Real-Time ROS Extension on Transparent CPU/GPU Coordination Mechanism

Author(s):  
Yuhei Suzuki ◽  
Takuya Azumi ◽  
Shinpei Kato ◽  
Nobuhiko Nishio
Author(s):  
Gen’ichi Yasuda

This chapter deals with modeling, simulation, and implementation problems encountered in robotic manufacturing control systems. Extended Petri nets are adopted as a prototyping tool for expressing real-time control of robotic systems and a systematic method based on hierarchical Petri nets is described for their direct implementation. A coordination mechanism is introduced to coordinate the event activities of the distributed machine controllers through friability tests of shared global transitions. The proposed prototyping method allows a direct coding of the inter-task cooperation by robots and intelligent machines from the conceptual Petri net specification, so that it increases the traceability and the understanding of the control flow of a parallel application specified by a net model. This approach can be integrated with off-the-shelf real-time executives. Control software using multithreaded programming is demonstrated to show the effectiveness of the proposed method.


2020 ◽  
Vol 26 (4) ◽  
pp. 2383-2406 ◽  
Author(s):  
Jyoti R Munavalli ◽  
Shyam Vasudeva Rao ◽  
Aravind Srinivasan ◽  
GG van Merode

Scheduling of resources and patients are crucial in outpatient clinics, particularly when the patient demand is high and patient arrivals are random. Generally, outpatient clinic systems are push systems where scheduling is based on average demand prediction and is considered for long term (monthly or bimonthly). Often, planning and actual scenario vary due to uncertainty and variability in demand and this mismatch results in prolonged waiting times and under-utilization of resources. In this article, we model an outpatient clinics as a multi-agent system and propose an intelligent real-time scheduler that schedules patients and resources based on the actual status of departments. Two algorithms are implemented: one for resource scheduling that is based on predictive demand and the other is patient scheduling which performs path optimization depending on the actual status of departments. In order to match resources with stochastic demand, a coordination mechanism is developed that reschedules the resources in the outpatient clinics in real time through auction-bidding procedures. First, a simulation study of intelligent real-time scheduler is carried out followed by implementation of the same in an outpatient clinic of Aravind Eye Hospital, Madurai, India. This hospital has huge patient demand and the patient arrivals are random. The results show that the intelligent real-time scheduler improved the performance measures like waiting time, cycle time, and utilization significantly compared to scheduling of resources and patients in isolation. By scheduling resources and patients, based on system status and demand, the outpatient clinic system becomes a pull system. This scheduler transforms outpatient clinics from open loop system to closed-loop system.


2012 ◽  
pp. 577-593
Author(s):  
Gen’ichi Yasuda

This chapter deals with modeling, simulation, and implementation problems encountered in robotic manufacturing control systems. Extended Petri nets are adopted as a prototyping tool for expressing real-time control of robotic systems and a systematic method based on hierarchical Petri nets is described for their direct implementation. A coordination mechanism is introduced to coordinate the event activities of the distributed machine controllers through friability tests of shared global transitions. The proposed prototyping method allows a direct coding of the inter-task cooperation by robots and intelligent machines from the conceptual Petri net specification, so that it increases the traceability and the understanding of the control flow of a parallel application specified by a net model. This approach can be integrated with off-the-shelf real-time executives. Control software using multithreaded programming is demonstrated to show the effectiveness of the proposed method.


2013 ◽  
Vol 13 (5) ◽  
pp. 683-691 ◽  
Author(s):  
Steven K.C. Lo ◽  
Huan-Chao Keh ◽  
Chia-Ming Chang

Author(s):  
Bo Chen ◽  
Harry H. Cheng ◽  
Joe Palen

This paper studies the generic architecture and coordination mechanism of an FIPA (Foundation for Intelligent Physical Agents) compliant heterogeneous multi-agent system (MAS) in a distributed control scenario. Proposed generic MAS framework has been applied to a real-time traffic detection and management system. The agent-based real-time traffic detection and management system (ABRTTDMS) is designed for the information fusion of different traffic detection systems on highways to optimize real-time traffic detection and management. ABRTTDMS is a multi-level agent system. The lowest level agents are responsible for processing the real-time traffic data and monitoring traffic conditions. The middle level agents coordinate all of the lowest level agents in a subnetwork. The highest-level agent is located in the transportation management center (TMC) to accept human commands and delegate tasks to lower level agents. The re-configurable hybrid control architecture of the system provides the capability of dynamically grouping distributed heterogeneous agents (intelligent control systems) into virtual clusters to accomplish tasks related to different geographical areas and different purposes. A platform independent agent execution engine has been implemented using an embeddable C/C++ interpreter called Ch. The communication between agents that reside on different hosts has been simulated in the Integration Engineering Laboratory at the University of California, Davis. The use of agent technology greatly enhances the distributed computing and cooperation capabilities of traffic detection and management systems.


2017 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Anderson R. Tavares ◽  
Gianlucca Lodron Zuin ◽  
Héctor Azpúrua ◽  
Luiz Chaimowicz

Real time strategy games are complex scenarios where multiple agents must be coordinated in a dynamic, partially observable environment. In this work, we model coordination as a task allocation problem, in which specific tasks must be properly assigned to agents. We employ a task allocation algorithm based on swarm intelligence and adjust its parameters using a genetic algorithm. A fitness estimation method is employed to accelerate execution of the genetic algorithm. To evaluate this approach, we implement this coordination mechanism in the AI of a popular video game: StarCraft: BroodWar. Experiment results show that the genetic algorithm successfully adjusts task allocation parameters. Besides, we assess the trade-off between solution quality and execution time of the genetic algorithm with fitness estimation.


1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.


Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.


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