OTA vehicle-mounted terminals are the executors of OTA upgrades. Taking the OTA push method as an example, there are many parts that users can perceive and experience. The design focus of vehicle-mounted terminals needs to consider human-computer interaction, network diagnosis architecture design, ECU refresh time, software storage and refresh. Policy, remote fault diagnosis mechanism. The vehicle terminal network framework is shown in Figure 4. The OTA master control node is in charge of TBOX and the central gateway (GW), and the upgrade interface is in charge of the vehicle machine. The updated ECU is required to support vehicle Ethernet (DoIP) or CAN bus (DoCAN) communication Protocol, if the ECU upgrade package is large (such as hundreds of megabytes), it needs to support the data difference algorithm.
When OTA upgrades, in addition to the cloud platform pushing the upgrade task to the car owner’s APP for reminders, the car terminal (car machine or central control) needs to cooperate with the development to display some upgrade interfaces (such as upgrade progress, upgrade condition reminders, etc.) to remind the car owner Cooperate with operations such as leaving the car.
At present, the backbone network of the vehicle network is still based on the mature CAN bus communication, but for the ECU with a large software package, due to factors such as refresh time, the vehicle Ethernet technology is used to break through the bandwidth limitation of the CAN bus.