Abstract
Independency between replicated modules is very important in fault-tolerant systems. To achieve the independency, the input signals are sampled at different sampling points and processed separately, so that simultaneous errors caused by transient effects can be tolerated. By the use of a new method called “intelligent error detection”, the errors in a single module can be detected within itself, and the erroneous states can be recovered from the other module.
On the other hand, high-speed error detection is significant in digital control systems, to keep the real-time processing and to reduce the system risk. From this point of view, a high-speed detection method called “priority error detection” is proposed. First, the priorities for error detection rules are evaluated on the basis of their effects on the system risk. Then, the number of error detection rules is compressed according to their priorities, so that the inference time can be greatly reduced.
The relation between the system risk and the number of error detection rules is studied, and it is demonstrated that the proposed method is very useful to the highly safe digital control systems.
