A Lightweight, Component-based Approach to Engineering Reconfigurable Embedded Real-Time Control Software

The cost of poor or repeat engineering in complex control systems is extremely high, and flexibility in software design and implementation is one of the key factors in staying competitive in the market. Complexity can be managed most effectively if the underlying software systems support structured, standardised, high-level abstraction layers that encapsulate unnecessary details behind well-defined interfaces. Moreover, since the costs of software maintenance are often as high as that of initial development, the ease with which it is possible flexibly to reconfigure, re-engineer, and replace software components in operational systems is also critical. In this paper, we present a lightweight, component-based approach to engineering embedded real-time control software, which is realized in the form of a middleware system named MIREA. The middleware supports dynamic reconfiguration of components written in C/C++, and addresses variability management in relation to non-functional properties, such as quality-of-service (QoS) and real-time scheduling. Users are allowed to componentize existing libraries easily, such as the standard NIST 4D/Real-time Control Systems (RCS) library, which has been successfully used in many U.S government-driven intelligent control projects, and to reuse them as dynamically reconfigurable components. A realistic illustration is provided showing how control systems are structured and reconfigured using our approach. In fact, we discuss our approach to control using a fusion of NIST RCS as a means of architecting a real time control system and MIREA as a means of realising that architecture. Our progress to date suggests that MIREA is indeed well suited as a middleware facilitating the construction of efficient, lightweight, and scalable real-time embedded control systems.