A dual-CAN communication method and device applied to an emergency lighting centralized power supply

Abstract

The application provides a dual-CAN communication method and device applied to an emergency lighting centralized power supply, relates to the technical field of communication, and solves the technical problem that the communication network structure of the fire emergency lighting centralized power supply in the prior art is single and it is difficult to meet the flexible wiring requirement. The method comprises the following steps: after power-on, parameters of communicable nodes around each emergency lighting centralized power supply are collected respectively, and a plurality of candidate relay node sets are established; based on a preset evaluation rule, an optimal node is selected as a relay node, and a trunk and branch relationship is established; when the relay node receives communication data, data not belonging to the node or the branches under the node is discarded, data belonging to the node or the branches under the node is determined according to the data type to determine the priority, the communication data is written into a cache queue corresponding to the priority, and the cache queue is scheduled according to the emergency state. The application is used in the communication process of the emergency lighting centralized power supply.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a dual CAN communication method and device for centralized power supply of emergency lighting. Background Technology

[0002] Current technology for centralized power supplies in fire emergency lighting employs a simplistic communication network structure, making it difficult to meet flexible cabling requirements. Existing fire emergency lighting and evacuation guidance systems typically use CAN communication networks to transmit information to the controller, with centralized power supplies generally equipped with only one or two CAN interface terminals. In engineering applications, multiple centralized power supplies communicate with the controller via a daisy-chain or chain-like network architecture using CAN interface terminals. These two network architectures, which connect centralized power supplies in series, are unsuitable for tree or star network topologies in engineering sites. Furthermore, the complex cabling requires additional dedicated CAN communication hubs, increasing system complexity and construction costs. In addition, to ensure communication quality, the cable laying distance for this type of network architecture is typically limited to around one kilometer, resulting in limited communication coverage and a restricted number of centralized power supply nodes. Therefore, there is an urgent need for a communication method for centralized power supplies in emergency lighting to achieve flexible network topology construction. Summary of the Invention

[0003] This application provides a dual CAN communication method and device for centralized power supplies for emergency lighting, which solves the technical problem that the existing centralized power supplies for fire emergency lighting have a simple communication network structure and cannot meet the requirements for flexible wiring.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] Firstly, a dual-CAN communication method for a centralized emergency lighting power supply is provided, comprising: equipping each centralized emergency lighting power supply with two CAN interfaces; after power-on, collecting the identifiers, distances, link quality, and node load parameters of communicable nodes around each centralized emergency lighting power supply to establish multiple candidate relay node sets; wherein, the first CAN interface is used for communication with the upper-level bus, and the second CAN interface is used for communication with lower-level branch nodes; based on preset evaluation rules, selecting the optimal node from the multiple candidate relay node sets as the relay node, and establishing a trunk and branch relationship; based on the trunk and branch relationship, when a relay node receives communication data from the first or second CAN interface, parsing the machine number and branch identifier in the data frame, discarding data that does not belong to this node or its subordinate branches, and proceeding to subsequent processing for data belonging to this node or its subordinate branches; for data belonging to this node or its subordinate branches, determining the priority according to the data type, writing the communication data into a buffer queue corresponding to its priority, and scheduling the buffer queue according to the emergency status.

[0006] In conjunction with the first aspect mentioned above, in one possible implementation, the optimal node is selected from multiple candidate relay node sets based on preset evaluation rules, and a backbone and branch relationship is established. This includes: comprehensively evaluating each candidate relay node according to preset evaluation rules based on distance, link quality, and node load parameters, and determining the node with the highest comprehensive score as the current relay node; forming a backbone communication link with emergency lighting centralized power supplies directly connected to the upper-level bus, with all emergency lighting centralized power supplies on the backbone communication link connected using the first CAN interface, and relay nodes connected to the first CAN interface of the lower-level emergency lighting centralized power supplies through their second CAN interface, thus gradually expanding to form a backbone and branch relationship.

[0007] In conjunction with the first aspect mentioned above, in one possible implementation, the comprehensive score S j Satisfy the following formula:

[0008] S j =W D ·f D (D i,j )+W Q ·f Q (Q i,j )+W L ·f L (L i,j )

[0009] Among them, W D W is the distance weight. Q W represents the link quality weight. L f represents the node load weight. D f is a function for calculating the distance D score. Q The function f is used to calculate the link quality Q score. L This is a function for calculating the node load score L.

[0010] In conjunction with the first aspect mentioned above, in one possible implementation, scheduling is performed on the cache queue, including: forwarding the filtered and scheduled data according to its destination node; data belonging to the upper-level bus direction is forwarded uplink via the first CAN interface, and data belonging to the lower-level branch direction is forwarded downlink via the second CAN interface; during the forwarding process, the service payload is transparently transmitted without parsing its content.

[0011] In conjunction with the first aspect mentioned above, in one possible implementation, uplink forwarding includes: after the relay node's second CAN interface receives a data frame sent by the lower-level branch node, it stores the data frame in the downlink FIFO buffer; the secondary MCU reads the data frame from the downlink FIFO buffer, identifies the CAN frame ID and branch ID in the frame; if it determines that the data frame is related to this branch, it forwards it to the uplink FIFO buffer of the first CAN interface, waiting to be sent to the upper-level node or controller. Downlink forwarding includes: the relay node's first CAN interface receives upper-level bus data and stores it in the uplink FIFO buffer; the secondary MCU reads and identifies the data frame, forwards the data related to this branch to the downlink FIFO buffer of the second CAN interface, and then sends it to the lower-level branch node.

[0012] In conjunction with the first aspect mentioned above, in one possible implementation, scheduling the cache queue based on the emergency status includes: in the initial setup, assigning the highest priority flag to emergency information; when emergency information arrives at the node, it will be processed immediately regardless of the current state of the FIFO cache; for normal state data, it will be processed according to the pre-set batch size or delay time.

[0013] In conjunction with the first aspect mentioned above, in one possible implementation, the two CAN interfaces are electrically isolated, and both physical layers are equipped with TVS diodes, common-mode inductors, and resettable fuses.

[0014] In conjunction with the first aspect mentioned above, in one possible implementation, the relationship between relay nodes and the backbone and branches is re-evaluated periodically or by event triggering during operation. When link quality degradation, abnormal node load, or communication failure is detected, relay switching is performed among the candidate nodes according to the evaluation rules, and the branch identifier and / or routing entry are updated synchronously. At the same time, the buffer queue length and batch threshold are adaptively adjusted according to the bus occupancy.

[0015] In conjunction with the first aspect mentioned above, in one possible implementation, the hardware of this technical solution is equipped with dual MCUs working in tandem, wherein the main MCU is used to control the centralized power supply for emergency lighting, and the secondary MCU is used for CAN data forwarding and processing.

[0016] Secondly, a dual-CAN communication device for centralized emergency lighting power supplies is provided, comprising: a communication unit and a processing unit; the communication unit is used to equip each centralized emergency lighting power supply with two CAN interfaces, and after power-on, collects the identifiers, distances, link quality, and node load parameters of communicable nodes around each centralized emergency lighting power supply to establish multiple candidate relay node sets; wherein, the first CAN interface is used to communicate with the upper-level bus, and the second CAN interface is used to communicate with lower-level branch nodes. The processing unit is used to select the optimal node as the relay node from the multiple candidate relay node sets based on preset evaluation rules, and establish a trunk and branch relationship; based on the trunk and branch relationship, when a relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to this node or its subordinate branches, and proceeds to subsequent processing for data that belongs to this node or its subordinate branches; for data belonging to this node or its subordinate branches, it determines the priority according to the data type, writes the communication data into a buffer queue corresponding to its priority, and performs scheduling on the buffer queue according to the emergency status.

[0017] Thirdly, this application provides an electronic device, including: a processor and a storage medium; the storage medium includes instructions, and the processor is configured to execute the instructions to implement the methods described in the first aspect and any possible implementation thereof. This electronic device may be an electronic device or a chip within an electronic device.

[0018] Fourthly, this application provides a dual CAN communication system for centralized emergency lighting power supplies, comprising: a communication device and an electronic device; wherein, the communication device is used to equip each centralized emergency lighting power supply with two CAN interfaces, and after power-on, collects the identifiers, distances, link quality, and node load parameters of communicable nodes around each centralized emergency lighting power supply, establishing multiple candidate relay node sets; wherein, the first CAN interface is used for communication with the upper-level bus, and the second CAN interface is used for communication with lower-level branch nodes. The electronic device is used to select the optimal node as the relay node from the multiple candidate relay node sets based on preset evaluation rules, and establish a trunk and branch relationship; based on the trunk and branch relationship, when a relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to this node or its subordinate branches, and proceeds to subsequent processing for data that belongs to this node or its subordinate branches; for data belonging to this node or its subordinate branches, it determines the priority according to the data type, writes the communication data into a buffer queue corresponding to its priority, and performs scheduling on the buffer queue according to the emergency status.

[0019] Fifthly, this application provides a computer-readable storage medium storing instructions that, when executed on an electronic device, cause the electronic device to perform the methods described in the first aspect and any possible implementation thereof.

[0020] In a sixth aspect, this application provides a computer program product containing instructions that, when the computer program product is run on a dual CAN communication device applied to a centralized power supply for emergency lighting, causes the dual CAN communication device applied to the centralized power supply for emergency lighting to perform the methods described in the first aspect and any possible implementation thereof.

[0021] To address the technical problem that existing centralized power supplies for fire emergency lighting have a simple communication network structure that fails to meet flexible cabling requirements, this application provides a dual-CAN communication method and device for centralized power supplies for emergency lighting. By configuring dual CAN interfaces on each centralized power supply and collecting the identifiers, distances, link quality, and node load parameters of surrounding nodes after power-on, the optimal relay node can be dynamically selected based on preset evaluation rules. This allows for the flexible construction of tree or star network topologies combining backbones and branches on-site, avoiding the limitations of existing technologies that can only use daisy-chain or chain-like architectures and reducing reliance on additional CAN hubs. Simultaneously, during forwarding, relay nodes parse data frames for machine number and branch identifiers, forwarding only data belonging to their own node and its subordinate branches. This effectively reduces redundant transmission of irrelevant messages, improves bus utilization and overall communication efficiency, and solves the technical problem of existing centralized power supplies for fire emergency lighting having a simple communication network structure that fails to meet flexible cabling requirements.

[0022] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0023] Figure 1 A system architecture diagram of a dual CAN communication system for centralized power supply of emergency lighting provided in this application embodiment;

[0024] Figure 2 A flowchart illustrating a dual CAN communication method for a centralized power supply for emergency lighting, provided in an embodiment of this application;

[0025] Figure 3 A flowchart illustrating another dual CAN communication method for centralized power supply of emergency lighting provided in an embodiment of this application;

[0026] Figure 4 A flowchart illustrating another dual CAN communication method for centralized power supply of emergency lighting provided in an embodiment of this application;

[0027] Figure 5 A schematic diagram of a dual CAN communication topology for a centralized power supply for emergency lighting provided in an embodiment of this application;

[0028] Figure 6 A schematic diagram of a dual CAN communication device for a centralized power supply for emergency lighting provided in this application embodiment;

[0029] Figure 7 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0031] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0032] The dual CAN communication method for centralized power supplies for emergency lighting provided in this application embodiment can be applied to, for example... Figure 1 The dual CAN communication system 100 shown is used in the centralized power supply for emergency lighting, such as Figure 1 As shown, the communication system includes: a communication device 101 and an electronic device 102.

[0033] The communication equipment is used to equip each emergency lighting centralized power supply with two CAN interfaces. After power-on, it collects the identification, distance, link quality and node load parameters of the communicable nodes around each emergency lighting centralized power supply to establish multiple candidate relay node sets. The first CAN interface is used to communicate with the upper-level bus, and the second CAN interface is used to communicate with the lower-level branch nodes.

[0034] The electronic device is used to select the optimal node as the relay node from multiple candidate relay node sets based on preset evaluation rules, and establish a trunk and branch relationship. Based on the trunk and branch relationship, when the relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to the node or its subordinate branches, and proceeds to the next processing for data that belongs to the node or its subordinate branches. For data that belongs to the node or its subordinate branches, it determines the priority according to the data type, writes the communication data into the buffer queue corresponding to its priority, and performs scheduling on the buffer queue according to the emergency status.

[0035] To address the technical problem that the existing communication network structure of centralized power supplies for emergency lighting is too simple to meet the requirements of flexible wiring, this application provides a dual CAN communication method for centralized power supplies for emergency lighting. Figure 2 A flowchart illustrating a dual CAN communication method for centralized power supplies for emergency lighting, as provided in this application embodiment, is shown below. Figure 2 As shown, the method includes:

[0036] S201. Each emergency lighting centralized power supply is equipped with two CAN interfaces. After power-on, the identification, distance, link quality and node load parameters of the communicable nodes around each emergency lighting centralized power supply are collected to establish a set of multiple candidate relay nodes.

[0037] In one possible implementation, after the emergency lighting centralized power supply is powered on, it simultaneously sends broadcast frames through the first CAN interface and the second CAN interface. After receiving the broadcast frames, the surrounding nodes return response frames containing their own information, thereby collecting identification, distance, link quality and node load parameters, and forming a set of candidate relay nodes based on these parameters.

[0038] It should be noted that this technical solution is equipped with dual MCUs working in tandem. The main MCU is used to control the centralized power supply for emergency lighting, while the secondary MCU is used for CAN data forwarding and processing. The first CAN interface is used to communicate with the upper-level bus, and the second CAN interface is used to communicate with the lower-level branch nodes. The two CAN interfaces are electrically isolated, and both are equipped with TVS diodes, common-mode inductors, and resettable fuses at the physical layer.

[0039] Among them, node identifier refers to the information used to uniquely identify each centralized power node, such as node ID, machine number or physical address, which is used to distinguish different nodes in subsequent data transmission.

[0040] As an example, in this embodiment, distance is estimated using the round-trip delay of communication messages; link quality is determined by parameters such as the error frame rate, retransmission count, or successful reception rate of statistical messages; and node load parameters reflect the processing pressure of the node during current operation, measured by parameters such as buffer occupancy, forwarding rate, or MCU processing capability. After a centralized power supply is powered on, it detects nearby communicable neighboring nodes, measures their link delay, error frame rate, and buffer occupancy, and establishes a set of candidate node records accordingly.

[0041] S202. Based on the preset evaluation rules, select the optimal node from multiple candidate relay node sets as the relay node, and establish the trunk and branch relationships.

[0042] In one possible implementation, after acquiring the candidate node parameters, each centralized power supply node calculates its comprehensive score according to preset rules, and the node with the highest score is determined as a relay node. Then, the centralized power supply directly connected to the upper-level bus is used as the backbone node, and the relay nodes are connected to the first CAN interface of the next-level centralized power supply through the second CAN interface, thus expanding step by step to form a communication relationship combining backbone and branches.

[0043] Among them, the preset evaluation rule refers to the algorithm that comprehensively evaluates the candidate nodes based on their distance, link quality, and node load parameters. It is usually implemented by weighted scoring to ensure that the selected relay nodes meet the requirements in terms of communication quality and processing capabilities.

[0044] It should be noted that the preset evaluation rules can be flexibly set according to different engineering scenarios and are not limited to fixed formulas. For example, in some scenarios, link quality can be given a higher weight to ensure communication stability; in other scenarios, node load parameters can be given a higher weight to avoid overloading individual nodes.

[0045] S203. Based on the trunk and branch relationship, when a relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to this node or its subordinate branches, and proceeds to subsequent processing for data that belongs to this node or its subordinate branches.

[0046] In one possible implementation, after receiving a CAN message, the relay node first temporarily stores it in a buffer, and then the MCU reads and parses its ID field. If the message ID matches the registered ID of the node or its subordinate branch, it proceeds to further processing; otherwise, it is discarded, thereby reducing invalid data transmission.

[0047] The node ID, carried in the CAN message ID, uniquely identifies the node to which the message belongs; the branch identifier distinguishes the network branch to which the message belongs. By parsing the node ID and branch identifier of the message, the relay node can determine whether the data is related to itself or its subordinate branches.

[0048] It should be noted that the parsing process does not involve parsing the message service payload, but only judges its identification part, so the processing speed is fast and does not add extra computational burden.

[0049] It should be noted that during operation, the relationship between relay nodes and the backbone and branches is re-evaluated periodically or by event triggering. When link quality degradation, abnormal node load, or communication failure is detected, relay switching is performed among the candidate nodes according to the evaluation rules, and the branch identifier and / or routing entry are updated synchronously. At the same time, the buffer queue length and batch threshold are adaptively adjusted according to the bus occupancy.

[0050] S204. For data belonging to this node or its subordinate branches, determine the priority based on the data type, write the communication data into the cache queue corresponding to its priority, and perform scheduling on the cache queue according to the emergency status.

[0051] In one possible implementation, independent buffer queues are set up for data with different priorities. For data belonging to the current node or its subordinate branches, the priority is determined based on the data type, and the communication data is written into the buffer queue corresponding to its priority. During scheduling, high-priority data is dequeued and forwarded first; when an emergency is detected, even if there is already data to be sent in the current buffer queue, the emergency data will be immediately inserted and forwarded with priority to ensure that critical information is delivered in a timely manner.

[0052] As an example, in this embodiment, the data types may include fire alarm information, evacuation instruction information, status monitoring information, and general operational data. Based on the importance and real-time requirements of the data, they are divided into different priorities. Emergency information is assigned the highest priority, and general operational data is assigned a lower priority.

[0053] It should be noted that, in order to avoid low-priority data from not being forwarded for a long time, a dynamic adjustment mechanism can be set in the scheduling strategy to force the processing of low-priority data within a certain time interval, thereby balancing real-time performance and fairness.

[0054] It should be noted that the cache queue is scheduled according to the emergency status. In the initial setting, the emergency information is assigned the highest priority flag. When the emergency information arrives at the node, it will be processed immediately regardless of the current state of the FIFO cache. For normal state data, it is processed according to the pre-set batch size or delay time.

[0055] As an example, in this embodiment of the application, when a fire alarm arrives, the system will immediately interrupt the batch forwarding of normal status data and send the fire alarm information to the controller first, thus ensuring the timeliness of the emergency response.

[0056] This application embodiment equips each emergency lighting centralized power supply with two CAN interfaces and collects the identification, distance, link quality, and load parameters of surrounding nodes to establish a candidate relay node set, achieving comprehensive understanding of node status and dynamic adaptation of network topology. By selecting the optimal relay node through preset evaluation rules and constructing a backbone and branch topology, communication paths can be optimized, node overload can be avoided, and network reliability and scalability can be improved. Relay nodes filter irrelevant data based on message machine number and branch identifier, reducing invalid transmissions and improving processing efficiency. Simultaneously, through priority caching and scheduling mechanisms, high-priority emergency data can be forwarded promptly, ensuring the real-time nature of critical emergency information. This solves the technical problem of existing fire emergency lighting centralized power supplies having a simple communication network structure that cannot meet flexible wiring requirements.

[0057] In one possible implementation of the embodiments of this application, combined with Figure 2 ,like Figure 3 As shown, the above S202 can be specifically implemented through the following S301 and S302, which are explained in detail below:

[0058] S301. Based on distance, link quality, and node load parameters, conduct a comprehensive evaluation of each candidate relay node according to the preset evaluation rules, and determine the node with the highest comprehensive score as the current relay node.

[0059] In one possible implementation, after obtaining the candidate node parameters, each emergency lighting centralized power supply node calculates the comprehensive score of each candidate node according to the preset evaluation rules. The node with the highest score is determined as the relay node, thereby ensuring that the selected relay node meets the requirements in terms of communication quality and processing capability.

[0060] As an example, in this embodiment of the application, if candidate node A has good link quality but is a little far away, while candidate node B is close but has poor link quality, then node A may be selected as the relay node to ensure the communication reliability of the overall network.

[0061] As an example, in an embodiment of this application, the comprehensive score S jSatisfy the following formula:

[0062] S j =W D ·f D (D i,j )+W Q ·f Q (Q i,j )+W L ·f L (L i,j )

[0063] Among them, W D W is the distance weight. Q W represents the link quality weight. L f represents the node load weight. D f is a function for calculating the distance D score. Q The function f is used to calculate the link quality Q score. L This is a function for calculating the node load score L.

[0064] S302. The emergency lighting centralized power supply is directly connected to the upper-level bus to form a backbone communication link. The emergency lighting centralized power supplies on the backbone communication link are all connected using the first CAN interface. The relay node is connected to the first CAN interface of the lower-level emergency lighting centralized power supply through its second CAN interface, and the backbone and branch relationships are formed step by step.

[0065] In one possible implementation, the system uses a centralized power supply node directly connected to the upper-level bus as the backbone node, and the backbone nodes are interconnected through the first CAN interface; the relay node uses its second CAN interface to connect to the first CAN interface of the lower-level node, and expands step by step to form a topology structure combining backbone and branches, thereby realizing an efficient, hierarchical communication network.

[0066] Among them, the backbone communication link refers to the core communication path formed by the centralized power supply node directly connected to the upper-level bus; the branch relationship refers to the network topology branch formed by the relay node extending to the lower-level node through the second CAN interface.

[0067] This application embodiment comprehensively scores candidate relay nodes and selects the node with the highest score as the relay node. This avoids communication instability or node overload caused by selecting based on a single indicator, achieving scientific and rational relay node selection, thereby improving network reliability and adaptability. By forming a backbone communication link with a centralized power supply directly connected to the upper-level bus, and using relay nodes to progressively expand into a topology combining backbone and branches, communication stability is ensured, and zone management is facilitated, improving the overall communication efficiency and maintainability of the emergency lighting system.

[0068] In one possible implementation of the embodiments of this application, combined with Figure 2 ,like Figure 4 As shown, the above S204 can be implemented through the following S401 and S402, which are explained in detail below:

[0069] S401. The filtered and scheduled data is forwarded according to its destination node.

[0070] In one possible implementation, after filtering and prioritizing received packets, the relay node parses the target identifier of the data frame to identify its destination node. If the destination node belongs to this node, the data will enter the processing flow within this node; if the destination node belongs to a subordinate branch or a higher-level bus, it will enter the corresponding forwarding stage. This method ensures that the packet forwarding behavior has a clear target orientation, preventing irrelevant packets from continuing to be transmitted in the network.

[0071] The destination node refers to the pre-defined target node for receiving data messages in the CAN network. It is distinguished by the message ID or identifier field and is used to determine the direction and target to which the data should be forwarded.

[0072] It should be noted that the determination of the destination node is based solely on the packet's identification field, without involving the decoding of the service payload. Therefore, it can ensure high-speed forwarding while avoiding additional computational overhead and improving the overall processing efficiency of the system.

[0073] As an example, if the destination node of an alarm message is identified as a lower-level branch node, the relay node can accurately forward the message to the link where that node is located after completing the scheduling, ensuring that the information is delivered quickly and in a targeted manner.

[0074] S402: Data belonging to the upper-level bus direction is forwarded uplink via the first CAN interface, and data belonging to the lower-level branch direction is forwarded downlink via the second CAN interface; during the forwarding process, the service payload is transparently transmitted without parsing its content.

[0075] In one possible implementation, the relay node categorizes messages into uplink and downlink based on the destination node's affiliation: if the destination node is on the upper-level bus or backbone, uplink forwarding is performed via the first CAN interface; if the destination node is on a lower-level branch, downlink forwarding is performed via the second CAN interface. During forwarding, the relay node does not parse or modify the service data payload, but only maintains the original format for transparent transmission, ensuring that the data can be delivered to the target node without loss.

[0076] In this context, the upstream bus direction refers to the direction in which messages need to be uploaded to the main link or control center; the downstream branch direction refers to the direction in which messages need to be sent to child nodes or terminal devices. Transparent transmission means that only the message header identifier is identified and routed, without disassembling or modifying the message's service payload, thus ensuring the integrity of the data content and transmission efficiency.

[0077] It should be noted that this transparent transmission mechanism not only improves forwarding efficiency but also avoids compatibility issues caused by differences in service content, giving the system good versatility and scalability. Furthermore, uplink and downlink are handled by independent interfaces, electrically isolated from each other, which avoids signal interference and link conflicts, further enhancing network reliability.

[0078] It should also be noted that during uplink forwarding, after the relay node's second CAN interface receives a data frame sent by the lower-level branch node, it stores the data frame in the downlink FIFO buffer. The secondary MCU reads the data frame from the downlink FIFO buffer, identifies the CAN frame ID and branch ID in the frame, and if it determines that the data frame is related to this branch, it forwards it to the uplink FIFO buffer of the first CAN interface, waiting to be sent to the upper-level node or controller. During downlink forwarding, the relay node's first CAN interface receives data from the upper-level bus and stores it in the uplink FIFO buffer. The secondary MCU reads and identifies the data frame, forwards the data related to this branch to the downlink FIFO buffer of the second CAN interface, and then sends it to the lower-level branch node.

[0079] As an example, when the target of a fire alarm message is the upper-level control center, the message is uploaded via the first CAN interface; if the message is an evacuation instruction sent to the emergency lighting fixtures on a certain floor, it is distributed downlink to the corresponding branch node via the second CAN interface, ensuring that data from different directions can be forwarded quickly and accurately.

[0080] In another possible implementation, Figure 5 This is a schematic diagram of the dual CAN communication topology constructed based on the technical solution of this application in this embodiment, as shown below. Figure 5As shown, the centralized power supply system adopts a hierarchical tree-like dual-CAN communication topology. The top layer is established by the controller connecting to centralized power supply 1 via a CAN interface. The main CAN interface of centralized power supply 1 is further connected to centralized power supply 2, and the main CAN interface of centralized power supply 2 is connected to centralized power supply 3, and so on, forming the backbone link. Simultaneously, the secondary CAN interfaces of each centralized power supply are used for downlink branch expansion. For example, the secondary CAN interface of centralized power supply 2 can connect to centralized power supplies 21 and 22, the secondary CAN interface of centralized power supply 3 can connect to centralized power supplies 31 and 32, and the secondary CAN interface of centralized power supply 4 can connect to centralized power supplies 41 and 42, thus forming a multi-level cascaded, branch-expanded hierarchical network structure. In this structure, uplink data is uploaded to the controller level by level via the main CAN interfaces, while downlink data is sent down to the target node level by level via the secondary CAN interfaces. This achieves a hierarchical forwarding mechanism for transparent uplink and downlink transmission, reducing communication congestion caused by network-wide broadcasting and improving system reliability and scalability.

[0081] This application embodiment forwards messages according to the destination node, preventing irrelevant messages from continuing to be transmitted in the network, reducing link load and collisions, and ensuring the efficiency and directionality of data transmission, thereby improving the overall communication efficiency and stability of the system. By distinguishing between uplink and downlink directions and forwarding them through independent CAN interfaces, fast and lossless message transmission is achieved, which not only improves forwarding efficiency but also avoids latency and compatibility issues caused by message parsing; at the same time, the uplink and downlink channels are electrically isolated, effectively improving the system's reliability and anti-interference capability.

[0082] The above primarily describes the solutions of the embodiments of this application from the perspective of device implementation. It is understood that each device, such as a dual CAN communication device applied to a centralized power supply for emergency lighting, includes at least one of the hardware structures and software modules corresponding to each function in order to achieve the above-mentioned functions. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0083] This application embodiment can divide the dual CAN communication device applied to centralized power supply for emergency lighting into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0084] When using integrated units, Figure 6 A possible structural schematic diagram of a dual CAN communication device (referred to as dual CAN communication device 60 for emergency lighting centralized power supply) involved in the above embodiments is shown. The dual CAN communication device 60 for emergency lighting centralized power supply includes a processing unit 601 and a communication unit 602, and may also include a storage unit 603. Figure 6 The schematic diagram shown can be used to illustrate the structure of the dual CAN communication device applied to the centralized power supply for emergency lighting involved in the above embodiments.

[0085] when Figure 6 The schematic diagram shown illustrates the structure of the dual CAN communication device for emergency lighting centralized power supply involved in the above embodiments. The processing unit 601 is used to control and manage the operation of the dual CAN communication device for emergency lighting centralized power supply, the communication unit 602 is used for the dual CAN communication device for emergency lighting centralized power supply to communicate with other devices, and the storage unit 603 is used to store the program code and data of the dual CAN communication device for emergency lighting centralized power supply.

[0086] For example, the communication unit 602 is used to equip each emergency lighting centralized power supply with two CAN interfaces. After power-on, it collects the identification, distance, link quality and node load parameters of the communicable nodes around each emergency lighting centralized power supply to establish a set of multiple candidate relay nodes. The first CAN interface is used to communicate with the upper-level bus, and the second CAN interface is used to communicate with the lower-level branch nodes.

[0087] The processing unit 601 is used to select the optimal node as the relay node from multiple candidate relay node sets based on preset evaluation rules, and establish the trunk and branch relationship; based on the trunk and branch relationship, when the relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to the current node or its subordinate branches, and proceeds to the next processing for data that belongs to the current node or its subordinate branches; for data that belongs to the current node or its subordinate branches, it determines the priority according to the data type, writes the communication data into the buffer queue corresponding to its priority, and performs scheduling on the buffer queue according to the emergency status.

[0088] In one possible implementation, the processing unit 601 is further configured to select the optimal node from multiple candidate relay node sets as relay nodes based on preset evaluation rules, and establish a backbone and branch relationship, including: comprehensively scoring each candidate relay node according to preset evaluation rules based on distance, link quality and node load parameters, and determining the node with the highest comprehensive score as the current relay node; forming a backbone communication link with emergency lighting centralized power supplies directly connected to the upper-level bus, wherein all emergency lighting centralized power supplies on the backbone communication link are connected using the first CAN interface, and the relay node is connected to the first CAN interface of the lower-level emergency lighting centralized power supply through its second CAN interface, thereby expanding step by step to form a backbone and branch relationship.

[0089] In one possible implementation, the comprehensive score S j Satisfy the following formula:

[0090] S j =W D ·f D (D i,j )+W Q ·f Q (Q i,j )+W L ·f L (L i,j )

[0091] Among them, W D W is the distance weight. Q W represents the link quality weight. L f represents the node load weight. D f is a function for calculating the distance D score. Q The function f is used to calculate the link quality Q score. L This is a function for calculating the node load score L.

[0092] In one possible implementation, the processing unit 601 is further configured to perform scheduling on the cache queue, including: forwarding the filtered and scheduled data according to its destination node; forwarding data belonging to the upper bus direction via the first CAN interface uplink, and forwarding data belonging to the lower branch direction via the second CAN interface downlink; and passing through the service payload without parsing its content during the forwarding process.

[0093] In one possible implementation, the processing unit 601 is also used for uplink forwarding, including: after the relay node's second CAN interface receives a data frame sent by the lower-level branch node, it stores the data frame in the downlink FIFO buffer; the secondary MCU reads the data frame from the downlink FIFO buffer, identifies the CAN frame ID and branch ID in the frame; if it determines that the data frame is related to this branch, it forwards it to the uplink FIFO buffer of the first CAN interface, waiting to be sent to the upper-level node or controller. Downlink forwarding includes: the relay node's first CAN interface receives upper-level bus data and stores it in the uplink FIFO buffer; the secondary MCU reads and identifies the data frame, forwards the data related to this branch to the downlink FIFO buffer of the second CAN interface, and then sends it to the lower-level branch node.

[0094] In one possible implementation, the processing unit 601 is further configured to perform scheduling on the cache queue based on the emergency status, including: assigning a highest priority flag to emergency information in the initial setup; when emergency information arrives at a node, it will be processed immediately regardless of the current FIFO cache status; and for normal status data, it will be processed according to a pre-set batch size or delay time.

[0095] In one possible implementation, the two CAN interfaces are electrically isolated, and both physical layers are equipped with TVS diodes, common-mode inductors, and resettable fuses.

[0096] In one possible implementation, the processing unit 601 is also used to re-evaluate the relationship between the relay node and the backbone and branches in a periodic or event-triggered manner during operation. When link quality degradation, abnormal node load, or communication failure is detected, relay switching is performed in the candidate nodes according to the evaluation rules, and the branch identifier and / or routing entry are updated synchronously. At the same time, the buffer queue length and batch threshold are adaptively adjusted according to the bus occupancy.

[0097] In one possible implementation, the hardware of this technical solution is equipped with dual MCUs working together, where the main MCU is used to control the centralized power supply for emergency lighting, and the secondary MCU is used for CAN data forwarding and processing.

[0098] The processing unit 601 can be a processor or a controller, and the communication unit 602 can be a communication interface, transceiver, transceiver circuit, transceiver device, etc. The term "communication interface" is a general term and may include one or more interfaces. The storage unit 603 can be a memory. When the dual CAN communication device 60 used in the centralized power supply for emergency lighting is a chip, the processing unit 601 can be a processor or a controller, and the communication unit 602 can be an input interface and / or an output interface, pins, or circuits, etc. The storage unit 603 can be a storage unit within the chip (e.g., a register, cache, etc.) or a storage unit located outside the chip (e.g., read-only memory (ROM), random access memory (RAM, etc.)).

[0099] The communication unit can also be called a transceiver unit. The antenna and control circuit with transceiver functions in the dual CAN communication device 60 for centralized emergency lighting power supply can be considered as the communication unit 602 of the dual CAN communication device 60 for centralized emergency lighting power supply, and the processor with processing functions can be considered as the processing unit 601 of the dual CAN communication device 60 for centralized emergency lighting power supply. Optionally, the device in the communication unit 602 that implements the receiving function can be considered as a communication unit, which is used to execute the receiving steps in the embodiments of this application. The communication unit can be a receiver, a receiver circuit, etc. The device in the communication unit 602 that implements the transmitting function can be considered as a transmitting unit, which is used to execute the transmitting steps in the embodiments of this application. The transmitting unit can be a transmitter, a transmitter, a transmitting circuit, etc.

[0100] Figure 6 If the integrated units in the process are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of software products. These computer software products are stored in a storage medium and include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. Storage media for storing computer software products include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0101] Figure 6 The units in the process can also be called modules; for example, a processing unit can be called a processing module.

[0102] This application also provides a hardware structure diagram of an electronic device (denoted as electronic device 70), see [link to diagram]. Figure 7 The electronic device 70 includes a processor 701, and optionally, a memory 702 connected to the processor 701.

[0103] In the first possible implementation, see Figure 7 The electronic device 70 also includes a transceiver 703. The processor 701, memory 702, and transceiver 703 are connected via a bus. The transceiver 703 is used to communicate with other devices or communication networks. Optionally, the transceiver 703 may include a transmitter and a receiver. The device in the transceiver 703 that implements the receiving function can be considered as a receiver, which is used to perform the receiving steps in the embodiments of this application. The device in the transceiver 703 that implements the transmitting function can be considered as a transmitter, which is used to perform the transmitting steps in the embodiments of this application.

[0104] Based on the first possible implementation method Figure 7 The structural diagram shown can be used to illustrate the structure of the electronic device involved in the above embodiments.

[0105] in, Figure 7 This can also be illustrated by a system chip in an electronic device. In this case, the actions performed by the aforementioned electronic device can be implemented by this system chip; the specific actions performed can be found above and will not be repeated here.

[0106] In implementation, each step of the method provided in this embodiment can be completed by integrated logic circuits in the processor or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or being executed by a combination of hardware and software modules in the processor.

[0107] The processor in this application may include, but is not limited to, at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, etc., and other computing devices that run software. Each computing device may include one or more cores for executing software instructions to perform calculations or processing. The processor may be a standalone semiconductor chip or integrated with other circuits into a single semiconductor chip. For example, it may form a System-on-a-Chip (SoC) with other circuits (such as encoding / decoding circuits, hardware acceleration circuits, or various bus and interface circuits), or it may be integrated as a built-in processor within an ASIC. The ASIC with the integrated processor may be packaged separately or together with other circuits. In addition to the cores for executing software instructions to perform calculations or processing, the processor may further include necessary hardware accelerators, such as field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), or logic circuits that implement dedicated logic operations.

[0108] The memory in the embodiments of this application may include at least one of the following types: read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions; random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions; or electrically erasable programmable-only memory (EEPROM). In some scenarios, the memory may also be a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0109] This application also provides a computer-readable storage medium including instructions that, when run on a computer, cause the computer to perform any of the methods described above.

[0110] This application also provides a computer program product containing instructions that, when run on a computer, cause the computer to perform any of the methods described above.

[0111] This application also provides a chip including a processor and an interface circuit. The interface circuit is coupled to the processor. The processor is used to run computer programs or instructions to implement the above-described method. The interface circuit is used to communicate with other modules outside the chip.

[0112] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks (SSDs)).

[0113] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0114] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A dual CAN communication method for centralized power supplies for emergency lighting, characterized in that, include: Each emergency lighting centralized power supply is equipped with two CAN interfaces. After power-on, the identification, distance, link quality and node load parameters of the communicable nodes around each emergency lighting centralized power supply are collected to establish multiple candidate relay node sets. The first CAN interface is used to communicate with the upper-level bus, and the second CAN interface is used to communicate with the lower-level branch nodes. Based on preset evaluation rules, the optimal node is selected as the relay node from the multiple candidate relay node sets, and the trunk and branch relationships are established. Based on the trunk and branch relationships, when the relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to this node or its subordinate branches, and proceeds to subsequent processing for data that belongs to this node or its subordinate branches. The machine number refers to the node number carried in the CAN message ID, used to uniquely identify the node to which the message belongs; the branch identifier is used to distinguish the network branch to which the message belongs. For data belonging to this node or its subordinate branches, priority is determined based on data type, communication data is written into the cache queue corresponding to its priority, and scheduling is performed on the cache queue according to the emergency status. The step of selecting the optimal node from the multiple candidate relay node sets based on preset evaluation rules and establishing trunk and branch relationships includes: Based on the distance, the link quality, and the node load parameters, each candidate relay node is comprehensively scored according to a preset evaluation rule, and the node with the highest comprehensive score is determined as the current relay node. The emergency lighting centralized power supply is directly connected to the upper-level bus to form the backbone communication link. All emergency lighting centralized power supplies on the backbone communication link are connected using the first CAN interface. The relay node is connected to the first CAN interface of the lower-level emergency lighting centralized power supply through its second CAN interface, and the backbone and branch relationship is formed step by step. Performing scheduling on the cache queue includes: The filtered and scheduled data is forwarded according to its destination node; Data belonging to the upper-level bus direction is forwarded uplink via the first CAN interface, and data belonging to the lower-level branch direction is forwarded downlink via the second CAN interface. During forwarding, the service payload is passed through without parsing its content; The uplink forwarding includes: After the relay node receives the data frame sent by the lower branch node through the second CAN interface, it stores the data frame in the downlink FIFO buffer. The secondary MCU reads data frames from the downlink FIFO buffer and identifies the CAN frame ID and branch ID in the frames; If the data frame is determined to be data related to this branch, it is forwarded to the uplink FIFO buffer of the first CAN interface, waiting to be sent to the next higher node or controller. The downlink forwarding includes: The first CAN interface of the relay node receives data from the upper-level bus and stores it in the uplink FIFO buffer. The secondary MCU reads and identifies the data frame, forwards the relevant data of this branch to the downlink FIFO buffer of the second CAN interface, and then sends it to the next-level branch node.

2. The method according to claim 1, characterized in that, The step of scheduling the cache queue based on the emergency status includes: In the initial settings, the highest priority flag is assigned to emergency information; When the emergency information arrives at the node, it will be processed immediately and with priority, regardless of the current state of the FIFO buffer. For normal status data, processing is performed according to the preset batch size or delay time.

3. The method according to claim 1, characterized in that, The two CAN interfaces are electrically isolated, and both physical layers are equipped with TVS diodes, common-mode inductors, and resettable fuses.

4. The method according to claim 1, characterized in that, During operation, the relationship between the relay node and the backbone and branches is re-evaluated periodically or by event triggering. When link quality degradation, abnormal node load, or communication failure is detected, relay switching is performed among the candidate nodes according to the evaluation rules, and the branch identifier and / or routing entry are updated synchronously. At the same time, the buffer queue length and batch threshold are adaptively adjusted according to the bus occupancy.

5. The method according to claim 1, characterized in that, This technical solution is equipped with dual MCUs working together. The main MCU is used to control the centralized power supply for emergency lighting, and the secondary MCU is used for CAN data forwarding and processing.

6. A dual CAN communication device for centralized power supply of emergency lighting, characterized in that, The device includes: a communication unit and a processing unit; The communication unit is used to equip each emergency lighting centralized power supply with two CAN interfaces. After power-on, it collects the identification, distance, link quality and node load parameters of the communicable nodes around each emergency lighting centralized power supply to establish multiple candidate relay node sets. The first CAN interface is used to communicate with the upper-level bus, and the second CAN interface is used to communicate with the lower-level branch nodes. The processing unit is configured to select the optimal node from the multiple candidate relay node sets as relay nodes based on preset evaluation rules, and establish a trunk and branch relationship. Based on the trunk and branch relationship, when the relay node receives communication data from the first CAN interface or the second CAN interface, it parses the machine number and branch identifier in the data frame, discards data that does not belong to the current node or its subordinate branches, and proceeds to subsequent processing for data that belongs to the current node or its subordinate branches. The machine number refers to the node number carried in the CAN message ID, used to uniquely identify the node to which the message belongs; the branch identifier is used to distinguish the network to which the message belongs. Network branches; for data belonging to this node or its subordinate branches, priority is determined according to data type, communication data is written into a buffer queue corresponding to its priority, and scheduling is performed on the buffer queue according to the emergency state; wherein, the step of selecting the optimal node as a relay node from the multiple candidate relay node sets based on preset evaluation rules and establishing trunk and branch relationships includes: comprehensively scoring each candidate relay node according to the distance, the link quality, and the node load parameters, and determining the node with the highest comprehensive score as the current relay node; forming a trunk communication link with the emergency lighting centralized power supply directly connected to the upper-level bus. The emergency lighting centralized power supply on the main communication link uses the first CAN interface for connection. Relay nodes connect to the first CAN interface of the lower-level emergency lighting centralized power supply via their second CAN interface, expanding hierarchically to form a backbone and branch relationship. Scheduling is performed on the buffer queue, including: forwarding filtered and scheduled data according to its destination node; data belonging to the upper-level bus direction is forwarded uplink via the first CAN interface, and data belonging to the lower-level branch direction is forwarded downlink via the second CAN interface; during forwarding, the service payload is transparently transmitted without parsing its content; wherein, the uplink forwarding includes: the relay node's second CAN interface... After receiving a data frame sent by a lower-level branch node, the data frame is stored in the downlink FIFO buffer. The secondary MCU reads the data frame from the downlink FIFO buffer and identifies the CAN frame ID and branch ID in the frame. If it is determined that the data frame is related to this branch, it is forwarded to the uplink FIFO buffer of the first CAN interface, waiting to be sent to the upper-level node or controller. The downlink forwarding includes: the relay node receives the upper-level bus data through the first CAN interface and stores it in the uplink FIFO buffer; the secondary MCU reads and identifies the data frame, forwards the data related to this branch to the downlink FIFO buffer of the second CAN interface, and then sends it to the lower-level branch node.

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