Dependable cyber-physical systems with redundant consumer single-board Linux computers

Abstract

There are a large number of small and inexpensive single-board computers with Linux operating systems available on the market today. Most of these aim for the consumer and enthusiast market, but can also be used in research and commercial applications. This paper builds on several years of experience with using such computers in student projects, as well as the development of cyber-physical and embedded control systems. A summary of the properties that are key for dependability for selected boards is given in tabulated form. These boards have interesting properties for many embedded and cyber-physical systems, e.g. high-performance, small size and low cost. The use of Linux for operating system means a development environment that is familiar to many developers, and the availability of many libraries and applications. While not suitable for applications were formally proven dependability is necessary, we argue that by actively mitigating some of the potential problems identified in this paper such computers can be used in many applications where high dependability is desirable, especially in combination with low-cost. A solution with redundant single-board computers is presented as a strategy for achieving high dependability. Due to the low cost and small size, this is feasible for applications were redundancy traditionally would be prohibitively too large or costly.