An architecture for safe and efficient multi-threaded robot software

Abstract

This paper describes the application of component-based software engineering concepts to the development of a C++ software library for multi-threaded robot control. The components in this design are tasks; each task encapsulates a thread and contains a state table and message queues for efficient thread-safe data exchange. A task can provide multiple interfaces, which is useful when the underlying hardware offers diverse capabilities. Communication between tasks is loosely coupled and relies on command objects that can implement both commands and events. The system is dynamically configurable because all components are self-describing. This enables an effective Interactive Research Environment (IRE), which provides a Python shell to configure and interact with the executing software. This library is part of the open source cisst software package for computer-assisted surgery systems and can be obtained from www.cisst.org/cisst.