The Strategy of Master Controller Automatically Downloading Three Slave Controller Software

This paper analyzes the configuration of automatic transmission and the relationship between automatic transmission controller, oil pump controller, shift motor controller and clutch motor controller. The PCM (Powertrain Control Module) is also connected to the OTA CAN for the vehicle controller. When it is necessary to update the software for the oil pump motor controller, clutch motor controller and shift motor controller on the private CAN, the on-board vehicle controller updates the PCM software to the PCM via OTA (Over-the-Air Technology). At this time, there are 3 free areas in the PCM for storing the software of the small motor controller. Then the download management software in the PCM downloads the small motor software stored in the PCM to the small motor controller. Thus, the update of small controller software on private CAN is realized. After the primary PCM controller is powered on, the software versions of the three secondary controllers are read in physical addressing mode. First read the software of the oil pump, then read the software version of the shift motor, and finally read the software version of the clutch executive motor. If the feedback from the controller is negative when reading the version number, it means that the software from the controller is incomplete, and then the download is performed immediately. If the software version number of the secondary controller is obtained, the latest software versions of the three secondary controllers in the primary controller are obtained. If the version number of the slave controller is different from that of the master controller, the slave controller software is downloaded only when the vehicle is ready to be powered off. Prevents communication faults between all primary and secondary controllers when downloading. For the slave controller that is powered off and downloaded, in order not to affect the driver's use of the vehicle, after downloading the slave controller software that is currently being downloaded, stop downloading other slave controller software. In this case, the vehicle can run normally. When the vehicle is ready to power off again, download the remaining slave controller software. During the download, all the secondary controllers must stop sending packets, restart all the secondary controllers, and notify the secondary controllers to prepare for the download and write. The host controller calculates the key based on the seed, sends the address of the SBL, sends the length of the SBL to be downloaded, transmits the first set of data with the feature identifier, transmits the first Block data, and transmits 8 frames of data. The secondary controller needs to confirm that the data is completely received and the secondary controller needs to confirm the correctness of the SBL (Secondary Bootloader). Then download the Appl, send the address of the Appl, send the length of the Appl to be downloaded, transmit the first set of data with the feature identifier, transmit the data in the Block, and after transmitting 8 frames of data, the secondary controller confirms that the data has been completely received, and continues to send the data in the Block every 8 frames in a cycle. After all the blocks are sent, that is, after the Appl data is transmitted, the secondary controller confirms the correctness of the Appl, restarts all the secondary controllers, and reads the software version number of the newly downloaded controller again.