José-Enrique Simó-Ten

Dynamic Reconfiguration of a RGBD Sensor Based on QoS and QoC Requirements in Distributed Systems

The inclusion of embedded sensors into a networked system provides useful information for many applications. A Distributed Control System (DCS) is one of the clearest examples where processing and communications are constrained by the client’s requirements and the capacity of the system. An embedded sensor with advanced processing and communications capabilities supplies high level information, abstracting from the data acquisition process and objects recognition mechanisms. The implementation of an embedded sensor/actuator as a Smart Resource permits clients to access sensor information through distributed network services. Smart resources can offer sensor services as well as computing, communications and peripheral access by implementing a self-aware based adaptation mechanism which adapts the execution profile to the context. On the other hand, information integrity must be ensured when computing processes are dynamically adapted. Therefore, the processing must be adapted to perform tasks in a certain lapse of time but always ensuring a minimum process quality. In the same way, communications must try to reduce the data traffic without excluding relevant information. The main objective of the paper is to present a dynamic configuration mechanism to adapt the sensor processing and communication to the client’s requirements in the DCS. This paper describes an implementation of a smart resource based on a Red, Green, Blue, and Depth (RGBD) sensor in order to test the dynamic configuration mechanism presented.

A Survey on Quality of Service Support on Middleware-Based Distributed Messaging Systems Used in Multi Agent Systems

Messaging systems are widely used in distributed systems to hide the details of the communications mechanism to the multi agents systems. However, the Quality of Service is treated in different way depending on the messaging system used. This article presents a review and further analysis of the quality of service treatment in the mainly messaging systems used in distributed multi agent systems. The review covers the issues related to the purpose of the functions provided and the scope of the quality of service offered by every messaging system. We propose ontology for classifying and decide which parameters are relevant to the user. The results of the analysis and the ontology can be used to select the most suitable messaging system to distributed multi agent architecture and to establish the quality of service requirements in a distributed system.

Performance and Results of the Triple Buffering Built-In in a Raspberry PI to Optimize the Distribution of Information from a Smart Sensor

Currently, 3D sensors can be considered an evolution of cameras by providing the image with its depth information. These sensors have a generic function and the programmer has to process the received information in order to be adapted and used in a specific environment. In robots navigation, the 3D information can be useful for basic behaviours such as “obstacles avoidance” or even more complex behaviours such as “maps generation”. In this article an image management system provided by the xTion intelligent sensor is presented. The xTion sensor provides a VGA image and a 3D depth, which allows it to be used for several purposes. In order to distribute the data, it is acquired, processed and sent to several clients with a triple buffer system modified to serve the most recent image to the client. The system is programmed in C for Linux and built-in in a Raspberry PI. The article exposes the performance and results from monitoring the frame’s delay comparing it with a simple and a double buffer system widely used in this kind of systems.

Multi-agent architecture with support to quality of service and quality of control

Multi Agent Systems (MAS) are one of the most suitable frameworks for the implementation of intelligent distributed control system. Agents provide suitable flexibility to give support to implied heterogeneity in cyber-physical systems. Quality of Service (QoS) and Quality of Control (QoC) parameters are commonly utilized to evaluate the efficiency of the communications and the control loop. Agents can use the quality measures to take a wide range of decisions, like suitable placement on the control node or to change the workload to save energy. This article describes the architecture of a multi agent system that provides support to QoS and QoC parameters to optimize de system. The architecture uses a Publish-Subscriber model, based on Data Distribution Service (DDS) to send the control messages. Due to the nature of the Publish-Subscribe model, the architecture is suitable to implement event-based control (EBC) systems. The architecture has been called FSACtrl.

Distributed Sensor Architecture for Intelligent Control that Supports Quality of Control and Quality of Service

This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems.

Smart device definition and application on embedded system: performance and optimi-zation on a RGBD sensor

Embedded control systems usually are characterized by its limitations in terms of computational power and memory. Although this systems must deal with perpection and actuation signal adaptation and calculate control actions ensuring its reliability and providing a certain degree of fault tolerance. The allocation of these tasks between some different embedded nodes conforming a distributed control system allows to solve many of these issues. For that reason is proposed the application of smart devices aims to perform the data processing tasks related with the perception and actuation and offer a simple interface to be configured by other nodes in order to share processed information and raise QoS based alarms. In this work is introduced the procedure of implementing a smart device as a sensor as an embedded node in a distributed control system. In order to analyze its benefits an application based on a RGBD sensor implemented as an smart device is proposed.

Relationship between quality of control and quality of service in mobile robot navigation

This article presents the experimental work developed to test the viability and to measure the efficiency of an intelligent control distributed architecture. To do this, a simulated navigation scenario of Braitenberg vehicles has been developed. To test the efficiency, the architecture uses the performance as QoS parameter. The measuring of the quality of the navigation is done through the ITAE QoC parameter. Tested scenarios are: an environment without QoS and QoC managing, an environment with a relevant message filtering and an environment with a predictive filtering by the type of control. The results obtained show that some of the processing performed in the control nodes can be moved to the middleware to optimize the robot navigation.

Mobile-Based Distributed System for Managing Abandoned or Lost Pets

This paper presents the work in progress of a mobile-based distributed system which aims to minimize the social impact of abandoned or lost animals. System is based on the use of smart mobile devices to provide message warnings of animals localized. Messages are stored in a database to be processed. In order to enter data such as photography, audio and artificial images, system uses different mobile device interfaces. Data processing consists mainly in matching localized animals with lost animals, assigning abandoned animals at shelters and generating notifications for animal shelters or authorities. Currently, the system is in the development phase. The technical challenges in which we are working are to optimize data and metadata matching, and the management of message warning.

Quality of Service and Quality of Control Based Protocol to Distribute Agents

This paper describes an agent’s movement protocol. Additionally, a distributed architecture to implement such protocol is presented. The architecture allows the agents to move in accordance with their requirements. The protocol is based on division and fusion of the agents in their basic components called Logical Sensors. The movement of the agents is based on the quality of services (QoS) and quality of control (QoC) parameters that the system can provides. The protocol is used to know the impact that the movement of the agents may have on the system and obtain the equilibrium points where the impact is minimal.

CKMultipeer: Connecting Devices Without Caring about the Network

In the current context of distributed systems, the communications have moved from a model based on connected nodes, to a model that must connect processes, or including connect data. There are many paradigms, mechanisms and architectures to give support to these distributed systems. Most of these mechanisms are extensions or evolutions of distributed node based architecture where the knowledge about the physical node is necessary. To isolate communications from the physical aspects of distributed systems a middleware, centered on the data, and oriented to connect processes has been developed. The middleware, called “CKMultipeer”, allows processes to communicate data between them. Communication is integrated without worrying about the network configuration and management. This article describes the implementation of the middleware, as well as the tests developed. Through the design of a graphical interface, the communications performance is analyzed.