A gateway-based CAN bus redundancy routing method and device

Abstract

The application discloses a gateway-based CAN bus redundancy routing method and device, and is applied to a CAN network comprising a gateway controller, a first CAN bus link and a separately arranged second CAN bus link. The method comprises the following steps: firstly, obtaining a sending moment of a sending request issued by an application layer and an acknowledgement moment of a sending completion interrupt generated by a bottom layer hardware; based on the acknowledgement moment and the sending moment, obtaining a real-time load parameter of the link under a current message; if the real-time load parameter exceeds a preset load parameter threshold, determining that the first CAN bus link is in an abnormal state of high load, triggering a dynamic routing switching, and switching data transmission of a target node being the preset node to the second CAN bus link for transmission. The application can effectively monitor the bus state without occupying additional bus bandwidth and with low calculation power consumption, realizes dynamic targeted switching on key nodes, and guarantees the real-time performance and reliability of key service data of the whole vehicle.

Description

Technical Field

[0001] This invention relates to the field of CAN bus technology. Specifically, it relates to a gateway-based CAN bus redundant routing method and apparatus. Background Technology

[0002] Controller Area Network (CAN bus), as a mature automotive bus transmission protocol, has been widely used in vehicle networks due to its high reliability. Currently, with the increasing intelligence of vehicles, not only is there massive data interaction within the vehicle network, but some core control signals (such as auxiliary braking, power torque, and steering control) also place more stringent demands on the real-time performance and reliability of data transmission.

[0003] In existing vehicle CAN network architectures, a multi-master communication structure and CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) arbitration mechanism are typically employed, with all nodes on the same bus sharing a single physical link. Under conditions of high bus load and dense message concurrency, nodes often need to wait for the bus to become idle for extended periods, or repeatedly fail in arbitration, leading to retransmissions. This mechanism results in only one node transmitting data at a time, significantly increasing the transmission latency of some critical messages and even causing frame drops.

[0004] For monitoring bus load, most existing technologies employ "bitstream or frame count statistics." Specifically, within a set time window, software polls or parses packets to count the actual data bitstream length transmitted on the bus (usually requiring simulation calculation of padding bits) and divides it by the baud rate to obtain the average load rate for that time period. This macroscopic statistical method not only continuously consumes the gateway controller's computing resources but also exhibits significant time lag, making it difficult to reflect in real time the instantaneous congestion and arbitration delay experienced by a single frame on the underlying hardware medium.

[0005] Furthermore, to cope with high loads and bus failures, most common CAN bus redundancy solutions currently employ a "1+1 dual-segment global hot standby" mode, where the same full number of nodes are connected to both the primary and backup network segments. When the primary network segment becomes congested or experiences a bus shutdown failure, the entire network's data communication will globally switch to the backup network segment. Since the backup network segment also connects to a large number of non-critical ordinary nodes (such as some body control and entertainment systems), these ordinary nodes will still compete with critical nodes for bus bandwidth after the global switch. This approach merely transfers the congestion risk without providing effective physical isolation and communication guarantees for critical nodes, and the overall hardware implementation cost is high.

[0006] In summary, existing technologies lack a redundant routing mechanism that can both assess bus transient load in real time with low computing power overhead and provide independent physical isolation and targeted traffic splitting for critical nodes under high load or bus anomalies. Summary of the Invention

[0007] To address the shortcomings of the existing technologies, the technical problem to be solved by this invention is: how to provide a gateway-based CAN bus redundant routing method and apparatus that can effectively monitor CAN bus congestion or fault status and dynamically switch communication links of key nodes without significantly increasing gateway computing power overhead, thereby ensuring the real-time performance and reliability of data transmission of key vehicle business data.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A gateway-based CAN bus redundancy routing method is applied in a CAN network, the CAN network including a gateway controller and a first CAN bus link connected to the gateway controller, the CAN network also having an independently configured second CAN bus link, the second CAN bus link connecting to a preset node in the CAN network and connected to the gateway controller; the method includes the following steps: S1. When the gateway controller sends a message to any of the preset nodes through the first CAN bus link, it obtains the sending time of the message sending request from the application layer and the confirmation time of the sending completion interrupt generated by the underlying hardware. S2. Based on the confirmation time and the transmission time, obtain the real-time load parameters of the first CAN bus link under the current message; S3. Determine whether the real-time load parameter exceeds the corresponding preset load parameter threshold; if it does, determine the preset node corresponding to the message as the alarm preset node, and determine that the first CAN bus link is in a high load abnormal state. The gateway controller triggers dynamic routing switching to switch the data transmission with the target node being the alarm preset node from the first CAN bus link to the second CAN bus link for transmission.

[0009] Further, in step S2, the real-time load parameter is the time interval between the confirmation time and the sending time; in step S3, the preset load parameter threshold is the preset time interval threshold corresponding to the message.

[0010] Furthermore, when the gateway controller detects that the CAN controller error counter of the first CAN bus link has reached a preset value and triggers a bus shutdown interruption, it determines that the first CAN bus link is in a faulty state. The gateway controller then triggers dynamic routing switching, switching all data transmissions with the preset node as the target node from the first CAN bus link to the second CAN bus link for transmission.

[0011] Furthermore, after the gateway controller triggers dynamic route switching, the following steps are also included: The gateway controller periodically attempts to send messages through the first CAN bus link; when the underlying hardware successfully sends the message and regenerates the transmission completion interrupt, it is determined that the first CAN bus link has returned to normal. After determining that the first CAN bus link has returned to normal, the gateway controller continues to transmit on the second CAN bus link for a preset delay time. After the delay time ends, the data transmission that was transferred to the second CAN bus link is switched back to the first CAN bus link.

[0012] Furthermore, each of the preset nodes in the CAN network is pre-configured with a corresponding communication priority; the preset load parameter thresholds include a first light congestion threshold, a second moderate congestion threshold, and a third severe congestion threshold, which are progressively increased for the message; triggering dynamic routing switching in step S3 specifically includes: When the real-time load parameter exceeds the first mild congestion threshold but does not exceed the second moderate congestion threshold, only the data transmission of the target node being the alarm preset node is switched from the first CAN bus link to the second CAN bus link for transmission. When the real-time load parameter exceeds the second moderate congestion threshold but does not exceed the third severe congestion threshold, the data transmission of the target node being the alarm preset node and other preset nodes with a communication priority not lower than the alarm preset node will be switched from the first CAN bus link to the second CAN bus link for transmission. When the real-time load parameter exceeds the third severe congestion threshold, the data transmission of all preset nodes will be switched from the first CAN bus link to the second CAN bus link for transmission.

[0013] Furthermore, the preset node includes at least one of the power control node, braking control node, and steering control node in the CAN network.

[0014] A gateway-based CAN bus redundancy routing device is applied in a CAN network. The CAN network includes a gateway controller and a first CAN bus link connected to the gateway controller. The CAN network also has an independently configured second CAN bus link, which connects to a preset node in the CAN network and is connected to the gateway controller. The device operates within the gateway controller and includes: The time acquisition module is used to acquire the sending time of the message sending request issued by the application layer and the confirmation time of the sending completion interrupt generated by the underlying hardware when sending a message to any of the preset nodes through the first CAN bus link. The parameter acquisition module is used to acquire the real-time load parameters of the first CAN bus link under the current message based on the confirmation time and the transmission time. The routing switching module is used to determine whether the real-time load parameter exceeds the corresponding preset load parameter threshold; if it does, the preset node corresponding to the message is identified as the alarm preset node, and the first CAN bus link is determined to be in a high load abnormal state. Dynamic routing switching is triggered to switch the data transmission with the target node being the alarm preset node from the first CAN bus link to the second CAN bus link for transmission.

[0015] In summary, the present invention has the following beneficial effects: 1. This invention eliminates the need for the gateway to monitor all messages on the bus in real time or send probe frames to calculate the global load rate. Instead, it uses the time difference between the application layer and the physical layer when sending messages to preset nodes as a load parameter, which effectively reduces the computing power overhead of the gateway and does not occupy additional bus bandwidth resources.

[0016] 2. This invention changes the global one-size-fits-all redundant routing mode. By setting multi-level congestion thresholds and node communication priorities for specific messages, it realizes a tiered dynamic load reduction strategy of "single node switching, peer node switching, and full node switching", thereby ensuring the communication needs of critical services under different congestion conditions.

[0017] 3. This invention not only solves the problem of high load congestion caused by data concurrency, but also designs a low-level switching mechanism for physical layer disconnection faults such as bus shutdown interruption, thereby improving the fault tolerance of the CAN network under various abnormal operating conditions.

[0018] 4. This invention periodically attempts to send messages to detect the recovery status of the first CAN bus link and introduces a delayed switchback mechanism, which can effectively avoid frequent network switching caused by fluctuations in bus load at critical states and maintain the stability of the in-vehicle communication network. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a redundant CAN network topology provided in an embodiment of the present invention.

[0020] Figure 2 This is a flowchart illustrating a gateway-based CAN bus redundancy routing method provided in an embodiment of the present invention. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the embodiments.

[0022] Example 1: As Figure 1 and Figure 2 As shown, this embodiment provides a gateway-based CAN bus redundancy routing method applied to a vehicle's CAN network. The CAN network includes a gateway controller and a first CAN bus link connected to the gateway controller, as shown below. Figure 1 As shown by the thin solid line; the CAN network also has an independently configured second CAN bus link, such as... Figure 1 As shown by the thick solid line in the diagram; the second CAN bus link connects to a preset node in the CAN network and is connected to the gateway controller.

[0023] In this embodiment, the first CAN bus link serves as the default data transmission path for the entire vehicle, connecting the gateway controller to all bus nodes; the second CAN bus link serves as a redundant backup path, connecting only the gateway controller to a preset node. The preset node is a critical control unit with extremely high requirements for the real-time performance and reliability of data transmission, specifically including at least one of the power control node, braking control node, and steering control node in the CAN network.

[0024] The gateway-based CAN bus redundancy routing method provided in this embodiment specifically includes the following steps: S1. When the gateway controller sends a message to any of the preset nodes through the first CAN bus link, it obtains the sending time of the message sending request from the application layer and the confirmation time of the sending completion interrupt generated by the underlying hardware.

[0025] Specifically, traditional CAN bus load rate calculation methods typically require the gateway to monitor all messages on the bus in real time and calculate the bit stream length per unit time. This method not only increases the gateway's computing power burden but also fails to accurately reflect high-priority message congestion caused by the CAN arbitration mechanism. In this embodiment, the gateway controller only performs time tracking when it sends messages to preset nodes. By recording the transmission time when the application layer pushes the message into the transmission queue and the confirmation time of the transmission completion interrupt triggered by the CAN controller's underlying hardware after successfully transmitting the message frame on the bus, the congestion status of the bus is indirectly assessed. This step does not consume any additional CAN bus bandwidth and has extremely low computing power overhead.

[0026] S2. Based on the confirmation time and the transmission time, obtain the real-time load parameters of the first CAN bus link under the current message.

[0027] In this embodiment, the real-time load parameter is specifically the time interval between the acknowledgment time and the transmission time. This time interval directly reflects the actual queuing delay of the current message in the first CAN bus link due to waiting for the bus to become idle or participating in arbitration.

[0028] S3. Determine whether the real-time load parameter exceeds the corresponding preset load parameter threshold; if it does, determine the preset node corresponding to the message as the alarm preset node, and determine that the first CAN bus link is in a high load abnormal state. The gateway controller triggers dynamic routing switching to switch the data transmission with the target node being the alarm preset node from the first CAN bus link to the second CAN bus link for transmission.

[0029] Since the arbitration mechanism of the CAN bus is closely related to the CAN ID of the message (the smaller the ID, the higher the priority and the shorter the natural waiting time), the preset load parameter threshold is not a fixed value uniform across the entire network, but a preset time interval threshold specific to this message.

[0030] To achieve more flexible network switching and implement tiered dynamic load reduction, in this embodiment, each preset node in the CAN network is pre-configured with a corresponding communication priority. The preset load parameter thresholds set for this message include a first light congestion threshold, a second moderate congestion threshold, and a third severe congestion threshold, which increase progressively. The step of triggering dynamic routing switching in step S3 specifically includes: (1) When the real-time load parameter exceeds the first mild congestion threshold but does not exceed the second moderate congestion threshold, it is determined that the current bus is slightly congested. At this time, only the data transmission of the target node is the alarm preset node is switched from the first CAN bus link to the second CAN bus link for transmission, so as to realize single-point pressure relief.

[0031] (2) When the real-time load parameter exceeds the second moderate congestion threshold but does not exceed the third severe congestion threshold, it is determined that the current bus congestion has intensified. At this time, the data transmission of the target node is the alarm preset node and other preset nodes with communication priority not lower than the alarm preset node is switched from the first CAN bus link to the second CAN bus link for transmission, so as to prioritize the communication security of high priority nodes.

[0032] (3) When the real-time load parameter exceeds the third severe congestion threshold, it is determined that the current bus is in a severe congestion state. At this time, the data transmission of all preset nodes with the target node is switched from the first CAN bus link to the second CAN bus link for transmission.

[0033] To address the shutdown interruption of the first CAN bus link, the method in this embodiment further includes: when the gateway controller detects that the CAN controller error counter of the first CAN bus link reaches a preset value (e.g., reaches 255) and triggers a bus shutdown interruption, it determines that the first CAN bus link is in a faulty state, and the gateway controller triggers dynamic routing switching to forcibly switch all data transmissions with the preset node as the target node from the first CAN bus link to the second CAN bus link for transmission.

[0034] Furthermore, after the gateway controller triggers a dynamic route switch, this embodiment also provides a delayed switchback step, which specifically includes the following steps: The gateway controller periodically attempts to send messages (or probe frames) through the first CAN bus link; when the underlying hardware successfully sends the message and regenerates the transmission completion interrupt, it is determined that the first CAN bus link has returned to normal. After determining that the first CAN bus link has returned to normal, the gateway controller does not immediately switch the data transmission back. Instead, it continues to transmit on the second CAN bus link for a preset delay time (e.g., 500ms to 2s). After the delay time ends, the data transmission transferred to the second CAN bus link is switched back to the first CAN bus link. This delay-based switching mechanism effectively avoids the "ping-pong effect" of frequent switching between the two links caused by the first CAN bus link being under critical load or experiencing physical connection jitter, thus ensuring the stability of the vehicle network communication.

[0035] For ease of understanding, the method provided in this embodiment will be fully described below with reference to the network topology and specific message parameters in the accompanying drawings: Assuming the target node is a pre-defined node in the vehicle network (e.g., Figure 1 Node N-2 in the context, such as the braking control node), the source node of the message is a regular node in another functional domain (such as...). Figure 1 (Node 2-2 in the example). Pre-calibrated through testing, a preset time interval threshold of 50μs is set for specific messages sent to node N-2 (e.g., messages with CAN ID=0x100).

[0036] 1. Under normal circumstances (low bus load and bus not shut down): After receiving the message sent by node 2-2, the gateway controller will... Figure 1 The combined link of path ① and path ② successfully forwarded the message to the target node N-2. During this process, the gateway controller obtained the actual transmission time interval of the message (CAN ID=0x100). Since the network was normal, this time interval was less than 50μs.

[0037] 2. First abnormal scenario (high bus load): When the gateway controller detects that the actual transmission interval of the message (CAN ID=0x100) destined for node N-2 is greater than 50μs, it triggers dynamic routing switching. The gateway controller switches the data transmission to node N-2 from path ② of the first CAN bus link to path ③ of the independent second CAN bus link, that is, the message is routed according to... Figure 1 The transmission is carried out by combining the links of path ① and path ③, thereby ensuring that the communication of the critical node N-2 is not interfered with without affecting the communication of ordinary nodes.

[0038] 3. Second abnormal situation (bus off): such as Figure 1 As shown, in the abnormal situation of bus shutdown, the gateway controller will forcibly switch the data transmission to critical nodes 1-1, 3-3, N-2 and Nk from the first CAN bus link (thin solid line) to an independent second CAN bus link (thick solid line).

[0039] 4. In case of abnormal recovery: When the gateway controller periodically detects successful transmission on path ② of the first CAN bus link and determines that the bus status has returned to normal, the system continues to transmit on path ③ of the independent path for a preset delay time (e.g., t=5s) to ensure that the original link is completely stable before smoothly switching the communication path back to the original path ① and path ②.

[0040] Furthermore, this embodiment also provides a gateway-based CAN bus redundancy routing device, applied to the aforementioned CAN network and operating in the gateway controller. The device includes: a time acquisition module for performing step S1, a parameter acquisition module for performing step S2, and a routing switching module for performing step S3. Since this device embodiment is based on the same inventive concept as the aforementioned method embodiment, the specific implementation logic, parameter configuration, and beneficial effects of each functional module in the device are completely identical to those in the aforementioned method embodiment. For the sake of brevity, further details are omitted here.

[0041] Example 2: As another preferred embodiment of the present invention, this embodiment has the same network topology and main steps as Example 1. The main difference is that steps S2 and S3 have been replaced and optimized in this embodiment.

[0042] Specifically, in step S2, the real-time load parameter is the transient equivalent load rate of the message, and in step S3, the preset load parameter threshold is the preset equivalent load rate threshold corresponding to the message.

[0043] In this embodiment, the step of obtaining the transient equivalent load rate includes: (1) Calculate the time difference between the confirmation time and the sending time, and use it as the actual transmission time; (2) Obtain the theoretical transmission time of the message in the bus idle state, and the maximum allowable delay time of the message; (3) Calculate the difference between the actual transmission time and the theoretical transmission time, and normalize the difference with the maximum tolerable delay time to obtain the transient equivalent load factor in percentage form. The specific normalization calculation formula is as follows: In the formula: The transient equivalent load factor; The actual transmission time is the time difference between the confirmation time and the sending time. This represents the theoretical transmission time of the message when the bus is idle. This is the maximum allowable delay time for this message.

[0044] Specifically, in step S3, before triggering the dynamic route switching, the following steps are also included: If the transient equivalent load rate exceeds the preset equivalent load rate threshold corresponding to the message, a sliding time window pre-built for the message is invoked. The sliding time window is used to record abnormal records during the most recent N consecutive transmissions of the message. Each time the transient equivalent load rate exceeds the preset equivalent load rate threshold corresponding to the message, it is recorded as an anomaly and updated in the sliding time window; Statistically count the frequency of abnormal records within the sliding time window; If the abnormal frequency reaches the preset frequency alarm threshold, the first CAN bus link is determined to be in a high load abnormal state, and the preset node corresponding to the message is identified as the alarm preset node to trigger the dynamic routing switch.

[0045] Furthermore, in step S3, if the transient equivalent load rate exceeds the preset extreme load rate threshold corresponding to the message, the first CAN bus link is directly determined to be in a high load abnormal state, and the preset node corresponding to the message is determined as the alarm preset node to trigger the dynamic routing switch; the preset extreme load rate threshold is greater than the preset equivalent load rate threshold.

[0046] To facilitate understanding, the algorithm logic of this embodiment is fully explained below with reference to specific message parameters: Assume that for a specific message (CAN ID=0x100) destined for critical node N-2, its theoretical transmission time in idle state is calibrated to be 20μs, and the maximum allowable latency time at the application layer is 100μs. The system sets a preset equivalent load rate threshold of 80% and a preset extreme load rate threshold of 150%. Simultaneously, a sliding time window of length N=10 is allocated in the gateway controller memory for this message, and the set frequency alarm threshold is 6 times.

[0047] 1. Under normal anti-jitter judgment (normal congestion): After sending a certain frame of the message, the gateway controller records its actual transmission time as 105μs. At this time, the difference between the actual transmission time (105μs) and the theoretical transmission time (20μs) is 85μs. Normalizing this difference with the maximum tolerable delay time (100μs), the transient equivalent load rate is calculated to be 85%. Since 85% exceeds the preset equivalent load rate threshold (80%), but is below the extreme load rate threshold (150%), this exceeding state is recorded as an abnormal record and updated in the sliding time window. The gateway controller counts the last 10 transmission records. If the abnormal frequency reaches 6 times, it determines a high load abnormal state and identifies the preset node corresponding to the message as the alarm preset node to trigger a dynamic routing switch to the second CAN bus link.

[0048] 2. In the case of rapid switching (extreme congestion): After the gateway controller sends a certain frame of the message, due to severe bus congestion, the actual transmission time reaches 180μs. After normalization calculation, the transient equivalent load rate at this time is 160% (i.e., (180μs-20μs) / 100μs = 160%). Since the transient equivalent load rate (160%) exceeds the preset extreme load rate threshold (150%), the system directly determines that the first CAN bus link is in a high-load abnormal state and instantly triggers a dynamic routing switch to the second CAN bus link.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gateway-based CAN bus redundancy routing method, characterized in that, Applied in a CAN network, the CAN network includes a gateway controller and a first CAN bus link connected to the gateway controller. The CAN network also has an independently configured second CAN bus link, which connects to a preset node in the CAN network and is connected to the gateway controller. The process includes the following steps: S1. When the gateway controller sends a message to any of the preset nodes through the first CAN bus link, it obtains the sending time of the message sending request from the application layer and the confirmation time of the sending completion interrupt generated by the underlying hardware. S2. Based on the confirmation time and the transmission time, obtain the real-time load parameters of the first CAN bus link under the current message; S3. Determine whether the real-time load parameter exceeds the corresponding preset load parameter threshold; If the load exceeds the limit, the preset node corresponding to the message is identified as the alarm preset node, and the first CAN bus link is determined to be in a high-load abnormal state. The gateway controller triggers dynamic routing switching to switch the data transmission with the target node being the alarm preset node from the first CAN bus link to the second CAN bus link for transmission.

2. The gateway-based CAN bus redundancy routing method as described in claim 1, characterized in that, In step S2, the real-time load parameter is the time interval between the confirmation time and the sending time; in step S3, the preset load parameter threshold is the preset time interval threshold corresponding to the message.

3. The gateway-based CAN bus redundancy routing method as described in claim 1, characterized in that, When the gateway controller detects that the CAN controller error counter of the first CAN bus link has reached a preset value and triggers a bus shutdown interrupt, it determines that the first CAN bus link is in a faulty state. The gateway controller then triggers a dynamic routing switch, switching all data transmissions with the preset target node from the first CAN bus link to the second CAN bus link for transmission.

4. The gateway-based CAN bus redundancy routing method as described in any one of claims 1 to 3, characterized in that, After the gateway controller triggers a dynamic route switch, the following steps are also included: The gateway controller periodically attempts to send messages through the first CAN bus link; when the underlying hardware successfully sends the message and regenerates the transmission completion interrupt, it is determined that the first CAN bus link has returned to normal. After determining that the first CAN bus link has returned to normal, the gateway controller continues to transmit on the second CAN bus link for a preset delay time. After the delay time ends, the data transmission that was transferred to the second CAN bus link is switched back to the first CAN bus link.

5. The gateway-based CAN bus redundancy routing method as described in claim 1 or 2, characterized in that, Each preset node in the CAN network is pre-configured with a corresponding communication priority; the preset load parameter thresholds include a first light congestion threshold, a second moderate congestion threshold, and a third severe congestion threshold, which are progressively increased for the message; the triggering of dynamic routing switching in step S3 specifically includes: When the real-time load parameter exceeds the first mild congestion threshold but does not exceed the second moderate congestion threshold, only the data transmission of the target node being the alarm preset node is switched from the first CAN bus link to the second CAN bus link for transmission. When the real-time load parameter exceeds the second moderate congestion threshold but does not exceed the third severe congestion threshold, the data transmission of the target node being the alarm preset node and other preset nodes with a priority not lower than the alarm preset node will be switched from the first CAN bus link to the second CAN bus link for transmission. When the real-time load parameter exceeds the third severe congestion threshold, the data transmission of all preset nodes will be switched from the first CAN bus link to the second CAN bus link for transmission.

6. The gateway-based CAN bus redundancy routing method as described in claim 1, characterized in that, The preset node includes at least one of the power control node, braking control node, and steering control node in the CAN network.

7. A gateway-based CAN bus redundancy routing device, applied in a CAN network, the CAN network including a gateway controller and a first CAN bus link connected to the gateway controller, the CAN network also having an independently configured second CAN bus link, the second CAN bus link connecting to a preset node in the CAN network and connected to the gateway controller; characterized in that, The device operates within the gateway controller and includes: The time acquisition module is used to acquire the sending time of the message sending request issued by the application layer and the confirmation time of the sending completion interrupt generated by the underlying hardware when sending a message to any of the preset nodes through the first CAN bus link. The parameter acquisition module is used to acquire the real-time load parameters of the first CAN bus link under the current message based on the confirmation time and the transmission time. The routing switching module is used to determine whether the real-time load parameter exceeds the corresponding preset load parameter threshold; if it does, the preset node corresponding to the message is identified as the alarm preset node, and the first CAN bus link is determined to be in a high load abnormal state. Dynamic routing switching is triggered to switch the data transmission with the target node being the alarm preset node from the first CAN bus link to the second CAN bus link for transmission.

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