CAN FD bus communication conflict avoiding method applied to hydraulic active suspension

Abstract

The invention discloses a CAN FD bus communication conflict avoidance method applied to a hydraulic active suspension, and the method comprises the following steps: S1, node configuration: distributing a dynamic ID priority and embedding a timestamp mark; s2, judging whether the dynamic ID priority and the timestamp mark are correct or not, if not, starting a standby channel, and ending the process; if yes, S3 is carried out; s3, optimizing multiple paths of signals, packaging signal clusters, and generating optimized frames; s4, judging whether the performance of the optimized frame meets requirements or not, if not, starting a standby channel, and ending the process; if the performance of the optimized frame meets the requirement, performing S5; s5, judging a signal transmission stage, and switching different rates for communication according to the signal transmission stage; s6, judging whether the rate switching transmission improves the data transmission efficiency while maintaining the reliability of the CAN bus, and if yes, performing redundant bus verification; otherwise, starting the standby channel and ending the flow.

Description

Technical Field

[0001] The present invention relates to a CAN FD bus communication conflict avoidance method applied to a hydraulic active suspension, belonging to the technical field of vehicle-mounted networks and industrial control communications. Background Art

[0002] CAN bus (Controller Area Network) is a serial communication network that can realize distributed real-time control.

[0003] In high-speed, multi-channel communication scenarios, the fixed priority of the traditional CAN bus can easily lead to long-term congestion of low-priority messages. When devices with the same priority conflict, the backoff mechanism is inefficient, affecting real-time performance. Inconsistent timing in hybrid CAN / CAN FD networks leads to the propagation of error frames. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a CAN FD bus communication conflict avoidance method for hydraulic active suspension, which can significantly reduce the probability of conflict between devices of the same level and improve real-time performance and bandwidth utilization.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] A CAN FD bus communication conflict avoidance method applied to a hydraulic active suspension includes the following steps:

[0007] S1. Node configuration, including assigning dynamic ID priority and embedding timestamp;

[0008] S2. Determine whether the dynamic ID priority and timestamp are correct. If they are not correct, start the backup channel and the process ends. If they are correct, proceed to S3.

[0009] S3, optimize multi-channel signals, package signal clusters, and generate optimized frames;

[0010] S4. Determine whether the performance of the optimized frame meets the requirements. If the performance of the optimized frame does not meet the requirements, start the backup channel and the process ends. If the performance of the optimized frame meets the requirements, proceed to S5.

[0011] S5. Determine the signal transmission stage and switch to different communication rates according to the signal transmission stage;

[0012] S6. Determine whether rate switching transmission improves data transmission efficiency while maintaining CAN bus reliability. If so, perform redundant bus verification. If rate switching transmission does not improve data transmission efficiency while maintaining CAN bus reliability, start the backup channel and the process ends.

[0013] Furthermore, the performance of the optimized frame in S4 includes efficiency, reliability, delay, and energy consumption.

[0014] Furthermore, in S5 , the signal transmission stage is determined by the BRS segment, and the signal transmission stage includes an arbitration segment and a data segment.

[0015] Furthermore, the communication rate includes a first rate and a second rate, the first rate is used for communication in the arbitration segment, and the second rate is used for transmission in the data segment.

[0016] Furthermore, the first rate is 0-1000 kbit / s; and the second rate is 1000 to 10000 kbit / s.

[0017] Furthermore, when the backup channel is started, the faulty node is isolated, communication is maintained, and the process ends.

[0018] Furthermore, the redundant bus verification includes the following steps:

[0019] S100, start, system initialization;

[0020] S200, self-check bus A and automatic bus B;

[0021] S300, determine whether bus A and bus B are normal. If bus A and bus B are normal, proceed to S400;

[0022] S400, collecting data from bus A and bus B;

[0023] S500, determine whether the data on bus A and bus B are consistent; if the data on bus A and bus B are consistent, proceed to S600;

[0024] S600, receiving data from bus A and data from bus B, and retaining data from bus A;

[0025] S700, return to cycle monitoring.

[0026] Furthermore, if bus A and bus B are abnormal in S300 , an alarm is triggered or the bus is switched to a standby mode.

[0027] Furthermore, if the data of bus A and bus B are inconsistent in S500, the fault tolerance mechanism is activated.

[0028] Furthermore, the variable-length signal field in the signal cluster package includes a 2-bit length identifier and N bits of data; and the reserved check bit in the frame is CRC8.

[0029] Furthermore, the accuracy of the timestamp in S1 is 100ns.

[0030] Furthermore, the timestamp embedded in S1 is marked as the first byte of the embedded data segment.

[0031] Compared with the prior art, the advantages of the present invention include:

[0032] 1) The CAN FD bus communication conflict avoidance method for hydraulic active suspension provided by this invention significantly reduces the conflict probability of devices of the same level (the conflict probability is reduced by 80%) through dynamic ID priority allocation, signal cluster packaging optimization, dual-rate switching, and redundant bus verification, thereby improving real-time performance and bandwidth utilization.

[0033] 2) The CAN FD bus communication conflict avoidance method for hydraulic active suspension provided by the present invention reduces the average response time for messages of the same priority level to 12 μs (compared to 35 μs for traditional methods);

[0034] 3) The CAN FD bus communication conflict avoidance method for a hydraulic active suspension provided by the present invention can support an effective data transmission rate of up to 8 Mbps. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is a system framework diagram of a CAN FD bus communication conflict avoidance method applied to a hydraulic active suspension, provided in a typical embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of a signal cluster packaging format provided in a typical implementation case of the present invention;

[0038] Figure 3 This is a timing diagram of dual-rate switching between arbitration segment and data segment provided in a typical implementation case of the present invention;

[0039] Figure 4 This is a flowchart of a "two-out-of-two" verification of a redundant bus provided in a typical implementation case of the present invention; DETAILED DESCRIPTION

[0040] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The following will further explain this technical solution, its implementation process and principles.

[0041] like Figure 1 As shown, the present invention discloses a CAN FD bus communication conflict avoidance method applied to a hydraulic active suspension, and the CAN FD bus communication conflict avoidance method applied to a hydraulic active suspension comprises the following steps:

[0042] S1. Node configuration, including assigning dynamic ID priority and embedding a timestamp. Specifically, the timestamp has an accuracy of 100 ns and is embedded in the first byte of the data segment.

[0043] In practice, dynamic ID priority management utilizes a hybrid arbitration mechanism based on event triggering and network load sensing. When a node sends an emergency fault code, the system dynamically assigns node ID priorities based on the network topology. The priority algorithm comprehensively considers the node's functional level, historical communication quality, and real-time load. Hardware-based priority arbitration ensures that critical messages are transmitted first. For example, in an electric vehicle control system, the battery management unit (BMS) is given higher communication priority than the in-vehicle entertainment system.

[0044] In terms of timestamp embedding, hardware-level marking needs to be implemented at the data link layer, using the built-in 32-bit timer of the CAN controller to automatically write the current value of the timer into the reserved bit of the data frame when the message is sent.

[0045] S2. After the dynamic ID and timestamp configuration is complete, determine whether the dynamic ID priority and timestamp are correct. If they are incorrect, start the backup channel to isolate the faulty node and maintain communication, and the process ends. If they are correct, proceed to S3.

[0046] S3, optimize multi-channel signals, package signal clusters, and generate optimized frames; specifically, Figure 2 As shown, the format of the signal cluster packaging includes: the variable length signal field in the signal cluster packaging includes a 2-bit length identifier and N bits of data; the reserved check bit in the frame is CRC8;

[0047] S4. Evaluate the optimized frame, i.e., determine whether the performance of the optimized frame meets the requirements. Specifically, the performance of the optimized frame includes efficiency, reliability, latency, and energy consumption. If the performance of the optimized frame does not meet the requirements, activate the backup channel, isolate the faulty node, maintain communication, and the process ends. If the performance of the optimized frame meets the requirements, proceed to S5.

[0048] S5, judging the signal transmission stage through the BRS segment, wherein the signal transmission stage includes the arbitration segment and the data segment; switching different rate communications according to the signal transmission stage; Figure 3 As shown, the communication rate includes a first rate and a second rate, the first rate is used for communication in the arbitration segment, and the second rate is used for transmission in the data segment; more specifically, the first rate is 0-1000 kbit / s; the second rate is 1000 to 10000 kbit / s.

[0049] In the CAN FD protocol, the BRS bit is a key control bit for determining the transmission phase and switching between different rates. This bit enables rate switching from the arbitration phase to the data phase, thereby improving data transmission efficiency without increasing bus load. In practical applications, the BRS bit configuration must be set in the CAN controller, and all nodes must have the same BRS bit configuration to ensure correct communication.

[0050] S6. Determine whether rate switching transmission improves data transmission efficiency while maintaining CAN bus reliability. If rate switching transmission does not improve data transmission efficiency while maintaining CAN bus reliability, activate a backup channel to isolate the faulty node and maintain communication, and the process ends. If rate switching transmission improves data transmission efficiency while maintaining CAN bus reliability, perform redundant bus verification.

[0051] Specific: such as Figure 4 As shown, redundant bus verification includes the following steps:

[0052] S100, start, system initialization;

[0053] S200, self-check bus A and automatic bus B, specifically, checking the first rate and the second rate of bus A and bus B;

[0054] S300, determining whether bus A and bus B are normal, that is, determining whether bus A and bus B meet the first rate of 0-1000 kbit / s and the second rate of 1000 to 10000 kbit / s; if bus A and bus B meet the requirements, proceed to S400; if bus A and bus B do not meet the requirements, triggering an alarm or switching to standby;

[0055] S400, collecting data from bus A and bus B, where the data refers to the first n bits of a custom data segment;

[0056] S500, determining whether the data of bus A and bus B are consistent, that is, determining whether the first n bits of the customized data segments of bus A and bus B are consistent; if the data of bus A and bus B are consistent, proceed to S600; if the data of bus A and bus B are inconsistent, activate the fault tolerance mechanism;

[0057] S600, receiving data from bus A and data from bus B, and retaining data from bus A;

[0058] S700, return to cycle monitoring.

[0059] This application significantly reduces the probability of conflicts between devices of the same level, improves real-time performance and bandwidth utilization, and is suitable for high-reliability communication scenarios such as intelligent driving and industrial control through dynamic ID priority allocation, signal cluster packaging optimization, dual-rate switching, and redundant bus verification.

[0060] It should be understood that the above embodiments are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent variations or modifications made in accordance with the spirit and substance of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. A CAN FD bus communication conflict avoidance method for a hydraulic active suspension, characterized by: The steps include: S1. Node configuration, including assigning dynamic ID priority and embedding timestamp; S2. Determine whether the dynamic ID priority and timestamp are correct. If they are not correct, activate the backup channel and the process ends. If the dynamic ID priority and timestamp are correct, proceed to S3; S3, optimize multi-channel signals, package signal clusters, and generate optimized frames; S4. Determine whether the performance of the optimized frame meets the requirements. If the performance of the optimized frame does not meet the requirements, start the backup channel and the process ends. If the performance of the optimized frame meets the requirements, proceed to S5; S5. Determine the signal transmission stage and switch to different communication rates according to the signal transmission stage; S6. Determine whether rate switching transmission improves data transmission efficiency while maintaining CAN bus reliability. If so, perform redundant bus verification. If rate switching transmission does not improve data transmission efficiency while maintaining CAN bus reliability, start the backup channel and the process ends.

2. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 1, wherein: The performance of the optimized frame described in S4 includes efficiency, reliability, delay, and energy consumption.

3. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 1, wherein: In S5 , the signal transmission phase is determined through the BRS segment, and the signal transmission phase includes an arbitration segment and a data segment.

4. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 3, wherein: The communication rate includes a first rate and a second rate, wherein the first rate is used for communication in the arbitration section and the second rate is used for transmission in the data section; And / or, the first rate is 0-1000 kbit / s; the second rate is 1000 to 10000 kbit / s.

5. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 1, wherein: When the backup channel is started, the faulty node is isolated, communication is maintained, and the process ends.

6. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 1, wherein: Redundant bus verification includes the following steps: S100, start, system initialization; S200, self-check bus A and automatic bus B; S300, determine whether bus A and bus B are normal. If bus A and bus B are normal, proceed to S400; S400, collecting data from bus A and bus B; S500, determining whether the data on bus A and bus B are consistent; If the data of bus A and bus B are consistent, proceed to S600; S600, receiving data from bus A and data from bus B, and retaining data from bus A; S700, return to cycle monitoring.

7. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 6, characterized in that: In S300, if bus A and bus B are abnormal, an alarm is triggered or the backup is switched.

8. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 6, characterized in that: In S500 , if the data on bus A and bus B are inconsistent, the fault tolerance mechanism is activated.

9. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 1, wherein: The variable-length signal field in the signal cluster package includes a 2-bit length identifier and N bits of data; the reserved check bit in the frame is CRC8.

10. The CAN FD bus communication conflict avoidance method for a hydraulic active suspension according to claim 1, characterized in that: The accuracy of the timestamp described in S1 is 100ns; And / or, the timestamp embedded in S1 is marked as the first byte of the embedded data segment.

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