Real-Time Scheduling Method for Middleware of Industrial Automation Devices

In this study, a real-time scheduling algorithm, which supports periodic and sporadic executions with event handling, is proposed for the middleware of industrial automation devices or controllers, such as industrial robots and programmable logic controllers. When sensors and embedded controllers are included in control loops having different control periods, they should transmit their data periodically to the controllers and actuators; otherwise, fatal failure of the system including the devices could occur. The proposed scheduling algorithm manages modules, namely, the thread type (or .so type) and process type (or .exe type), for periodic execution, sporadic execution, and non-real-time execution. The program structures for the thread-type and process-type modules that can make the proposed algorithm manage the modules efficiently are suggested; then, they are applied in periodic and sporadic executions. For sporadic executions, the occurrences of events are first examined to invoke the execution modules corresponding to the events. The proposed scheduling algorithm is implemented using the Xenomai real-time operating system (OS) and Linux, and it is validated through several examples

Event-driven industrial robot control architecture for the Adept V+ platform

Modern industrial robotic systems are highly interconnected. They operate in a distributed environment and communicate with sensors, computer vision systems, mechatronic devices, and computational components. On the fundamental level, communication and coordination between all parties in such distributed system are characterized by discrete event behavior. The latter is largely attributed to the specifics of communication over the network, which, in terms, facilitates asynchronous programming and explicit event handling. In addition, on the conceptual level, events are an important building block for realizing reactivity and coordination. Eventdriven architecture has manifested its effectiveness for building loosely-coupled systems based on publish-subscribe middleware, either general-purpose or robotic-oriented. Despite all the advances in middleware, industrial robots remain difficult to program in context of distributed systems, to a large extent due to the limitation of the native robot platforms. This paper proposes an architecture for flexible event-based control of industrial robots based on the Adept V+ platform. The architecture is based on the robot controller providing a TCP/IP server and a collection of robot skills, and a high-level control module deployed to a dedicated computing device. The control module possesses bidirectional communication with the robot controller and publish/subscribe messaging with external systems. It is programmed in asynchronous style using pyadept, a Python library based on Python coroutines, AsyncIO event loop and ZeroMQ middleware. The proposed solution facilitates integration of Adept robots into distributed environments and building more flexible robotic solutions with eventbased logic

Event Management Proposal for Distribution Data Service Standard

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-00551-5_32This paper presents a proposal to extend the event management subsystem of the Distribution Data Service standard (DDS). The proposal allows user to optimize the use of DDS in networked control systems (NCS). DDS offers a simple event management system based on message filtering. The aim of the proposal is to improve the event management with three main elements: Events, Conditions and Actions. Actions are the new element proposed. Actions perform basic operations in the middleware, discharging the process load of control elements. The proposal is fully compatible with the standard and can be easily added to an existing system. Proposal has been tested in a distributed mobile robot navigation system with interesting results.The study described in this paper is a part of the coordinated project COBAMI: Mission-based Hierarchical Control. Education and Science Department, Spanish Government. CICYT: MICINN: DP1201 1-28507-C02-01/02.Poza-Lujan, J.; Posadas-Yagüe, J.; Simó Ten, JE. (2013). Event Management Proposal for Distribution Data Service Standard. En Distributed Computing and Artificial Intelligence. Springer. 259-266. https://doi.org/10.1007/978-3-319-00551-5_32S259266Sánchez, J., Guarnes, M.Á., Dormido, S.: On the Application of Different Event-Based Sampling Strategies to the Control of a Simple Industrial Process. Sensors 9, 6795–6818 (2009)Sandee, J.H., Heemels, W.P.M.H., van den Bosch, P.P.J.: Case Studies in Event-Driven Control. In: Bemporad, A., Bicchi, A., Buttazzo, G. (eds.) HSCC 2007. LNCS, vol. 4416, pp. 762–765. Springer, Heidelberg (2007)Hadim, S., Nader, M.: Middleware Challenges and Approaches for Wireless Sensor Networks. IEEE Distributed Systems Online 7(3) (2006)Pardo-Castellote, G.: OMG Data-Distribution Service: architectural overview. In: Proceedings of 23rd International Conference on Distributed Computing Systems Workshops, Providence, USA, vol. 19-22, pp. 200–206 (2003)Object Management Group. Data Distribution Service for Real-time Systems Version 1.2 (2007), http://www.omg.org/Dorf, R.C., Bishop, R.H.: Modern Control Systems, 11th edn. Prentice Hall (2008)Poza-Luján, J., Posadas-Yagüe, J., Simó-Ten, J.: Quality of Service and Quality of Control Based Protocol to Distribute Agents. In: DCAI, pp. 73–80 (2010)Waldbusser, S.: RFC 2819 - Remote Network Monitoring Management Information Base. Network Working Group. Lucent Technologies (2000)Poza-Luján, J., Posadas-Yagüe, J., Simó-Ten, J.: Relationship between Quality of Control and Quality of Service in Mobile Robot Navigation. In: DCAI, pp. 557–564 (2012)K-Team Corporation. Khepera III robot, http://www.k-team.comBraitenberg, V.: Vehicles: Experiments on Synthetic Psychology. MIT Press, Cambridge (1984)Poza-Luján, J.: Propuesta de arquitectura distribuida de control inteligente basada en políticas de calidad de servicio. Universitat Politècnica de València Press (2012

Robotics Middleware: A Comprehensive Literature Survey and Attribute-Based Bibliography

Autonomous robots are complex systems that require the interaction between numerous heterogeneous components (software and hardware). Because of the increase in complexity of robotic applications and the diverse range of hardware, robotic middleware is designed to manage the complexity and heterogeneity of the hardware and applications, promote the integration of new technologies, simplify software design, hide the complexity of low-level communication and the sensor heterogeneity of the sensors, improve software quality, reuse robotic software infrastructure across multiple research efforts, and to reduce production costs. This paper presents a literature survey and attribute-based bibliography of the current state of the art in robotic middleware design. The main aim of the survey is to assist robotic middleware researchers in evaluating the strengths and weaknesses of current approaches and their appropriateness for their applications. Furthermore, we provide a comprehensive set of appropriate bibliographic references that are classified based on middleware attributes.http://dx.doi.org/10.1155/2012/95901