An application of parallel processing to distributed real time control of aircraft testing

This paper describes a multi-channel digital control system developed for durability testing of aircraft structures. The system uses parallel processing and inter-processor communication to provide high-speed synchronous MIMO control at update rates to 1000 Hz. Up to 511 separate controllers, each using one Inmos T805 transputer as a processor, are connected in a binary tree to make a single distributed control system. Controllers are located adjacent to actuators, with up to 20 metres between any pair of directly connected controllers. Pneumatic, hydraulic and electromagnetic actuators are supported, with appropriate control laws. A special hardware broadcast link spans the whole network tree and provides critical real-time communications and synchronisation. The application requirements and system design are described. Hardware and software design are discussed, including communications, system management, control software, and safety aspects. Implementation issues are briefly considered. System performance is presented, followed by some general conclusions and observations