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CN-121989990-A - Automatic driving CAN communication safety redundant system

CN121989990ACN 121989990 ACN121989990 ACN 121989990ACN-121989990-A

Abstract

The application belongs to the field of automatic driving automobile control, and provides an automatic driving CAN communication safety redundant system which comprises an automatic driving domain controller (ADU) and a whole automobile controller (VCU), wherein a double-channel communication architecture of a main CAN bus and a backup CAN bus is adopted between the ADU and the VCU to realize bidirectional information interaction, the VCU integrates a CAN communication quality evaluation module, a CAN channel arbitration module, a CAN communication fault prompting and protecting module and a CAN signal processing module, the ADU sends an automobile control instruction to the VCU through the main CAN bus and the backup CAN bus, and the VCU feeds back real-time automobile state information to the ADU. The system can adaptively adjust the operation parameters under the working conditions of different vehicle speeds and different electromagnetic interference intensities, can complete fault diagnosis, data switching and safety protection without manual intervention, and provides key communication guarantee for large-scale application of the automatic driving technology in complex scenes such as urban roads, highways and the like.

Inventors

  • SUN YONGZHENG
  • LUO YONGCHANG
  • HU ZHONG
  • XUE JINLIN

Assignees

  • 苏州力牧汽车科技有限公司

Dates

Publication Date
20260508
Application Date
20260225

Claims (9)

  1. 1. The automatic driving CAN communication safety redundancy system is characterized by comprising an automatic driving domain controller (ADU) and a whole Vehicle Controller (VCU), wherein a double-channel communication architecture of a main CAN bus and a backup CAN bus is adopted between the ADU and the VCU, so that bidirectional information interaction is realized; the VCU integrates a CAN communication quality evaluation module, a CAN channel arbitration module, a CAN communication fault prompting and protecting module and a CAN signal processing module; the ADU sends a vehicle control instruction to the VCU through the main CAN bus and the backup CAN bus, and the VCU feeds back real-time vehicle state information to the ADU.
  2. 2. The automatic driving CAN communication safety redundant system according to claim 1, wherein the CAN communication quality evaluation module comprises a CAN communication state diagnosis unit, a CAN message cycle counting unit and a CAN communication quality scoring unit, wherein the CAN communication state diagnosis unit monitors vehicle control messages on the main CAN bus and the backup CAN bus by adopting a rolling counter, and the rolling counter value is increased by 1 when a target control message is not received and is decreased by 1 when the target control message is received in a specified CAN message protocol period; And when the rolling counter value is smaller than or equal to 0, judging that the communication is normal, and adaptively adjusting the CAN communication abnormal loss threshold according to the real-time speed of the vehicle and the electromagnetic interference intensity.
  3. 3. The automatic driving CAN communication safety redundant system according to claim 2, wherein the default value of the CAN communication abnormal loss threshold is 10 CAN message protocol periods, the threshold is adjusted to 5 CAN message protocol periods when the vehicle is in a high speed working condition, and the threshold is adjusted to 20 CAN message protocol periods when the vehicle is in a strong electromagnetic interference working condition.
  4. 4. The automatic driving CAN communication safety redundant system according to claim 2, wherein the CAN message cycle count unit adds 0-15 cycle count signals into the CAN message, and identifies whether the ADU is lost or jammed by comparing cycle count values of adjacent cycles.
  5. 5. The automatic driving CAN communication safety redundant system according to claim 2, wherein the scoring dimension of the CAN communication quality scoring unit comprises CAN message cycle count, CAN message cycle jitter, CAN bus load rate, and weight ratio is 40%, 30% respectively; The calculation formula of the CAN communication quality score is that the CAN communication quality score=CAN message cycle count score, CAN message cycle jitter score and CAN bus load rate score.
  6. 6. The automatic driving CAN communication safety redundant system according to claim 5, wherein the CAN message cycle count scoring rule is that 40 points are obtained without count discontinuity and repetition phenomenon in 30 continuous periods, 2 points are subtracted from count discontinuity every time, 4 points are subtracted from count repetition every time, 6 points are added in 10 periods when no abnormality occurs continuously, and the final score is not higher than 40 points and not lower than 0 points; The CAN message period jitter scoring rule is that 30 points are obtained by 30 continuous periods with the deviation rate average value less than or equal to 5%, 21-29 points are obtained by the deviation rate average value between 5% and 8%, 10-20 points are obtained by the deviation rate average value between 8% and 12%, and 0-10 points are obtained by the deviation rate average value > 12%; the CAN bus load rate scoring rule is that a load rate average value of 30 percent is 30 percent, a load rate average value of 21-29 percent is 30-45 percent, a load rate average value of 11-20 percent is 45-60 percent, and a load rate average value of >60 percent is 0-10 percent in a 1-minute statistical period.
  7. 7. The autopilot CAN communication safety redundancy system of claim 1 wherein the arbitration logic of the CAN channel arbitration module is as follows: (1) When the communication of the main CAN bus is interrupted, unconditionally adopting the backup CAN bus data; (2) When the backup CAN bus communication is interrupted, the main CAN bus data is unconditionally adopted; (3) When the main CAN bus and the backup CAN bus are normal, comparing the communication quality scores of the two buses and the data consistency to screen optimal data; (4) When the main CAN bus and the backup CAN bus are interrupted, the system enters a fault protection mode, and safety value configuration is started.
  8. 8. The autopilot CAN communication safety redundancy system of claim 7 wherein the primary CAN bus and the backup CAN bus are both normal and have a communication quality score difference of less than 2 timescales, performing an arbitration operation on floating point data as follows: (1) When the difference value of the two paths of data is smaller than the threshold value capable of solving the average value, the average value is used as control data; (2) When the difference value of the two paths of data is larger than the average value threshold value and smaller than the maximum boundary threshold value, selecting a more approximate value by combining the control data at the previous moment; (3) When the difference value of the two paths of data is larger than the maximum boundary threshold value, starting safety value configuration; for non-floating point data, adopting the main CAN bus data; and when the communication quality score of the main CAN bus is lower than the communication quality score of the backup CAN bus by more than 5 minutes, adopting the backup CAN bus data, otherwise adopting the main CAN bus data.
  9. 9. The automatic driving CAN communication safety redundant system according to claim 1 is characterized in that the CAN communication fault prompting and protecting module has a working mechanism that when a single CAN bus is disconnected or two paths of data are extremely poor in consistency, the VCU reports abnormal working condition information to the ADU, when both CAN buses are lost, the system triggers a fault protecting mode and sends out a manual taking over prompting signal, and the CAN signal processing module executes signal filtering anti-shake and output boundary limiting preprocessing on the arbitrated control instructions, and after preprocessing is completed, the VCU sends out the signals to each executor.

Description

Automatic driving CAN communication safety redundant system Technical Field The application belongs to the field of automatic driving automobile control, and particularly relates to an automatic driving CAN communication safety redundancy system. Background In an automatic driving control system, key vehicle control instructions such as braking, steering, driving and the like are generally transmitted to a whole Vehicle Controller (VCU) through a single-path CAN bus by an automatic driving domain controller (ADU), so that cooperative control of a vehicle chassis system is realized. With the rapid development of intelligent traffic and automatic driving technologies, vehicle control systems have placed extremely high demands on the real-time, reliability and safety of data transmission. The existing single-path CAN bus transmission scheme lacks a safety redundancy mechanism, and when the CAN bus is interrupted due to electromagnetic interference, line faults and other factors, a vehicle control instruction CAN be directly lost, so that driving safety is seriously threatened. Therefore, it is desirable to design a CAN communication system with redundant backup and fault adaptation capabilities to improve the control reliability of an autonomous vehicle. Disclosure of Invention The embodiment of the application provides an automatic driving CAN communication safety redundant system for solving the problems of the related technology, which comprises an automatic driving domain controller (ADU) and a whole Vehicle Controller (VCU), wherein a two-channel communication architecture of a main CAN bus and a backup CAN bus is adopted between the ADU and the VCU to realize bidirectional information interaction; the VCU integrates a CAN communication quality evaluation module, a CAN channel arbitration module, a CAN communication fault prompting and protecting module and a CAN signal processing module; the ADU sends a vehicle control instruction to the VCU through the main CAN bus and the backup CAN bus, and the VCU feeds back real-time vehicle state information to the ADU. The CAN communication quality evaluation module further comprises a CAN communication state diagnosis unit, a CAN message cycle counting unit and a CAN communication quality scoring unit, wherein the CAN communication state diagnosis unit monitors vehicle control messages on the main CAN bus and the backup CAN bus by adopting a rolling counter, and the rolling counter value is increased by 1 when a target control message is not received and is decreased by 1 when the target control message is received in a specified CAN message protocol period; And when the rolling counter value is smaller than or equal to 0, judging that the communication is normal, and adaptively adjusting the CAN communication abnormal loss threshold according to the real-time speed of the vehicle and the electromagnetic interference intensity. Further, the default value of the CAN communication abnormal loss threshold is 10 CAN message protocol periods, the threshold is adjusted to 5 CAN message protocol periods when the vehicle is in a high-speed working condition, and the threshold is adjusted to 20 CAN message protocol periods when the vehicle is in a strong electromagnetic interference working condition. Further, the CAN message cycle counting unit adds 0-15 cycle counting signals into the CAN message, and by comparing the cycle counting values of adjacent periods, whether the ADU is lost or blocked is identified. Further, the scoring dimension of the CAN communication quality scoring unit comprises CAN message cycle count, CAN message cycle jitter and CAN bus load rate, and the weight ratio is 40%, 30% and 30% respectively; The calculation formula of the CAN communication quality score is that the CAN communication quality score=CAN message cycle count score, CAN message cycle jitter score and CAN bus load rate score. Further, the CAN message cycle counting scoring rule is that 40 points are obtained when no counting discontinuity and repetition phenomenon occur in 30 continuous periods, 2 points are subtracted from each counting discontinuity, 4 points are subtracted from each counting repetition, 6 points are added in 10 continuous periods when no abnormality occurs, and the final score is not higher than 40 points and not lower than 0 points; The CAN message period jitter scoring rule is that 30 points are obtained by 30 continuous periods with the deviation rate average value less than or equal to 5%, 21-29 points are obtained by the deviation rate average value between 5% and 8%, 10-20 points are obtained by the deviation rate average value between 8% and 12%, and 0-10 points are obtained by the deviation rate average value > 12%; the CAN bus load rate scoring rule is that a load rate average value of 30 percent is 30 percent, a load rate average value of 21-29 percent is 30-45 percent, a load rate average value of 11-20 percent is 45-60 percent, and a load rate averag