Reconfigurable CAN in real-time embedded platforms

This paper¹ deals with the dynamic reconfiguration of the frame packing as well as the traffic of real-time packets on a CAN network. This network is assumed to link distributed reconfigurable STM32F4 microcontrollers that can automatically add-remove-update periodic and aperiodic OS tasks at run-time. These tasks may exchange messages to be loaded in packets and to be sent on the network. After the addition of a pair of dependent tasks on two microcontrollers, a message should be added on CAN and should respect a corresponding deadline related to these tasks. After several additions of messages, some deadlines may be violated and the CAN may not support the added messages. In addition, the frame packing should be adapted at run-time to any reconfiguration scenario in the different microcontrollers. We propose a multi-agent based architecture to check the correct transmission of messages. If some deadlines are violated, these agents propose technical solutions for the feasibility of the whole system. They can suggest first the modification of periods or deadlines of tasks and messages. They can propose also the removal of some OS tasks or messages from the controllers according to their priorities. We propose in addition new solutions to construct the dynamic frame-packing while the bandwidth is minimized. A tool is developed at LISI and Cynapsys to support the different contributions of this paper.