Special Coverage

Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines
Vibration Tables Shake Up Aerospace and Car Testing
Supercomputer Cooling System Uses Refrigerant to Replace Water
Computer Chips Calculate and Store in an Integrated Unit
Electron-to-Photon Communication for Quantum Computing

Algorithm-Based Fault Tolerance for Numerical Subroutines

A software library implements a new methodology of detecting faults in numerical subroutines, thus enabling application programs that contain the subroutines to recover transparently from single-event upsets. The software library in question is fault-detecting middleware that is wrapped around the numerical- subroutines. Conventional serial versions (based on LAPACK and FFTW) and a parallel version (based on ScaLAPACK) exist. The source code of the application program that contains the numerical subroutines is not modified, and the middleware is transparent to the user.

Posted in: Briefs, Software, Computer software and hardware

Computational Support for Technology- Investment Decisions

Strategic Assessment of Risk and Technology (START) is a user-friendly computer program that assists human managers in making decisions regarding research- and- development investment portfolios in the presence of uncertainties and of non- technological constraints that include budgetary and time limits, restrictions related to infrastructure, and programmatic and institutional priorities. START facilitates quantitative analysis of technologies, capabilities, missions, scenarios and programs, and thereby enables the selection and scheduling of value-optimal development efforts. START incorporates features that, variously, perform or support a unique combination of functions, most of which are not systematically performed or supported by prior decision-support software. These functions include the following:

Posted in: Briefs, TSP, Software, Computer software and hardware, Cost analysis, Financial management, Research and development

DSN Resource Scheduling

TIGRAS is client-side software, which provides tracking-station equipment planning, allocation, and scheduling services to the DSMS (Deep Space Mission System). TIGRAS provides functions for schedulers to coordinate the DSN (Deep Space Network) antenna usage time and to resolve the resource usage conflicts among tracking passes, antenna calibrations, maintenance, and system testing activities. TIGRAS provides a fully integrated multi-pane graphical user interface for all scheduling operations. This is a great improvement over the legacy VAX VMS command line user interface.

Posted in: Briefs, Software, Antennas, Computer software and hardware

Distributed Operations Planning

Maestro software provides a secure and distributed mission planning system for long-term missions in general, and the Mars Exploration Rover Mission (MER) specifically. Maestro, the successor to the Science Activity Planner, has a heavy emphasis on portability and distributed operations, and requires no data replication or expensive hardware, instead relying on a set of services functioning on JPL institutional servers.

Posted in: Briefs, Software, Computer software and hardware, Autonomous vehicles, Spacecraft

Industry Update: Analysis & Simulation Software

Multiphysics, simulation lifecycle management, unified simulation, and other terms are becoming the new trends in analysis and simulation software. There are new capabilities, new options for analysis and simulation management, and even room for growth in the market. We polled executives from leading software companies that provide analysis and simulation tools to find out what major changes have taken place in the products and how users will benefit.

Posted in: Articles, Simulation Software, Software, Computer simulation, Life cycle analysis

Designing Rolling-Element Bearings

Bearing Analysis Tool (BAT) is a computer program for designing rolling-element bearings for cryogenic turbomachines. BAT provides a graphical user interface (GUI) that guides the entry of data to develop mathematical models of bearings. The GUI breaks model data into logical subsets that are entered through logic-driven input screens. The software generates a three- dimensional graphical model of a bearing as the data are entered. Most data-entry errors become immediately obvious in the graphical model. BAT provides for storage of all the data on a shaft/bearing system, enabling the creation of a library of proven designs. Data from the library can be transferred to subsequent projects by use of simple cut-and-paste routines.

Posted in: Briefs, TSP, Software, CAD, CAM, and CAE, Computer software and hardware, Bearings

Interface for Physics Simulation Engines

DSS-Prototyper is an open-source, real-time 3D virtual environment software that supports design simulation for the new Vision for Space Exploration (VSE). This is a simulation of NASA’s proposed Robotic Lunar Exploration Program, second mission (RLEP2). It simulates the Lunar Surface Access Module (LSAM), which is designed to carry up to four astronauts to the lunar surface for durations of a week or longer. This simulation (see figure) shows the virtual vehicle making approaches and landings on a variety of lunar terrains. The physics of the descent engine thrust vector, production of dust, and the dynamics of the suspension are all modeled in this set of simulations.

Posted in: Briefs, Software, Computer simulation, Virtual reality, Robotics, Entry, descent, and landing, Spacecraft

Assessing the Friction Stir Welding Process With Mathematical Modeling

A multiphysics model allows engineers to determine a weld’s thermal properties and strength.

Patented in 1991, friction stir welding (FSW) has since been used widely to create strong joints in aluminum alloys. The aircraft industry has started to adapt this technology, and now the largest manufacturers, including Airbus, are studying how to cut manufacturing costs with it. First, though, they want mathematical modeling to help them fully understand the process before making massive investments in retooling their manufacturing lines.

Posted in: Briefs, Software, Mathematical models, Welding

Solving Fluid-Structure-Acoustic Interactions With Multiphysics Modeling

Solutions to complex two-way coupled fluid-structure interactions are difficult to solve.

Computational analysis of fluid-structure interactions (FSI) represents a considerable challenge for most computational analysis codes. Simple one-way coupled problems, in which the fluid pressure deforms a structure but does not substantially affect the fluid flow characteristics, can be solved by a variety of techniques. Solutions to the more complex two-way coupled fluid-structure interactions are more elusive. These occur when pressure of the flow of fluid deforms a structure in such a way that the resulting deformation alters the flow of fluid. The two-way coupled approach solves this problem and produces accurate, time-dependent results.

Posted in: Briefs, Software, Computational fluid dynamics, Acoustics

Solving Equations of Multibody Dynamics

Darts++ is a computer program for solving the equations of motion of a multibody system or of a multibody model of a dynamic system. It is intended especially for use in dynamical simulations performed in designing and analyzing, and developing software for the control of, complex mechanical systems. Darts++ is based on the Spatial- Operator- Algebra formulation for multibody dynamics. This software reads a description of a multibody system from a model data file, then constructs and implements an efficient algorithm that solves the dynamical equations of the system. The efficiency and, hence, the computational speed is sufficient to make Darts++ suitable for use in real-time closed-loop simulations. Darts++ features an objectoriented software architecture that enables reconfiguration of system topology at run time; in contrast, in related prior software, system topology is fixed during initialization. Darts++ provides an interface to scripting languages, including Tcl and Python, that enable the user to configure and interact with simulation objects at run time.

Posted in: Briefs, Software, Computer simulation, Computer software and hardware

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