As an illustration, a design of an aircraft onboard system will be used through
the whole document. This type of system depicts a typical example of a
safety-critical system where no faults and errors in the system can be tolerated.
We are using the standard taxonomy in dependable computing which is summarized in [1]. An error is thus a deviation from the correct system service state.
The cause of such an error is called a fault and can emerge system internally or
system externally.
The requirements of such an onboard system are challenging as they are almost
self-contradictory: the required performance and reliability infer at first glance the
need for significant power, size, weight, and maintenance.
At the same time, all of them are severely limited. In terms of functionality,
onboard real-time systems usually implement control theory algorithms, require
well-developed logic and math calculations, real-time data extraction from various
external devices during operation, perform matrix calculations, and do a complete
prognostic of the system behavior before an event impact such as an internal flight
control system error or an external plane problem becomes dangerous.
There is no doubt that the requirements of RT safety-critical systems must be
addressed in both—hardware design and system software design.
The conceptual challenges and requirements might be grouped as shown in
Figure 1.1.
GLL on Figure 1.1 stands for Graph Logic Language and will be introduced in a
special section; HW and SW stand for hardware and software, respectively.
The standard redundancy theory for fault-tolerant system design was introduced
in the late 80s [2], applied for econometrics [3] and further developed in [4–6].
Fig. 1.1 Principles and challenges of research in FT systems
2
1 Introduction
the whole document. This type of system depicts a typical example of a
safety-critical system where no faults and errors in the system can be tolerated.
We are using the standard taxonomy in dependable computing which is summarized in [1]. An error is thus a deviation from the correct system service state.
The cause of such an error is called a fault and can emerge system internally or
system externally.
The requirements of such an onboard system are challenging as they are almost
self-contradictory: the required performance and reliability infer at first glance the
need for significant power, size, weight, and maintenance.
At the same time, all of them are severely limited. In terms of functionality,
onboard real-time systems usually implement control theory algorithms, require
well-developed logic and math calculations, real-time data extraction from various
external devices during operation, perform matrix calculations, and do a complete
prognostic of the system behavior before an event impact such as an internal flight
control system error or an external plane problem becomes dangerous.
There is no doubt that the requirements of RT safety-critical systems must be
addressed in both—hardware design and system software design.
The conceptual challenges and requirements might be grouped as shown in
Figure 1.1.
GLL on Figure 1.1 stands for Graph Logic Language and will be introduced in a
special section; HW and SW stand for hardware and software, respectively.
The standard redundancy theory for fault-tolerant system design was introduced
in the late 80s [2], applied for econometrics [3] and further developed in [4–6].
Fig. 1.1 Principles and challenges of research in FT systems
2
1 Introduction