Detailed explanation of the essential bus test solution for intelligent connected vehicles

CANFD and automotive Ethernet have been widely used in the new generation of intelligent connected vehicles, but they also bring new challenges to engineers in vehicle testing and troubleshooting. To address this pain point, ZLG launched the CANFDDTU recorder to help improve the bus testing of intelligent connected vehicles.

1. Application of CANFD and In-vehicle Ethernet in Intelligent Connected Vehicles

As shown in Figure 1, the intelligent connected car is the intersection of the Internet of Vehicles, intelligent transportation and smart cars. It is a new generation of cars that can realize information interaction between cars and X (cars, people, roads, background), etc. and have intelligent decision-making capabilities.

Figure 1 Definition of intelligent connected vehicles

In the wave of the new generation of intelligent connected vehicles, with the daily doubling of on-board ECUs and the rapid development of processor computing power and hardware, the network connecting ECUs requires a larger bandwidth, which far exceeds the capacity limit of traditional on-board networks such as CAN.

Therefore, the clear trend is to transition to CAN FD, which provides 64-byte data throughput and a maximum transmission rate of 5Mbps. Due to the high bandwidth, low latency and low cost characteristics of automotive Ethernet, it will replace the CAN bus and become the preferred network architecture in the next-generation vehicle architecture.

As shown in Figure 2, the core domain controllers (powertrain, body, entertainment, ADAS) are connected together using the in-vehicle Ethernet as the backbone network. Each domain controller not only implements dedicated control functions, but also provides powerful gateway functions. Below the domain controller, communication between components is basically achieved through CANFD to share data, among which windows, lights and sunroofs transmit data through the LIN bus. This architecture based on domain controllers changes the traditional point-to-point communication mode of ECU to ECU in the in-vehicle network.

Figure 2: Next-generation smart car network architecture

The new generation of intelligent connected cars covers in-vehicle Ethernet, CANFD and LIN buses. During the vehicle testing phase, especially the road test phase, engineers need a large amount of test data for analysis to determine the vehicle operation or troubleshoot. At the same time, different test recording methods are required to obtain messages for different vehicle buses, which brings great trouble to engineers. If the data of the vehicle's CANFD network, LIN bus and in-vehicle Ethernet can be recorded and obtained locally or remotely, it will greatly reduce the cycle of the vehicle's overall architecture testing, reduce the difficulty for engineers to obtain test data, and help with subsequent vehicle troubleshooting.

2. CANFD DTU series: a three-in-one test tool for intelligent connected vehicle bus

As shown in Figure 3, the CANFDDTU series of vehicle-mounted CAN (FD)-bus data recorders launched by Guangzhou Zhiyuan Electronics Co., Ltd. integrate 4 independent CAN-bus channels that comply with the ISO11898 standard, support 4G real-time communication, and can upload data on the CAN FD bus to a designated server; it also supports Beidou/GPS positioning, real-time recording of device location information, and supports vehicle-mounted Ethernet and LIN bus test records, improving the vehicle-mounted multi-bus test system. The intelligent network transmission filter can effectively reduce network resource usage. The standard storage medium is a 32G high-speed SD card (up to 128G), which can record CAN FD message information for a long time and is widely used in fault detection occasions such as high-speed trains, subways, wind turbines, and autonomous vehicles.

Figure 3 Schematic diagram of CANFDDTU-400EWGR

1. Support 4G communication and cloud data

As shown in Figure 4, CANFDDTU-400EWGR can meet the needs of various application scenarios. It can synchronously monitor and collect data from the CAN FD bus, LIN bus, and vehicle Ethernet in different scenarios in real time, and upload the data to the designated cloud server in real time through 4G communication.

Figure 42. CANFDDTU product 4G upload data

3. Bus recording and playback, simulating field data

As shown in Figure 5, CANFDDTU can collect and record bus data in real time, support conversion into various software formats commonly used by users through configuration tools, and send the stored data to user devices through the device to accurately simulate on-site application scenarios.

Figure 5 Schematic diagram of CANFDDTU data simulation

4. Support Beidou/GPS positioning to optimize trajectory algorithm in real time

As shown in Figure 6, CANFDDTU-400EWGR has a unique Beidou/GPS positioning function, which can record device location information in real time and upload it to a designated server. This allows users to quickly locate devices and perform algorithm data analysis and optimization when they need device data.

Figure 6 CANFDDTU product GPS positioning function

5. One-click trigger mark to quickly locate faults

As shown in Figure 7, CANFDDTU-400EWGR provides a trigger button, which can mark the CANFD message data in real time, making it easy for users to find and locate the record files in the SD card and quickly locate the fault.

Figure 7 One-click triggering of marking function

6. Support WiFi communication, convenient for exporting data

As shown in Figure 8, CANFDDTU-400EWGR supports WiFi communication, which can easily realize data export and analysis through WiFi, helping users expand usage scenarios.

Figure 8 CANFDDTU product WiFi transmission function

7. Electrical isolation of each channel enables domain-specific recording

As shown in Figure 9, CANFDDTU-400EWGR can simultaneously record 4-channel CANFD messages, implement single-channel independent operation for each automotive functional domain, and improve the richness of the records.

Figure 9 CANFDDTU channel isolation