A near-infrared pyramid wavefront sensor for Keck adaptive optics: real-time controller

A new real-time control system will be implemented within the Keck II adaptive optics system to support the new near-infrared pyramid wavefront sensor. The new real-time computer has to interface with an existing, very productive adaptive optics system. We discuss our solution to install it in an operational environment without impacting science. This solution is based on an independent SCExAO-based pyramid wavefront sensor realtime processor solution using the hardware interfaces provided by the existing Keck II real-time controller. We introduce the new pyramid real-time controller system design, its expected performance, and the modification of the operational real-time controller to support the pyramid system including interfacing with the existing deformable and tip-tilt mirrors. We describe the integration of the Saphira detector-based camera and the Boston Micromachines kilo-DM in this new architecture. We explain the software architecture and philosophy, the shared memory concept and how the real-time computer uses the power of GPUs for adaptive optics control. We discuss the strengths and weaknesses of this architecture and how it can benefit other projects. The motion control of the devices deployed on the Keck II adaptive optics bench to support the alignment of the light on the sensors is also described. The interfaces, developed to deal with the rest of the Keck telescope systems in the observatory distributed system, are reviewed. Based on this experience, we present which design ideas could have helped us integrate the new system with the previous one and the resultant performance gains

Java-based MIDI interface for robot control

Robot offers an excellent means of utilizing high level technology to make a given manufacturing operation more profitable and competitive. Apart from manufacturing, robots are also being utilized in the areas of medicine and agriculture with great returns. Robotic applications now require multiple robots working in a coordinated manner, something similar to an orchestra. This lead to the concept of a Robotic Instrument Digital Interfacing (RIDI) system for real time coordinated control of robotic devices. It provides a novel runtime environment that supports the building and deployment of distributed robotic devices.;The objective of this research is to design and develop a Graphical User Interface (GUI). The GUI aims at providing extensive support for monitoring multiple device activity in real time. With the exception of code for device-specific interfaces, the prototype RIDI-GUI implementation will be coded in Java. This thesis details on the various aspects involved in the design and implementation of the GUI software for two robot arms

Analysis of communication systems with timed token protocols using the power-series algorithm

The IEEE 802.4 and FDDI (Fibre Distributed Data Interface) standards are high speed MAC (Medium Access Control) protocols for LAN/MANs employing a timer-controlled token passing mechanism, the so-called Timed Token Protocol, to control station access to the shared media. These protocols support synchronous and real-time (i.e., time-critical) applications, and provide priority among asynchronous (i.e., non time-critical) applications. During the last few years, much research has focused on the study of timed token protocols, to obtain performance measures such as throughputs or mean waiting times. The recent development of the Power-Series Algorithm (PSA) has opened new perspectives in the analysis of this class of protocols. This paper shows the versatility of the PSA technique when evaluating the station buffer occupancy and delay distributions of a very general model that can be used to represent the behavior of several LAN/MANs MAC protocols, among which the timed token MAC protocols. Specifically, the focus of the paper is on the solution of an almost exact model of the IEEE 802.4 MAC protocol. Since the model we propose and solve numerically by exploiting the PSA technique, is an approximate model of the FDDI MAC protocol, the paper also reports on a comparison between performance measures obtained for this model and simulation results for the corresponding exact model of FDDI

The Early Assessment of System Performance in Distributed Real-time Systems

Distributed real-time process control systems are notoriously difficult to develop. They frequently overrun time schedules and break cost constraints. The problems are compounded where there are multiple development teams and stakeholders. Conventional model-driven development has been examined to see if it can be extended to resolve some of these problems. It may be possible to use early system design stages to identify performance issues which would otherwise not be identified until late in the development of the system. A functional model is proposed, in addition to those conventionally used for model-driven development, based on loosely coupled functional elements, to represent the behaviour of each system component. The model complements existing requirements and design specifications and addresses the combination of individual component abstractions to produce a complete system specification. The functional model enables the accurate prediction of system performance prior to the detailed design of each component. The thesis examines how performance can be calculated and modelled. An animator tool and associated code generator are used to predict system and component performance in a distributed aircraft navigation system. The use of the animator to support the system design prior to the generation of the component contract specifications and interface control documents provides a means of assessing performance which is accessible to domain experts and system designers alike. The model also enables the effects of requirements changes and component design issues on the system design to be assessed in terms of the system design to provide system wide solutions. This performance assessment model and animator compliments the existing 'fix-it-later' approach, reducing the chances of performance failure detected late during the system development process when they are most expensive to fix

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

[EN] 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 a smart device is proposed.This work has been supported by the coordinated project COBAMI: Mission-based Hierarchical Control. Education and Science Department, Spanish Government. CICYT: MICINN:DPI2011-28507-C02-01/02 and project “Real time distributed control systems” of the Support Program for Research and Development 2012 UPV (PAID-06-12)Jimenez-Garcia, J.; Baselga-Masia, D.; Munera Sánchez, E.; Poza-Lujan, J.; Posadas-Yagüe, J.; Simó-Ten, J. (2014). Smart device definition and application on embedded system: performance and optimi-zation on a RGBD sensor. ADCAIJ : Advances in Distributed Computing and Artificial Intelligence Journal. 3(8):46-55. https://doi.org/10.14201/ADCAIJ2014384655S46553

Asynchronous Message Service Reference Implementation

This software provides a library of middleware functions with a simple application programming interface, enabling implementation of distributed applications in conformance with the CCSDS AMS (Consultative Committee for Space Data Systems Asynchronous Message Service) specification. The AMS service, and its protocols, implement an architectural concept under which the modules of mission systems may be designed as if they were to operate in isolation, each one producing and consuming mission information without explicit awareness of which other modules are currently operating. Communication relationships among such modules are self-configuring; this tends to minimize complexity in the development and operations of modular data systems. A system built on this model is a society of generally autonomous, inter-operating modules that may fluctuate freely over time in response to changing mission objectives, modules functional upgrades, and recovery from individual module failure. The purpose of AMS, then, is to reduce mission cost and risk by providing standard, reusable infrastructure for the exchange of information among data system modules in a manner that is simple to use, highly automated, flexible, robust, scalable, and efficient. The implementation is designed to spawn multiple threads of AMS functionality under the control of an AMS application program. These threads enable all members of an AMS-based, distributed application to discover one another in real time, subscribe to messages on specific topics, and to publish messages on specific topics. The query/reply (client/server) communication model is also supported. Message exchange is optionally subject to encryption (to support confidentiality) and authorization. Fault tolerance measures in the discovery protocol minimize the likelihood of overall application failure due to any single operational error anywhere in the system. The multi-threaded design simplifies processing while enabling application nodes to operate at high speeds; linked lists protected by mutex semaphores and condition variables are used for efficient, inter-thread communication. Applications may use a variety of transport protocols underlying AMS itself, including TCP (Transmission Control Protocol), UDP (User Datagram Protocol), and message queues