Search NASA⌕ Search

SEARCH · Search NASA

Results for “control software”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23

CCD camera systems and support electronics for a White Light Coronagraph and X-ray XUV solar telescope

Two instruments, a White Light Coronagraph and an X-ray XUV telescope built into the same housing, share several electronic functions. Each instrument uses a CCD as an imaging detector, but due to different spectral requirements, each uses a different type. Hardware reduction, required by the stringent weight and volume allocations of the interplanetary mission, is made possible by the use of a microprocessor. Most instrument functions are software controlled with the end use circuits treated as peripherals to the microprocessor. The instruments are being developed for the International Solar Polar Mission.

Harrison, D. C.↗

Trace constituents in the middle atmosphere by high resolution UV spectroscopy

An array of 5 autonomous spectrometers, the imaging spectrometric observatory covers a broad wavelength range (approximately 200 to 12,000 A), has a resolution selectable down to approximately 0.5 A, and a dynamic range of approximately 10 to the 7th power and is designed to select experiment measurement sequences by software control. Because current models of thermospheric ionic processes produce too much N2(+) ionization, the N2(+) reaction with O and the chemistry of metastable (N(+) ions and of O2(+) ions are objects of study on Spacelab 1.

Torr, D. G.↗

Onboard utilization of ground control points for image correction. Volume 3: Ground control point simulation software design

The software developed to simulate the ground control point navigation system is described. The Ground Control Point Simulation Program (GCPSIM) is designed as an analysis tool to predict the performance of the navigation system. The system consists of two star trackers, a global positioning system receiver, a gyro package, and a landmark tracker.

Source record↗

GCF Mark IV development

The Mark IV ground communication facility (GCF) as it is implemented to support the network consolidation program is reviewed. Changes in the GCF are made in the area of increased capacity. Common carrier circuits are the medium for data transfer. The message multiplexing in the Mark IV era differs from the Mark III era, in that all multiplexing is done in a GCF computer under GCF software control, which is similar to the multiplexing currently done in the high speed data subsystem.

Mortensen, L. O.↗

A method for determining the flight readiness of the integrated Space Shuttle system

The Space Shuttle Dynamic Integrated Test (DIT) system is described. The DIT is an open-loop system which makes no attempt to simulate Shuttle sensors, and by which the Shuttle redundancy management system is left unmodified. Open-loop operation is shown to inherently require less computing capacity during a test than the closed-loop alternative. DIT tests have generated a high degree of confidence in the Shuttle hardware, allowing the identification of such problems as a sluggish main fuel valve, which caused a countdown hold seconds before the simulated T-zero, and Main Engine Controller software malfunctions. Attention is given to the combination and substitution of sensor data, the modification of nominal flight software, and the preparation of simulation data. It is noted that greater performance would have been achieved if the interface with DIT had been a design requirement from the outset of Space Shuttle development.

Bacon, I.↗

Role of simulation and emulation in the development of Shuttle-Centaur (STS-Centaur)

To support the task of integrating the Centaur liquid-fueled upper-stage space vehicle into the space shuttle program. A system to simulate and emulate the STS-Centaur avionic flight system and its supporting ground control and checkout equipment was selected and designated the systems integration facility (SIF). Located in San Diego, California, the SIF is composed of integrated simulators that form a composite control system complement to the STS-Centaur airborne and avionic support equipment. An off-line capability to verify the system design of the Centaur airborne support equipment (CASE) and the Centaur avionic flight system is provided as well as a realistic medium for the development and integration of ground checkout and airborne control software programs. Each simulator is composed of prototype hardware, where feasible, to maximize configuration likeness. Where emulated flight or ground hardware is used, it provides physical characteristics (loads, signals, etc.) equivalent to those of the flight hardware. The hardware and software implementation of the SIF are described.

Gordan, A. L.↗

Modified timing module for Loran-C receiver

Hardware documentation is provided for the modified LORAN-C timing module, which uses interrupt-driven software control in determining loop sample times. Computer loading is reduced by eliminating polled operation of the timing loop.

Lilley, R. W.↗

Research Furnace for Crystal Preparation

Three-zone furnace tested and characterized for preparation of lead-tintelluride (LTT) crystals. Tests show temperature in furnace controlled to obtain constant rate of movement of high-temperature isotherm down length of furnace. Temperature profiles accurately controlled by three independent heaters. Control software brings separate heaters to any desired temperature.

Crouch, R. K.↗

Certification of advanced systems

Advanced cockpit systems in helicopters are evaluated in terms of safety certification areas of concern include: (1) power supply system, failure analysis; (2) software control; (3) lightning substantiation; and (4) adequacy of certification regulations.

Swihart, J. D., Jr.↗

Space shuttle main engine hardware simulation

The Huntsville Simulation Laboratory (HSL) provides a simulation facility to test and verify the space shuttle main engine (SSME) avionics and software system using a maximum complement of flight type hardware. The HSL permits evaluations and analyses of the SSME avionics hardware, software, control system, and mathematical models. The laboratory has performed a wide spectrum of tests and verified operational procedures to ensure system component compatibility under all operating conditions. It is a test bed for integration of hardware/software/hydraulics. The HSL is and has been an invaluable tool in the design and development of the SSME.

Vick, H. G.↗

Vibration control experiment design for the 15-m hoop/column antenna

A test program is designed for a ground-based vibration control experiment utilizing as the test article the 15-M Hoop/Column Antenna. Overall objectives of the designed ground-based test program include: (1) the validation of large space structure (LSS) control systemm techniques; (2) the validation of LSS parameter identification techniques: (3) the evaluation of actuator of actuator and sensor placement methodology; and (3) the validation of LSS computer models. Critical concerns in LSS Controls and Dynamics are: low frequency vibrational modes, close modal spacing, parameter uncertainties, controller software limitations, nonlinearities and coupling of modes through damping. Analytical results are presented which include compensator designs for varying compensator order.

Ham, F. M.↗

Robot arm geometric link parameter estimation

A general method for estimating serial link manipulator geometric parameter errors is proposed in this paper. The positioning accuracy of the end-effector may be increased significantly by updating the nominal link parameters in the control software to represent the physical system more accurately. The proposed method is applicable for serial link manipulators with any combination of revolute or prismatic joints, and is not limited to a specific measurement technique.

Hayati, S. A.↗

Improving the absolute positioning accuracy of robot manipulators

The absolute positioning accuracy of robot manipulator can be increased substantially by updating the nominal link parameters in the control software. This paper presents a general method to estimate the link parameter errors for any serial link manipulator (i.e., n links, and any combination of revolute and prismatic joints). The parameters are estimated through a linear kinematic model which relates the link bias errors to the end-effector positioning error. Only end-effector measurements are required instead of individual link measurements to implement this method.

Hayati, S.↗

Modified timing module for Loran-C receiver

Hardware documentation is provided for the modified Loran-C timing module, which used interrupt-driven software control in determing loop sample times. Computer loading is reduced by eliminating polled operation of the timing loop.

Lilley, Robert W.↗

New capabilities and recent research programs of the NASA/Army CH-47B variable-stability helicopter

The CH-47B is the third in a series of variable-stability helicopters developed and operated by NASA since 1952 to investigate helicopter and VTOL handling qualities. Recently, several new capabilities were added to this helicopter to enable it to better support new and evolving research requirements. The installation of a programmable force-feel system for the evaluation pilot's conventional cyclic stick, and a four-axis side-stick controller permit a range of in-flight investigations concerning manipulator characteristics and augmentation system features that had not been possible with earlier NASA research helicopters. A recently installed color electronic display system with a programmable symbol generator will permit the investigation of display formats for a variety of VTOL and helicopter missions. Finally, a powerful new general-purpose flight computer is now in operation. It is programmable in high-level languages and will provide more efficient support of research programs. In addition to these new hardware capabilities, flight-control software has been developed to improve the in-flight simulation capability of the aircraft. A brief description of the CH-47B's variable-stability research equipment is provided, recent research programs are summarized, and some remarks concerning the potential of the helicopter are presented.

Hindson, W. S.↗

Research On The CH-47B Helicopter

Report describes equipment added to, and research capabilities of CH-47B helicopter. Programmable symbol generator provides display formats for variety of missions - those of vertical-takeoff-and-landing aircraft and helicopters. Powerful general-purpose flight computer in operation. Computer programmable in high-level languages and supports research more efficiently. Flight-control software developed to improve capability of helicopter to perform simulations in flight.

Hilbert, Kathryn B.↗

Automatic Inspection During Machining

In experimental manufacturing process, numerically-controlled machine tool temporarily converts into inspection machine by installing electronic touch probes and specially-developed numerical-control software. Software drives probes in paths to and on newly machined parts and collects data on dimensions of parts.

Ransom, Clyde L.↗