Markus Graube

Linked Data as Integrating Technology for Industrial Data

In a globalised world the process industry faces great challenges regarding data management. Rising demands for agility and rapid shortening of innovation cycles have lead to project-based collaborations. Highly specialised small and medium enterprises are forming so-called virtual companies to profit from each other. Today, however, industrial data structures are characterised by high heterogeneity. This complicates collaborative work and hinders the flow of data between different stakeholders from various domains. Existing solutions are much too rigid and potentially cumbersome. There still is a broad gap between the need of virtual companies to share data from mixed sources in a controlled way and the available technologies to accomplish this. Our approach to close this gap is the usage of semantic web technologies for representing industrial data in a generic way. Major advantages in comparison to traditional approaches arise from the inherent merging abilities and from the extensibility of Linked Data. Distributed information spaces from different domains can be condensed into an interlinked cloud. Existing data can be integrated either on-the-fly using appropriate adapters or by complete migration. Furthermore, operations from graph theory can be performed on the Linked Data networks to generate aggregated views. This paper discusses a set of proven web technologies for cloud-driven industrial data sharing in virtual companies and presents preliminary results.

Beyond app-chaining: Mobile app orchestration for efficient model driven software generation

Mobile apps are a success story for mobile devices, particularly in the consumer sector. Tailored to a specific task, they offer optimal usability for a defined class of devices. However, todays apps are neither designed to collaborate with complex workflows nor to support these. To overcome this limitation, we developed the concept of Mobile App Orchestration. This pragmatic model driven software generation approach makes it possible to use mobile apps even in complex industrial workflows. We demonstrate the entire development process in a use case and explain solutions and challenges of our approach. An experimental evaluation of a manually conducted orchestration with 11 participants supports our design hypothesis that the proposed approach can deliver usable mobile support systems for Virtual Factories.

Open source as enabler for OPC UA in industrial automation

As a standardized communication protocol, OPC UA is the main focal point with regard to information exchange in the ongoing initiative Industrie 4.0. But there are also considerations to use it within the Internet of Things. The fact that currently no open reference implementation can be used in research for free represents a major problem in this context. The authors have the opinion that open source software can stabilize the ongoing theoretical work. Recent efforts to develop an open implementation for OPC UA were not able to meet the requirements of practical and industrial automation technology. This issue is addressed by the open62541 project which is presented in this article including an overview of its application fields and main research issues.

Information modeling for middleware in automation

Middleware in automation serves the connection of hardware and software components of applications in automation-like control or human-machine interfaces. To cope with todays flexibility requirements, there is an urgent demand to not only communicate data but to describe the semantics of the distinct elements of the distributed information space. Therefore, middleware in automation needs to provide some means for information modeling. To derive general concepts and recommendations on how to implement information models on middleware in automation, we discuss several relevant standards that provide partial information models. We then identify the fundamental information modeling constructs of these partial models and derive general requirements for the information modeling capabilities of middleware in automation.

Linked data as enabler for mobile applications for complex tasks in industrial settings

Nowadays, apps provide support for various simple tasks. They are easy to use and highly usable. However, future apps should support more complex workflows especially when trying to enter the professional business world. They need to provide higher reusability and composability in order to make them suitable for complex and alterable workflows that are common in industry. The concept of App Orchestration allows supporting complex tasks with aid of an ensemble of adapted and managed apps. Therefore, the apps raise several demands on the underlying information backend. This article describes these requirements and presents the Linked Data approach, which is a possible methodology for an integrated, semantically described information space for this purpose. It describes possible uses and benefits for the concept of App Orchestration and shows them in a use case of mobile maintenance. It further discusses the current status of the approach and provides future research challenges.

RFID as universal entry point to linked data clouds

Semantic web technologies are a key enabler for future information systems. The concept of Linked Data allows flexible inter-organizational collaboration and dynamic data integration. It surpasses the limitations of prevalent relational databases and proprietary access technologies. RFID, on the other hand, has been successfully applied to integrate physical artifacts into complex information systems. It allows the identification of artifacts by a unique identifier leveraging concepts such as the Internet of Things. Using the existing RFID ecosystem as universal entry point to Linked Data clouds makes it possible to connect the semantic description of the real world with the physical artifacts within this world. This provides new ways of merging and exploring real and virtual content. This paper presents an approach for using RFID as universal entry point to Linked Data clouds for task-driven and context-aware mobile support systems.

ComVantage: Mobile Enterprise Collaboration Reference Framework and Enablers for Future Internet Information Interoperability

Future Internet Networked Enterprise Systems demand enhanced collaboration and mobility support. FI technologies are fundamental for increased service differentiation and cost optimisation in manufacturing environments. However, such ICT-based capabilities are not easy to introduce, in particular to SMEs, due to high costs and complexity. To progress in more effective development of value added services based on Web 2.0 principles within a mobile enterprise collaboration context, the complexity of collaboration in terms of information management needs to be leveraged from the end-users. Linked Data (LD) provides a universal and lightweight approach for the collaboration network. However, the elaboration of collaborative business processes based on LD still needs to be properly formulated for FI systems. The aim of this paper is to present a reference architecture for mobile enterprise collaboration based on LD interoperability. Moreover, security, semantic data lifting, business process modelling interoperability and mobile app orchestration enablers are presented to facilitate trustful and effective inter-organisational collaboration.

Towards collaborative plant control using a distributed information and interaction space

As Smart Manufacturing, Industrial Internet, Industrie 4.0, and Cyber-Physical Production System (CPPS) are becoming reality, the way process and manufacturing plants are operated has to change. Additionally, these developments - constituting the pervasive digitalisation of industry - have a profound effect on the way human workers and machines interact. This paper contrasts the current state of the art in plant control with a vision for the future. The scenario is illustrated by a realistic problem-solving process in a chemical plant. It describes an integrated industrial information and interaction space that leverages emerging technologies to enable plant operators to remain in control of future flexible modularised process plants. Our approach shows the advantages of an integrated information space which feeds interaction and collaboration using Virtual Reality (VR), novel display technologies and mobile devices.

Flexibility vs. security in linked enterprise data access control graphs

Linked Data offers easy extensibility and interoperability of information spaces. This provides a great potential for industrial companies allowing to share information with partners in a virtual enterprise. Hence, together they can become faster and more flexible which results in an advantage in the market. However, there is still the barrier to protect own information with a fine grain. Access control graphs are an approach for this issue. Information is put into different views by executing infer mechanisms on role-based policy rules. Afterwards queries are automatically rewritten at runtime in order to match the generated views and provide only data from views that should be accessible by the authenticated role. This paper demonstrates the balance between flexibility and security using this approach. The amount and complexity of the policy rules are highly dependent on the information model used. However, a moderate restriction of the huge flexibility in the information modelling allows for few rules but those are powerful ones. Additionally, the approach allows can also be leveraged for consistency checking of Linked Data data structures. Thus, clients can rely on these information invariants and the information provider can rely on the fact that fine grained access is granted.

Open Semantic Revision Control with R43ples: Extending SPARQL to access revisions of Named Graphs

The Semantic Web provides mechanisms to interlink data in a fast and efficient way and build complex information networks. However, one of the most important features missing for industrial application is version control which allows recording changes and rolling them back at any time if necessary. It is not sufficiently supported by todays triplestores and recent version control systems are not very well integrated into the Semantic Web. This paper shows a way of dealing with version and revision control using SPARQL. It presents R43ples as an approach using named graphs for semantically storing the differences between revisions. Furthermore it allows a direct access and manipulation of revisions with extended version of SPARQL. Smart mechanisms for restoring old revisions relying on query rewriting provide a fast way of querying old revisions of big datasets. A prototypical implementation of the system prove an appropriate performance under different conditions.