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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.

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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

TCV software test and validation tools and technique

The paper describes techniques for testing and validating software for the TCV (Terminal Configured Vehicle) program which is intended to solve problems associated with operating a commercial transport aircraft in the terminal area. The TCV research test bed is a Boeing 737 specially configured with digital computer systems to carry out automatic navigation, guidance, flight controls, and electronic displays research. The techniques developed for time and cost reduction include automatic documentation aids, an automatic software configuration, and an all software generation and validation system.

Straeter, T. A.↗
NASA NTRS1976

STOLAND

The STOLAND system includes air data, navigation, guidance, flight director (including a throttle flight director on the Augmentor Wing), 3-axis autopilot and autothrottle functions. The 3-axis autopilot and autothrottle control through parallel electric servos on both aircraft and on the augmentor wing, the system also interfaces with three electrohydraulic series actuators which drive the roll control surfaces, elevator and rudder. The system incorporates automatic configuration control of the flaps and nozzles on the augmentor wing and of the flaps on the Twin Otter. Interfaces are also provided to control the wing flap chokes on the Augmentor Wing and the spoilers on the Twin Otter. The STOLAND system has all the capabilities of a conventional integrated avionics system. Aircraft stabilization is provided in pitch, roll and yaw including control wheel steering in pitch and roll. The basic modes include altitude hold and select, indicated airspeed hold and select, flight path angle hold and select, and heading hold and select. The system can couple to TACAN and VOR/DME navaids for conventional radial flying.

Grgurich, J.↗
NASA NTRS1977

Computer simulation incorporating a helicopter model for evaluation of aircraft avionics systems

A computer program was developed to integrate avionics research in navigation, guidance, controls, and displays with a realistic aircraft model. A user oriented program is described that allows a flexible combination of user supplied models to perform research in any avionics area. A preprocessor technique for selecting various models without significantly changing the memory storage is included. Also included are mathematical models for several avionics error models and for the CH-47 helicopter used in this program.

Ostroff, A. J.↗
NASA NTRS1977

Digital flight control design for a tandem-rotor helicopter

Methods and results in the continuing development of a digital flight control system (DFCS) for the CH-47B helicopter are examined. The helicopter is the research vehicle for the NASA VTOL Approach and Landing Technology (VALT) Program. It is equipped with comprehensive equipment for the investigation of navigation, guidance, and control requirements for future VTOL aircraft. Two control modes (attitude-command and velocity-command) are implemented, and each mode provides 'Type 1' response to guidance commands. DFCS design is based upon optimal estimation and control methods, which are found to provide flexible and efficient means for defining practical digital control systems.

Stengel, R. F.↗
NASA NTRS1978

Approach and landing simulation

Computer program integrates avionics research in navigation, guidance, controls, and displays with realistic aircraft model. Program gives researchers capability of evaluating avionics area independently from other research areas and thus allows more flexibility in time schedules. Program comprises many independent modules that represent specific hardware onboard actual aircraft.

Ostroff, A. J.↗
NASA NTRS1977

Sail GTS ground system analysis: Avionics system engineering

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design.

Lawton, R. M.↗
NASA NTRS1977

Models for interrupted monitoring of a stochastic process

As computers are added to the cockpit, the pilot's job is changing from of manually flying the aircraft, to one of supervising computers which are doing navigation, guidance and energy management calculations as well as automatically flying the aircraft. In this supervisorial role the pilot must divide his attention between monitoring the aircraft's performance and giving commands to the computer. Normative strategies are developed for tasks where the pilot must interrupt his monitoring of a stochastic process in order to attend to other duties. Results are given as to how characteristics of the stochastic process and the other tasks affect the optimal strategies.

Palmer, E.↗
NASA NTRS1978

A concept study of a remotely piloted vehicle for Mars exploration

Candidate configurations are discussed for shuttle-transported, spacecraft-deployed remotely piloted vehicles having individual aeroshells, parachutes, and scientific payloads for Mars exploration. Topics covered include aerodynamics; powerplants; structural materials; deployment and descent interface systems; payloads; secondary power; thermal control; navigation, guidance and control, communications, weight and center of gravity; performance; and flight testing. The advantages of the recommended electric-powered cruiser/lander configuration are summarized.

Source record↗
NASA NTRS1979

A Mars airplane

An airplane specifically designed for Mars flight is described, emphasizing its conceivable role as an aerial surveyor for visual imaging, gamma-ray and IR reflectance spectroscopy, studies of atmospheric composition and dynamics, and gravity-field, magnetic-field, and electromagnetic sounding. Possible imaging systems and surveying tasks are considered, along with a plausible mission scenario for a fleet of 12 airplanes, which would be taken to Mars in squadrons of four by three Shuttle/IUS Twin Stage/spacecraft carriers. A basic configuration closely resembling that of a competition glider is examined, and four types of airplane are discussed: hydrazine-powered cruisers and landers and electrically powered cruisers and landers. Attention is given to navigation, guidance, and control avionics, vehicle weight, the use of composite materials for the wing, and flight testing on earth.

Clarke, V. C.↗
NASA NTRS1979

Technology for future air transports

The requirements and opportunities for technological development in transport aircraft of the next generation are reviewed, focusing primarily on conventional, subsonic aircraft. Advances in computational aerodynamics and computer-aided design and manufacturing (in numerically controlled processes) are noted as well as improved wind tunnel testing and drag reduction techniques. Advances in aeroelasticity prediction have made it possible to use flexible, high-aspect-ratio wings without large weight penalties. Weight reduction may be achieved by the use of composite aircraft structures and superplastic forming combined with diffusion bonding, however composites require improvement in manufacturing techniques and mechanical properties in order to gain general acceptance. Propulsion systems can be improved in engine fuel efficiency, control, durability, environmental compatibility (exhaust and noise emissions), and fuel specifications. In avionics, due to the growth of low-cost, miniaturized packages, opportunities exist in the fields of digital controls, navigation, guidance and communication. Applications of new technologies to various aspects of flight safety are also outlined.

Klineberg, J. M.↗
NASA NTRS1979

Aerocapture - A system design for planetary exploration

The paper presents the results of a study that developed conceptual designs of an atmospheric entry system with moderate to high L/D ratios to establish the concepts of aerocapture into low circular Mars orbits from hyperbolic flyby trajectories. The payloads considered in this study were those currently conceived for the Mars Sample Return (MSR) mission including single mission (SM) and multi-mission (MM) modes. The design concepts developed are also applicable (with small modification) for establishment of closed orbits about Venus and Saturn. The MSR mission payload requires an orbiter, lander, ascent vehicle, and rover, with a total mass of approximately 4000 kg. The emphasis during the study was placed on development of concepts for aerodynamic configuration, the aeroshell design, and a guidance, navigation, and control subsystem.

Cruz, M. I.↗
NASA NTRS1980

Avionics and controls in review

The article surveys the changes which will occur in avionics and controls due to microprocessor technology. Attention is given to five broadly applicable technologies: (1) flight path management technology, (2) automatic control systems, (3) crew station technology, (4) integration and interfacing technology, and (5) fundamental technologies. Areas discussed include inertial navigation, guidance, weather avoidance, propulsion control systems, display technology, flight-system management, functional integration of avionics, and airborne information processing.

Smyth, R. K.↗
NASA NTRS1981

MIT Annotated Bibliography

A bibliography is presented which covers a wide variety of navigation, guidance, control, and display research. Fifteen citations are included.

Source record↗
NASA NTRS1981

The Inertial Upper Stage - A space transportation system element nearing first flight

The Inertial Upper Stage (IUS) developed by the USAF and NASA is a highly reliable, cost-effective solid propellant upper stage, with inherent flexibility and adaptability for integration with the Space Shuttle. The propulsion system is simple, utilizing safe, solid rocket motors with extremely light-weight nonmetallic cases and nozzles. The IUS can deliver 2268 kg from the Shuttle to geosynchronous altitude; it consists of a 9700 kg propellant weight first stage, an interstage structure, a 2720 kg propellant weight second stage, and an equipment support section. The avionics system includes the electronic and electrical hardware used to perform all signal conditioning, data processing, and software formatting associated with navigation, guidance, control, data management, and redundancy management. The generic thermal design of the IUS is suited to a wide range of thermal environments; the software design provides for selectable thermal maneuvers (rotisserie, reciprocating, toasting, space facing, sun facing) to satisfy different payload thermal requirements. A 1982 launch with the Titan 34D and a 1983 launch with the Shuttle Orbiter are planned.

Rohrbaugh, D. J.↗
NASA NTRS1980

Integrated application of active controls (IAAC) technology to an advanced subsonic transport project. Conventional baseline configuration study

Characteristics of the U.S. domestic fleet were evaluated to determine the mission characteristics that would have the most impact on U. S. transport fuel use in the future. This resulted in selection of a 197-passenger (plus cargo), about 3710-km (2000 nmi) mission. The existing data base was reviewed and additional analysis was conducted as necessary to complete the technical descriptions. The resulting baseline configuration utilizes a double-lobe, but nearly circular, body with seven-abreast seating. External characteristics feature an 8.71 aspect ratio, 31.5-degree sweep wing, a T-tail empennage, and a dual CF6-6D2, wing-mounted engine arrangement. It provides for 22 LD-2 or 11 LD-3 containers plus bulk cargo in the lower lobe. Passenger/cargo loading, servicing provisions, taxi/takeoff speeds, and field length characteristics are all compatible with accepted airline operations and regulatory provisions. The baseline configuration construction uses conventional aluminum structure except for advanced aluminum alloys and a limited amount of graphite epoxy secondary structure. Modern systems are used, including advanced guidance, navigation, and controls which emphasize application of digital electronics and advanced displays.

Source record↗
NASA NTRS1981

Verification of the Space Shuttle entry GN&C system

The certification procedures for the initial Shuttle flight are discussed. Particular attention is paid to the entry guidance, navigation, and control (GNC) verification, comprising tests, analysis, demonstration, inspection, and simulation. Flow diagrams for the verification and operational flight sequences are provided, along with a block diagram of the GNC circuitry interfaces. The development of the test matrix software for the GNC is outlined, noting the constant interplay between software verification and spacecraft reconfiguration to meet simulated performance requirements. Comparison of GNC performance predictions with actual entry flight data showed a good match in all performance areas except for sideslip excursions, bank overshoots, an area of transonic buffet, and an increased lift/drag ratio in the preflare to landing flight phase.

Van Hoften, J. D. A.↗