Keyword: Optimization

Application Briefs: Imaging

Today’s robots easily execute “pick-and-place” tasks: finding an object in one specified location and bringing it to another. But what if there are obstacles in a robot’s way? And what...

Briefs: Software
Optimal Prioritized Actuator Allocation

For formation flying, rendezvous and docking, and proximity operations with small bodies of the solar system, spacecraft require simultaneous translational and rotational agility. The necessary agility is generally provided by combinations of multiple small thrusters and torque-only actuators. To use these...

Briefs: Information Technology
BALFIT Version 3.1 Multivariate Regression Analysis and Regression Model Optimization Software

The software package BALFIT was developed for both the processing of wind tunnel strain-gage balance data and the analysis of more general multivariate experimental data sets. The software uses automatically generated regression models for the...

Briefs: Information Technology
Mariana Text Classification System

Support Vector Machines (SVM) can be used as a binary classifier for a wide range of data and problems. For text, it is often used to determine automatically if a document belongs to a given topic category. Automatic and reliable classification of documents can be an invaluable tool for industries that monitor...

Briefs: Photonics/Optics
One-Micron (1064-nm) Planar External Cavity Laser (PLANEX)

A highly reliable, very low-phase and low-amplitude-noise laser is required as an oscillator for the LISA mission. A commercial product made by Redfern Integrated Optics met these requirements (1550 nm PLANEX External Cavity Laser), but it operated at 1.5 microns, not the required LISA...

Briefs: Imaging

High-performance thermal imagers like Mars Climate Sounder (MCS) on the Mars Reconnaissance Orbiter (MRO) and the Diviner Lunar Radiometer Experiment on the Lunar...

Briefs: Sensors/Data Acquisition
Flight Test Maneuvers for Efficient Aerodynamic Modeling

Flight testing is expensive. It is therefore important that necessary flight data be collected in the most efficient manner possible. Inputs traditionally used for flight test maneuvers to collect aircraft stability and control data include doublets, impulses (stick raps), multisteps, and...

Briefs: Mechanical & Fluid Systems
Constraint Force Equation (CFE) Solver for Multi-Body Dynamics and its Implementation in POST2

Existing aerospace flight trajectory programs simulate the motion of aerospace vehicles by modeling external forces and moments acting on each body, but lack provisions for determining reaction forces and moments exerted by one body on another through...

Briefs: Information Technology
Mixed-Integer Convex Programming Algorithm for Constrained Attitude Guidance

A general problem in spaceflight since its beginning is attitude guidance: how to turn a spacecraft — also called a slew — so as to point science instruments at their targets. The slew must be done while avoiding pointing sensitive science instruments (e.g., a...

Briefs: Electronics & Computers
Miller-Jogging for Synthesizer Lock Algorithm Extension

The University of California Los Angeles (UCLA) has developed a wide range of CMOS (complementary metal–oxide–semiconductor) phase lock loop (PLL) chips with self-healing/self-calibration capabilities, allowing them to adapt, on the fly, to changes in temperature and other environment...

Briefs: Electronics & Computers
Method for Automatic Optimization of Yaw Maneuvers for Orbiting Space Vehicles

A new method for optimizing yaw attitude maneuvers on the International Space Station (ISS) was developed. Docking and undocking operations often require 180° yaw rotations, which are the most common large maneuvers on the ISS. When optimized, some large maneuvers,...

Briefs: Software
Architecture Framework for Fault Management Assessment and Design

Modern spacecraft, aircraft, and surface vehicles support complex science missions in harsh environments. These spacecraft and vehicles provide diverse functionality that is deployed on increasingly complex and heterogeneous hardware and mechanical systems, with stringent...

Articles: Software
SVANTE LITTMARCK
President and CEO
COMSOL, Inc.
Burlington, MA
www.comsol.com

With the birth some 50 years ago of computers based on integrated circuits and semiconductors, engineers...

Briefs: Aerospace
Station/Orbiter Multibody Berthing/Docking Analysis Tool (SOMBAT)

The main objective of this work was to develop a high-fidelity, nonlinear simulation of complex flexible structures with active control systems. A multibody system can consist of several flexible articulating components. The system can also have multiple control systems. The main...

Briefs: Manufacturing & Prototyping
Uniformly Etched Lateral Gratings Applied to Pre-existing Ridge Waveguides

There is great difficulty in implementing lateral gratings in GaSb-based lasers. Commercially, single-frequency GaSb lasers have been fabricated using metal gratings deposited laterally to the ridge-waveguide (RWG) stripe. The disadvantage of this is that the laser...

Briefs: Information Technology
NASA App

The NASA App showcases a huge collection of the latest NASA content in a mobile optimized format, including images, videos on-demand, NASA Television, mission information, news and feature stories, tweets, ISS sighting opportunities, satellite tracking, Third Rock Radio, featured educational content, and much more for iOS and Android...

Briefs: Imaging
Modified-Wolter-Schwarzschild X-ray Telescope

X-ray survey missions require nested grazing incidence telescopes with a large field of view (1° or larger) and moderately high resolution across the field of view. This cannot be accomplished using flat focal plane detectors. The telescopes have excellent on-axis resolution, but unacceptable...

Briefs: Materials
Aerogel-Filled Foam Core Insulation for Cryogenic Propellant Storage

Current cryogenic insulation materials suffer from various drawbacks including high cost and weight, lack of structural or load-bearing capability, fabrication complexity, and property anisotropy. A need clearly exists for lightweight thermal insulation that is isotropic and...

Briefs: Sensors/Data Acquisition

An algorithm for analyzing wave reflections and time-of-flight ultrasonic pulse-echo data has been developed for monitoring the health of steam...

Briefs: Information Technology
Obstacle Avoidance Methods

Obstacle avoidance is a difficult problem due to the non-convex state constraints. Therefore, the feasible state space needs to be convexified, or split, into convex regions at which point the search for an optimal solution among those convex regions is done. Methods for obstacle avoidance include two mixed integer...

Briefs: Green Design & Manufacturing

The SWOT Science Simulator simulates projected SWOT altimetry observations that can be applied to an ocean general circulation model, allowing the exploration of ideas and methods to...

Briefs: Photonics/Optics

Every lens has an absolute upper performance limit dictated by the laws of physics. This limitation is controlled by the working f/# of the lens and the wavelength( s) of light that pass through the...

Briefs: Information Technology
Precision Navigation Strategies for Primitive Solar-System-Body Sample Return Missions

This project investigated advanced navigation strategies required to approach, perform proximity operations, and return a sample from an asteroid or comet. An optimized navigation strategy for a notional mission to a near-Earth asteroid was developed to serve...

Briefs: Aerospace
Direct Multiple Shooting Optimization with Variable Problem Parameters

Solving complex trajectory problems optimally is of vital importance to the success of future aerospace programs. Trajectory optimization research has been divided into two main categories: indirect methods and direct methods. Both methodologies have been tested and...

Briefs: Aerospace
Constructing Composite Response Surfaces for Aircraft

The design of aerodynamic components of aircraft, such as wings or engines, involves a process of obtaining the optimal component shape that can deliver the desired level of component performance, subject to various constraints, e.g., total weight or cost. Aerodynamic design can be formulated...

Briefs: Test & Measurement
Improved Detection of Kidney Stones Using S-mode Ultrasound

Ultrasound has been a useful tool in the detection of kidney stones. It is a low-cost solution that does not require ionizing radiation that would be harmful to vulnerable populations such as children and recurrent stone formers. However, it suffers from a broad range of sensitivity (78...

Briefs: Test & Measurement
Estimation of Algae Growth Stage, Growth Rate, and Lipid Content

This invention provides a method using light of different wavelengths to estimate freshwater and marine algae growth stage and algae growth rates as well as lipid content in standard media. Light absorption by the algae is measured for a specified light intensity in each of two or...

Briefs: Robotics, Automation & Control
Autonomous Guidance Algorithm to Auto-Pilot Spacecraft in the Vicinity of Primitive Celestial Bodies

The dynamics in the vicinity of small bodies are highly nonlinear. Trajectory design in small-body environments requires accurate gravity and solar radiation pressure models to guarantee the satisfaction of spacecraft operational constraints such...

Briefs: Robotics, Automation & Control
Human Grasp Assist

Repetitive manual operations can degrade the work efficiency of a human operator over time, with the cumulative stresses of repetitive motion potentially affecting the resultant product quality and/or process efficiency. Accordingly, a lightweight, motorized device has been created that a user/operator may wear on a hand and...