embedded world 2012: VAKOMO – Developing and Testing Modular Control Units
Release from Tue., February 14, 2012
Ever more frequently, safety-critical control units today consist of small, networked controllers that can be developed with minimal effort. However, norms such as IEC 61508 make high demands on the certification of such devices. At the ”embedded world” in Nuremberg, Fraunhofer FIRST will demonstrate how control units for safety-critical applications can be developed and verified using models. This leads to increasing transparency and time savings in the certification process.
Safety-critical functions, such as control of the safety switch of a punching machine which turns the machine off in case of improper operation, are today often conducted by modular control nodes. They consist of small, cooperating nodes that process a multitude of sensor data and facilitate various functions of the overall system. They have to meet strict requirements in certification to ensure proper operation in emergency situations. In the VaKoMo project (validation of cost-efficient, modular control units), Fraunhofer FIRST and a medium-size industry partner have developed distributed, modular architectures for control units according to IEC 61508, which is the standard norm for safety requirements in electronic systems. A SIL3 (Safety Integration Level)-capable control unit created in the project is currently undergoing concept testing at TÜV (quality and safety inspection testing group).
In the project, Fraunhofer FIRST’s researchers have created a design for a redundant software architecture in addition to the hardware architecture. It ensures that external influences such as magnetic fields cannot cause data distortions. Each control unit was thus designed on two channels. Both channels process all inputs and outputs and reciprocally control their findings. Model-based development methods utilizing UML (Unified Modeling Language) models describing the subsequent functions were applied for the design of the redundant software architecture. In a next step, the software can be generated automatically from these models and be tested for correctness using model-based testing methods. Additionally, they facilitate documentation and quality assurance early on in the development process. The VaKoMo project has demonstrated that using these methods, cost-efficient development and certification of modular control units is possible.
The VaKoMo project is funded by the German Federal Ministry of Education and Research (BMBF) in the scope of the IKT 2020 program.
You are cordially invited to visit the Fraunhofer booth in hall 5, booth 228. We will gladly arrange a date and time for a personal meeting in advance.