Application of a CAN BUS transport for DDS middleware

Abstract

The publish/subscribe paradigm matches well with these systems. Data distribution service (DDS) is a publish/subscribe data-centric middleware. It specifies an API designed for enabling real-time data distribution and is well suited for such complex distributed systems and QoS-enabled applications. Unfortunately, the need to transmit a large number of sensor measurements over a network negatively affects the timing parameters of the control loops. The CAN-bus enables the information from a large number of sensor measurements to be conveyed within a few messages. Its priority-based medium access control is used to select the sensor messages with high timing constraints. This approach greatly reduces the time for obtaining a snapshot of the environment state and therefore supports the realtime requirements of feedback control loops. The use of the publish/subscribe/distribute" paradigm and the underlying real-time CAN-bus is a currently research topic an d only today few works exist in this area. These activities are headed by University of ULM & German National Research Center for Information Technology and by Software Architecture Lab, Seoul National University as well as by our "Control and Communication Technologies" research group at the National School of Engineering of Tunis (ENIT), Department of Computer and Communication Technologies, headed by myself. The main objective of this paper is to demonstrate how DDS API is implemented on a CAN-bus.