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Paper details
Number 1 - March 2015
Volume 25 - 2015
A probabilistic method for certification of analytically redundant systems
Bin Hu, Peter Seiler
Abstract
Analytical fault detection algorithms have the potential to reduce the size, power and weight of safety-critical aerospace
systems. Analytical redundancy has been successfully applied in many non-safety critical applications. However, acceptance
for aerospace applications will require new methods to rigorously certify the impact of such algorithms on the overall
system reliability. This paper presents a theoretical method to assess the probabilistic performance for an analytically redundant system. Specifically, a fault tolerant actuation system is considered. The system consists of dual-redundant actuators and an analytical fault detection algorithm to switch between the hardware components. The exact system failure rate per hour is computed using the law of total probability. This analysis requires knowledge of the failure rates for the hardware components. In addition, knowledge of specific probabilistic performance metrics for the fault detection logic is needed. Numerical examples are provided to demonstrate the proposed analysis method.
Keywords
avionics, certification, safety-critical systems, reliability, fault detection, fault-tolerant systems