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Automation systems must primarily be deterministic and reliable, especially in safety-critical environments. With recent trends such as mass customization or Industry 4.0, there is an increasing need for automation systems to be dynamic. Changing parts of the software of today's automation systems, however, typically requires rebooting the controller, which makes software updates a complex and costly...
In mechatronics engineering the execution of experiments and tests is an important activity during development of new products and maintenance of released products. Planning and execution of experiments and tests is an essential cost and time factor. To keep the development time short it is necessary to have well-managed processes in the test department and to plan, organize, source out or execute,...
For companies in the automation industry, the development of real-time Ethernet to connect devices is of high economic interest to replace conventional fieldbus systems. Therefore, many approaches for adapting Ethernet to real-time requirements come from industrial applications. This is a challenging task as the original Ethernet standard IEEE 802.3 was not designed for real-time data transmission...
Condition monitoring based on currents circulating between parallel stator windings of a synchronous motor has been demonstrated. Circulating currents arise from any asymmetries in the motor that influence the air-gap magnetic field such as an eccentric rotor or an inter-turn short circuit. A measurement system based on six individual current sensors has been designed to acquire current data on an...
This work investigates the composition of interdependent software components on a shared platform from a timing perspective. Because we consider software components for vehicular systems, which are often sensitive to timing, the individual components and the composed system require timing analysis. In order to support independent development of components, the real-time systems community proposed...
In this paper, a state-feedback linear-quadratic regulator (LQR) is proposed for event-based control of a linear system. An interesting property of LQRs is that an optimal response of the system can be obtained in accordance to some specifications, like the actuator limits. An integral action is also added in order to not only restrict the study to null stabilization but also to tracking. The idea...
This work presents the application of Lagrange interpolation method for a signal reconstruction in event-based Generalized Predictive Control (GPC). The event-based control system is governed by level crossing sampling techniques, which monitors the controlled variable. The Lagrange interpolation method is used to reconstruct signal values between two consecutive events. The interpolated signal values...
In this paper we analyse the conditions that produce oscillations in event based PID controllers. A Symmetric Send-On-Delta scheme (SSOD) is assumed, and the describing function is the tool used to address the problem. Once the conditions for oscillations are established, a new robustness to oscillations performance measure is introduced. Then a very simple and intuitive rule of thumb is given about...
For a distributed embedded system (DES) to operate continuously in a dynamic environment, it must be flexible and highly reliable. This applies in particular to its communication subsystem. The Flexible Time-Triggered Replicated Star for Ethernet (FTTRS) aims at providing such a subsystem by means of a highly-reliable switched-Ethernet architecture based on the Flexible Time-Triggered paradigm (FTT),...
The resource constrained legacy embedded systems are widely found in today's Industrial Control System networks. The Manufacturing message service (MMS) protocol is an international messaging service standard for industrial communications with very limited security provisioning. Legacy embedded systems and real-time applications impose challenges to secure the MMS protocol. Analysing the relevant...
In this paper, we develop a predictive maintenance (PdM) method to determine the most effective time to apply maintenance to an equipment and study its application to a real semiconductor etching chamber. More specifically, we first apply linear regression to predict the (output) equipment health condition from the (input) operational parameters. This choice of linear model also allows us to propose...
In this paper an FPGA-based wideband wireless channel emulator is presented which is suitable for early evaluation of Wireless Sensor and Actuator Networks in industrial environments. The emulator works in complex baseband and has a 100 MHz-wide RF interface which covers the full Industrial, Scientific and Medical (ISM) band of 2.45 GHz (2.4–2.5 GHz); this allows the direct connection of either custom...
With the growth of complexity in the embedded domain, the use of distributed systems to support multiple realtime applications has become commonplace. These applications may share processor and network resources, and real-time scheduling policies can guarantee that these applications do not interfere with each other's ability to meet their temporal constraints. We believe that these applications should...
Real-Time Ethernet networks increasingly gain importance for the employment in industrial applications. Certain Real-Time Ethernet networks were optimized to reach very small cycle times well below 100 μs by modifying the Ethernet hardware. Two important and wide-spread systems of this class are EtherCAT and Profinet IRT. VABS is a newer high-performance system which is still under development. This...
Distributed systems rely in communication networks, typically a bus, in order to exchange messages and fulfill their goals. However, message transmission is subject to interferences that ultimately can lead to message corruption. In systems where a high-reliability is sought, error recovery mechanisms can be deployed in order to give the required reliability level, and this can be done in the spatial...
Cooperative cyber-physical systems (CCPS) are driven by the tight coordination between computational components, physical sensors and actuators, and the interaction with each other over system bounds. The software development of CCPS is getting more complex because of the tight integration, heterogeneous technologies, as well as safety and timing requirements. Therefore, new engineering approaches,...
Devices in industrial automation systems are becoming more and more intelligent. Consequently, functions such as server services are migrating into the device level. To solve the resulting connection mesh, this paper entails the concept of aggregation of servers connected to devices in an industrial automation scenario. The first section discusses the basic requirements for aggregation and proposes...
In this study, a nonlinear system is controlled using a linear adaptive method. A nonlinear system is approximated a linear model at each operating point, and a control law is designed based on the approximated linear model. To obtain a suitable linear model at each operating point, many linear models are simultaneously identified. However, the computation load for identifying many models is considerably...
Production plants need to be set up and reconfigured faster to fulfill increasing market demands. Highly flexible automation systems are needed and a promising approach is Service Oriented Architecture (SOA) which has recently received much attention in both academia and industry. OPC Unified Architecture (OPC UA), the next generation of the de facto standard for interoperability in the automation...
Machine learning has been applied in image processing system for object recognition, inspection and measurement. It assumes that the provided training objects are representative enough to the real objects. However in real application, new (unlearned) objects always emerge over time, which may deviate from the trained (learned) objects. The conventional image processing system using machine learning...
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