to generate a unified data block.

[0049] The data structure template specifies the names, order, and data types of each field. For example, a data block structure can be defined as follows: the first field is the tag ID, a string type with a length of 24 bytes; the second field is the maintenance and repair operation record, a string type with a variable length; the third field is the timestamp, in ISO8601 format; the fourth field is the reader's geographical location, including latitude and longitude; and the fifth field is the collision density index, a floating-point number.

[0050] After a tag interaction is completed, all relevant information is collected. For example, if the tag ID is identified as E2001024880A0130154018C4, the operation record is "valve replacement," the timestamp is 20231027103000, the location is 30.5 degrees North latitude and 114.3 degrees East longitude, and the collision density at that time is 0.25, the data is filled and serialized according to a predetermined structure, for example, concatenated into a string separated by a specific delimiter such as a vertical bar: "E2001024880A0130154018C4|valve replacement|20231027103000|30.5,114.3|0.25", thus generating a regular and uniform data block.

[0051] In an optional embodiment, the step of generating and storing a digest of the current data block by combining the hash value of the current data block with that of the previous data block through hash operation, thus forming a full lifecycle traceability chain for the explosion-proof monitoring device, includes:

[0052] Through a preset hash function For the current data block The content is the same as the hash value of the previous data block. The concatenation of data is used to generate a summary of the current data block. The calculation formula is:

[0053]

[0054] Each generated data block is treated as a node, and each node contains the current data block and a hash value pointing to the previous node, thus linking all data blocks into a chain structure in chronological order;

[0055] For the first node, the hash value pointing to the previous node is the preset genesis hash value.

[0056] Pre-define a standard cryptographic hash function, such as the SHA-256 algorithm, which can map input data of arbitrary length to a fixed-length 256-bit hash value. Retrieve the current data block generated in the previous step. And the hash value of the previous data block stored in the system. .

[0057] Perform a concatenation operation to concatenate the current data block. The content is treated as a byte sequence, along with the previous hash value. The byte sequence is concatenated end-to-end to form a longer new byte sequence. For example, if It is the text "Data A". If the hash value is "abc", then the concatenation result is "data Aabc". The concatenated result is then fed into a preset SHA-256 hash function for calculation, and the output is the digest of the current data block. The new hash value It not only represents the content of the current data block, but also implies information about all historical data blocks.

[0058] Define an initial hash value, also known as the genesis hash value, such as a string consisting entirely of zeros, as the starting point of the chain. When the first dimensional repair operation operates on a data block... After generation, the data block is concatenated with the genesis hash value, and the first hash digest is calculated. At this point, the first node on the chain is formed, which logically contains data. and the link to the genesis block .

[0059] After that, whenever there is a new data block Each generation process repeats this process, which involves obtaining the hash value of the last node in the chain. With new data blocks Concatenate the strings and calculate the new hash value. The newly generated node contains data. and hash value ,and It also contains This information allows for the cryptographic linking of new nodes to the preceding nodes. In this way, all data blocks are linked together sequentially according to the time of the operations, forming a complete and verifiable lifecycle traceability chain that can be traced back from the current node to the genesis node.

[0060] In the second embodiment, the present invention also proposes a full life-cycle traceability system for explosion-proof monitoring instruments at oil and gas maintenance and repair sites, comprising the following modules:

[0061] The estimation module is used by the RFID reader to analyze the degree of in-phase orthogonal constellation diagram distortion of the mixed baseband signal in the identified collision time slot within a communication frame, and to estimate the number of tags in the collision time slot according to the preset mapping relationship between the degree of constellation diagram distortion and the number of tags.

[0062] The control module is used to obtain the number of successful time slots and the number of idle time slots counted by the MAC layer, combine the estimated number of tags with all collision time slots, calculate the total number of tags to be identified, and set the frame length of the next communication frame according to the total number; at the same time, it calculates the collision density index according to the ratio of the number of collision time slots to the current frame length, and controls the reader's transmission power based on the collision density index.

[0063] The generation module is used to encode the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index into a data block for each successfully identified explosion-proof monitoring device tag; through hash operation, the current data block is generated and stored by combining the hash value of the data block with the hash value of the previous data block, thus forming a full life cycle traceability chain for the explosion-proof monitoring device.

[0064] In an optional embodiment, analyzing the degree of in-phase quadrature constellation diagram distortion of the mixed baseband signal within the collision time slot includes:

[0065] Calculate the N received baseband signal sampling points within the collision time slot. and the corresponding ideal constellation point The average Euclidean distance D between them is used as an indicator of the degree of distortion, and the calculation formula is as follows: .

[0066] In an optional embodiment, estimating the number of tags within the collision time slot based on a preset mapping relationship between constellation diagram distortion and tag number includes:

[0067] The distortion level indicator is compared with multiple preset threshold intervals, and the corresponding number of tags is determined according to the interval in which it is located.

[0068] In an optional embodiment, setting the frame length of the next communication frame based on the total number includes:

[0069] Frame length of the next communication frame ,in, This represents the total number of tags to be identified.

[0070] In an optional embodiment, controlling the reader's transmission power based on the collision density index includes:

[0071] Update the reader transmit power according to the following rules. :

[0072]

[0073] in, As a collision density index, To preset the congestion threshold, To preset the power adjustment step size, and These are the preset minimum and maximum transmit power.

[0074] In an optional embodiment, encoding the tag ID, maintenance and repair operation record, timestamp, reader geographic location, and collision density index into a single data block includes:

[0075] The tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index are formatted according to a predetermined data structure to generate a unified data block.

[0076] In an optional embodiment, the step of generating and storing a digest of the current data block by combining the hash value of the current data block with that of the previous data block through hash operation, thus forming a full lifecycle traceability chain for the explosion-proof monitoring device, includes:

[0077] Through a preset hash function For the current data block The content is the same as the hash value of the previous data block. The concatenation of data is used to generate a summary of the current data block. The calculation formula is:

[0078]

[0079] Each generated data block is treated as a node, and each node contains the current data block and a hash value pointing to the previous node, thus linking all data blocks into a chain structure in chronological order;

[0080] For the first node, the hash value pointing to the previous node is the preset genesis hash value.

[0081] The functional modules shown in the above-described block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0082] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for tracing the entire lifecycle of an explosion-proof monitoring instrument at an oil and gas maintenance and repair site, characterized in that, Includes the following steps: Within a communication frame, the RFID reader analyzes the degree of in-phase orthogonal constellation diagram distortion of the mixed baseband signal in the identified collision time slot, and estimates the number of tags in the collision time slot based on the preset mapping relationship between the degree of constellation diagram distortion and the number of tags. The number of successful time slots and the number of idle time slots are obtained from the MAC layer statistics. Combined with the estimated number of tags from all collision time slots, the total number of tags to be identified is calculated, and the frame length of the next communication frame is set according to the total number. Simultaneously, a collision density index is calculated based on the ratio of the number of collision time slots to the current frame length, and the reader's transmission power is controlled based on the collision density index. For each successfully identified explosion-proof monitoring device tag, the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and the collision density index are encoded into a data block. Through hash operation, the hash value of the current data block is combined with that of the previous data block to generate a summary of the current data block and store it, forming a full life cycle traceability chain for the explosion-proof monitoring device.

2. The method according to claim 1, characterized in that, The analysis of the in-phase orthogonal constellation diagram distortion of the mixed baseband signal within the collision time slot includes: The average Euclidean distance D between the N received baseband signal sampling points and the corresponding ideal constellation points within the collision time slot is calculated as an indicator of the degree of distortion.

3. The method according to claim 2, characterized in that, The step of estimating the number of tags within the collision time slot based on a preset mapping relationship between constellation diagram distortion and tag number includes: The distortion level indicator is compared with multiple preset threshold intervals, and the corresponding number of tags is determined according to the interval it falls within.

4. The method according to claim 1, characterized in that, Setting the frame length of the next communication frame based on the total number includes: Frame length of the next communication frame ,in, This represents the total number of tags to be identified.

5. The method according to claim 1 or 4, characterized in that, The control of the reader's transmission power based on the collision density index includes: Update the reader transmit power according to the following rules. : like Greater than ,but ; like Less than or equal to ,but ; in, As a collision density index, To preset the congestion threshold, To preset the power adjustment step size, and The preset minimum and maximum transmit power, This is the current transmission power. This represents the transmission power at the next moment.

6. The method according to claim 1, characterized in that, The process of encoding the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index into a single data block includes: The tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index are formatted according to a predetermined data structure to generate a unified data block.

7. The method according to claim 6, characterized in that, The process involves generating and storing a digest of the current data block by combining the hash value of the current data block with that of the previous data block through hash operations, thus forming a full lifecycle traceability chain for the explosion-proof monitoring device, including: Through a preset hash function For the current data block The content is the same as the hash value of the previous data block. The concatenation of data is used to generate a summary of the current data block. ; Each generated data block is treated as a node, and each node contains the current data block and a hash value pointing to the previous node, thus linking all data blocks into a chain structure in chronological order; For the first node, the hash value pointing to the previous node is the preset genesis hash value.

8. A full life-cycle traceability system for explosion-proof monitoring instruments at oil and gas maintenance and repair sites, characterized in that, Includes the following modules: The estimation module is used by the RFID reader to analyze the degree of in-phase orthogonal constellation diagram distortion of the mixed baseband signal in the identified collision time slot within a communication frame, and to estimate the number of tags in the collision time slot according to the preset mapping relationship between the degree of constellation diagram distortion and the number of tags. The control module is used to obtain the number of successful time slots and the number of idle time slots counted by the MAC layer, combine the estimated number of tags in all collision time slots, calculate the total number of tags to be identified, and set the frame length of the next communication frame based on the total number. Simultaneously, a collision density index is calculated based on the ratio of the number of collision time slots to the current frame length, and the reader's transmission power is controlled based on the collision density index. The generation module is used to encode the tag ID, maintenance and repair operation record, timestamp, reader geographical location, and collision density index into a data block for each successfully identified explosion-proof monitoring device tag; through hash operation, the current data block is generated and stored by combining the hash value of the data block with the hash value of the previous data block, thus forming a full life cycle traceability chain for the explosion-proof monitoring device.

9. The system according to claim 8, characterized in that, The analysis of the in-phase orthogonal constellation diagram distortion of the mixed baseband signal within the collision time slot includes: The average Euclidean distance between the N received baseband signal sampling points and the corresponding ideal constellation points within the collision time slot is calculated as an indicator of the degree of distortion.

10. The system according to claim 8, characterized in that, The step of estimating the number of tags within the collision time slot based on a preset mapping relationship between constellation diagram distortion and tag number includes: The distortion level indicator is compared with multiple preset threshold intervals, and the corresponding number of tags is determined according to the interval it falls within.

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