Information Technology & Software

Remote Agent as Applied to the Deep Space 1 Spacecraft

A report presents updated information about the Remote Agent — a reusable artificial-intelligence software system that was described in “A Remote Agent Prototype for Spacecraft Autonomy” (NPO-19992), NASA Tech Briefs, Vol. 21, No. 3 (March 1997), page 106. This system was conceived to enable spacecraft to operate robustly with minimal human supervision, even in the face of hardware failures or unexpected events. It also is expected to offer similar benefits for communication networks, chemical plants, and other complex systems on Earth.

Posted in: Briefs, TSP, Information Sciences, Artificial intelligence, Computer software and hardware, Spacecraft

Multirover Coordination Based on Contract Net Protocol

NASA’s Jet Propulsion Laboratory, Pasadena, California

A computer program coordinates operations of multiple cooperating rovers (small exploratory robotic vehicles deployed from a lander spacecraft), each of which is equipped with computer hardware and software that schedule the tasks assigned to it. The program implements a contract net protocol — a type of coordination protocol commonly used in distributed artificial intelligence. In a contract net protocol, a manager announces a task to a set of contractors, each contractor bids for the task, and the manager awards the task to the contractor with the best bid. In the present program, the lander (manager) incrementally transmits tasks to each rover (contractor). Upon receiving a task, a rover tries to fit the task into its current schedule. If the rover can do so, it bids the total distance it would have to travel to complete all of its tasks (including the newly inserted one). Rovers that fail to fit the task into their schedules within a time limit do not participate in the auction. Upon receiving all bids, the lander awards the task to the rover with the smallest bid.

Posted in: Briefs, Information Sciences, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Robotics

External Data and Attribute Hyperlink Programs for Promis•e®

External Data and Attribute Hyperlink are computer programs that can be added to Promis•e®, which is a commercial software system that automates routine tasks in the design (including drawing schematic diagrams) of electrical control systems. The programs were developed under the Stennis Space Center's (SSC's) Dual Use program to provide capabilities for SSC's 3 MCS configuration management system, which uses Promis•e®. The External Data program enables the storage and management of information in an external database linked to a drawing. Changes can be made either in the database or on the drawing. Information that originates outside Promis•e® can be stored in custom fields that can be added to the database. Although this information is not available in Promis•e® printed drawings, it can be associated with symbols in the drawings, and can be retrieved through the drawings when the software is running. The Attribute Hyperlink program enables the addition of hyperlink information as attributes of symbols. This program enables the formation of a direct hyperlink between a schematic diagram and an Internet site or a file on a compact disk, on the user's hard drive, or on another computer on a network to which the user's computer is connected. The user can then obtain information directly related to the part (e.g., maintenance, or troubleshooting information) associated with the hyperlink.

Posted in: Briefs, Information Sciences, CAD / CAM / CAE, CAD, CAM, and CAE, Electrical systems, Electrical systems, Human machine interface (HMI), Automation

Compressed Symbology — Making Its Mark at NASA

The bar-code concept has been generalized into a powerful method of tracking manufactured parts.

Compressed symbology is a product-identification method that was pioneered by NASA for tracking space-shuttle parts and is now being used to mark everything from groceries to automobile parts. Based on a system of two-dimensional marks applied to parts, compressed symbology was developed at NASA's Marshall Space Flight Center in response to the inherent need in the aerospace industry to track parts for configuration management.

Posted in: Briefs, Information Sciences, Identification, Parts, Reusable launch vehicles and shuttles

Automated Planning and Scheduling for a Large Interferometer

A report discusses the potential application of artificial intelligence (AI) to planning, scheduling, and control of the optical configuration and other aspects of the operations of a large astronomical interferometer. Scientific demand and technical requirements necessitate streamlining and optimization of the operation of such an interferometer, but it is difficult and often impossible to achieve the streamlining and optimization manually.

Posted in: Briefs, TSP, Information Sciences, Optimization, Artificial intelligence, Waveguides, Artificial intelligence, Waveguides, Test equipment and instrumentation

Self-Organization Based on Quantum Entanglement

A report presents a theoretical study of communication among intelligent agents in the presence of quantum entanglement and the absence of classical (in the sense of non-quantum) communication channels. Several paradigms of self-organization based on quantum entanglement are introduced and discussed. These paradigms include inverse diffusion, transmission of conditional information, decentralized coordination, cooperative computing, competitive games, and topological evolution in active systems.

Posted in: Briefs, TSP, Information Sciences, Research and development

An Improved Genetic Algorithm for Optimal Spacecraft Scheduling

A genetic algorithm and heuristic routine are combined to improve scheduling performance.

A method of computing globally optimal schedules and plans in the face of possibly temporally varying constraints involves the use of an improved genetic algorithm. The method and computer program are directed toward the eventual use to schedule tasks to be performed on spacecraft.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Computer software / hardware, Computer software and hardware, Flight management systems, Computer software / hardware, Computer software and hardware, Flight management systems, Spacecraft

Timeout Algorithm for Communications With Long Delays

Communications over long or intermittent links would be more efficient.

A query timeout detection algorithm has been proposed to support a protocol for reliable communications over links that are characterized by long delays because of (1) propagation of signals over interplanetary distances and/or (2) intermittency. The protocol could be an interplanetary analogue of Transmission Control Protocol/Internet Protocol (TCP/IP) of the terrestrial Internet. The protocol would enable the interconnection of the terrestrial Internet with the internets planned for Mars and other destinations in the Solar system. Potential beneficiaries include operators of space-exploration missions in the short term and commercial internet users in the long term.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Communication protocols, Internet, Communication protocols, Internet, Reliability, Reliability

Generating Commands for the Mars Polar Lander Robotic Arm

A report discusses the use of the Web Interface for Telescience (WITS) for visualization and command sequence generation in the Mars Polar Lander (MPL) mission. WITS, which has been described in prior articles in NASA Tech Briefs, is an Internet-based software system that enables geographically dispersed scientists and engineers to participate in sequence generation for planetary lander and rover missions. Public outreach versions of WITS enable the general public to use WITS to view mission images and plan and simulate their own missions. WITS enables scientists to view mission data and generate command sequences from their home institutions, making it unnecessary for them to travel to a mission control center to participate in the mission. The present report describes how WITS fits in the MPL mission operations architecture and how it was used for Robotic Arm and Robotic Arm Camera sequence generation.

Posted in: Briefs, TSP, Information Sciences, Architecture, Communication protocols, Electronic control systems, Architecture, Communication protocols, Electronic control systems, Robotics, Spacecraft

Advances in Parallel Computing on Adaptive Grids

Five papers address interrelated topics in parallel computing and the use of adaptive, unstructured computational grids. The titles of the papers and their general subject matters are the following:

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Data exchange, Data exchange, Technical reference, Technical review

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