Assistant Professorship of Safe Embedded Systems
Specification of fault-tolerant systems, verification and validation of safety-critical systems
n The focus of the Assistant Professorship of Safe Embedded Systems (SES) in 2015 was to further develop methods and approaches in the fields of specification and validation of safety-critical distributed appli- cations.
Design-to-Test
Prof. Dr. Julien Provost
Contact
www.ses.mw.tum.de Phone +49.89.289.16424
Validation by testing is a mandatory procedure for safety-critical controllers. However, the validation of a logic con- troller is often only considered in the later phases of its development. Thus, if speci- fic non-functional requirements related to testing are not initially considered in the specification models, this could lead to
the impossibility of validating the behavior of a controller by means of testing.
Design-to-test approaches aim at improv- ing the testability of controllers and
reducing the additional human workload
required to trustfully test critical logic
controllers.
In 2015, SES developed and implemented a design-to-test approach for discrete event systems. A demonstration software has been developed for MATLAB State- flow specifications.
Projects
n TUM – Design-to-test approach for black-box testing of programmable controllers
Reconfigurable Distributed Architecture
Reconfigurable architecture applied to an automated guided vehicle
The control of automated systems is increasingly achieved by distributed controllers. However, for critical systems the global implementation needs to be
fault-tolerant. In order to achieve a desired level of fault-tolerance and ensure high
dependability, two approaches can be
used: redundancy and reconfiguration
of systems. When these approaches are combined, the research questions to be regarded are as follows: How many sub- systems may fail simultaneously without losing complete control of the global system? and How long can a subsystem stay in its fail state before a reconfigura- tion is needed?
In 2015, SES investigated the implementa- tion of redundant reconfigurable distri- buted architecture for automated guided vehicles. This approach is using a service- oriented architecture and has been implemented on a microcontroller-based architecture.
Projects
n TUM – Redundant reconfigurable distributed architecture using service-oriented architecture
196 Assistant Professorship of Safe Embedded Systems
Supervisory Control Theory
Supervisory Control Theory (SCT) is a model-based approach that permits to automatically generate correct-by-con- struction supervisory controllers. Thanks to SCT approach, which is using mathemati- cally proved algorithms, generated cont- rollers do not need to be verified anymore. The designers can then focus more on the requirements definition and the specifi- cation modeling. A set of specifications permits to specify independently each requirement (functional and non-functional requirements, safety and liveness requi- rements, optimization criteria…). Then, synthesis algorithms are applied on the
set of specifications and plants models
to generate a supervisory controller. The obtained supervisory controller is then guaranteed to be deadlock-free and maxi- mally permissive (all the specifications
are fulfilled and only these specifications
are fulfilled).
In 2015, SES investigated two obstacles for a wide application of SCT in industry. First, while many industrial applications use signals and dataflow to represent and
exchange sensors and actuator values, the fundaments and most of the works related to SCT use event-based modeling. Secondly, most of the tools that use SCT algorithms are not easily connected to industrial programming tools, thus limiting their application in industry. To cope with these obstacles, SES investigated a signal- based SCT approach, and developed
a demonstration software for MATLAB Stateflow models. This approach has been successfully applied to our didactic production system platform.
Projects
n TUM – Supervisory Control Theory for mechanical engineers
Didactic platform: SCT for
mechanical engineers
Research Focus
n Fault-tolerant systems
n Formal verification validation
n Distributed control systems
n Diagnosis of automated systems
Competence
n Control of discrete event systems
n Conformance testing
n Supervisory control theory
n Fault-tree analysis
Infrastructure
n Test bench for (safety) programmable logic controllers
n Didactic platform for supervisory
control and diagnosis
Courses
n Basics of Dependable Systems
n Control of Discrete Event Systems
n Safe Embedded Systems
Management
Prof. Dr. Julien Provost
Research Scientist
Canlong Ma, M.Sc.
Publications 2015
n C. Ma, J. Provost: Design-to-test approach for black-box testing of programmable controllers. IEEE International Conference on Automation Science and Engineering (CASE), 2015. DOI:
10.1109/CoASE.2015.7294232
n A. Theorin, K. Bengtsson, J. Provost, M. Lieder, C. Johnsson, T. Lundholm, B. Lennartson, An Event-Driven Manufacturing Information System
Architecture. 15th IFAC Symposium on Information Control Problems in Manufacturing (INCOM), 2015. DOI:10.1016/j.ifacol.2015.06.138
n S. Rösch, S. Ulewicz, J. Provost, B. Vogel-Heuser:
Review of Model-Based Testing Approaches in roduction Automation and Adjacent Domains — Current Challenges and Research Gaps. Journal of Software Engineering and Applications 8 (09), 499. DOI: 10.4236/jsea.2015.89048
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