Summary
In recent years, the realization of high-bandwidth communication for vehicles based on Ethernet is undoubtedly a hot topic in vehicle research and development. Whether it is to reduce wiring harness costs based on in-vehicle Ethernet, realize technologies such as ADAS, infotainment systems, or realize Ethernet diagnosis (DoIP) based on new electrical and electronic architecture and remote diagnosis requirements, various OEMs have invested a lot of manpower and material resources Cost is involved in research and development. One of the original intentions of using DoIP for diagnostic communication is to increase the speed of vehicle flashing.
Currently, the Softing diagnostic tool chain, from diagnostic data development to diagnostic testing, has covered DoIP diagnostic requirements and functions. Next, we will explain the DoIP flashing function from three aspects: UDSonDoIP database development, DoIP diagnostic communication connection, and DoIP flashing examples, and provide a comparative analysis of DoIP flashing speed and CAN.
One, UDSonDoIP database
Compared with CAN and DoIP, data transmission is optimized at the physical layer and the transport layer to increase the speed. In the application layer and diagnostic service links, CAN and DoIP are implemented based on the 14229 protocol. In the ODX database part, in addition to adding DoIP protocol communication parameters and related controllers, in general, no additional adjustments are required, which greatly saves the time and cost of diagnostic data development.
Figure 1: UDSonCAN and UDSonDoIP communication comparison
Figure 2: Diagnostic database integration DoIP
2. DoIP communication connection method
Currently, there are two commonly used DoIP diagnostic connection methods:
1. Direct connection of Ethernet cable: In the case of the whole vehicle, make OBD-Ethernet cable direct connection;
Figure 3: Direct connection form
2. Compatible with CAN/CAN FD communication to meet production and after-sales needs, use the diagnostic VCI to integrate the Ethernet Activation function to achieve DoIP communication;
Figure 4: VCI form
Three, UDSonDoIP flashing example
After the database is created, use the relevant diagnostic tools to implement the vehicle flashing process.
In the example, the flash controller uses Softing T-Box; VCI communication uses Softing VIN|ING2000 diagnostic communication card;
Connection method: use Ethernet direct connection and VCI connection; the diagnostic instrument uses DTS Moanco and Q-Tester software;
Figure 5: Connection diagram-directly connected to the computer
Figure 6: Connection diagram-VCI connection
After the vehicle identification and handshake are completed, we can perform DoIP flashing in the diagnostic apparatus. All configuration flashing process is consistent with CAN configuration process.
Figure 7: DTS Monaco DoIP flashing
Figure 9: 36 service message record
36 services to write data, based on the TCP/IP protocol, according to the TCP data transmission sub-packaging mechanism, the transmission is realized.
Fourth, UDSonDoIP flashing speed comparison analysis
In the ISO 13400 protocol, the maximum length of a diagnostic message is 4GB. This means that in theory, the maximum amount of data that can be sent by 36 services at a time is 4GB, while in CAN communication, the maximum amount of data is 4kB.
Figure 10: Extracted from the ISO13400-2 protocol
In fact, limited by the performance of the controller, the bandwidth of the wiring harness, and the processing speed of the diagnostic instrument, the data transmission volume of a single service is less than the theoretical value, but the transmission speed is still far beyond CAN communication.
Example: In the test, the amount of data transferred in a single 36 service is 1.5M, and the flash file size is 1.5GB. The flashing time for direct connection with the network cable is 7 minutes. Using VIN|ING 2000 hardware, using wireless transmission, the flashing time is about 20 minutes.
Figure 11: Flashing time
In HS CAN flashing, it takes about 4 hours to flash a file with 1.5GB.
It can be found by comparison. With DoIP, the effect of improving the flashing speed is very significant.
In summary, based on the Softing diagnostic tool chain, the DoIP function extension development is carried out. DoIP diagnosis can be achieved through minimal database changes and VCI tool upgrades, while the existing Softing diagnosis software does not need to be adjusted. On the basis of the minimum cost investment, the DoIP flashing requirements are realized and the maximum benefit is obtained.