SUMMARY

Development of efficient and reliable control software requires efficient development tools. Controller development using MATLAB/Simulink is becoming increasingly popular in both university research and industry applications. This offers a possibility to integrate controller development with simulation of the controlled machine, which allows early evaluation of control system performance. To achieve reliable and sophisticated real-time control software, additional techniques to avoid faults or to tolerate faults in the software are needed.

RESULT

A verifier for Simulink models has been developed that can automatically check that the Simulink models always behave correctly according to (functional) specifications. Combined with automatic code generation from models it is possible to ensure absence of many types of software defects. Although this tool can detect many types of defects in the software, these types of tools have limited scalability. In order to ensure reliability of large complex real-time systems, we have developed a fault-tolerant architecture and real-time scheduling algorithms to handle possible software faults, such as incorrect results from computation, runtime errors and deadline misses. The software architecture developed enables majority of the system functionality even if the main controller is defect. The system is therefore operable until next scheduled service break. Furthermore, this kind of architecture enables live upgrades of running systems.

MOTIVATION

Achieving high reliability of software is a challenging problem, which has not been generally solved for embedded systems. It is also increasingly important as more and more features in machines are implemented in software or have significant software components. This is especially relevant in embedded control systems, since faulty software can harm humans, the environment or expensive machinery

APPLICATIONS/
IMPACT

The verification tool is a proof-of-concept that these kinds of tools are becoming feasible for industrial use. The tool can check the absence of many types of defects in the software and thereby greatly increase its reliability. The fault tolerance mechanisms can be applied directly in industry, where there is a need for advanced real-time software for which the quality cannot be guaranteed.

MAIN CONTACT

Pontus Boström, Åbo Akademi University

Mikko Huova, Tampere University of Technology

Tero Peippola, VTT

PROJECT PARTNERS

Åbo Akademi University, Tampere University of Technology, VTT, Cargotec, Metso Automation, Norrhydro, Valmet, Wärtsilä

AUTHORS

Author missing

Pontus Boström

pontus.bostrom(at)nospamabo.fi

Åbo Akademi University

Author missing

Mikko Huova

mikko.huova(at)nospamtut.fi

Tampere University of Technology

Author missing

Tero Peippola

tero.peippola(at)nospamvtt.fi

VTT