Fault Tolerance in Real-Time Systems through Time-Triggered Approach

Abstract

Fault-tolerant real-time systems are applied with more complex and critical applications in automobile, aircraft and railway industry. Such critical applications impose high dependability and reliability requirements. Reliability in Safety critical systems are designed to be redundant systems with increased complexity. Task activation and scheduling for highly dynamic systems become more complex when event-triggered approach is used which can be overcome by time-triggered approach systems. These systems can be simple table-driven where timing is guaranteed which is to avoid the risk of missing a critical deadline. Hence the real-time systems architecture which has time-predictability becomes easy for validation. The interface in such systems is a time-triggered state message interface required to block all asynchronous external control signals, otherwise it disrupts the deterministic timing of the subsystem. This gives transparent fault tolerance in time domain as well as in value domain for the safety critical real-time system.