Rumen Kyusakov

Integration of Wireless Sensor and Actuator Nodes With IT Infrastructure Using Service-Oriented Architecture

A large number of potential applications for Wireless Sensor and Actuator Networks (WSAN) have yet to be embraced by industry despite high interest amongst academic researchers. This is due to various factors such as unpredictable costs related to development, deployment and maintenance of WSAN, especially when integration with existing IT infrastructure and legacy systems is needed. Service-Oriented Architecture (SOA) is seen as a promising technique to bridge the gap between sensor nodes and enterprise applications such as factory monitoring, control, and tracking systems where sensor data is used. To date, research efforts have focused on middleware software systems located in gateway devices that implement standard service technology, such as Devices Profile for Web Services (DPWS), for interacting with the sensor network. This paper takes a different approach-deploying interoperable Simple Object Access Protocol (SOAP)-based web services directly on the nodes and not using gateways. This strategy provides for easy integration with legacy IT systems and supports heterogeneity at the lowest level. Twofold analysis of the related overhead, which is the main challenge of this solution, is performed; Quantification of resource consumption as well as techniques to mitigate it are presented, along with latency measurements showing the impact of different parts of the system on system performance. A proof-of-concept application using Mulle-a resource-constrained sensor platform-is also presented.

Enabling Cloud Connectivity for Mobile Internet of Things Applications

The number of small embedded devices connected to the Internet is increasing. This growth is mostly due to the large number of Internet of Things (IoT) deployments, with applications such as: industrial monitoring, home automation, and others. One common aspect with the majority of application areas is the lack of mobility. Most IoT devices are stationary and often use IEEE 802.15.4/6LoWPAN solutions. When a high level of mobility is required, the use of IEEE 802.15.4 is not possible without adding additional hardware for the user to carry. In this article, a holistic network architecture consisting of heterogeneous devices is presented. The architecture is composed of Embedded Internet Systems (EIS) and uses standard communication protocols. One important feature is the use of the Service-oriented architecture (SOA) paradigm. The use of SOA, by utilization of the CoAP protocol and standard services, enables the proposed architecture to exchange sensor- and actuator data with an Internet-based cloud as well as a users local cloud consisting of sensor IoT devices, smart phones and laptops. Another component of the architecture is a web-based human-machine interface for configuration, monitoring and visualization of sensor and actuator data using emerging web technologies for structured data processing. Results from experiments and real-world tests show that the proposed architecture can support sample rates of up to several kHz while enabling sensor data to be transmitted to SOA services in real time. This proves that the use of SOA, and Restful web services in particular, is feasible on resource-constrained platforms while supporting true mobility.

Technologies for SOA-based distributed large scale process monitoring and control systems

In a SOA-based system the applications are organized in a manner such that interoperable services can be used from different domains. In a process industry context, different domains can refer to, for example, process instrumentation and monitoring, execution of process control, data acquisition, etc. Large process industry systems are a complex and potentially very large sets of multi-disciplinary, heterogeneous, networked distributed systems. Current industrial process control systems are typically vendor specific; in addition the different domains are associated with different layers, different standards and different technologies. In the paper the authors report about the investigations and assessments performed to find answers for four major critical questions that arise as key when technologies have to be selected and used in a true Service Oriented Architecture (SOA) based distributed large scale Process Monitoring and Control system: (1) Real-time SOA (what are the limits of bringing SOA into high performance control loops?); (2) Management of large scale industrial distributed control systems (is it feasible to manage up to tens of thousands of service-oriented devices?); (3) Distributed event-based systems are asynchronous (what are the limits compared to traditional periodic scanning systems?) and (4) Service specification (which semantics are the most suitable for specifying process control and monitoring services?).

A migration approach towards a SOA-based next generation process control and monitoring

Interest in Service Oriented Architectures (SOA) in the automation domain has seen a rapid increase both from the academia as well as the industry recent years. Since green field plants today are not common, the partial migration of plant automation to SOA design is needed to introduce new functionalities. Thus strategies and approaches for migration from legacy to SOA architectures becomes of vital interest. This paper discusses different views on partial migration of a process monitoring and control system from legacy to SOA. The discussion includes a global top down view, a bottom up view, hardware/software considerations and a hint on training of personnel.

Efficient structured data processing for web service enabled shop floor devices

State of the art factory automation systems are now using Service Oriented Architecture (SOA) in order to increase flexibility and lower complexity of process monitoring and control. However, the service technology has not yet penetrated into the lower levels of plant-wide automation processes i.e. throughout shop floor devices such as programmable controllers, embedded sensors and actuators. Different techniques to adapt the web service technology to the specific requirements of embedded systems domain are intensively investigated by researchers and yet real-time properties, limited resources and wireless links are still posing immense challenges. The most promising solutions proposed are based on a newly emerging structured data format - Efficient XML Interchange (EXI). It is designed to compensate for the inefficiency of widely used throughout service implementations XML format. This paper investigates the design of EXI processor targeted at highly resource constrained embedded devices found at the shop floor level. The EXI processor is proposed as an alternative to the XML parsers and serializers currently used in web service implementations. Among the results presented are a novel low level processor interface and measurements quantifying the gained efficiency compared to traditional XML-like interfaces. Reference open source implementation equipped with the new interface is also provided.

EXIP: A Framework for Embedded Web Development

Developing and deploying Web applications on networked embedded devices is often seen as a way to reduce the development cost and time to market for new target platforms. However, the size of the messages and the processing requirements of todays Web protocols, such as HTTP and XML, are challenging for the most resource-constrained class of devices that could also benefit from Web connectivity. New Web protocols using binary representations have been proposed for addressing this issue. Constrained Application Protocol (CoAP) reduces the bandwidth and processing requirements compared to HTTP while preserving the core concepts of the Web architecture. Similarly, Efficient XML Interchange (EXI) format has been standardized for reducing the size and processing time for XML structured information. Nevertheless, the adoption of these technologies is lagging behind due to lack of support from Web browsers and current Web development toolkits. Motivated by these problems, this article presents the design and implementation techniques for the EXIP framework for embedded Web development. The framework consists of a highly efficient EXI processor, a tool for EXI data binding based on templates, and a CoAP/EXI/XHTML Web page engine. A prototype implementation of the EXI processor is herein presented and evaluated. It can be applied to Web browsers or thin server platforms using XHTML and Web services for supporting human-machine interactions in the Internet of Things. This article contains four major results: (1) theoretical and practical evaluation of the use of binary protocols for embedded Web programming; (2) a novel method for generation of EXI grammars based on XML Schema definitions; (3) an algorithm for grammar concatenation that produces normalized EXI grammars directly, and hence reduces the number of iterations during grammar generation; (4) an algorithm for efficient representation of possible deviations from the XML schema.

Efficient XML Interchange in factory automation systems

The advent of Service-Oriented Architecture (SOA) in the automation domain has made possible the cross-layer vertical integration of devices, manufacturing systems and business processes. However, the use of standard web service technologies is not always possible in an industrial environment with high real-time requirements and limited hardware resources due to the overhead connected to XML processing. The work presented in this paper analyses the opportunities, advantages and challenges when applying the newly emerged Efficient XML Interchange (EXI) standard for XML encoding to the factory automation systems. The two major SOA-based automation middleware architectures, namely OPC Unified Architecture (OPC UA) and Devices Profile for Web Services (DPWS), were investigated. Furthermore, we present an EXI-based approach for extending the reach of the service technology covering deployments on resource constrained embedded devices.

Application of Service Oriented Architecture for Sensors and Actuators in District Heating Substations

Hardwired sensor installations using proprietary protocols found in todays district heating substations limit the potential usability of the sensors in and around the substations. If sensor resources can be shared and re-used in a variety of applications, the cost of sensors and installation can be reduced, and their functionality and operability can be increased. In this paper, we present a new concept of district heating substation control and monitoring, where a service oriented architecture (SOA) is deployed in a wireless sensor network (WSN), which is integrated with the substation. IP-networking is exclusively used from sensor to server; hence, no middleware is needed for Internet integration. Further, by enabling thousands of sensors with SOA capabilities, a System of Systems approach can be applied. The results of this paper show that it is possible to utilize SOA solutions with heavily resource-constrained embedded devices in contexts where the real-time constrains are limited, such as in a district heating substation.

Emerging energy management standards and technologies — Challenges and application prospects

The continuously rising costs and the environmental impact of energy generation, transmission and consumption are a major concern for governments, industry and society alike. Among research in renewable energy sources as well as in energy efficiency of buildings, electrical appliances, vehicles etc., a considerable amount of attention has been devoted to effective energy management. In this paper, we present a survey on emerging energy management standards with focus on enabling application layer Information and Communications Technologies (ICT) that are a central part of these standards. The presented work includes an analysis on the challenges, future trends, security and application prospects of energy management standards. As part of the survey, the emerging Open Automated Demand Response (OpenADR) version 2.0 and Smart Energy Profile (SEP) version 2.0 were identified as the most promising and complete solutions. The presented survey provides an important insight on the future developments in the area of energy management protocols and highlights a number of key ICT solutions and challenges.

Promising Technologies for SOA-Based Industrial Automation Systems

In the last years service-oriented architectures have been extensively used to enable seamless interaction and integration among the various heterogeneous systems and devices found in modern factories. The emerging Industrial Automation Systems are increasingly utilising them. In the cloud-based vision of IMC-AESOP such technologies take an even more key role as they empower the backbone of the new concepts and approaches under development. Here we report about the investigations and assessments performed to find answers to some of the major questions that arise as key when technologies have to be selected and used in an industrial context utilizing Service-Oriented Architecture (SOA)-based distributed large-scale process monitoring and control system. Aspects of integration, real-timeness, distributeness, event-based interaction, service-enablement, etc., are approached from different angles and some of the promising technologies are analysed and assessed.