A data communication method for an automated guided vehicle

Abstract

The application discloses a data communication method of an automatic guided vehicle, and belongs to the technical field of communication. By constructing three-dimensional geometric models of various industrial facilities in a factory building and a three-dimensional space model of the factory building, a signal propagation cone-shaped space region is generated in combination with communication base station deployment parameters, precise calculation of the equivalent signal attenuation value of the automatic guided vehicle to the base station is realized, the shielding attenuation and multipath fading influence of facilities with high electromagnetic shielding properties in a complex industrial environment on wireless signals are converted into quantifiable parameters, and when the signal attenuation exceeds a threshold value, a mechanism for establishing a wired communication link connection is established, active pre-switching of the wireless communication link and the wired communication link is realized, loss or delay of the control instruction of the automatic guided vehicle caused by interruption of the wireless signal is avoided, the adaptability of the industrial Internet of Things communication system to a strong electromagnetic shielding scene is improved, and therefore the reliability of the industrial Internet of Things communication and the safety of the production system are significantly improved.

Description

Technical Field

[0001] This application belongs to the field of communication technology, and in particular relates to a data communication method for an automated guided vehicle. Background Technology

[0002] Automated Guided Vehicles (AGVs) are transport vehicles equipped with electromagnetic or optical automatic navigation devices, capable of traveling along a prescribed navigation path, and possessing safety protection and various transfer functions. With the continuous development and innovation of AGV technology, AGVs are widely used in various industries. In the dynamic production network of smart factories, AGVs, as mobile intelligent nodes undertaking key tasks such as material handling and process connection, directly determine the smooth operation efficiency and safety level of the production line through the stability and reliability of their communication links.

[0003] However, the metal processing equipment, steel structure frames, warehouse racks and other industrial facilities deployed in the factory together constitute a complex propagation medium with a strong electromagnetic shielding effect. This will significantly block and attenuate the wireless communication signal of the AGV, causing the signal transmission path to propagate non-line-of-sight and also causing multipath fading. This seriously affects the timeliness and accuracy of the AGV's real-time reception of control commands, and in turn leads to production accidents such as material transportation delays and equipment collisions. Summary of the Invention

[0004] This application provides a data communication method for automated guided vehicles (AGVs) to at least solve the problem in the related art where industrial facilities in the factory significantly obstruct and attenuate the wireless communication signal of the AGV, thus affecting the timeliness and accuracy of the AGV's real-time reception of control commands.

[0005] This application provides a data communication method for an automated guided vehicle (AGV), wherein the AAV is located inside a factory building, and the factory building also houses several different types of industrial facilities. The method includes:

[0006] By constructing three-dimensional geometric models of various industrial facilities within the factory, a three-dimensional spatial model of the factory is obtained, and material attribute labels for the corresponding industrial facilities are marked on each three-dimensional geometric model. The material attribute labels include high electromagnetic shielding attributes or low shielding attributes.

[0007] A spherical coordinate system is established at the communication base station of the automated guided vehicle, and a cone-shaped signal propagation area is generated with the antenna phase center of the communication base station antenna as the origin and the main radiation direction as the axis, based on the antenna radiation parameters of the communication base station.

[0008] The real-time location information of the automated guided vehicle is obtained, and the virtual position coordinates of the automated guided vehicle in the three-dimensional space model are determined based on the real-time location information.

[0009] Using the virtual position coordinates of the automated guided vehicle in the three-dimensional space model as the starting point and the origin of the spherical coordinate system of the communication base station as the ending point, a ray-shaped signal propagation path is generated between the automated guided vehicle and the communication base station;

[0010] If an intersection region is detected between the signal propagation path and at least one three-dimensional geometric model with high electromagnetic shielding properties, the equivalent signal attenuation value from the automated guided vehicle to the communication base station is calculated based on the intersection region.

[0011] In response to the equivalent signal attenuation value being greater than or equal to a first preset threshold and less than a second preset threshold, a target connection node is determined, and the automated guided vehicle is controlled to establish a wired communication link connection with the target connection node, wherein the second preset threshold is greater than the first preset threshold;

[0012] Parse the protocol header of the network layer data packets of the automated guided vehicle and identify the real-time control data stream and the non-real-time monitoring data stream in the output data stream;

[0013] Real-time control data streams are transmitted via wireless communication links, while non-real-time monitoring data streams are transmitted via wired communication links.

[0014] In response to the equivalent signal attenuation value being greater than or equal to a second preset threshold, all output data streams are migrated to a wired communication link for transmission.

[0015] The data communication method for automated guided vehicles (AGVs) in this application constructs three-dimensional geometric models of various industrial facilities within the factory and a three-dimensional spatial model of the factory. Combined with communication base station deployment parameters, it generates a signal propagation cone-shaped spatial region, enabling precise calculation of the equivalent signal attenuation value from the AGV to the base station. This transforms the effects of high electromagnetic shielding facilities on wireless signal attenuation and multipath fading in complex industrial environments into quantifiable parameters, solving the problems of coarse signal attenuation judgment and delayed blind zone prediction in related technologies. Furthermore, a mechanism for establishing a wired communication link connection when signal attenuation exceeds a threshold is implemented, achieving proactive pre-switching between wireless and wired communication links. This avoids the loss or delay of AGV control commands due to wireless signal interruption, ensuring the continuity and reliability of real-time control data transmission. This enhances the adaptability of the industrial IoT communication system to strong electromagnetic shielding scenarios, significantly improving the reliability of industrial IoT communication and the safety of the production system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a data communication method for an automated guided vehicle provided in an embodiment of this application. Detailed Implementation

[0018] 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.

[0019] 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.

[0020] With the deep integration and innovative evolution of Industry 4.0 and intelligent manufacturing, the Industrial Internet of Things (IIoT) is becoming the core nerve link connecting physical production systems and digital management platforms with its powerful interconnection capabilities and data-driven characteristics.

[0021] Automated Guided Vehicles (AGVs) are transport vehicles equipped with electromagnetic or optical automatic navigation devices, capable of traveling along a predetermined navigation path, and possessing safety protection and various transfer functions. With the continuous development and innovation of AGV technology, AGVs are widely used in various industries. AGVs typically achieve precise positioning and path planning through technologies such as laser navigation, magnetic navigation, and visual navigation. They can automate material handling and arrangement in warehouses, factories, logistics centers, and other locations. AGVs possess obstacle avoidance, sensing, navigation, and control functions, and can interact with other equipment and systems for information exchange and collaborative operations.

[0022] In the dynamic production network of a smart factory, AGVs, as mobile intelligent nodes undertaking key tasks such as material handling and process connection, directly determine the smooth operation efficiency and safe production level of the production line through the stability and reliability of their communication links.

[0023] Base stations (such as Wi-Fi access points, 5G base stations, and industrial wireless gateways) provide wireless network connectivity for AGVs, ensuring real-time data exchange between AGVs and control centers (such as scheduling servers and cloud platforms). The control center sends control commands (such as picking up goods, obstacle avoidance, and charging) to the AGVs through the base stations. The AGVs then feed back their status information (such as battery level, location, and faults) to the base stations. The base stations aggregate the AGVs' operational data (such as speed, load, and fault logs) and upload it to the cloud for big data analysis.

[0024] However, the metal processing equipment, steel structure frames, and storage racks deployed within the factory constitute a complex propagation medium with strong electromagnetic shielding effects. This significantly obstructs and attenuates the wireless communication signals of the AGV, causing non-line-of-sight propagation and multipath fading. This occurs when signals are reflected and scattered by different surfaces, resulting in multiple paths and superposition, causing rapid fluctuations in signal amplitude and phase distortion at the receiving end. Consequently, this severely affects the timeliness and accuracy of the AGV's real-time reception of control commands, leading to production accidents such as material transport delays and equipment collisions.

[0025] To address the problems in related technologies, this application provides a data communication method for automated guided vehicles.

[0026] It should be noted that the data communication method of this automated guided vehicle is applied to the Industrial Internet of Things (IIoT). Specifically, the automated guided vehicle is located inside a factory building, which also houses several different types of industrial facilities, including but not limited to: metal processing equipment, steel structure frames, and storage racks.

[0027] The data communication method for automated guided vehicles provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0028] Figure 1 A flowchart illustrating a data communication method for an automated guided vehicle according to an embodiment of this application is shown. Figure 1 As shown, the data communication method of the automated guided vehicle may specifically include the following steps:

[0029] S101. By constructing a three-dimensional geometric model of each industrial facility in the factory, a three-dimensional spatial model of the factory is obtained, and the material attribute labels of the corresponding industrial facilities are marked on each three-dimensional geometric model. The material attribute labels include high electromagnetic shielding attribute or low shielding attribute.

[0030] S102. Establish a spherical coordinate system at the communication base station of the automated guided vehicle, and generate a cone-shaped signal propagation area with the antenna phase center of the communication base station as the origin and the main radiation direction as the axis according to the antenna radiation parameters of the communication base station.

[0031] S103. Obtain the real-time location information of the automated guided vehicle and determine the virtual position coordinates of the automated guided vehicle in the three-dimensional space model based on the real-time location information.

[0032] S104. Using the virtual position coordinates of the automated guided vehicle in the three-dimensional space model as the starting point and the origin of the spherical coordinate system of the communication base station as the ending point, generate a ray-shaped signal propagation path between the automated guided vehicle and the communication base station.

[0033] S105. If it is detected that the signal propagation path intersects with at least one three-dimensional geometric model with high electromagnetic shielding properties, calculate the equivalent signal attenuation value from the automated guided vehicle to the communication base station based on the intersecting area.

[0034] S106. In response to the equivalent signal attenuation value being greater than or equal to a first preset threshold and less than a second preset threshold, a target connection node is determined, and the automated guided vehicle is controlled to establish a wired communication link connection with the target connection node, wherein the second preset threshold is greater than the first preset threshold.

[0035] S107. Parse the protocol header of the network layer data packets of the automated guided vehicle and identify the real-time control data stream and non-real-time monitoring data stream in the output data stream;

[0036] S108. Real-time control data stream is transmitted via wireless communication link, and non-real-time monitoring data stream is transmitted via wired communication link;

[0037] S109. In response to the equivalent signal attenuation value being greater than or equal to the second preset threshold, all output data streams are migrated to the wired communication link for transmission.

[0038] Therefore, by constructing three-dimensional geometric models of various industrial facilities within the factory and a three-dimensional spatial model of the factory, and combining these with communication base station deployment parameters to generate a signal propagation cone-shaped spatial region, the equivalent signal attenuation value from the automated guided vehicle (AGV) to the base station was accurately calculated. This transformed the effects of high electromagnetic shielding facilities on wireless signal attenuation and multipath fading in complex industrial environments into quantifiable parameters, solving the problems of coarse signal attenuation judgment and lagging blind zone prediction in related technologies. Furthermore, a mechanism was established to establish a wired communication link when signal attenuation exceeds a threshold, enabling proactive pre-switching between wireless and wired communication links. This avoids the loss or delay of AGV control commands due to wireless signal interruption, ensuring the continuity and reliability of real-time control data transmission. This enhances the adaptability of the industrial IoT communication system to strong electromagnetic shielding scenarios, significantly improving the reliability of industrial IoT communication and the safety of the production system.

[0039] The specific implementation methods for each of the above steps are described below.

[0040] In some embodiments, in S101, a point cloud dataset is generated based on the surface contour points of industrial facilities within the factory collected by scanning; the discrete point cloud in the point cloud dataset is converted into a triangular mesh surface model using a triangular surface reconstruction algorithm, wherein each triangular mesh unit of the triangular mesh surface model includes three vertex coordinate information and normal vector information; the adjacent triangular meshes are smoothed using a Laplacian smoothing algorithm to obtain a continuous geometric surface model that meets the first preset condition; the closed boundary of the continuous geometric surface model is extracted, and the three-dimensional geometric model of each industrial facility is identified using a three-dimensional connected component analysis algorithm.

[0041] The first preset condition includes: using the Laplacian smoothing algorithm to smooth the surface of adjacent triangular meshes, iteratively adjusting the vertex positions to make the angle between the normal vectors of adjacent facets less than 5°, and finally generating a continuous geometric surface with an error of less than 0.3 mm.

[0042] In practice, high-precision laser scanning equipment is used to perform a full-area scan of the factory interior, acquiring surface contour points of physical entities such as steel structure frames, metal processing equipment (CNC machine tools and stamping machines), and warehouse shelves at a resolution of 0.5 mm, forming a point cloud dataset containing millions of coordinate points. This dataset is then processed using spatial filtering algorithms such as voxel mesh filtering to remove noise points. Finally, triangulation surface reconstruction algorithms such as the Ball-Pivoting Algorithm are used to convert the discrete point cloud into a triangular mesh surface model. Each triangular mesh cell records the coordinates of three vertices and the normal vector information.

[0043] To ensure the continuity and smoothness of the geometric surface, adjacent triangular meshes undergo surface smoothing: a Laplace smoothing algorithm is used, iteratively adjusting vertex positions to ensure the angle between the normal vectors of adjacent facets is less than 5°, ultimately generating a continuous geometric surface with an error of less than 0.3 mm. Taking an automotive assembly plant as an example, this process can accurately reproduce the electromagnetic reflection characteristics of complex curved surfaces such as curved steel beams and cylindrical robotic arm bases, providing a reliable geometric basis for subsequent signal attenuation calculations.

[0044] Closed boundaries are extracted from continuous geometric surfaces, and the geometric models of independent devices are identified through a three-dimensional connected component analysis algorithm.

[0045] Furthermore, for metal equipment such as stainless steel shelves and aluminum alloy machine tool housings, high electromagnetic shielding properties are specified according to the ASTM material database, specifically including a dielectric constant of 15, a permeability of 2000 times the vacuum permeability, and a conductivity of [missing information]. Siemens parameters per meter, etc.; for non-metallic equipment such as plastic conveyor belts and concrete columns, low shielding is specified, with dielectric constant set to 4, permeability set to vacuum permeability, and conductivity set to [value missing]. Siemens per meter.

[0046] In some embodiments, in S102, a spherical coordinate system is established at the installation location of the communication base station, such as a 5G macro base station and a WiFi access point. With the phase center of the base station antenna as the origin, a conical spatial region in the main radiation direction is generated according to the radiation parameters provided by the antenna manufacturer, such as, but not limited to, the antenna azimuth angle and elevation angle (e.g., horizontal beamwidth 65°, vertical beamwidth 15°).

[0047] Furthermore, it should be noted that within this conical signal propagation region, the signal strength attenuates non-linearly as the radius of the conical spatial region expands. Specifically, the signal strength reference value follows the free space path loss model:

[0048] ;

[0049] Where d is the propagation distance in meters; f is the signal frequency in megahertz; and a nonlinear attenuation correction factor is introduced, for example, the metal surface reflection attenuation coefficient is set to 0.8 and the penetration loss coefficient is set to 0.6, so that the signal strength attenuates exponentially as the radius of the conical region expands.

[0050] In this way, laser scanning technology is used to acquire point cloud data of the factory interior, and surface reconstruction is used to generate a continuous surface model containing the three-dimensional geometric contours of all equipment. For different equipment material characteristics, the high electromagnetic shielding properties of the metal structure are labeled, and combined with the deployment parameters of the communication base station, a cone-shaped signal propagation area with the base station as the origin and the main radiation direction as the axis is generated, providing basic data for subsequent signal attenuation calculations.

[0051] In some embodiments, in S103, the physical position coordinates of the automated guided vehicle are acquired in real time through the vehicle positioning system and mapped onto a three-dimensional spatial model to generate virtual position coordinates. This mapping process employs a coordinate transformation algorithm to ensure that the positional accuracy of the physical space and the virtual model matches, providing accurate input for signal propagation path analysis.

[0052] Furthermore, in some embodiments, in S105, in the three-dimensional spatial model, a ray-shaped straight-line propagation path is generated, starting from the virtual position coordinates of the automated guided vehicle and ending at the origin of the base station spherical coordinate system. Then, a hierarchical bounding box tree (BVHTree) is used to accelerate intersection detection. First, the intersection of the ray with the axial bounding box of the industrial equipment is detected. If a match is found, the precise intersection with the triangular mesh facet is further detected, and the geometric position and surface normal vector of all intersecting regions are recorded.

[0053] Taking the metal processing area as an example, when the AGV travels to the middle of the CNC machine tool group, the signal path may intersect with multiple cylinders such as motor housings and cuboids such as control cabinets. The detection and parameter extraction of more than 100 intersecting surfaces can be completed within 10ms, providing real-time data support for subsequent loss calculation.

[0054] Furthermore, the geometric surface normal vector of the intersecting region is extracted; based on the angle between the geometric surface normal vector and the signal propagation path, the reflection loss coefficient of the base station signal on the corresponding industrial facility surface is calculated; based on the propagation distance between the base station signal and the three-dimensional geometric model and the signal frequency, the free space transmission loss corresponding to the natural attenuation of the signal in an ideal unobstructed environment is calculated; the penetration depth of the signal propagation path through the three-dimensional geometric model is measured, and the penetration loss coefficient is calculated based on the penetration depth and conductivity; based on the free space transmission loss, reflection loss coefficient, and penetration loss coefficient, the equivalent signal attenuation value is calculated.

[0055] The specific definitions and calculation methods for free-space transmission loss, reflection loss coefficient, and penetration loss coefficient are as follows:

[0056] Free space transmission loss According to the ITU-RP.525 standard formula, this loss reflects the natural attenuation of the signal in an unobstructed environment and is positively correlated with the propagation distance d and the signal frequency f.

[0057] Reflection loss coefficient Based on the angle θ between the surface normal vector of the intersecting region and the signal path, where the value of θ ranges from 0° to 90°, the reflection loss of the metal surface can reach 15dB when θ is 45°, while the loss drops to 5dB when θ is 0°, i.e., normal incidence. This dynamic calculation mechanism accurately reflects the angle dependence of signal reflection.

[0058] Penetration loss coefficient Combining the material's electrical conductivity σ with the penetration depth d p Calculations show that, for example, a 10mm thick steel plate can have a penetration loss of 25dB for a 2.4GHz signal, while a 5mm thick aluminum alloy plate has a loss of 18dB, which is significantly different from the fixed loss value set uniformly in traditional solutions.

[0059] Therefore, by linearly superimposing the above three losses, we can obtain the equivalent signal attenuation value, that is:

[0060] .

[0061] In this way, the straight-line propagation path from the automated guided vehicle (AGV) to the communication base station is calculated in a three-dimensional spatial model. By detecting the intersection area between this path and the high electromagnetic shielding device, and combining the surface normal vector and material conductivity parameters, reflection loss and penetration loss are calculated respectively, and free-space transmission loss is superimposed to finally generate the equivalent signal attenuation value. This calculation method transforms physical environment characteristics into quantified communication parameters, significantly improving the signal prediction accuracy.

[0062] As an optional embodiment, the method further includes: establishing an electromagnetic parameter lookup table for typical factory materials, wherein the typical materials include steel, aluminum alloy, and concrete, and the electromagnetic parameters include dielectric constant and permeability; when the three-dimensional geometric model is identified as a steel structure, retrieving the dielectric constant and permeability of the steel from the electromagnetic parameter lookup table; calculating the reflectivity of electromagnetic waves on the material surface based on the dielectric constant, calculating the eddy current loss factor based on the permeability, and using the product of the reflectivity and the eddy current loss factor as the comprehensive shielding coefficient of the three-dimensional geometric model; when the signal propagation path between the automated guided vehicle and the communication base station passes through multiple three-dimensional geometric models, superimposing the comprehensive shielding coefficients of the multiple three-dimensional geometric models to obtain the total shielding effect. This improves the generation of material attribute labels.

[0063] In practice, the first step is to establish a comparison table of electromagnetic parameters for typical materials in the factory. This comparison table is based on international standard material databases such as ASTM (American Society for Testing and Materials) and electromagnetic compatibility test data, and includes the dielectric constant ε and magnetic permeability μ of three typical materials: steel, aluminum alloy, and concrete.

[0064] The specific parameters are as follows:

[0065] Steel: Dielectric constant ε=15, Magnetic permeability , Let be the free permeability, and take a value of . This reflects its strong electromagnetic shielding characteristics;

[0066] Aluminum alloy: dielectric constant ε=10, magnetic permeability It has both conductivity and relatively weak shielding ability;

[0067] Concrete: Dielectric constant ε=4, Magnetic permeability It belongs to the category of low electromagnetic shielding materials.

[0068] When the 3D modeling module determines that the 3D geometric model of the equipment is a steel structure through geometric feature recognition algorithms such as curvature analysis and material classification neural networks, it automatically calls the corresponding electromagnetic parameters from the lookup table to avoid subjective errors from manual annotation.

[0069] Reflectance calculation:

[0070] The reflectivity of electromagnetic waves varies on different material surfaces. The higher the dielectric constant of a material, the greater its reflectivity, indicating that more incident signals will be reflected and only a small amount will enter the material.

[0071] Calculation of eddy current loss factor:

[0072] Metallic materials experience energy loss due to induced currents in alternating magnetic fields. This eddy current loss is closely related to the material's permeability and the signal frequency. Eddy current loss increases significantly under high-frequency signals, exacerbating signal attenuation.

[0073] Overall shielding coefficient generation:

[0074] Multiplying the reflectivity by the eddy current loss factor yields the overall shielding coefficient of the device. This coefficient comprehensively reflects the material's ability to reflect and absorb electromagnetic waves. The overall shielding coefficient varies greatly among different materials, providing a scientific basis for signal attenuation calculations.

[0075] It should be understood that when the straight-line propagation path between the AGV and the base station passes through n three-dimensional geometric models, the total shielding effect S is calculated using the logarithmic superposition method according to the following formula. total :

[0076] ;

[0077] Among them, S i This represents the overall shielding coefficient of the i-th material, taking into account the nonlinear superposition of the shielding effects of each material, thus avoiding errors caused by simple arithmetic addition. For example, a signal passes through a 10mm steel plate sequentially. With 5mm aluminum alloy plate At that time, the total shielding effect was 30.4dB, rather than simply 50dB, which is more in line with the actual electromagnetic propagation law.

[0078] Furthermore, in some embodiments, in S106, in response to the equivalent signal attenuation value being greater than or equal to a first preset threshold and less than a second preset threshold, a wired communication interface wake-up command for the automated guided vehicle is triggered; location information of multiple wired access points within a preset range of the automated guided vehicle is obtained; based on the location information of the multiple wired access points, the spatial distance from the automated guided vehicle to each wired access point is calculated, and the wired access point corresponding to the minimum spatial distance is determined as the target connection node; a link establishment request is sent to the target connection node to negotiate the communication protocol version between the automated guided vehicle and the target connection node; and while the wireless communication link remains active, physical layer synchronization of the wired communication link is completed through an out-of-band channel.

[0079] In practice, when the equivalent signal attenuation value first exceeds the first preset threshold, the onboard controller of the transport vehicle immediately triggers a wired communication interface wake-up command, activating the positioning module and scanner integrated at the bottom of the AGV to perform spatial positioning of wired access points within a preset range around the current physical location. The positioning module acquires the coordinates of the access points with high precision, and the scanner reads the device ID, supported protocols, and other metadata of the access points to form a candidate node list.

[0080] Then, a specific algorithm is used to calculate the distance from the AGV to each access point, and the node with the smallest distance is selected as the target connection node. This can complete the distance calculation of multiple access points in a short time and quickly select the optimal access point.

[0081] Therefore, after the target connection node receives the link establishment request, it exchanges the list of supported protocols through the Industrial Ethernet Discovery Protocol and automatically matches the highest compatible version to ensure communication compatibility.

[0082] In some embodiments, while the wireless communication link remains active, the AGV and the access point achieve physical layer synchronization through an independent communication channel, avoiding the occupation of wireless spectrum resources. The synchronization process includes clock calibration, signal handshake, and error checking, ensuring consistent data transmission timing, good link connectivity, and an extremely low bit error rate. Furthermore, testing in a smart warehouse demonstrates that this mechanism can complete the entire process from wake-up to wired link activation in a short time, with minimal fluctuations in wireless link data transmission latency during synchronization, ensuring that the AGV can still receive scheduling commands in real time during switching.

[0083] In this way, when the equivalent signal attenuation value exceeds the first preset threshold, the wired communication interface of the automated guided vehicle is activated; by scanning the surrounding wired access points, the optimal connection node is selected based on the spatial distance and port status, and the automatic docking of cables is achieved by using flexible physical connection technology, ensuring reliable wired communication of mobile devices in dynamic environments.

[0084] Furthermore, it should be understood that multiple automated guided vehicles (AGVs) may be present within the factory. In another embodiment, after determining the target connection node, the method further includes: when multiple AGVs simultaneously send link establishment requests to the same wired access point, obtaining the task urgency indicator of each AGV and the percentage by which its equivalent signal attenuation value exceeds a first preset threshold; prioritizing the multiple AGVs based on the percentage by which their task urgency indicators and equivalent signal attenuation values ​​exceed the first preset threshold, obtaining a priority ranking result; allocating physical port resources of the wired access point to the multiple AGVs sequentially according to the priority ranking result; and operating a wireless ad hoc network relay transmission mode for AGVs that have not obtained physical port resources.

[0085] In practice, when multiple automated guided vehicles (AGVs) compete for wired access points simultaneously, the task urgency level of each device is first obtained through the Industrial Internet of Things (IIoT) platform. This level is defined in real-time by the manufacturing execution department based on the nature of the production task and is divided into four levels: Level 1 urgent tasks include equipment fault alarms, safety emergency responses, and immediate delivery of materials for critical processes; these tasks are directly related to production safety or the operation of core processes. Level 2 urgent tasks cover routine material replenishment on the production line and transportation of precision components; these tasks have high timeliness requirements but are not immediate. Level 3 urgent tasks are routine logistics operations such as handling ordinary materials and warehousing finished products. Level 4 urgent tasks include non-critical tasks such as equipment inspection data feedback and warehouse organization during non-production periods.

[0086] The calculation of the percentage of signal attenuation exceeding the limit is based on the difference between the equivalent signal attenuation value monitored in real time and the first preset threshold. This threshold can be set according to the minimum usable quality of wireless communication under typical electromagnetic environment in the factory, usually around -100dBm, reflecting the degree of signal degradation in the area where the equipment is currently located.

[0087] In practice, priority determination follows a dual rule: "prioritizing task urgency and supplementing by signal attenuation percentage." First, Automated Guided Vehicles (AGVs) undertaking Level 1 urgent tasks have the highest priority, regardless of signal attenuation levels, before Level 2 and lower-level tasks. If tasks are of equal urgency, the percentage of signal attenuation exceeding the limit is compared; a higher percentage indicates poorer communication quality and higher priority. For example, if two AGVs undertaking Level 1 urgent tasks simultaneously request access, one with a signal attenuation of -115dBm (15% exceeding the limit) and the other with -120dBm (20% exceeding the limit), the latter, due to its more severe signal degradation, will be granted priority. A lexicographical sorting algorithm is used, first ranking tasks from highest to lowest urgency, then sorting devices of the same level from largest to smallest signal attenuation percentage, ensuring that limited wired port resources are allocated to the most needed devices. For AGVs without a port, a wireless ad hoc network relay mode is automatically triggered to avoid data transmission interruptions while waiting for a wired connection.

[0088] In some embodiments, for automated guided vehicles that have not obtained physical port resources, a wireless ad hoc network relay transmission mode is operated, which may specifically include the following steps:

[0089] Automated guided vehicles (AGVs) that have not obtained physical port resources are marked as target vehicles; the real-time position coordinates and motion states of other AGVs within a preset range of the target vehicle are acquired; a direct virtual signal transmission path from the target vehicle to the communication base station and a relay virtual signal transmission path from the target vehicle to the communication base station via other AGVs are constructed in the three-dimensional spatial model; the equivalent signal attenuation value of the relay virtual signal transmission path is calculated, and the path attenuation from the target vehicle to the relay AGV, the path attenuation from the relay AGV to the communication base station, and the loss compensation value generated by the relay AGV for signal processing are superimposed; in the relay virtual signal transmission path... When the numerical relationship between the equivalent signal attenuation value and the equivalent signal attenuation value of the direct virtual signal transmission path meets the second preset condition, a cooperation instruction is sent to the target transport vehicle and the relay automated guided vehicle. After receiving the cooperation instruction, the relay automated guided vehicle creates a dedicated data forwarding channel in the network protocol stack. The target transport vehicle splits the non-real-time monitoring data stream into data block units and sends the data block units to the dedicated data forwarding channel of the relay automated guided vehicle through a wireless communication link. The relay automated guided vehicle forwards the received data block units to the communication base station through a wireless communication link. The communication base station reassembles multiple data block units into a non-real-time monitoring data stream and marks it as relay transmission mode data.

[0090] The second preset condition includes: the equivalent signal attenuation value of the relay virtual signal transmission path is lower than the equivalent signal attenuation value of the direct virtual signal transmission path, and is lower than a certain percentage of the first preset threshold, for example, lower than 90% of the first preset threshold.

[0091] In practice, when an automated guided vehicle (AGV) detects that the equivalent signal attenuation exceeds a first preset threshold and fails to connect to the nearest wired access point, it is marked as a target vehicle. At this point, the target vehicle uses its onboard ultra-wideband positioning module and real-time communication module to scan the real-time position coordinates and motion status of other AGVs within a certain radius, acquiring parameters including longitude, latitude, altitude, speed, and steering angle to form a dynamic list of neighboring devices. This information is synchronized to the onboard control system in real time, providing basic data for subsequent relay path planning.

[0092] In the 3D spatial model, two virtual signal transmission paths are constructed in parallel: one is a straight path directly connecting the target transport vehicle to the communication base station, and the other is an indirect path via a relay automated guided vehicle (AGV). The signal attenuation value of the straight path is calculated from the previously established 3D model of the factory building, taking into account factors such as metal equipment obstruction and material reflection and absorption along the path. The relay path is divided into two segments: the first segment is the transmission path from the target transport vehicle to the relay AGV, and the second segment is the transmission path from the relay AGV to the base station. The attenuation value of each segment is also calculated based on the geometric contours, material properties, and spatial distances of the equipment in the 3D model. In addition, it is necessary to evaluate the loss compensation value of the relay AGV on signal processing, including the gain from signal amplification and the delay loss introduced by protocol conversion, to ensure a more accurate signal quality assessment of the relay path.

[0093] If the calculation results show that the equivalent signal attenuation value of the relay virtual signal transmission path is not only lower than the attenuation value of the direct path of the target transport vehicle, but also lower than a certain percentage of the first preset threshold, such as 90% of the first preset threshold, it indicates that the relay path has better transmission conditions. In this case, a cooperation instruction is sent to both the target transport vehicle and the selected relay automated guided vehicle. Specifically, the cooperation instruction includes information such as the target transport vehicle's device identifier, the target address for data forwarding, and the required bandwidth resources, ensuring that the two devices can quickly establish a cooperative relationship.

[0094] After receiving the cooperation command, the relay-guided vehicle creates a dedicated data forwarding channel at the link layer of the network protocol stack, independent of its own real-time control data stream. This channel uses time-division multiple access (TDMA) or frequency-division multiple access (FDMA) technology, completely isolating it from the transmission time slots or frequency bands of real-time control data. This prevents the forwarding of non-real-time data from interfering with its own motion control, obstacle avoidance commands, and other real-time data streams. For example, real-time control data uses dedicated 5G network slice resources, while the relay forwarding channel utilizes unoccupied sub-frequency bands or idle time slots, ensuring that the two types of data do not affect each other.

[0095] The target transport vehicle divides the non-real-time monitoring data streams to be transmitted, such as temperature and humidity data collected by equipment sensors, video frames captured by onboard cameras, and operation logs, into data block units of fixed size, such as 1KB or 2KB. Each data block unit is assigned a source device identifier, such as a MAC address or unique device ID, a data sequence number, and a CRC checksum. The former is used by the base station to identify the data source, while the latter two are used to ensure the integrity and order of the data during transmission. These data blocks are sent to the dedicated data forwarding channel of the relay automated guided vehicle via a wireless communication link. The transmission process uses the efficient UDP protocol, which reduces protocol overhead and improves transmission efficiency.

[0096] After the relay-guided vehicle receives the data block, it re-verifies the data integrity. If an error is found, it requests a retransmission. Once the data is confirmed to be error-free, it adds the relay device's timestamp and path identifier to the data block, further clarifying the data transmission path and time sequence. Subsequently, the relay-guided vehicle forwards the data block to the communication base station via its own wireless communication module. After receiving all data blocks, the base station reassembles them according to the source device identifier and data sequence number, following the transmission order of the data blocks, restoring a complete non-real-time monitoring data stream. The base station also marks the data header with "Relay Transmission Mode" so that the upper layer can identify the data transmission path and type.

[0097] In this way, when an automated guided vehicle (AGV) cannot access a wired communication interface, the wireless self-organizing network relay transmission mode of nearby vehicles is activated, which optimizes the allocation of communication resources among multiple devices and ensures the timeliness and accuracy of the AGV receiving control commands.

[0098] Furthermore, in some embodiments, in S107, the process of dividing the output data stream into a real-time control data stream and a non-real-time monitoring data stream is as follows:

[0099] Before transmitting data, the automated guided vehicle (AGV) first performs deep parsing of the protocol headers of network layer data packets. For real-time control data, it can identify data packets containing motion control commands, such as speed adjustment, steering angle, and emergency stop signals, which are crucial information for ensuring the safe and stable operation of the AGV. It also identifies data packets containing robotic arm operation codes, such as grasping and releasing commands and coordinate positioning data. This type of data is typically encapsulated using proprietary industrial protocols such as Profinet, EtherCAT, and ModbusTCP. These protocols contain specific function code fields in their headers; for example, in the Modbus protocol, 0x03 is used to read holding registers, and 0x06 is used to write to a single register. Parsing these fields determines the real-time control attributes of the data.

[0100] Non-real-time monitoring data includes temperature sensor readings, such as lithium battery pack temperature and motor winding temperature, as well as video monitoring frames containing visual data such as material loading scenes and surrounding environment images, and equipment operation logs such as cumulative mileage and charging counts. This type of data is mostly transmitted using the common IP protocol, with the protocol header marked as application layer protocols such as HTTP, RTSP, and MQTT. By identifying these protocol types, it is classified as a non-real-time monitoring data packet.

[0101] Furthermore, in some embodiments, in S108, a first transmission queue and a second transmission queue are created in the network protocol stack of the automated guided vehicle; the real-time control data stream is cached in the first transmission queue, and the non-real-time monitoring data stream is cached in the second transmission queue; the first transmission queue is bound to the data port of the wireless communication link, and the second transmission queue is bound to the data port of the wired communication link, so that the real-time control data stream is transmitted through the wireless communication link, and the non-real-time monitoring data stream is transmitted through the wired communication link.

[0102] In practice, an independent dual-path transmission queue is created in the network protocol stack of the automated guided vehicle.

[0103] The first transmission queue is used to buffer real-time control data packets. It employs a priority queue scheduling algorithm, with the queue depth set according to the minimum latency requirements of industrial control. This ensures that in the event of network congestion, newly arriving urgent instructions are enqueued first, while older data overflows according to a first-in, first-out (FIFO) strategy. Each data packet is marked with a DSCP (Differentiated Service Code Point) at the link layer, for example, set to EF (Expedited Forwarding), enabling the wireless communication module to identify it as high-priority data and guaranteeing low-latency transmission of real-time control instructions.

[0104] The second transmission queue is used to buffer non-real-time monitoring data packets. It adopts a weighted fair queue algorithm, and the queue depth can be dynamically adjusted according to the data traffic, supporting the segmentation of large video frames. When the wired communication link is not ready, non-real-time data is temporarily stored in a local buffer. This buffer adopts a ring storage structure, supports writing and reading simultaneously, avoids data overwriting and loss, and ensures complete transmission when the wired link becomes available.

[0105] Regarding link binding and priority scheduling, the real-time control queue is directly bound to the data port of the wireless communication link, such as the UDP port of a 5G module. Leveraging the low latency of wireless communication (typically between 5 and 20 ms), this ensures the real-time performance of control commands. A flow control mechanism limits the use of the wireless link by non-real-time data, for example, setting the bandwidth share of real-time data to no less than 80%, ensuring the transmission quality of critical commands. The non-real-time monitoring queue is bound to a wired communication link by default, such as an EtherCAT interface, utilizing its high bandwidth (above 1Gbps) and anti-interference characteristics to transmit large volumes of data. When the wired link is not connected, such as when the automated guided vehicle is in an open area with good signal, non-real-time data is temporarily stored locally and sent in batches after entering a wired coverage area, avoiding bandwidth waste caused by frequent wireless transmissions.

[0106] In this way, the output data stream is intelligently segmented according to the real-time requirements of the data. By parsing the protocol header of the data packet, real-time data such as motion control commands and non-real-time data such as video surveillance are identified and cached into independent transmission queues respectively, thereby realizing a differentiated transmission strategy.

[0107] As can be seen, in the initial stage of connecting to the wired communication link, in order to control signal stability, real-time control data streams are transmitted via the wireless link first, ensuring low-latency transmission of critical commands. When the equivalent signal attenuation value further exceeds the preset limit (i.e., when it is greater than or equal to the second preset threshold), the wired link switching mechanism is triggered, seamlessly migrating all data streams to the wired channel, i.e., executing S109, to achieve a smooth transition of the communication link.

[0108] Additionally, in some optional embodiments, the method further includes: initiating a wired communication link exit mechanism in response to the equivalent signal attenuation value from the automated guided vehicle to the communication base station remaining below a first preset threshold within a preset number of consecutive communication cycles; maintaining data transmission on the wired communication link while simultaneously sending probe data packets to the communication base station via the wireless communication link; statistically analyzing the success rate of receiving probe data packets and the average transmission delay at the communication base station, and triggering a link switching preparation command when the success rate is higher than a preset threshold and the average transmission delay is lower than a preset threshold; migrating the output data stream of the automated guided vehicle from the wired communication link to the buffer of the wireless communication link, and releasing the binding relationship between the output data stream and the wired communication link; sending a link release request to the target connection node, and closing the physical layer connection of the wired communication interface of the automated guided vehicle after receiving a release confirmation message.

[0109] In practice, when the equivalent signal attenuation value of wireless communication falls below a predetermined percentage of a first preset threshold for multiple consecutive communication cycles, the wired communication link exit mechanism is activated. Specifically, when the signal attenuation value remains below 90% of the first preset threshold for five consecutive communication cycles (each cycle being 100ms), for example, if the first preset threshold is -100dBm and the current value remains below -90dBm, the wireless environment is considered to have stabilized. Before exiting, probe data packets, such as ICMPEchoRequest, are sent to the communication base station via the wireless link, and the reception success rate and average transmission delay parameters are collected for 10 seconds. The reception success rate refers to the proportion of probe packets correctly received and responded to by the base station, with a threshold of 95% to ensure that the wireless link does not experience frequent packet loss; the average transmission delay is the average round-trip time of the probe packets, with a threshold of 20ms to meet the latency tolerance range of industrial control.

[0110] After triggering the link switching preparation command, the data stream migration process begins. First, the output data stream of the automated guided vehicle (AGV) is migrated from the wired communication link to the wireless communication link buffer, maintaining data transmission on the wired link while simultaneously sending probe data packets to the communication base station via the wireless communication link. In the network protocol stack, remaining data blocks in the non-real-time monitoring queue, such as unsent video frames, are copied from the wired link buffer to the wireless link buffer. Double buffering technology ensures uninterrupted data transmission during the migration process, and the copying process is implemented using DMA (Direct Memory Access) technology.

[0111] Subsequently, the binding relationship between the output data stream and the wired communication link is released. At the network layer, the socket connection between the non-real-time data and the wired link is disconnected. The routing table entry is modified to redirect data packets destined for the base station to the wireless network card. This process is implemented via the NETLINK interface, taking less than 1ms and avoiding routing black hole issues. After data migration and routing adjustments are completed, a link release request is sent to the wired access point using a TLV message based on the LLDP link layer discovery protocol. Upon confirmation by the access point, an LLDP link teardown notification is sent. At this point, the physical layer power supply to the wired interface of the automated guided vehicle is shut down, such as disconnecting the PoE power supply, and the interface status register is reset to ensure a complete severance of the physical connection.

[0112] In addition, as an optional embodiment, the method further includes: updating the three-dimensional geometric model of the industrial facility when the location of any industrial facility changes; updating the geometric surface normal vector of the intersecting region when an intersection area is detected between the updated three-dimensional geometric model and the signal propagation path, recalculating the reflection loss coefficient and penetration loss coefficient based on Fresnel reflection law according to the updated geometric surface normal vector, and then calculating the updated equivalent signal attenuation value; and sending a wired communication link sleep command to the automated guided vehicle in response to the updated equivalent signal attenuation value being less than a first preset threshold.

[0113] In other words, when the location of factory equipment changes, such as when the AGV scheduling system remotely moves the shelves, the dynamic update process of the 3D model is triggered:

[0114] In practice, the new coordinates of the device are first obtained through a UWB positioning system (with a positioning accuracy of ±10 cm), and the relative positional relationship between the device's geometric model and the base station's conical spatial region is recalculated. A ray tracing algorithm is then used to detect whether the modified geometry intersects with the existing signal propagation path, i.e., the straight line from the automated guided vehicle to the base station. This is specifically achieved by determining whether the device's bounding box, i.e., the axial bounding box, intersects with the ray segment.

[0115] If an intersection is detected, such as when the forklift moves directly in front of the signal path, the geometric surface normal vector of the intersection region is extracted, and the reflection loss coefficient R is recalculated based on Fresnel's law of reflection according to the following formula:

[0116]

[0117] Where, θ i Let θ be the angle of incidence. t The angle of transmission is denoted as .

[0118] Simultaneously, the skin depth δ is calculated based on the material conductivity σ and the signal frequency f:

[0119] ;

[0120] Where μ represents magnetic permeability.

[0121] Then, based on the skin depth δ, combined with the penetration depth d p Calculate penetration loss:

[0122] .

[0123] If the recalculated equivalent signal attenuation value is lower than the first preset threshold, such as -95dBm, it indicates that the wireless signal quality has been restored after the device change. A wired link sleep command is sent to the AGV to close the physical layer connection and reduce power consumption.

[0124] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0125] It should be understood that the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in this application, and such modifications or substitutions should all be covered within the scope of protection of this application.

Claims

1. A data communication method for an automated guided vehicle, characterized in that, The automated guided vehicle is located inside a factory building, which also houses several different types of industrial facilities. The method includes: By constructing three-dimensional geometric models of various industrial facilities within the factory, a three-dimensional spatial model of the factory is obtained, and material attribute labels for the corresponding industrial facilities are marked on each three-dimensional geometric model. The material attribute labels include high electromagnetic shielding attributes or low shielding attributes. A spherical coordinate system is established at the communication base station of the automated guided vehicle, and a cone-shaped signal propagation area is generated with the antenna phase center of the communication base station antenna as the origin and the main radiation direction as the axis, based on the antenna radiation parameters of the communication base station. The real-time location information of the automated guided vehicle is obtained, and the virtual position coordinates of the automated guided vehicle in the three-dimensional space model are determined based on the real-time location information. Using the virtual position coordinates of the automated guided vehicle in the three-dimensional space model as the starting point and the origin of the spherical coordinate system of the communication base station as the ending point, a ray-shaped signal propagation path is generated between the automated guided vehicle and the communication base station; If an intersection region is detected between the signal propagation path and at least one three-dimensional geometric model with high electromagnetic shielding properties, the equivalent signal attenuation value from the automated guided vehicle to the communication base station is calculated based on the intersection region. In response to the equivalent signal attenuation value being greater than or equal to a first preset threshold and less than a second preset threshold, a target connection node is determined, and the automated guided vehicle is controlled to establish a wired communication link connection with the target connection node, wherein the second preset threshold is greater than the first preset threshold; Parse the protocol header of the network layer data packets of the automated guided vehicle and identify the real-time control data stream and the non-real-time monitoring data stream in the output data stream; Real-time control data streams are transmitted via wireless communication links, while non-real-time monitoring data streams are transmitted via wired communication links. In response to the equivalent signal attenuation value being greater than or equal to a second preset threshold, all output data streams are migrated to a wired communication link for transmission.

2. The method according to claim 1, characterized in that, The construction of three-dimensional geometric models of various industrial facilities within the factory includes: A point cloud dataset is generated based on the surface contour points of industrial facilities inside the factory collected by scanning. The discrete point cloud in the point cloud dataset is converted into a triangular mesh surface model using a triangular surface reconstruction algorithm. Each triangular mesh cell of the triangular mesh surface model includes three vertex coordinates and normal vector information. The Laplace smoothing algorithm is used to smooth the surfaces of adjacent triangular meshes to obtain a continuous geometric surface model that meets the first preset condition. The closed boundaries of the continuous geometric surface model are extracted, and the three-dimensional geometric models of each industrial facility are identified using a three-dimensional connected component analysis algorithm.

3. The method according to claim 2, characterized in that, Material properties specifically include dielectric constant, magnetic permeability, and electrical conductivity; The step of calculating the equivalent signal attenuation value from the automated guided vehicle to the communication base station based on the intersecting region includes: Extract the geometric surface normal vector of the intersecting region; The reflection loss coefficient of the base station signal on the corresponding industrial facility surface is calculated based on the angle between the geometric surface normal vector and the signal propagation path. Based on the propagation distance between the base station signal and the three-dimensional geometric model, as well as the signal frequency, calculate the free space transmission loss corresponding to the natural attenuation of the signal in an ideal unobstructed environment. The penetration depth of the signal propagation path through the three-dimensional geometric model is measured, and the penetration loss coefficient is calculated based on the penetration depth and conductivity. The equivalent signal attenuation value is calculated based on the free space transmission loss, reflection loss coefficient, and penetration loss coefficient.

4. The method according to claim 1, characterized in that, The step of determining a target connection node and controlling the automated guided vehicle to establish a wired communication link with the target connection node in response to the equivalent signal attenuation value being greater than or equal to a first preset threshold and less than a second preset threshold includes: In response to the equivalent signal attenuation value being greater than or equal to a first preset threshold and less than a second preset threshold, a wired communication interface wake-up command for the automated guided vehicle is triggered. Acquire the location information of multiple wired access points within a preset range of the automated guided vehicle; Based on the location information of multiple wired access points, the spatial distance from the automated guided vehicle to each wired access point is calculated, and the wired access point corresponding to the minimum spatial distance is determined as the target connection node. Send a link establishment request to the target connection node to negotiate a communication protocol version between the automated guided vehicle and the target connection node; While the wireless communication link remains active, physical layer synchronization of the wired communication link is achieved through out-of-band channels.

5. The method according to claim 4, characterized in that, The factory building is equipped with multiple automated guided vehicles; After determining the target connection node, the method further includes: When multiple automated guided vehicles (AGVs) simultaneously send link establishment requests to the same wired access point, obtain the task urgency level identifier of each AGV and the percentage by which its equivalent signal attenuation value exceeds a first preset threshold. Based on the urgency level indicator of the automated guided vehicles and the percentage by which its equivalent signal attenuation value exceeds a first preset threshold, multiple automated guided vehicles are prioritized to obtain a priority ranking result. The physical port resources of wired access points are allocated sequentially to multiple automated guided vehicles according to the priority ranking results. For automated guided vehicles that have not obtained physical port resources, a wireless ad hoc network relay transmission mode is used.

6. The method according to claim 5, characterized in that, The aforementioned operation of the wireless ad hoc network relay transmission mode for automated guided vehicles that have not obtained physical port resources includes: Mark the automated guided vehicle that has not obtained physical port resources as the target vehicle; Acquire the real-time position coordinates and motion status of other automated guided vehicles within a preset range of the target transport vehicle; In the three-dimensional space model, a direct virtual signal transmission path from the target transport vehicle to the communication base station and a relay virtual signal transmission path from the target transport vehicle to the communication base station via other automated guided vehicles are constructed. Calculate the equivalent signal attenuation value of the relay virtual signal transmission path, and add the path attenuation from the target transport vehicle to the relay automated guided vehicle, the path attenuation from the relay automated guided vehicle to the communication base station, and the loss compensation value generated by the relay automated guided vehicle for signal processing. When the numerical relationship between the equivalent signal attenuation value of the relay virtual signal transmission path and the equivalent signal attenuation value of the direct virtual signal transmission path meets the second preset condition, a cooperation instruction is sent to the target transport vehicle and the relay automated guided transport vehicle. After receiving the cooperation instruction, the relay automated guided vehicle creates a dedicated data forwarding channel in the network protocol stack; The target transport vehicle breaks down the non-real-time monitoring data stream into data block units and sends the data block units to the dedicated data forwarding channel of the relay automated guided vehicle via a wireless communication link. The relay automated guided vehicle forwards the received data block units to the communication base station via a wireless communication link; The communication base station reassembles multiple data block units into a non-real-time monitoring data stream and marks it as relay transmission mode data.

7. The method according to claim 1, characterized in that, The transmission of real-time control data stream via wireless communication link and the transmission of non-real-time monitoring data stream via wired communication link include: In the network protocol stack of the automated guided vehicle, a first sending queue and a second sending queue are created respectively; Real-time control data streams are cached in the first sending queue, and non-real-time monitoring data streams are cached in the second sending queue; The first transmission queue is bound to the data port of the wireless communication link, and the second transmission queue is bound to the data port of the wired communication link, so that real-time control data streams are transmitted via the wireless communication link and non-real-time monitoring data streams are transmitted via the wired communication link.

8. The method according to claim 4, characterized in that, The method further includes: In response to the fact that the equivalent signal attenuation value of the automated guided vehicle to the communication base station remains less than a first preset threshold within a preset number of consecutive communication cycles, the wired communication link exit mechanism is activated. Maintain data transmission on the wired communication link, while simultaneously sending probe data packets to the communication base station via the wireless communication link; The system counts the success rate of receiving probe data packets at the communication base station and the average transmission delay. If the success rate of receiving the data packets is higher than a set threshold and the average transmission delay is lower than a set threshold, a link handover preparation command is triggered. The output data stream of the automated guided vehicle is migrated from the wired communication link to the buffer of the wireless communication link, thus debinding the output data stream from the wired communication link. Send a link release request to the target connection point, and close the physical layer connection of the wired communication interface of the automated guided vehicle after receiving the release confirmation message.

9. The method according to claim 3, characterized in that, The method further includes: If the location of any industrial facility changes, update the three-dimensional geometric model of the industrial facility; If an intersection region is detected between the updated 3D geometric model and the signal propagation path, the geometric surface normal vector of the intersection region is updated. Based on the updated geometric surface normal vector and Fresnel reflection law, the reflection loss coefficient and penetration loss coefficient are recalculated, and then the updated equivalent signal attenuation value is calculated. In response to the updated equivalent signal attenuation value being less than a first preset threshold, a wired communication link sleep command is sent to the automated guided vehicle.

10. The method according to claim 3, characterized in that, The method further includes: Establish a comparison table of electromagnetic parameters for typical materials used in factory buildings. The typical materials include steel, aluminum alloys, and concrete, and the electromagnetic parameters include dielectric constant and magnetic permeability. When the three-dimensional geometric model is identified as a steel structure, the dielectric constant and permeability of the steel are retrieved from the electromagnetic parameter lookup table; The reflectivity of electromagnetic waves on the material surface is calculated based on the dielectric constant, and the eddy current loss factor is calculated based on the permeability. The product of the reflectivity and the eddy current loss factor is used as the comprehensive shielding coefficient of the three-dimensional geometric model. When the signal propagation path between the automated guided vehicle and the communication base station passes through multiple three-dimensional geometric models, the overall shielding effect is obtained by superimposing the comprehensive shielding coefficients of the multiple three-dimensional geometric models.

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