Efficient implementation of fault-tolerant data structures in pc-based control software

Recent years have seen an increased interest in the use of open-architecture, PC-based controllers for robotic and mechatronic systems. Although such systems give increased flexibility and performance at low unit cost, the use of commercial processors and memory devices can be problematic from a safety perspective as they lack many of the built-in integrity testing features that are typical of more specialised equipment. Previous research has shown that the rate of undetected corruptions in industrial PC memory devices is large enough to be of concern in systems where the correct functioning of equipment is vital. In this paper the mechanisms that may lead to such corruptions and the level of risk is examined. A simple, portable and highly effective software library is also presented in this paper that can reduce the impact of such memory errors. The effectiveness of the library is verified in a small example.