Can controller bus failure processing method and device

Abstract

The invention provides a CAN controller bus fault processing method and device. The method comprises detecting status bit of a CAN controller periodically; accumulating duration time detected when the status bit is in a Busoff state each time to obtain first fault duration time; when the first fault duration time reaches a preset short closing threshold value, carrying out zero clearing on the first fault duration time and closing the CAN controller; and when the closing duration time of the CAN controller reaches a first starting threshold value, restarting the CAN controller, and returning to the step of detecting the status bit of the CAN controller every a preset detection period. The method effectively guarantees that the CAN controller does not occupy too many CAN bus resources after having the Busoff fault; during the time when the CAN controller stops working, CAN bus channels are released to ensure normal communication of other controllers, and thus communication efficiency of the CAN bus is improved; and meanwhile, load of frequent restart of the CAN bus due to the Busoff fault in the prior art is reduced.

Description

technical field [0001] The invention relates to automobile bus control technology, in particular to a CAN bus fault processing method and device. Background technique [0002] CAN is the abbreviation of Controller Area Network (CAN), and it is one of the most widely used field buses in the world. Among them, CAN communication is used in the automotive field, and it is the main communication path between various controllers in the vehicle. [0003] At present, if there is an open circuit, short power supply or short ground wire in the control system of the car, the CAN controller of the controller may send error frames all the time. When the error frame reaches 32 frames, that is, when the error counter TEC reaches 255, the system Confirm that the controller is in the Busoff state where the CAN bus is disconnected. Generally, the CAN controller will be restarted within 20ms; if the CAN controller sends the correct frame after restarting, the value of the error counter TEC wi...

AI Technical Summary

Problems solved by technology

[0003] At present, if there is an open circuit, short power supply or short ground wire in the control system of the car, the CAN controller of the controller may send error frames all the time. When the error frame reaches 32 frames, that is, when the error counter TEC reaches 255, the system Confirm that the controller is in the Busoff state where the CAN bus is disconnected. Generally, the CAN controller will be restarted within 20ms; if the CAN controller sends the correct frame after restarting, the value of the error counter TEC will decrement; if the CAN controller sends an error after restarting frame, the value of the error counter TEC is accumulated, and the TEC value is greater than or equal to 255, and the CAN controller will continue to be in the Busoff state; the CAN controller will continue to restart, and so on. The sent error frame will greatly occupy the CAN communication channel of the whole vehicle, affect the normal communication of other controllers on the CAN bus, affect the real-time signal of other controllers, and have a great impact on the CAN communication of the whole vehicle; The CAN controller in the Busoff state is frequently in the restart state, which increases the load on the CAN controller

Images