Networking in hard real time vehicle applications

Computer-based control systems are widely used in vehicle applications (e.g., aircraft, marine and automobile). The earlier forms of control systems were typified by a central computer connected to sub-systems using hard-wired point-to-point communication links. However, such systems suffered from several major drawbacks: (i) fault-tolerance problems, (ii) maintenance and cabling costs, and (iii) excessive cable weight. These problems were minimised by using master-slave networks with distributed control architecture. However, using such networks raises the question of fault-tolerance and integrity of the communication system. In view of this, efforts have been made to employ the architecture provided by the IEEE 802.4 Token Bus for real time control applications although the performance of the Token Bus is not adequate for applications where fast response times are required. [Continues.]