1,461 research outputs found
Comparison of communication architectures for a fiber-positioning spectrograph
Copyright 2009 Society of PhotoâOptical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.The communication architecture required to provide a bidirectional communication between a central
command node and a full set of fiber positioners feeding a spectrograph is studied. Six different architectures have
been analyzed in terms of communication time and power consumption. These architectures are the result of the
combination of three different communication protocols: transmission control protocol/internet protocol (TCP/IP)
over ethernet, interintegrated circuit (I2C), and controller area network. The design of communication architecture
must prioritize between communication time and power consumption. The fastest architecture is the hybrid TCP/IP
over ethernet-I2C. This architecture requires the least time to provide a full set of coordinates to every fiber
positioner less than 50 ms. The most power efficient solution is the I2CâI2C with demultiplexers. This architecture
solves a bidirectional communication between a central node and a full set of fiber positioners requiring only an
addition of 27 mW.This work was funded by the Spanish MINECO, under Grant
No. AYA2014-60641-C2 coordinated project of the EPS-UAM
and IAA-CSIC research groups. The authors declare no conflicts
of interests
The NASA/OAST telerobot testbed architecture
Through a phased development such as a laboratory-based research testbed, the NASA/OAST Telerobot Testbed provides an environment for system test and demonstration of the technology which will usefully complement, significantly enhance, or even replace manned space activities. By integrating advanced sensing, robotic manipulation and intelligent control under human-interactive supervision, the Testbed will ultimately demonstrate execution of a variety of generic tasks suggestive of space assembly, maintenance, repair, and telescience. The Testbed system features a hierarchical layered control structure compatible with the incorporation of evolving technologies as they become available. The Testbed system is physically implemented in a computing architecture which allows for ease of integration of these technologies while preserving the flexibility for test of a variety of man-machine modes. The development currently in progress on the functional and implementation architectures of the NASA/OAST Testbed and capabilities planned for the coming years are presented
Improving the Performance of Wireless LANs
This book quantifies the key factors of WLAN performance and describes methods for improvement. It provides theoretical background and empirical results for the optimum planning and deployment of indoor WLAN systems, explaining the fundamentals while supplying guidelines for design, modeling, and performance evaluation. It discusses environmental effects on WLAN systems, protocol redesign for routing and MAC, and traffic distribution; examines emerging and future network technologies; and includes radio propagation and site measurements, simulations for various network design scenarios, numerous illustrations, practical examples, and learning aids
A METHODOLOGY FOR AUTONOMOUS ROOF BOLT INSTALLATION USING INDUSTRIAL ROBOTICS
The mining sector is currently in the stage of adopting more automation, and with it, robotics. Autonomous bolting in underground environments remains a hot topic for the mining industry. Roof bolter operators are exposed to hazardous conditions due to their proximity to the unsupported roof, loose bolts, and heavy spinning mass. Prolonged exposure to the risk inevitably leads to accidents and injuries.
The current thesis presents the development of a robotic assembly capable of carrying out the entire sequence of roof bolting operations in full and partial autonomous sensor-driven rock bolting operations to achieve a high-impact health and safety intervention for equipment operators. The automation of a complete cycle of drill steel positioning, drilling, bolt orientation and placement, resin placement, and bolt securing is discussed using an anthropomorphic robotic arm.A human-computer interface is developed to enable the interaction of the operators with the machines. Collision detection techniques will have to be implemented to minimize the impact after an unexpected collision has occurred. A robust failure-detection protocol is developed to check the vital parameters of robot operations continuously. This unique approach to automation of small materials handling is described with lessons learned.
A user-centered GUI has been developed that allows for a human user to control and monitor the autonomous roof bolter. Preliminary tests have been conducted in a mock mine to evaluate the developed system\u27s performance. In addition, a number of different scenarios simulating typical missions that a roof bolter needs to undertake in an underground coal mine were tested
Advanced manned space flight simulation and training: An investigation of simulation host computer system concepts
The findings of a preliminary investigation by Southwest Research Institute (SwRI) in simulation host computer concepts is presented. It is designed to aid NASA in evaluating simulation technologies for use in spaceflight training. The focus of the investigation is on the next generation of space simulation systems that will be utilized in training personnel for Space Station Freedom operations. SwRI concludes that NASA should pursue a distributed simulation host computer system architecture for the Space Station Training Facility (SSTF) rather than a centralized mainframe based arrangement. A distributed system offers many advantages and is seen by SwRI as the only architecture that will allow NASA to achieve established functional goals and operational objectives over the life of the Space Station Freedom program. Several distributed, parallel computing systems are available today that offer real-time capabilities for time critical, man-in-the-loop simulation. These systems are flexible in terms of connectivity and configurability, and are easily scaled to meet increasing demands for more computing power
Rapid Flight Control Prototyping - Steps Toward Cooperative Mission-Oriented Capabilities
The paper describes the latest advancements in
the development of the Rapid Flight Control Prototyping system
that were motivated primarily by the need to enable cooperative
missions of multiple unmanned aerial vehicles and to enhance
the capabilities of human operators to design and oversee the
collaborative behaviors of multiple heterogeneous UAVs. The
evolution of the system is driven by the mission level objectives
and supported on one hand by the progress in miniature
sensors, computational power, communication and portable
energy technologies and on the other hand by the advanced
capabilities of embedded control and communication-oriented
software. As a result the developed system enables rapid design,
onboard integration and in-flight verification of multiple UAV
collaborative concepts that seemed impossible just a couple of
years ago. Advantages of the designed system are illustrated by
a couple of scenarios that were recently developed and verified
in flight by multiple cooperating UAVs. The paper concentrates
on presenting the motivation and the conceptual design ideas
which drive the evolution of the flight prototyping platform.Evolution of RFCPS system has been funded in part by the National Air and Space Administration under Contracts NNX08BA64A, NNX08BA65A, NNX08AB97A, NNX08AC81A, and NNL08AA12I; ARO under Contract No.W911NF-06-1-0330, the USSOCOM/NPS Field Experimentation Cooperative, the Office of Naval Research under Contract N00014-05-1-0828
Development of a completely decentralized control system for modular continuous conveyors
To increase the flexibility of application of continuous conveyor systems, a completely decentralized control system for a modular conveyor system is introduced in the paper. This system is able to carry conveyor units without any centralized infrastructure. Based on existing methods of decentralized data transfer in IT networks, single modules operate autonomously and, after being positioned into the required topology, independently connect together to become a functioning conveyor system
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