Component-Based Robotics Engineering (Part II): Systems and Models

摘要

This article is the second of a two-part series intended as an introduction to Component-based Software Engineering (CBSE) in Robotics. In Part I, we regarded a component as a piece of software that implements robotic functionality. The focus was on design principles and implementation guidelines that enable the development of reusable and maintainable software building blocks. In Part II, we discuss the role of software components as architectural units of large, possibly distributed, softwareintensive robotic systems. The focus is on technologies to manage the heterogeneity of hardware, computational, and communication resources and on design techniques to assemble components into systems. A Component-based System is a composition of components and the way components interact with other components and with the computational environment greatly affects the flexibility of the entire system and the reusability of individual functionality. The paper is structured as follows. Section II discusses the challenges that make the development of reusable components and flexible component systems difficult in robotics. In particular, we analyze the different sources of variability in robotic technology and applications and the corresponding requirements for flexibility in robotic software component-based systems. The subsequent four sections introduce key concepts related to the development of reusable software components, such as threading, synchronization, resource awareness, distribution, and quality of service negotiation and illustrate architectural models that enable the independent evolution of different variability concerns of a component-based robotic system. They are classified in four categories related to main concerns of component-based systems, namely Computation (Section III), Configuration (Section IV), Communication (Section V), and Coordination (Section VI). Finally, Section VII draws the relevant conclusions. It should be noted that this paper is not a survey of the state-of-the-art in component-based software engineering, nor in robotics software development. While there is an increasing