Future architecture of flight control systems

The development of fault tolerant embedded control systems, such as flight control systems (FCS) are currently highly specialized and time-consuming. We introduce a conceptual architecture for the next decade control system where all control and logic are distributed to a number of computer nodes locally linked to actuators and connected via a communication network. In this way, we substantially reduce the life-cycle cost of embedded systems and attain scalable fault tolerance. All fault tolerance is based on redundancy. Our philosophy is to cover permanent faults with hardware replication and handle all error processing caused by both permanent and transient faults with software techniques. With intelligent nodes and use of inherent redundancy we introduce a robust and simple fault tolerant system that utilizes minimum hardware and has bandwidth requirements of less than 300 kbits/s, which can be met with an electrical bus. The study is based on an FCS for JAS 39 Gripen, a multi-role combat aircraft that is statically unstable at subsonic speed.