A method and system for simultaneous wireless communication in clean room space and maintenance interlayer

Abstract

The application discloses a method and system for synchronous wireless communication applied to clean room space and maintenance interlayer, relates to the technical field of wireless communication, and comprises the following steps: establishing a node mapping relationship between a clean area wireless terminal node and an interlayer wireless relay node through a dual-domain synchronous gateway; determining a candidate communication link based on a node installation position, and generating a partition attenuation feature according to a clean room partition structure passed through by the candidate communication link; performing logical clock calibration based on a gateway reference clock, and generating a clean area to-be-synchronized data frame carrying a synchronization identifier; determining a main synchronization link and a backup synchronization link in combination with wireless communication quality, the partition attenuation feature and a logical clock calibration error, and preferentially reissuing to-be-compensated synchronization data when synchronization fails. The application can improve the link selection accuracy of the clean room space and the maintenance interlayer under a partition shielding environment, and enhance the data synchronization continuity and reliability in the cross-space wireless communication process.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a method and system for synchronous wireless communication in cleanroom spaces and maintenance mezzanines. Background Technology

[0002] Currently, cleanrooms are widely used in semiconductor manufacturing, biomedicine, precision assembly, and other scenarios with high requirements for environmental cleanliness and equipment operational stability. Cleanroom spaces typically house equipment status acquisition points, environmental monitoring points, and alarm acquisition points, while ductwork, filters, cable trays, pipelines, and some equipment maintenance interfaces are mostly located within maintenance mezzanines. To reduce the impact of personnel entering the cleanroom and through-wall wiring on the cleanroom enclosure structure, existing technologies have begun to employ wireless terminal nodes, relay nodes, and gateway devices to achieve data transmission between the cleanroom space and the maintenance mezzanine, enabling the maintenance mezzanine side to obtain the operating status of equipment, environmental status, and alarm status within the cleanroom. While this approach reduces wiring complexity and improves maintenance convenience, most still rely on ordinary wireless forwarding or fixed relay communication, lacking specialized solutions for the unique isolation environment and synchronous communication needs between the cleanroom space and the maintenance mezzanine.

[0003] The existing methods have two main shortcomings: First, there are partitions between the cleanroom and the maintenance mezzanine, such as metal ceilings, dense ductwork areas, HEPA filters, equipment casings, and mezzanine cable trays. Wireless links are easily affected by obstruction, reflection, and multipath attenuation. If the link is selected solely based on the received signal strength, node distance, or fixed relay relationship, it can easily lead to a mismatch between the main communication link and the actual synchronization stability. Second, the wireless terminal nodes in the cleanroom and the wireless relay nodes in the mezzanine typically use their own local clocks. In the event of hardware clock drift, wireless transmission delay, or loss of acknowledgment frames, the data generated on the cleanroom side and the data received on the maintenance mezzanine side may have inconsistent synchronization cycles, inconsistent data versions, or the skipping of critical states from the previous cycle. This affects the continuous display and timely confirmation of critical data such as alarms, shutdowns, and pressure differential anomalies on the maintenance mezzanine side. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method and system for synchronous wireless communication in cleanroom spaces and maintenance mezzanines, which solves the problems of insufficient link selection accuracy and insufficient data synchronization continuity across spaces in existing methods under partition and obstruction environments.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for synchronous wireless communication in a cleanroom space and maintenance mezzanine, comprising,

[0008] Cleanroom wireless terminal nodes are set up in the cleanroom space, and mezzanine wireless relay nodes are set up in the maintenance mezzanine. The node mapping relationship between the cleanroom wireless terminal nodes and the mezzanine wireless relay nodes is established through a dual-domain synchronization gateway.

[0009] Candidate communication links are determined based on the node installation locations corresponding to the node mapping relationship, and partition attenuation characteristics are generated based on the cleanroom partition structures through which the candidate communication links pass.

[0010] The reference clock of the dual-domain synchronization gateway is used to perform logical clock calibration on the clean area wireless terminal node and the mezzanine wireless relay node, and the clean area wireless terminal node generates a clean area data frame to be synchronized carrying a synchronization identifier based on the calibrated logical clock.

[0011] The dual-domain synchronization gateway determines the primary synchronization link and the backup synchronization link based on the wireless communication quality, isolation attenuation characteristics and logical clock calibration error of the candidate communication links.

[0012] The clean area wireless terminal node sends the clean area data frames to be synchronized to the maintenance mezzanine via the mezzanine wireless relay node through the main synchronization link, and judges the data synchronization status based on the received synchronization confirmation information.

[0013] If synchronization is not completed, the clean area data frame to be synchronized will be marked as a data frame to be compensated for synchronization. Before the new data is sent in the next synchronization cycle, the data frame to be compensated for synchronization will be resent through the primary synchronization link or the backup synchronization link.

[0014] As a preferred embodiment of the synchronous wireless communication method for cleanroom spaces and maintenance mezzanine spaces described in this invention, the step of establishing a node mapping relationship between cleanroom wireless terminal nodes and mezzanine wireless relay nodes through a dual-domain synchronous gateway is as follows:

[0015] The dual-domain synchronization gateway receives node registration frames returned by the clean area wireless terminal node and the mezzanine wireless relay node, and generates a node registration table based on the node type, region, installation coordinates and local clock status in the node registration frame.

[0016] Based on the node registration table, the spatial proximity distance between the clean area wireless terminal node and each mezzanine wireless relay node is calculated. The mezzanine wireless relay nodes with the smallest and second smallest spatial proximity distances are selected as the priority candidate relay node and the backup candidate relay node, respectively. A wireless node mapping table is generated to establish the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node.

[0017] As a preferred embodiment of the method for synchronous wireless communication in cleanroom space and maintenance mezzanine as described in this invention, wherein: determining the candidate communication link based on the node installation position corresponding to the node mapping relationship means determining the spatial connection between each cleanroom wireless terminal node and the corresponding priority candidate relay node and backup candidate relay node as candidate communication links based on the node mapping relationship.

[0018] As a preferred embodiment of the method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines described in this invention, the step of generating partition attenuation characteristics based on cleanroom partition structures traversed by candidate communication links comprises the following steps: identifying cleanroom partition structures that candidate communication links pass through or are adjacent to, obtaining a corresponding set of partition structures; calculating the normalized influence degree corresponding to each type of partition structure based on the degree of crossing, proximity, and thickness level of the candidate communication links relative to various partition structures; and calculating the partition attenuation correction coefficient of the candidate communication links as the partition attenuation characteristics based on the normalized influence degree and attenuation weight of each type of partition structure.

[0019] As a preferred embodiment of the method for synchronous wireless communication in cleanroom spaces and maintenance mezzanine areas as described in this invention, the following steps are taken: The reference clock based on the dual-domain synchronization gateway performs logical clock calibration on the cleanroom wireless terminal nodes and the mezzanine wireless relay nodes:

[0020] Based on the wireless node mapping relationship, each clean area wireless terminal node and its corresponding priority candidate relay node and backup candidate relay node are determined as a set of synchronization calibration nodes, and the dual-domain synchronization gateway sends clock synchronization frames to each node in the set of synchronization calibration nodes.

[0021] Receive clock response frames returned by the synchronization calibration node, and calculate the hardware clock increment and latency-corrected synchronization error for each node based on the gateway sending timestamp, the gateway receiving timestamp, and the node's local clock state.

[0022] Based on the hardware clock increment and synchronization error, the logic clock rate of each node is updated using the normalized minimum mean square correction method to obtain the clock calibration result.

[0023] As a preferred embodiment of the method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines described in this invention, the step of generating a cleanroom data frame to be synchronized carrying a synchronization identifier by the cleanroom wireless terminal node based on a calibrated logical clock includes the following steps:

[0024] Based on the clock calibration results, the dual-domain synchronization gateway sends a synchronization data start frame carrying the synchronization cycle number and data version number to the cleanroom wireless terminal node. The cleanroom wireless terminal node generates a logical sampling timestamp according to the updated logical clock rate and collects the corresponding cleanroom status data.

[0025] The synchronization cycle number, data version number, clean area wireless terminal node identifier, logical sampling timestamp, clean room status data, and verification field are written into the same data frame to generate a clean area data frame to be synchronized, and the frame header summary information is returned to the dual-domain synchronization gateway.

[0026] As a preferred embodiment of the synchronous wireless communication method for cleanroom spaces and maintenance mezzanines described in this invention, the steps for determining the primary synchronization link and the backup synchronization link are as follows:

[0027] Based on the cleanroom wireless terminal node corresponding to the data frame to be synchronized in the cleanroom, the corresponding candidate communication link is determined from the wireless node mapping table.

[0028] Link detection is performed on candidate communication links to obtain and normalize the wireless communication quality parameters of candidate communication links, and the corresponding isolation attenuation characteristics and logic clock calibration errors are read.

[0029] The link synchronization score is calculated based on the normalized wireless communication quality parameters, isolation attenuation characteristics, and logic clock calibration error, and the primary synchronization link and backup synchronization link are determined based on the link synchronization score.

[0030] As a preferred embodiment of the method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines described in this invention, wherein: judging the data synchronization status based on the received synchronization confirmation information means comparing the synchronization confirmation information with the frame header summary information and the main synchronization link information. If the number, version, node, and status are all consistent and valid, then the data synchronization is determined to be complete; otherwise, the data synchronization is determined to be incomplete, and a synchronization failure result is generated.

[0031] As a preferred embodiment of the method for synchronous wireless communication in cleanroom space and maintenance mezzanine as described in this invention, the step of marking the clean area data frame to be synchronized as the data frame to be compensated means determining the corresponding clean area data frame to be synchronized based on the synchronization failure result, writing the compensation transmission identifier into the clean area data frame to be synchronized, and retaining the original synchronization cycle number, the original data version number and the original logical sampling timestamp.

[0032] Secondly, the present invention provides a system for synchronous wireless communication in cleanroom spaces and maintenance mezzanines, comprising,

[0033] The node mapping module is used to establish the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node;

[0034] The feature generation module is used to generate partition attenuation features based on the cleanroom partition structure through which the candidate communication link passes.

[0035] The clock calibration module is used to perform logical clock calibration on both sides of the node based on the reference clock of the dual-domain synchronization gateway.

[0036] The data frame generation module is used to generate clean area data frames to be synchronized, carrying synchronization identifiers.

[0037] The link determination module is used to determine the primary synchronization link and the backup synchronization link based on wireless communication quality, isolation attenuation characteristics, and logic clock calibration error.

[0038] The synchronization compensation module is used to complete the synchronous transmission of data frames to be synchronized in the clean area, and to resend the data frames to be compensated if synchronization is not completed.

[0039] The beneficial effects of this invention are as follows: By establishing a mapping relationship between wireless terminal nodes in the clean area and wireless relay nodes in the mezzanine, and combining this with the attenuation characteristics generated by the partition structure through which candidate communication links pass, the selection of primary and backup synchronization links no longer depends solely on signal strength or fixed relay relationships. This allows for more accurate adaptation to environments obstructed by metal ceilings, ducts, filters, and equipment housings, improving the stability of wireless synchronization transmission between the cleanroom space and the maintenance mezzanine. Simultaneously, based on the dual-domain synchronization gateway reference clock, logical clock calibration is performed on the nodes on both sides. Continuous data transmission is ensured through synchronization cycle numbering, data version numbering, and a compensation-before-send mechanism, preventing critical alarms, shutdowns, or voltage difference abnormal data from being displayed in skipped frames on the mezzanine side, thereby improving the consistency and reliability of synchronization communication. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart of the method for synchronous wireless communication in a cleanroom space and maintenance mezzanine, as described in Example 1.

[0042] Figure 2 This is a structural diagram of the system used in Example 1 for synchronous wireless communication in cleanroom space and maintenance mezzanine.

[0043] Figure 3 Select a data relationship diagram for the link.

[0044] Figure 4 This is a schematic diagram of the node mapping relationship. Detailed Implementation

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0046] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0047] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0048] Example 1, referring to Figure 1 , Figure 3 and Figure 4 This is the first embodiment of the present invention, which provides a method for synchronous wireless communication in a cleanroom space and maintenance mezzanine, comprising the following steps:

[0049] S1. Set up clean area wireless terminal nodes in the cleanroom space, set up mezzanine wireless relay nodes in the maintenance mezzanine, and establish node mapping relationship between clean area wireless terminal nodes and mezzanine wireless relay nodes through dual-domain synchronization gateway.

[0050] S1.1: Establish a unified spatial coordinate system covering the cleanroom space and the maintenance mezzanine, and record the design height difference between the two;

[0051] Specifically, based on the floor plan of the cleanroom space and the floor plan of the maintenance mezzanine, a unified three-dimensional spatial coordinate system covering the cleanroom space and the maintenance mezzanine is established. A corner of the cleanroom floor is set as the origin of the coordinate system, the direction parallel to the length of the cleanroom is set as the X-axis, the direction parallel to the width of the cleanroom is set as the Y-axis, and the vertical upward direction is set as the Z-axis. The design height difference between the cleanroom ceiling and the installation surface of the maintenance mezzanine is recorded as h, so that the installation positions of the nodes in the cleanroom space and the nodes in the maintenance mezzanine can be represented in the same coordinate system.

[0052] S1.2: Set up cleanroom wireless terminal nodes in the cleanroom space, set up mezzanine wireless relay nodes in the maintenance mezzanine, and establish wireless communication connections with the nodes on both sides through a dual-domain synchronization gateway;

[0053] Specifically, cleanroom wireless terminal nodes are fixedly installed at equipment status acquisition points, environmental monitoring points, and alarm acquisition points within the cleanroom space; in the maintenance mezzanine, mezzanine wireless relay nodes are fixedly installed within the vicinity of the vertical projection positions of the cleanroom wireless terminal nodes on the installation surface of the maintenance mezzanine; and a dual-domain synchronization gateway is installed at the adjacent boundary between the cleanroom space and the maintenance mezzanine, enabling the dual-domain synchronization gateway to establish wireless communication connections with both the cleanroom wireless terminal nodes and the mezzanine wireless relay nodes.

[0054] Specifically, for each cleanroom wireless terminal node, a unique node identifier, node type, cleanroom area to which it belongs, installation coordinates, service data type, communication capability, local hardware clock value, and current logical clock value are written. For each mezzanine wireless relay node, a unique node identifier, node type, maintenance mezzanine area to which it belongs, installation coordinates, communication capability, local hardware clock value, and current logical clock value are written.

[0055] It should be noted that the node type is used to characterize the functional attributes of the node in synchronous communication. The node type of the clean area wireless terminal node is determined to be a clean area acquisition terminal, and the node type of the mezzanine wireless relay node is determined to be a mezzanine forwarding relay. The service data type is used to characterize the type of data to be synchronized generated by the clean area wireless terminal node, specifically including equipment operation status data, environmental status data, or alarm status data. The communication capability of the clean area wireless terminal node is used to characterize the basic capabilities of the node to participate in synchronous wireless communication, including at least the working channel, transmission power level, data frame transmission and reception capability, synchronization frame reception capability, and acknowledgment frame return capability. The communication capability of the mezzanine wireless relay node includes at least the working channel, reception sensitivity level, forwarding capability, synchronization frame transmission and reception capability, and acknowledgment frame generation capability.

[0056] S1.3: The dual-domain synchronization gateway receives node registration frames returned by the clean area wireless terminal node and the mezzanine wireless relay node, and generates a node registration table based on the node type, region, installation coordinates and local clock status in the node registration frame.

[0057] Specifically, after the dual-domain synchronization gateway is powered on, it generates a node discovery frame and broadcasts it to the cleanroom space and the maintenance mezzanine. After receiving the node discovery frame, the cleanroom wireless terminal node and the mezzanine wireless relay node return a node registration frame within the same discovery cycle. After receiving the node registration frame, the dual-domain synchronization gateway divides the nodes into a cleanroom wireless terminal node set and a mezzanine wireless relay node set according to the node type, and writes the node identifier, region, installation coordinates, communication capabilities and local clock status of each node into the node registration table.

[0058] It should be noted that the node discovery frame includes the gateway identifier, discovery cycle number, node registration request field, and gateway base timestamp; the node registration frame includes the node identifier, node type, region, installation coordinates, communication capabilities, service data type, local hardware clock value, and current logical clock value.

[0059] S1.4: Calculate the spatial proximity distance between the clean area wireless terminal node and each mezzanine wireless relay node based on the node registration table, and select the mezzanine wireless relay node with the smallest and second smallest spatial proximity distance as the priority candidate relay node and the backup candidate relay node, respectively, to generate a wireless node mapping table to establish the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node.

[0060] Specifically, the dual-domain synchronization gateway uses each cleanroom wireless terminal node in the node registration table as the node to be mapped, and reads the installation coordinates of that cleanroom wireless terminal node. And read the installation coordinates of each mezzanine wireless relay node. Next, the spatial proximity distance is calculated; mezzanine wireless relay nodes belonging to the same vertical corresponding area as the current cleanroom wireless terminal node are retained, and then sorted in ascending order of spatial proximity distance. The mezzanine wireless relay node ranked first is determined as the priority candidate relay node for the cleanroom wireless terminal node, and the mezzanine wireless relay node ranked second is determined as the backup candidate relay node for the cleanroom wireless terminal node. The dual-domain synchronization gateway generates a wireless node mapping table according to the field format of "cleanroom wireless terminal node identifier and installation coordinates, priority candidate relay node identifier and installation coordinates, backup candidate relay node identifier and installation coordinates, cleanroom area, service data type, cleanroom wireless terminal node local clock status, and mezzanine wireless relay node local clock status". Each record in the wireless node mapping table is determined as a group of node candidate mapping relationships, thereby completing the establishment of wireless node candidate mapping relationships between the cleanroom wireless terminal node in the cleanroom space and the mezzanine wireless relay node in the maintenance mezzanine.

[0061] Calculate spatial proximity distance The expression is:

[0062]

[0063] In the formula, , , Represents the wireless terminal node in the clean area Installation coordinates in a unified spatial coordinate system , , Indicates a mezzanine wireless relay node Installation coordinates in the same unified spatial coordinate system This indicates the design vertical reference distance between the installation reference plane of the wireless terminal node in the clean area and the installation reference plane of the wireless relay node in the maintenance mezzanine. This represents the vertical deviation weighting coefficient, used to reduce the impact of height fluctuations in the interlayer mounting surface on the determination of node plane proximity.

[0064] The value range is set to The values ​​are determined by calibrating the node coordinates, RSSI, packet loss rate, and synchronization confirmation success rate on-site, and the least squares fitting method is used to select the weight values ​​that minimize the error between the spatial proximity distance sorting and the actual stable communication link sorting.

[0065] It should be noted that the cleanroom wireless terminal node identifier and its installation coordinates are used to determine the location of the synchronous data source on the cleanroom side; the priority candidate relay node identifier and its installation coordinates, and the backup candidate relay node identifier and its installation coordinates are used to determine the location of the candidate receiving path on the maintenance mezzanine side; the cleanroom area is used to determine the spatial correspondence between the cleanroom space and the maintenance mezzanine; the service data type is used to distinguish between equipment operating status, environmental status, and alarm status; and the local clock status is used for subsequent logical clock rate correction.

[0066] S2. Determine candidate communication links based on the node installation locations corresponding to the node mapping relationship, and generate partition attenuation characteristics based on the cleanroom partition structures through which the candidate communication links pass.

[0067] S2.1: Based on the node mapping relationship, the spatial connection between each clean area wireless terminal node and the corresponding priority candidate relay node and backup candidate relay node is determined as a candidate communication link.

[0068] Specifically, the wireless node mapping table is read, and each mapping record in the wireless node mapping table is used as the processing object; the node installation coordinates of the clean area wireless terminal node i, the priority candidate relay node, and the backup candidate relay node are extracted respectively, and the clean area wireless terminal node i and any candidate mezzanine wireless relay node j are combined to form a candidate communication link, thereby obtaining the set of candidate communication links corresponding to the current clean area wireless terminal node.

[0069] S2.2: Identify cleanroom partition structures through which candidate communication links pass or are adjacent, and obtain the corresponding set of partition structures;

[0070] Specifically, candidate communication links are read, and cleanroom space layout data pre-stored in the dual-domain synchronization gateway is invoked. For any candidate communication link between a cleanroom wireless terminal node i and a candidate mezzanine wireless relay node j, a spatial line segment is generated with the installation coordinates of the cleanroom wireless terminal node i and the installation coordinates of the candidate mezzanine wireless relay node j as endpoints, and the spatial line segment is used as the central path of the candidate communication link. It is determined whether the spatial line segment intersects with the boundary body of each cleanroom partition structure. If it intersects, the corresponding cleanroom partition structure is identified as passing through the partition structure. If it does not intersect, a cylindrical communication influence channel is generated with the spatial line segment as the central axis and a preset communication influence radius r. If the boundary body of a certain cleanroom partition structure enters the cylindrical communication influence channel, it is identified as the adjacent partition structure. The passing partition structure and the adjacent partition structure are merged to obtain the set of partition structures corresponding to the candidate communication link.

[0071] It should be noted that the cleanroom space layout data includes the structure type, boundary coordinates, thickness value and area of ​​each cleanroom partition structure in a unified spatial coordinate system; the cleanroom partition structure includes at least a metal ceiling, dense duct area, HEPA filter, equipment housing, cable tray, and maintenance passage shielding.

[0072] The preset communication influence radius is set to 0.3m to 1.0m. Specifically, it is determined and limited within this range by the sum of the node installation coordinate error, the partition structure mapping error, and the maximum radius of the first Fresnel zone corresponding to the current wireless communication frequency band, so as to cover the adjacent partition structures that are not directly passed through by the candidate communication link but will have the effect of blocking, reflection or attenuation on the link.

[0073] S2.3: Based on the degree of crossing, proximity and thickness of candidate communication links relative to various types of partition structures, calculate the normalized influence degree corresponding to each type of partition structure;

[0074] Specifically, taking the candidate communication links and their corresponding partition structure sets as input, the partition structures in the partition structure set are first classified according to their structure type to obtain the partition structure subsets corresponding to metal ceilings, dense duct areas, high-efficiency filters, equipment shells, mezzanine cable trays, and maintenance passage obstructions; the installation coordinates of the clean area wireless terminal node i and the installation coordinates of the candidate mezzanine wireless relay node j of any candidate communication link are read, and the length of the candidate communication link is calculated.

[0075] A path parameter interval is established with the candidate communication link as the axis, and the direction from the clean area wireless terminal node i to the candidate mezzanine wireless relay node j is defined as the positive direction. For the k-th type of partition structure subset, if the partition structure has been marked as passing through the partition structure, the length of the line segment of the candidate communication link located inside the boundary body of the partition structure of that type is calculated, and the lengths of the line segments corresponding to each partition structure passing through the partition structure under the same type are accumulated to obtain the cumulative traversal length corresponding to that type of partition structure. If a partition structure has been marked as a neighboring partition structure, the portion of that neighboring partition structure falling within the cylindrical communication influence channel is projected along the positive direction of the candidate communication link, and the length of the projection interval is taken as the neighboring influence length of that neighboring partition structure. Then, the neighboring influence lengths corresponding to all neighboring partition structures of the same type are summed to obtain the cumulative neighboring influence length corresponding to that type of partition structure. ;

[0076] Read the actual thickness value recorded in the cleanroom space layout data for this type of partition structure. And calculate the thickness normalization coefficient; when there are multiple partition structures of the same type, The maximum thickness of this type of partition structure is taken to reflect the maximum obstruction effect of this type of partition structure on wireless propagation;

[0077] The normalized influence degree corresponding to the k-th type of partition structure is calculated based on the candidate communication link length, cumulative traversal length, cumulative neighbor influence length, and thickness normalization coefficient.

[0078] Calculate candidate communication link length The expression is:

[0079]

[0080] Calculate the thickness normalization factor The expression is:

[0081]

[0082] In the formula, This indicates the preset maximum reference thickness value;

[0083] Calculate the degree of normalization effect The expression is:

[0084]

[0085] In the formula, This represents the reduction factor for proximity effects;

[0086] When the candidate communication link neither passes through nor is adjacent to the k-th type of barrier structure, let , and obtain the corresponding .

[0087] It should be noted that the cumulative crossing length has already been included. The portion is no longer included in the cumulative adjacent influence length. To avoid duplicate metering of the same candidate communication link using the same partition structure;

[0088] The value is taken as 0.05m to 1.0m, and is determined based on the maximum actual thickness of various partition structures involved in the calculation in the cleanroom space layout data;

[0089] Neighborhood effect reduction factor It is based on the indoor wireless ray tracing link budget method. It is set after simulating and comparing the difference in additional path loss caused by adjacent obstruction and direct passage through obstruction under the same wireless frequency band. The exemplary value range is 0.3~0.7. The basis for the value is to make the attenuation effect of adjacent obstruction structure on candidate communication link weaker than that of direct passage through obstruction structure, but still able to reflect its reflection, obstruction and scattering effects in the obstruction attenuation characteristic calculation.

[0090] S2.4: Based on the normalized influence degree and attenuation weight of various isolation structures, calculate the isolation attenuation correction coefficient of the candidate communication link as the isolation attenuation feature.

[0091] Specifically, a preset attenuation weight table is invoked to assign a corresponding attenuation weight to each type of partition structure. ;

[0092] The isolation attenuation correction coefficient of the candidate communication link is calculated based on the normalized influence degree and attenuation weight; the isolation attenuation correction coefficient is associated with the clean area wireless terminal node identifier, the candidate mezzanine wireless relay node identifier, the candidate communication link identifier, the normalized influence degree of various isolation structures and the corresponding attenuation weight and written into the isolation attenuation feature table; the value in the isolation attenuation feature table is used as the isolation attenuation feature of the candidate communication link.

[0093] Calculate the isolation attenuation correction factor The expression is:

[0094]

[0095] In the formula, m represents the number of partition structure types involved in the calculation.

[0096] It should be noted that when the dual-domain synchronous gateway pre-establishes the attenuation weight table, cleanroom wireless terminal nodes and mezzanine wireless relay nodes with the same wireless communication frequency band, transmit power, antenna height, and node model as this scheme are used as test nodes. First, the reference received signal strength is measured under the reference path without any obstructions. Then, the received signal strength under the obstructions is measured under the representative obstruction paths corresponding to the obstruction of metal ceiling, equipment shell, dense air duct area, mezzanine cable tray, HEPA filter, and maintenance passage. The difference between the reference received signal strength and the obstruction received signal strength is taken as the additional path loss of the corresponding obstruction structure. The measurement is repeated no less than three times for each type of obstruction structure, and the average value is taken to obtain the average additional path loss corresponding to each type of obstruction structure. Then, the average additional path loss of each type of obstruction structure is divided by the sum of the average additional path losses of all obstruction structures to obtain the dimensionless attenuation weight. and decay weight Write the structure type into the preset attenuation weight table.

[0097] S3. Based on the reference clock of the dual-domain synchronization gateway, the clean area wireless terminal node and the mezzanine wireless relay node are logically clocked, and the clean area wireless terminal node generates a clean area data frame to be synchronized carrying a synchronization identifier based on the calibrated logical clock.

[0098] S3.1: Based on the wireless node mapping relationship, each clean area wireless terminal node and its corresponding priority candidate relay node and backup candidate relay node are determined as a set of synchronization calibration nodes, and the dual-domain synchronization gateway sends clock synchronization frames to each node in the set of synchronization calibration nodes.

[0099] Specifically, the wireless node mapping table and the isolation attenuation characteristic table are read, and the clean area wireless terminal nodes, priority candidate relay nodes and backup candidate relay nodes in the wireless node mapping table are used as the current synchronization calibration node set; a clock synchronization frame is generated in the k-th synchronization calibration cycle and sent to each node in the synchronization calibration node set.

[0100] The clock synchronization frame includes a gateway identifier, a synchronization calibration cycle number, a target node identifier, a clock request field, and a gateway sending timestamp. (The transmission time recorded by its own reference clock when sending the clock synchronization frame is used as the starting time for subsequent delay correction).

[0101] S3.2: Receive the clock response frame returned by the synchronization calibration node, and calculate the hardware clock increment and the synchronization error after delay correction for each node based on the gateway sending timestamp, the gateway receiving timestamp, and the node's local clock state.

[0102] Specifically, after receiving the clock synchronization frame, the cleanroom wireless terminal node and the mezzanine wireless relay node read the current hardware clock count value and the timer operating frequency of the node timer, and divide the current hardware clock count value by the timer operating frequency to obtain the current local hardware clock value in seconds. Simultaneously, read the current logical clock value stored in the node's local synchronization status table. Current logic clock rate and the local hardware clock value saved in the previous synchronization calibration cycle. And will include node identifiers, synchronization calibration cycle numbers, , , and Write a clock acknowledgment frame to return to the dual-domain synchronization gateway; when the current synchronization calibration period is the first calibration period, use the local hardware clock value in the node registration frame as the local hardware clock value of the previous synchronization calibration period, and set the node's initial logical clock rate to 1.

[0103] After receiving the clock acknowledgment frame, the dual-domain synchronization gateway records the gateway's received timestamp. The gateway calibration reference time corresponding to the current node is determined based on the gateway sending timestamp and the gateway receiving timestamp. ;Then the nodes are calculated Hardware clock increment; then calculate node Synchronization error.

[0104] Calculate hardware clock increment The expression is:

[0105]

[0106] Calculate synchronization error The expression is:

[0107] .

[0108] It should be noted that, Pick and The intermediate moment is used to offset the round-trip delay of wireless transmission between the cleanroom space and the maintenance mezzanine.

[0109] The current logical clock value is calculated by the node based on the increment between the previous logical clock value, the hardware clock value of the previous synchronization calibration cycle, and the current hardware clock value stored in the local synchronization status table. Specifically, the increment of two adjacent hardware clock values ​​is corrected according to the current logical clock rate and then added to the previous logical clock value. The current logical clock rate is the rate parameter issued by the dual-domain synchronization gateway based on the clock calibration result in the previous synchronization calibration cycle and stored locally by the node.

[0110] S3.3: Based on the hardware clock increment and synchronization error, the logic clock rate of each node is updated using the normalized minimum mean square correction method to obtain the clock calibration result.

[0111] Specifically, based on hardware clock increments and synchronization error The updated logical clock rate is calculated. This calculation causes nodes with leading logical clocks to reduce their logical clock rate and nodes with lagging logical clocks to increase their logical clock rate, thereby reducing time skew in subsequent synchronization cycles. The dual-domain synchronization gateway then updates the logical clock rate. Write a clock calibration control frame and send it to the corresponding node; after receiving the clock calibration control frame, the corresponding node updates its local logical clock rate to... The dual-domain synchronization gateway receives the clock calibration confirmation frame and returns a clock calibration confirmation frame. After receiving the clock calibration confirmation frame, the dual-domain synchronization gateway writes the node identifier, synchronization calibration cycle number, hardware clock increment, synchronization error, and updated logical clock rate into the clock calibration result table.

[0112] Calculate the updated logic clock rate The expression is:

[0113]

[0114] in, Represents a node The logic clock rate used in the next synchronization calibration cycle Represents a node The logic clock rate used in the current synchronization calibration cycle This represents the normalized minimum mean square correction step size. To prevent positive numbers with a denominator of zero from being modified into normal quantities.

[0115] It should be noted that, It is based on the stable convergence condition of the existing normalized least mean square algorithm, and combined with the number of cleanroom space and maintenance interlayer nodes, synchronous calibration cycle and allowable clock convergence speed. The example value is 0.1. The basis for the value is to ensure that the logic clock rate correction can maintain convergence stability while avoiding excessive single correction amplitude. It is set based on the square of the minimum effective increment of the hardware clock within two adjacent synchronization calibration cycles of the node. An example value is 5% of the square of the minimum effective increment of the hardware clock. The basis for this value is to avoid the denominator being close to zero when the hardware clock increment is too small, which would cause the logical clock rate correction amount to be abnormally amplified.

[0116] S3.4: Based on the clock calibration results, the dual-domain synchronization gateway sends a synchronization data start frame carrying the synchronization cycle number and data version number to the cleanroom wireless terminal node. The cleanroom wireless terminal node generates a logical sampling timestamp according to the updated logical clock rate and collects the corresponding cleanroom status data.

[0117] Specifically, the dual-domain synchronization gateway reads the clock calibration result table and confirms, based on the clock calibration confirmation frame, that the current cleanroom wireless terminal node has completed the logical clock rate correction. After confirmation, the dual-domain synchronization gateway reads the node identifier, service data type, and updated logical clock rate corresponding to the cleanroom wireless terminal node, and generates a synchronization data start frame to send to the cleanroom wireless terminal node. Upon receiving the synchronization data start frame, the cleanroom wireless terminal node reads its updated logical clock rate and the local hardware clock value at the current sampling time. Subsequently, based on the local hardware clock value and logical clock value saved by the cleanroom wireless terminal node during logical clock calibration, the current logical sampling timestamp is calculated according to the updated logical clock rate, ensuring that the logical sampling timestamp corresponds to the reference time base of the dual-domain synchronization gateway.

[0118] Furthermore, after obtaining the current logical sampling timestamp, the cleanroom wireless terminal node collects the corresponding cleanroom status data according to the service data type in the synchronization data start frame; when the service data type is equipment status, it collects the start / stop status, operating parameters, and fault flags of the equipment in the cleanroom; when the service data type is environmental status, it collects the temperature, humidity, pressure difference, and particle concentration in the cleanroom; when the service data type is alarm status, it collects the alarm type, alarm trigger time, and alarm level, thereby obtaining the cleanroom status data corresponding to the current synchronization cycle and data version number.

[0119] It should be noted that the synchronization data start frame includes the synchronization cycle number, data version number, clean area wireless terminal node identifier, business data type, and gateway base timestamp;

[0120] S3.5: Write the synchronization cycle number, data version number, clean area wireless terminal node identifier, logical sampling timestamp, clean room status data and verification field into the same data frame to generate a clean area data frame to be synchronized, and return the frame header summary information to the dual-domain synchronization gateway.

[0121] Specifically, the cleanroom wireless terminal node takes the synchronization data start frame, logical sampling timestamp and cleanroom status data obtained in the previous step as input, and writes the synchronization cycle number, data version number, cleanroom wireless terminal node identifier, business data type, logical sampling timestamp and cleanroom status data into the data frame body in a preset frame format.

[0122] After writing the data frame body, the cleanroom wireless terminal node uses cyclic redundancy check to perform verification calculations on the synchronization cycle number, data version number, cleanroom wireless terminal node identifier, business data type, logical sampling timestamp, and cleanroom status data. The obtained verification fields are then written to the end of the data frame to form a cleanroom data frame to be synchronized. The cleanroom wireless terminal node temporarily stores the generated cleanroom data frame to be synchronized in its local transmission buffer and returns the frame header summary information to the dual-domain synchronization gateway.

[0123] It should be noted that the synchronization cycle number is used to identify the synchronization cycle to which the data belongs, the data version number is used to distinguish the data generated by the same clean area wireless terminal node in different synchronization cycles, the logical sampling timestamp is used for subsequent mezzanine wireless relay nodes to judge the timeliness of the data, and the verification field is used for subsequent mezzanine wireless relay nodes to verify the integrity of the data frame.

[0124] The frame header summary information includes the clean area wireless terminal node identifier, synchronization cycle number, data version number, service data type, and logical sampling timestamp, enabling the dual-domain synchronization gateway to continue determining the primary and backup synchronization links corresponding to the clean area data frames to be synchronized based on the frame header summary information.

[0125] S4. The dual-domain synchronization gateway determines the primary synchronization link and the backup synchronization link based on the wireless communication quality, isolation attenuation characteristics and logic clock calibration error of the candidate communication links.

[0126] S4.1: Based on the cleanroom wireless terminal node corresponding to the data frame to be synchronized in the cleanroom, determine the corresponding candidate communication link from the wireless node mapping table;

[0127] Specifically, after receiving the frame header summary information returned by the clean area wireless terminal node, the dual-domain synchronization gateway reads the frame header summary information and, using the clean area wireless terminal node identifier as an index, reads the priority candidate relay node and backup candidate relay node corresponding to the clean area wireless terminal node in the wireless node mapping table; determines the spatial communication link between the clean area wireless terminal node and the priority candidate relay node as the first candidate communication link, determines the spatial communication link between the clean area wireless terminal node and the backup candidate relay node as the second candidate communication link, and uses the first candidate communication link and the second candidate communication link as the candidate communication link set for the clean area data frames to be synchronized in the current synchronization period.

[0128] S4.2: Perform link detection on candidate communication links, obtain and normalize the wireless communication quality parameters of candidate communication links, and read the corresponding isolation attenuation characteristics and logic clock calibration error;

[0129] Specifically, the dual-domain synchronization gateway sends link probe commands to the cleanroom wireless terminal nodes, causing them to send a preset number of link probe frames to the mezzanine wireless relay nodes corresponding to the first and second candidate communication links, respectively. Upon receiving the link probe frames, the mezzanine wireless relay nodes return link probe response frames and record the received signal strength and signal-to-noise ratio. Based on the transmission and reception records of the link probe frames and response frames, the dual-domain synchronization gateway obtains the received signal strength of each candidate communication link. Signal-to-noise ratio Packet loss rate and round-trip delay The received signal strength is normalized using a linear normalization method. Signal-to-noise ratio Packet loss rate The normalized received signal strength is obtained. Signal-to-noise ratio Packet loss rate Round-trip delay is normalized using a threshold-based truncation normalization method. The normalized round-trip time is obtained. ;when or The calculation result is taken as 0 when it is less than 0 and as 1 when it is greater than 1; at the same time, the isolation attenuation correction coefficient of the corresponding candidate communication link, the synchronization error of the clean area wireless terminal node i and the synchronization error of the mezzanine wireless relay node j are read, and the normalized synchronization error is calculated by the threshold-based truncation normalization method.

[0130] It should be noted that the packet loss rate Round-trip time is determined by the proportion of link probe response frames not received to the total number of link probe frames. It is determined by the time difference between the time the link probe frame is sent and the time the corresponding link probe response frame is received.

[0131] S4.3: Calculate the link synchronization score based on the normalized wireless communication quality parameters, isolation attenuation characteristics, and logic clock calibration error, and determine the primary synchronization link and backup synchronization link based on the link synchronization score.

[0132] Specifically, the system reads the normalized received signal strength (RSS), normalized signal-to-noise ratio (SNR), normalized packet loss rate (SNR), normalized round-trip time (RTD), isolation attenuation correction coefficient (ATR), and normalized synchronization error (SEO) for each candidate communication link, and weights these parameters according to a pre-defined weight order. Higher RSS and SNR contribute more positively to link selection, while higher SNR, ATR, ATR, and SEO have a greater negative impact on link selection. During weighting, the dual-domain synchronization gateway uses RSS and SNR as positive evaluation terms and lowers the normalized signal-to-noise ratio (SNR) as the positive evaluation terms. After converting packet loss rate, normalized round-trip time, isolation attenuation correction coefficient, and normalized synchronization error into reverse evaluation items, they are included in the same scoring process to obtain the link synchronization score for each candidate communication link. The first and second candidate communication links corresponding to the wireless terminal nodes in the same clean area are sorted from high to low according to the link synchronization score. The candidate communication link with the highest link synchronization score is determined as the primary synchronization link, and the candidate communication link with the second highest link synchronization score is determined as the backup synchronization link. The primary synchronization link identifier, backup synchronization link identifier, link synchronization score, synchronization cycle number, and data version number are associated and written into the link selection result table.

[0133] S5. The clean area wireless terminal node sends the clean area data frame to be synchronized to the maintenance mezzanine through the mezzanine wireless relay node via the main synchronization link, and judges the data synchronization status based on the received synchronization confirmation information.

[0134] S5.1 Send clean area data frames to be synchronized based on the main synchronization link;

[0135] Specifically, the dual-domain synchronization gateway reads the link selection result table, determines the primary synchronization link corresponding to the clean area data frame to be synchronized within the current synchronization cycle, and sends the primary synchronization link identifier to the corresponding clean area wireless terminal node; the clean area wireless terminal node reads the clean area data frame to be synchronized corresponding to the current synchronization cycle number and data version number from its local transmission buffer according to the primary synchronization link identifier, and sends it to the corresponding mezzanine wireless relay node through the primary synchronization link.

[0136] S5.2 The mezzanine wireless relay node performs synchronization verification on the data frames to be synchronized in the clean area;

[0137] Specifically, after receiving the clean area data frame to be synchronized, the mezzanine wireless relay node reads the synchronization cycle number, data version number, clean area wireless terminal node identifier, logical sampling timestamp, and verification field. The mezzanine wireless relay node uses CRC-16 cyclic redundancy check to verify the integrity of the data frame, compares the synchronization cycle number and data version number with the current synchronization cycle record, and compares the logical sampling timestamp with its own calibrated current logical clock. When the data frame integrity verification passes, the synchronization cycle number is consistent, the data version number matches, and the logical sampling timestamp deviation does not exceed the maximum allowable synchronization error, the clean area data frame to be synchronized is determined to have passed the synchronization verification.

[0138] It should be noted that the maximum allowable synchronization error is 10ms to 100ms for example. Specifically, the dual-domain synchronization gateway uses a wireless sensor network clock synchronization calibration method to conduct multi-cycle tests on the deviation between the cleanroom field gateway reference clock and the node logic clock. The maximum clock deviation is determined based on the following: it does not exceed 10% of the current synchronization cycle, can ensure a synchronization confirmation success rate of not less than 95%, and avoids the display of data across synchronization cycles on the maintenance mezzanine side.

[0139] S5.3 After the synchronization verification passes, forward the data and generate a synchronization confirmation frame;

[0140] Specifically, after determining that the data frame to be synchronized in the clean area has passed the synchronization verification, the mezzanine wireless relay node forwards the data frame to be synchronized in the clean area to the receiving end on the maintenance mezzanine side and generates a synchronization confirmation frame to return to the dual-domain synchronization gateway.

[0141] It should be noted that the synchronization confirmation frame includes a synchronization cycle number, a received data version number, a clean area wireless terminal node identifier, a mezzanine wireless relay node identifier, a mezzanine reception timestamp, and a confirmation status. The mezzanine reception timestamp is generated by the mezzanine wireless relay node based on a calibrated logical clock, and the confirmation status indicates whether the clean area data frame to be synchronized has passed the synchronization check and been forwarded.

[0142] S5.4 The dual-domain synchronization gateway determines the data synchronization status based on the synchronization confirmation frame.

[0143] Specifically, after receiving a synchronization confirmation frame, the dual-domain synchronization gateway compares the synchronization cycle number, received data version number, cleanroom wireless terminal node identifier, and mezzanine wireless relay node identifier in the confirmation frame with the frame header summary information and the link selection result table, respectively. If the above information is consistent and the confirmation status is valid, it is determined that the data synchronization from the cleanroom space to the maintenance mezzanine is completed within the current synchronization cycle. If no synchronization confirmation frame is received, or the above information is inconsistent, or the confirmation status is invalid, it is determined that the cleanroom data frame to be synchronized has not been synchronized, and a synchronization failure result is generated.

[0144] It should be noted that the synchronization failure result includes the clean area wireless terminal node identifier, synchronization cycle number, data version number, logical sampling timestamp, and primary synchronization link identifier.

[0145] S6. If synchronization is not completed, the clean area data frame to be synchronized is marked as a data frame to be compensated for synchronization. Before the new data is sent in the next synchronization cycle, the data frame to be compensated for synchronization is resent through the main synchronization link or the backup synchronization link.

[0146] S6.1 Generate a synchronization data frame to be compensated based on the synchronization failure result;

[0147] Specifically, the dual-domain synchronization gateway determines the clean area data frame to be synchronized in the local transmission buffer of the corresponding clean area wireless terminal node based on the clean area wireless terminal node identifier, synchronization cycle number and data version number, and marks the clean area data frame to be synchronized as the data frame to be compensated for synchronization.

[0148] It should be noted that the data frame to be compensated retains the original synchronization cycle number, the original data version number, and the original logical sampling timestamp, and writes a compensation sending identifier, so that the data frame can be identified as data that was not synchronized in the previous synchronization cycle when it is resent in the future.

[0149] S6.2 Determine the compensation transmission link before sending new data in the next synchronization cycle;

[0150] Specifically, at the start of the next synchronization cycle, the dual-domain synchronization gateway first checks whether there is a synchronization data frame to be compensated. If there is no synchronization data frame to be compensated, it enters the new data transmission process of the next synchronization cycle. If there is a synchronization data frame to be compensated, the dual-domain synchronization gateway pauses triggering the new data transmission of the next synchronization cycle and reads the link selection result table to obtain the primary synchronization link identifier and backup synchronization link identifier corresponding to the synchronization data frame to be compensated. Subsequently, it obtains the current wireless communication quality of the primary synchronization link according to the link detection method in S4, and updates the current link synchronization score of the primary synchronization link in combination with the corresponding isolation attenuation characteristics and logical clock calibration error. When the current link synchronization score of the primary synchronization link is not lower than the preset link threshold, the primary synchronization link is determined as the compensation transmission link. When the current link synchronization score of the primary synchronization link is lower than the preset link threshold, the backup synchronization link is determined as the compensation transmission link.

[0151] It should be noted that the preset link threshold is exemplarily set to 0.6 to 0.8, and is specifically determined based on the lowest link synchronization score that enables a synchronization confirmation success rate of no less than 95% and a round-trip delay that does not exceed the maximum allowable round-trip delay during cleanroom on-site link calibration tests.

[0152] S6.3, Resend the synchronization data frame to be compensated through the compensation transmission link;

[0153] Specifically, a compensation transmission command is sent to the corresponding clean area wireless terminal node. The clean area wireless terminal node reads the synchronization data frame to be compensated from its local transmission buffer according to the compensation transmission command, and sends the synchronization data frame to be compensated to the corresponding mezzanine wireless relay node through the compensation transmission link. The mezzanine wireless relay node verifies the synchronization data frame to be compensated according to the synchronization verification method in S5, and forwards it to the maintenance mezzanine side receiver after the verification is successful, while returning a compensation synchronization confirmation frame to the dual-domain synchronization gateway.

[0154] It should be noted that the compensation transmission instruction includes the original synchronization cycle number, the original data version number, the compensation transmission identifier, and the compensation transmission link identifier.

[0155] S6.4 Release the new data transmission for the next synchronization cycle based on the compensation synchronization confirmation frame;

[0156] Specifically, after receiving the compensation synchronization confirmation frame, the dual-domain synchronization gateway compares the synchronization cycle number, received data version number, clean area wireless terminal node identifier, and confirmation status in the compensation synchronization confirmation frame with the data frame to be compensated synchronization. If the synchronization cycle number, received data version number, and clean area wireless terminal node identifier are all consistent, and the confirmation status is valid, then the compensation synchronization of the data frame to be compensated is determined to be complete, the corresponding compensation mark is cleared, and the clean area wireless terminal node is allowed to send new data for the next synchronization cycle. If no compensation synchronization confirmation frame is received, or the above comparison information is inconsistent, or the confirmation status is invalid, then the compensation status of the data frame is maintained, and compensation transmission will continue to be performed preferentially before the next synchronization transmission.

[0157] Reference Figure 2 This embodiment also provides a system for synchronous wireless communication in cleanroom spaces and maintenance mezzanines, comprising:

[0158] The node mapping module is used to establish the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node;

[0159] The feature generation module is used to generate partition attenuation features based on the cleanroom partition structure through which the candidate communication link passes.

[0160] The clock calibration module is used to perform logical clock calibration on both sides of the node based on the reference clock of the dual-domain synchronization gateway.

[0161] The data frame generation module is used to generate clean area data frames to be synchronized, carrying synchronization identifiers.

[0162] The link determination module is used to determine the primary synchronization link and the backup synchronization link based on wireless communication quality, isolation attenuation characteristics, and logic clock calibration error.

[0163] The synchronization compensation module is used to complete the synchronous transmission of data frames to be synchronized in the clean area, and to resend the data frames to be compensated if synchronization is not completed.

[0164] In summary, this invention establishes a collaborative mechanism between the cleanroom space and the maintenance mezzanine, including node mapping, partition attenuation identification, logical clock calibration, primary / backup link selection, and breakpoint compensation transmission. This mechanism enables the reliable transmission of equipment status, environmental status, and alarm status collected by wireless terminal nodes in the cleanroom to the maintenance mezzanine according to a unified synchronization cycle. This solution reduces the impact of through-wall wiring and personnel entry into the cleanroom on cleanliness levels. Furthermore, it optimizes synchronization link selection by incorporating actual obstruction structures such as metal ceilings, ducts, filters, and equipment casings, reducing the risk of link misjudgment and data delay. Simultaneously, data version numbers, logical sampling timestamps, and compensation transmission identifiers ensure data sequence continuity, allowing the maintenance mezzanine to obtain critical cleanroom status information promptly and accurately, thus improving the reliability of cleanroom operation monitoring and maintenance response.

[0165] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines, characterized in that, include: Cleanroom wireless terminal nodes are set up in the cleanroom space, and mezzanine wireless relay nodes are set up in the maintenance mezzanine. The node mapping relationship between the cleanroom wireless terminal nodes and the mezzanine wireless relay nodes is established through a dual-domain synchronization gateway. Candidate communication links are determined based on the node installation locations corresponding to the node mapping relationship, and partition attenuation characteristics are generated based on the cleanroom partition structures through which the candidate communication links pass. The reference clock of the dual-domain synchronization gateway is used to perform logical clock calibration on the clean area wireless terminal node and the mezzanine wireless relay node, and the clean area wireless terminal node generates a clean area data frame to be synchronized carrying a synchronization identifier based on the calibrated logical clock. The dual-domain synchronization gateway determines the primary synchronization link and the backup synchronization link based on the wireless communication quality, isolation attenuation characteristics and logical clock calibration error of the candidate communication links. The clean area wireless terminal node sends the clean area data frames to be synchronized to the maintenance mezzanine via the mezzanine wireless relay node through the main synchronization link, and judges the data synchronization status based on the received synchronization confirmation information. If synchronization is not completed, the clean area data frame to be synchronized will be marked as a data frame to be compensated for synchronization. Before the new data is sent in the next synchronization cycle, the data frame to be compensated for synchronization will be resent through the primary synchronization link or the backup synchronization link.

2. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 1, characterized in that: The steps for establishing the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node through the dual-domain synchronization gateway are as follows: The dual-domain synchronization gateway receives node registration frames returned by the clean area wireless terminal node and the mezzanine wireless relay node, and generates a node registration table based on the node type, region, installation coordinates and local clock status in the node registration frame. Based on the node registration table, the spatial proximity distance between the clean area wireless terminal node and each mezzanine wireless relay node is calculated. The mezzanine wireless relay nodes with the smallest and second smallest spatial proximity distances are selected as the priority candidate relay node and the backup candidate relay node, respectively. A wireless node mapping table is generated to establish the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node.

3. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 2, characterized in that: The step of determining candidate communication links based on the node installation location corresponding to the node mapping relationship means that, based on the node mapping relationship, the spatial connection between each clean area wireless terminal node and the corresponding priority candidate relay node and backup candidate relay node is determined as a candidate communication link.

4. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 3, characterized in that: The steps for generating partition attenuation features based on cleanroom partition structures traversed by candidate communication links are as follows: Identify cleanroom partition structures that candidate communication links pass through or are adjacent to, and obtain the corresponding partition structure set; calculate the normalized influence degree corresponding to each type of partition structure based on the degree of crossing, proximity, and thickness level of the candidate communication links relative to each type of partition structure; calculate the partition attenuation correction coefficient of the candidate communication links based on the normalized influence degree and attenuation weight of each type of partition structure, and use it as the partition attenuation feature.

5. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 4, characterized in that: The reference clock based on the dual-domain synchronization gateway performs logical clock calibration on the cleanroom wireless terminal node and the mezzanine wireless relay node. The steps are as follows: Based on the wireless node mapping relationship, each clean area wireless terminal node and its corresponding priority candidate relay node and backup candidate relay node are determined as a set of synchronization calibration nodes, and the dual-domain synchronization gateway sends clock synchronization frames to each node in the set of synchronization calibration nodes. Receive clock response frames returned by the synchronization calibration node, and calculate the hardware clock increment and latency-corrected synchronization error for each node based on the gateway sending timestamp, the gateway receiving timestamp, and the node's local clock state. Based on the hardware clock increment and synchronization error, the logic clock rate of each node is updated using the normalized minimum mean square correction method to obtain the clock calibration result.

6. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 5, characterized in that: The steps for generating a cleanroom synchronization data frame carrying a synchronization identifier by the cleanroom wireless terminal node based on the calibrated logical clock are as follows: Based on the clock calibration results, the dual-domain synchronization gateway sends a synchronization data start frame carrying the synchronization cycle number and data version number to the cleanroom wireless terminal node. The cleanroom wireless terminal node generates a logical sampling timestamp according to the updated logical clock rate and collects the corresponding cleanroom status data. The synchronization cycle number, data version number, clean area wireless terminal node identifier, logical sampling timestamp, clean room status data, and verification field are written into the same data frame to generate a clean area data frame to be synchronized, and the frame header summary information is returned to the dual-domain synchronization gateway.

7. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 6, characterized in that: The steps for determining the primary synchronization link and the backup synchronization link are as follows: Based on the cleanroom wireless terminal node corresponding to the data frame to be synchronized in the cleanroom, the corresponding candidate communication link is determined from the wireless node mapping table. Link detection is performed on candidate communication links to obtain and normalize the wireless communication quality parameters of candidate communication links, and the corresponding isolation attenuation characteristics and logic clock calibration errors are read. The link synchronization score is calculated based on the normalized wireless communication quality parameters, isolation attenuation characteristics, and logic clock calibration error, and the primary synchronization link and backup synchronization link are determined based on the link synchronization score.

8. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 7, characterized in that: The step of determining the data synchronization status based on the received synchronization confirmation information refers to comparing the synchronization confirmation information with the frame header summary information and the main synchronization link information. If the number, version, node, and status are all consistent and valid, the data synchronization is determined to be complete; otherwise, the data synchronization is determined to be incomplete, and a synchronization failure result is generated.

9. The method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines as described in claim 8, characterized in that: Marking the clean area data frame to be synchronized as a data frame to be compensated for synchronization means determining the corresponding clean area data frame to be synchronized based on the synchronization failure result, writing a compensation sending identifier into the clean area data frame to be synchronized, and retaining the original synchronization cycle number, the original data version number, and the original logical sampling timestamp.

10. A system for synchronous wireless communication in cleanroom spaces and maintenance mezzanines, based on the method for synchronous wireless communication in cleanroom spaces and maintenance mezzanines according to any one of claims 1 to 9, characterized in that, include: The node mapping module is used to establish the node mapping relationship between the clean area wireless terminal node and the mezzanine wireless relay node; The feature generation module is used to generate partition attenuation features based on the cleanroom partition structure through which the candidate communication link passes. The clock calibration module is used to perform logical clock calibration on both sides of the node based on the reference clock of the dual-domain synchronization gateway. The data frame generation module is used to generate clean area data frames to be synchronized, carrying synchronization identifiers. The link determination module is used to determine the primary synchronization link and the backup synchronization link based on wireless communication quality, isolation attenuation characteristics, and logic clock calibration error. The synchronization compensation module is used to complete the synchronous transmission of data frames to be synchronized in the clean area, and to resend the data frames to be compensated if synchronization is not completed.

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