Real-time software for robotics

This paper describes two components of real-time software for robotics: real-time operating systems and the systems programming language. In particular, the design issues related to real-time operating systems are discussed and our own system, derived from the UNIX® operating system, is described. No single real-time operating system is appropriate under all circumstances. However, it is shown that at least some continuity in the development environment can be provided. We have chosen to use a general-purpose programming language, C++, which has several advantages for real-time robot programming. In particular, it is shown how facilities within C++ can be used to guarantee initialization and proper termination of hardware subsystems. Support for concurrency is considered important, especially as robot systems become more complex. Proper support for concurrency can simplify communication and synchronization within a robot system. Two methods of providing concurrency within C++ are discussed.