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At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Model Checking Verification and Validation at JPL and the NASA Fairmont IV and V Facility

We show how a technology transfer effort was carried out. The successful use of model checking on a pilot JPL flight project demonstrates the usefulness and the efficacy of the approach. The pilot project was used to model a complex spacecraft controller. Software design and implementation validation were carried out successfully. To suggest future applications we also show how the implementation validation step can be automated. The effort was followed by the formal introduction of the modeling technique as a part of the JPL Quality Assurance process.

Schneider, Frank↗
NASA NTRS2002

Verification and Validation of Neural Networks for Aerospace Systems

The Dryden Flight Research Center V&V working group and NASA Ames Research Center Automated Software Engineering (ASE) group collaborated to prepare this report. The purpose is to describe V&V processes and methods for certification of neural networks for aerospace applications, particularly adaptive flight control systems like Intelligent Flight Control Systems (IFCS) that use neural networks. This report is divided into the following two sections: Overview of Adaptive Systems and V&V Processes/Methods.

Mackall, Dale↗
NASA NTRS2002

Verification and Validation of Neural Networks for Aerospace Systems

The Dryden Flight Research Center V&V working group and NASA Ames Research Center Automated Software Engineering (ASE) group collaborated to prepare this report. The purpose is to describe V&V processes and methods for certification of neural networks for aerospace applications, particularly adaptive flight control systems like Intelligent Flight Control Systems (IFCS) that use neural networks. This report is divided into the following two sections: 1) Overview of Adaptive Systems; and 2) V&V Processes/Methods.

Mackall, Dale↗
NASA NTRS2005

Verification and Validation of the RAGE Hydrocode in Preparation for Investigation of Impacts into a Volatile-rich Target

Before a hydrocode is used to investigate a question of scientific interest, it should be tested against analogous laboratory experiments and problems with analytical solutions. The Radiation Adaptive Grid Eulerian (RAGE) hydrocode[1], developed by Los Alamos National Laboratory (LANL) and Science Applications International Corporation (SAIC)[2,3] has been subjected to many tests during its development.[4,5] We extend and review this work, emphasizing tests relevant to impact cratering into volatile-rich targets.

Plesko, C. S.↗
NASA NTRS2005

Challenges in verification and validation of autonomous systems for space exploration

Space exploration applications offer a unique opportunity for the development and deployment of autonomous systems, due to limited communications, large distances, and great expense of direct operation. At the same time, the risk and cost of space missions leads to reluctance to taking on new, complex and difficult-to-understand technology. A key issue in addressing these concerns is the validation of autonomous systems. In recent years, higher-level autonomous systems have been applied in space applications. In this presentation, we will highlight those autonomous systems, and discuss issues in validating these systems. We will then look to future demands on validating autonomous systems for space, identify promising technologies and open issues.

Brat, Guillaume↗
NASA NTRS2006

Validation and Verification of Composite Pressure Vessel Design

Ten composite pressure vessels were instrumented with fiber Bragg grating sensors and pressure tested Through burst. This paper and presentation will discuss the testing methodology, the test results, compare the testing results to the analytical model, and also compare the fiber Bragg grating sensor data with data obtained against that obtained from foil strain gages.

Kreger, Stephen T.↗
NASA NTRS2000

Independent Verification and Validation (IV and V) Criteria

The purpose of this appendix is to establish quantifiable criteria for determining whether IV&V should be applied to a given software development. Since IV&V should begin in the Formulation Subprocess of a project, the process here described is based on metrics which are available before project approval.

McGill, Kenneth↗
NASA NTRS2009

Antenna reconfiguration verification and validation

A method of testing the electrical functionality of an optically controlled switch in a reconfigurable antenna is provided. The method includes configuring one or more conductive paths between one or more feed points and one or more test point with switches in the reconfigurable antenna. Applying one or more test signals to the one or more feed points. Monitoring the one or more test points in response to the one or more test signals and determining the functionality of the switch based upon the monitoring of the one or more test points.

Becker, Robert C.↗
NASA NTRS2011

Verification and Validation of Requirements on the CEV Parachute Assembly System Using Design of Experiments

The Crew Exploration Vehicle Parachute Assembly System (CPAS) project conducts computer simulations to verify that flight performance requirements on parachute loads and terminal rate of descent are met. Design of Experiments (DoE) provides a systematic method for variation of simulation input parameters. When implemented and interpreted correctly, a DoE study of parachute simulation tools indicates values and combinations of parameters that may cause requirement limits to be violated. This paper describes one implementation of DoE that is currently being developed by CPAS, explains how DoE results can be interpreted, and presents the results of several preliminary studies. The potential uses of DoE to validate parachute simulation models and verify requirements are also explored.

Schulte, Peter Z.↗
NASA NTRS2011

Ares I-X Range Safety Trajectory Analyses Overview and Independent Validation and Verification

All Flight Analysis data products were successfully generated and delivered to the 45SW in time to support the launch. The IV&V effort allowed data generators to work through issues early. Data consistency proved through the IV&V process provided confidence that the delivered data was of high quality. Flight plan approval was granted for the launch. The test flight was successful and had no safety related issues. The flight occurred within the predicted flight envelopes. Post flight reconstruction results verified the simulations accurately predicted the FTV trajectory.

Tarpley, Ashley F.↗
NASA NTRS2011

Validation and Verification of Operational Land Analysis Activities at the Air Force Weather Agency

The NASA developed Land Information System (LIS) is the Air Force Weather Agency's (AFWA) operational Land Data Assimilation System (LDAS) combining real time precipitation observations and analyses, global forecast model data, vegetation, terrain, and soil parameters with the community Noah land surface model, along with other hydrology module options, to generate profile analyses of global soil moisture, soil temperature, and other important land surface characteristics. (1) A range of satellite data products and surface observations used to generate the land analysis products (2) Global, 1/4 deg spatial resolution (3) Model analysis generated at 3 hours

Shaw, Michael↗
NASA NTRS2012

Comprehensive Approach to Verification and Validation of CFD Simulations Applied to Backward Facing Step-Application of CFD Uncertainty Analysis

There are inherent uncertainties and errors associated with using Computational Fluid Dynamics (CFD) to predict the flow field and there is no standard method for evaluating uncertainty in the CFD community. This paper describes an approach to -validate the . uncertainty in using CFD. The method will use the state of the art uncertainty analysis applying different turbulence niodels and draw conclusions on which models provide the least uncertainty and which models most accurately predict the flow of a backward facing step.

Groves, Curtis E.↗
NASA NTRS2013

Validation and Verification of LADEE Models and Software

The Lunar Atmosphere Dust Environment Explorer (LADEE) mission will orbit the moon in order to measure the density, composition and time variability of the lunar dust environment. The ground-side and onboard flight software for the mission is being developed using a Model-Based Software methodology. In this technique, models of the spacecraft and flight software are developed in a graphical dynamics modeling package. Flight Software requirements are prototyped and refined using the simulated models. After the model is shown to work as desired in this simulation framework, C-code software is automatically generated from the models. The generated software is then tested in real time Processor-in-the-Loop and Hardware-in-the-Loop test beds. Travelling Road Show test beds were used for early integration tests with payloads and other subsystems. Traditional techniques for verifying computational sciences models are used to characterize the spacecraft simulation. A lightweight set of formal methods analysis, static analysis, formal inspection and code coverage analyses are utilized to further reduce defects in the onboard flight software artifacts. These techniques are applied early and often in the development process, iteratively increasing the capabilities of the software and the fidelity of the vehicle models and test beds.

Gundy-Burlet, Karen↗
NASA NTRS2015

Independent Verification and Validation Program

Presentation to be given to European Space Agency counterparts to give an overview of NASA's IVV Program and the layout and structure of the Software Testing and Research laboratory maintained at IVV. Seeking STI-ITAR review due to the international audience. Most of the information has been presented to public audiences in the past, with some variations on data, or is in the public domain.

Research↗