Ahsan Qamar

A characterization of integrated multi-view modeling in the context of embedded and cyber-physical systems

Embedded systems, with their tight technology integration, and multiple requirements and stakeholders, are characterized by tightly interrelated processes, information and tools. Embedded systems will as a consequence be described by multiple, heterogeneous and interrelated descriptions such as for example requirements documents, design and analysis models, software and hardware descriptions. We refer to a system designed this way as a multi-view (MV) system. The main contribution of this paper is a characterization of model-based approaches to MV systems. The characterization takes three main perspectives for the relations between viewpoints: semantic relations (content), relations over time (process), and manipulation of views (operations). We complement these perspectives by investigating MV system challenges and by a survey of related approaches. The characterization aims to provide a basis for a better understanding, design and implementation of MV systems, and thereby to overcome the current fragmented points of view on integrated multi-view modeling (MVM).

Designing mechatronic systems, a model-based perspective, an attempt to achieve SysML-Matlab/Simulink model integration

Higher demands on efficiency, cost and functionality have contributed a great deal towards the advent of Mechatronic systems where mechanics, electronics and computer software integrate together to provide the required functionality. This integration has its effects in the design process as well, and a good design requires careful integration of methods and tools to satisfy the overlapping objectives. The set of requirements a designer needs to satisfy for a good design are in all three domains, hence various design and modelling tools are used by engineers to satisfy these multi-domain requirements. With the advent of systems modelling languages for specifying the complete system in one system model, there is an increased urge to link the system modelling tools to the domain specific tools such as Matlab/Simulink. In this paper we present an attempt to achieve an integrated design environment by building mapping between SysML and Matlab/Simulink models. The complexities that can be solved using SysML and the ones which necessitate a communication between SysML and other tools are discussed. Models of an industrial pattern generator are presented to explain the practical influence of this integration approach. The resulting integrated model is more comprehensive for the designer when investigating various design alternatives. This is important for companies considering they have to consistently embed innovation and sustainability in their products.

Dependency Modeling and Model Management in Mechatronic Design

Mechatronic design is traditionally supported through domain-specific design activities throughout the product development process. The partitioning into domain-specific problems leads to a situati ...

A Conceptual Framework for Consistency Management in Model-Based Systems Engineering

Developing complex engineering systems requires the consolidation of models from a variety of domains such as economics, mechanics and software engineering. These models are typically created using differing formalisms and by stakeholders that have varying views on the same problem statement. The challenging question is: what is needed to make sure that all of these different models remain consistent during the design process? A review of the related literature reveals that this is still an open challenge and has not yet been investigated at a fundamental level within the context of Model-Based Systems Engineering (MBSE). Therefore, this paper specifically focuses on examining the fundamentals of consistency management. We show that some inconsistencies cannot be detected and come to the conclusion that it is impossible to say whether or not a system is fully consistent. In this paper, we first introduce a mathematical foundation to define consistency in a formal manner. A decision-based approach to design is then studied and applied to the development of a real-world example. The research reveals several distinct types of inconsistencies that can occur during the design and development of a system. We show that these inconsistencies can be further classified into two groups: internal and external consistency. From these insights, the ontology of inconsistencies is constructed. Finally, requirements for possible tool support and methods to identify and manage specific types of consistency issues are proposed.Copyright

Challenges in Designing Mechatronic Systems

Development of mechatronic products is traditionally carried out by several design experts from different design domains. Performing development of mechatronic products is thus greatly challenging. ...

An Approach to Identifying Inconsistencies in Model-based Systems Engineering

Abstract A typical way of managing the inherent complexity of contemporary technical systems is to study them from different viewpoints. Such viewpoints are defined by a variety of factors, including the concerns of interest, level of abstraction, observers and context. Views conforming to these viewpoints are typically highly interrelated since the concerns addressed in the different viewpoints overlap semantically. Such overlaps can lead to inconsistencies. The challenge is to identify and resolve – that is, manage – such inconsistencies. This paper introduces an approach to identifying inconsistencies within the context of Model- Based Systems Engineering (MBSE). In current practice, inconsistencies are typically only discovered after long time intervals, e.g., during reviews. This can result in costly rework or even mission failure. Therefore, actively checking for inconsistencies, and doing so in a continuous fashion, can be valuable. We investigate the hypothesis that all models can be represented by graphs and that inconsistencies can be identified by means of pattern matching. We show that this process is equivalent to inferring inconsistencies by means of deductive reasoning. Finally, we present the results of a proof-of-concept implementation.

Mechatronic Design : Still A Considerable Challenge

Development of mechatronic products is traditionally carried out by several design experts from different design domains. Performing development of mechatronic products is thus greatly challenging. ...

Visual Analytics for Early-Phase Complex Engineered System Design Support

This article reports on our ongoing experiences in developing visual analytics tools for real-world CESs. Our work focuses on the early design phase during which a large design space is explored, poor alternatives are pruned, and valuable alternatives are considered further. Visual analytics tools can provide interactive discovery, exploration, and understanding of real-world complex engineered systems (CES). The proposed tool, which focuses on the early design phase, can help users perform routine CES design analysis tasks and offer stakeholder-specific visual representations of complex design models.

A mechatronic design infrastructure integrating heterogeneous models

Mechatronic system design is contemplated extensively through model-based approaches. To reflect the multi-domain integration inside a mechatronic system during the design process, integration approaches targeting heterogeneous models are essential. An infrastructure supporting the design of multi-domain systems is presented. The dependencies between the domain-specific models are managed by utilizing SysML as a common system modeling language between those models. A model integration framework supports model transformations between the system-model and the domain-specific models by utilizing Eclipse Modeling Framework. Structural and parameter type dependencies between different domain-models are handled to provide consistency between different views. This provides an ability to traverse between different views of the system, as well as maintaining consistency between those views. A case study on a robot system is presented to explain the integration of mechanical design model in Solid Edge, and dynamic analysis model in Simulink/SimMechanics through a SysML system model, all under the proposed design infrastructure. The approach is scalable towards other modeling formalisms by building new relations through the SysML model. This will support: co-evolution of domain-specific models, a better design of multi-domain systems, reduction in modeling in-consistencies, and a reduction in design time.

A comparison of inconsistency management approaches using a mechatronic manufacturing system design case study

Designing and developing complex mechatronic systems requires the consolidation of models from a variety of domains. These models are created by different stakeholders using a variety of formalisms for the purpose of addressing specific concerns, and are used for representing different views on the same system. While it is considered good practice to separate concerns as much as possible, a complete separation is impossible. The resulting model overlap opens the possibility of inconsistencies being introduced - that is, disagreements between views. Numerous approaches to identify and resolve such inconsistencies have been introduced in the software and systems engineering literature. However, in mechatronic design practice, these have gained little acceptance. The goal of this paper is two-fold: to investigate why their wide spread use is not common, and to assess which of the approaches is the most promising for multi-disciplinary systems design. To aid in the investigation, a change scenario is analyzed using the models of a mechatronic manufacturing system as a case study.