Petr Fiedler

Performance evaluation of symmetric cryptography in embedded systems

We consider the problem of implementing security algorithms into embedded systems deployed in automation applications. Such systems are typically built on embedded microcontrollers with limited resources and as hardware changes may not be possible or convenient, the software based cryptography is a suitable solution. In this paper we present results of performance benchmarks of different software-implemented symmetric cryptography algorithms on 8 and 16-bit microcontroller platforms. The contribution of the work is in comparing performance of different algorithms, embedded microcontroller platforms, effects of optimizations and different implementations.

Virtual Automation Networks

Industrial automation has been dominated by fieldbuses for several decades. Legacy fieldbuses, such as Profibus, were able to provide the required functions, as they were precisely tailored to automation needs. Fieldbuses represent a complex communication solution for automation, and they define automation-specific physical and link layers and a dedicated communication object model. Nevertheless, Ethernet-based communication ubiquitously appearing in offices fostered temptations to bring Ethernet to production. Ethernet provides market-proven cost-effective hardware components with high data rates and immense integration and network management support using the overlaid management protocols. However, Ethernet has not been designed for industrial applications and would fail to fulfill requirements of industrial automation in its generic form. Hence, adaptations in both end devices and sometimes even switching devices had to be carried out. Finally, various industrial requirements were met, and Ethernet-based fieldbuses became state-of-the-art technologies competing with legacy fieldbuses.

Wireless communication in automation

The paper shows the challenges associated with attempts to utilize Bluetooth communication interface for automation purposes like control and data acquisition. The paper describes major challenges, selected approach, first tests, first experiences with Bluetooth on Linux. and first prototypes of embedded devices used for testing. Moreover the paper discusses some specific challenges associated with utilization of wireless communication techniques (focused to Bluetooth) in automation. Finally the paper presents ideas (formal methods) that could be used to analyze, and improve reliability of such system, and approach (time triggered approach with clock synchronization) that could be used to improve the deterministicity of wireless communication channels.

Trends in Automation - investigation in Network Control Systems and Sensor Networks

Abstract Paper deals with two significant trends in the automation and control theory of the last decade. The problems are evoked by a lack between control theory and the automation praxis in the case of Networked Control Systems (NCS) and by penetration of wireless communication used in case of Sensor Networks. Authors define serious theoretical problems in Networked Control Systems analyses in the design of digital control such as non-periodical sampling period, variable delays in control feedback, lower dependability of feedback information and some other issues. Network Calculus is proposed as a possible mathematical and description tool. The paper also mentions an ambitious research program of the Deutsche Forschungsgemeinschaft to develop new theory of the NCS synthesis. In the second part of the paper the Sensor Networks as the new phenomenon in process values measurement and data acquisition systems are described. It is the opinion of the authors, that sensor networks represent totally other look on the utilization of sensors, than represents classical measurement engineering used in data acquisition systems.

On security of PAN wireless systems

This paper describes security features of ZigBee and Bluetooth PAN wireless networks. On examples of those two wireless systems are demonstrated challenges associated with utilization of present wireless systems for applications requiring secure data exchange. Recent penetration of wireless technologies into building and process automation applications even increases the need to fully understand the limitations of the security concepts used.

Electric vehicles charger as a part of home area network

With increasing oil price and environment pollution, especially in large cities, electric vehicles are getting to be more interesting than they were several years ago. Using electric vehicles in cities and large agglomerations lead to less pollution caused by common cars combustion engines (nitrogen oxides, carbon oxides, dust particles). Electric vehicles are more considerate to the environment than traditional cars even when the energy produced by non-renewable energy resources is used for their charging. The lack of the infrastructure prevents electric vehicles spreading. This paper describes standards and ideas how to integrate electric vehicle charger to the home area network. Home area network is a local part of SmartGrid network usually situated in homes. All devices connected to this network should implement several specifications. Basic requirements to charger properties are summarized.

Personal Navigation Algorithms Based on Wireless Networks and Inertial Sensors

Abstract The work aims at a development of positioning algorithm suitable for low-cost indoor or urban pedestrian navigation application. The sensor fusion was applied to increase the localization accuracy. Due to required low application cost only low grade inertial sensors and wireless network based ranging were taken into account. The wireless network was assumed to be preinstalled due to other required functionality (for example: building control) therefore only received signal strength (RSS) range measurement technique was considered. Wireless channel loss mapping method was proposed to overcome the natural uncertainties and restrictions in the RSS range measurements The available sensor and environment models are summarized first and the most appropriate ones are selected secondly. Their effective and novel application in the navigation task, and favorable fusion (Particle filtering) of all available information are the main objectives of this thesis.

Prepaid energy in time of Smart Metering

Abstract Prepaid energy meters are relatively widespread in the world. These meters allow for distribution of electricity in developing and politically unstable countries. In developed countries, prepaid meters help distributors to solve problems with defaulters and they help underprivileged customers to better control the finances spent on consumption of energy. Currently smart metering technologies are being tested and introduced on the market. The Smart Meters bring significant changes in the measurement and billing of energy consumption. This paper deals with possible solutions for prepaid energy in the smart metering age.

Protocol gateways for HART sensors

Abstract The paper presents description of three different protocol gateways for interfacing HART pressure sensors. The gateways have been designed, programmed and realized as hardware prototypes. The first gateway is a wireless transducer between the HART interface of the sensor and a Bluetooth network. The second gateway connects the sensor to an Ethernet network with Modbus protocol. The third gateway is a wireless transducer for ZigBee networks. The gateways are based on embedded microcontrollers with the required interfaces. The software implementation is done in C using protocol libraries. Hardware and enclosure are designed for industrial applications. The gateways are adapted for use with HART pressure sensors.

Interoperable technologies for automation

The demand for integration of all levels of plant control into a single system has been increasing during last years. However the plants have been built on heterogeneous communication technologies that use various approaches for representation of data. Heterogeneity of the plants is faced using combinations of various software and hardware gateways. The presented paper describes why the use of gateways is not a good solution in general, and presents a technology that can be the ultimate solution of interoperability issues in automation. The paper presents disadvantages of gateway based interoperability solutions in heterogeneous control environments and emphasizes possible interoperable solution. The proposed solution is based on emerging open technologies that promise to deliver interoperable services for exchange of all kinds of data among computer systems without the need to perform frustrating conversions between disparate protocols and incompatible data structures. Moreover the proposed interoperability solution will guarantee both interoperability in the field of process automation, and interoperability with future applications of ubiquitous computing too. Disadvantages of proposed solution compared to present communication technologies are mentioned as well.