Model-based analysis of safety critical systems

Abstract

Safe operation of a critical embedded system requires reliable information about the state of the system and signal condition of the system. Validity of sensors which measure the process variables are of great importance. Signal validation comprises of detection, isolation and characterization of faulty signals. Signals that are validated are critical for their increased availability in the system. Model-Based Engineering (MBE) approach provides means of modeling, analyzing, and validating the signals for critical embedded system design, and development. The abstract nature of the models provides mechanisms to analyze verify and validate the system functionality, at a much early stage in their development process. In this paper we present MBE approach to analyze the input signal processing algorithm with the case study of analog signal for Stall Warning System (SWS) of an aircraft using NI LabVIEW. The approach helps in analysing the functionality and completeness of the algorithm, mathematically and by simulation. The validation of analog signals with different frequencies and amplitude establishes data prudency and maintains the integrity of avionics systems. The result of this approach highlights the advantage of using MBE which enables in analysing the data algorithm for its correctness and guarantees the properties of the model early in the development life-cycle. MBE approach also helps in re-assuring the integrity of the system, before it is developed. This also terminates the contiguous data set and annunciates the sensor fault conditions.