Optimal control in second-order relay-pulse systems
Automatic control of two-dimensional motion of material point described by two finite difference equations
DIFFERENCE EQUATION↗
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Automated weld torch guidance control system
A device for automatically controlling the movement of a welding torch while welding an elongated joint is described. A charge injection television camera is carried on a movable support. The camera includes a matrix of individual light sensing video elements which generate voltages responsive to light reflected off of the joint and surrounding areas of the work piece. The voltages produced by the pixels are converted to digital words which are fed to a microprocessor for generating an error signal. This error signal is fed to a digital motor which is used to drive a movable support upon which the television camera is carried.
Smith, H. E.↗
Study of control system effectiveness in alleviating vortex wake upsets.
The problem of an airplane being upset by encountering the vortex wake of a large transport on takeoff or landing is currently receiving considerable attention. This paper describes the technique and results of a study to assess the effectiveness of automatic control systems in alleviating vortex wake upsets. A six-degree-of-freedom nonlinear digital simulation was used for this purpose. The analysis included establishing the disturbance input due to penetrating a vortex wake from an arbitrary position and angle. Simulations were computed for both a general aviation airplane and a commercial jet transport. Dynamic responses were obtained for the penetrating aircraft with no augmentation and with various command augmentation systems. The results of this preliminary study indicate that it is feasible to use an automatic control system to alleviate vortex encounter upsets.
Johnson, W. A.↗
Control of large cryogenic tunnels
For the efficient and economic operation of large cryogenic wind tunnels, automatic control is necessary to precisely regulate the temperature, pressure, and Mach number. The features of the control system currently in operation at the U.S. National Transonic Facility are presented. Some unique features of the tunnel temperature control law are the automatic tunnel cool down utilizing structural temperature feedback and the fan power based liquid nitrogen nozzle switching logic that have played a key role in realizing good automatic tunnel control.
Balakrishna, S.↗
Development and evaluation of automatic landing control laws for power lift STOL aircraft
A series of investigations were conducted to generate and verify through ground bases simulation and flight research a data base to aid in the design and certification of advanced propulsive lift short takeoff and landing aircraft. Problems impacting the design of powered lift short haul aircraft that are to be landed automatically on STOL runways in adverse weather were examined. An understanding of the problems was gained by a limited coverage of important elements that are normally included in the certification process of a CAT 3 automatic landing system.
Feinreich, B.↗
Automatic charge control system for satellites
The SCATHA and the ATS-5 and 6 spacecraft provided insights to the problem of spacecraft charging at geosychronous altitudes. Reduction of the levels of both absolute and differential charging was indicated, by the emission of low energy neutral plasma. It is appropriate to complete the transition from experimental results to the development of a system that will sense the state-of-charge of a spacecraft, and, when a predetermined threshold is reached, will respond automatically to reduce it. A development program was initiated utilizing sensors comparable to the proton electrostatic analyzer, the surface potential monitor, and the transient pulse monitor that flew in SCATHA, and combine these outputs through a microprocessor controller to operate a rapid-start, low energy plasma source.
Shuman, B. M.↗
Image Control In Automatic Welding Vision System
Orientation and brightness varied to suit welding conditions. Commands from vision-system computer drive servomotors on iris and Dove prism, providing proper light level and image orientation. Optical-fiber bundle carries view of weld area as viewed along axis of welding electrode. Image processing described in companion article, "Processing Welding Images for Robot Control" (MFS-26036).
Richardson, Richard W.↗
An analytical study of the response of a constant-attitude aircraft to atmospheric turbulence
A light airplane equipped with an automatic control system which drives large wing flaps and the stabilator so as to produce a constant pitch attitude in all flight modes was analyzed for its response to a specific gust. The aircraft was also equipped with a bank-angle steering, zero sideslip automatic control system which was studied for its effectiveness in suppressing a specific lateral gust. The gusts were assumed to be comprised of 200 lateral and 400 vertical sinusoids. Each was used to excite the controlled aircraft and the time response to the sum of all sinusoids was plotted. The assumption was that the gust may be treated as stationary in space but variable in time rather than the reverse. Results indicate that such a control system can suppress vertical gusts up to the limit of control authority. Either the lateral accelerations or the yawing velocity response to lateral gusts can be suppressed with this system but not both simultaneously.
Smetana, F. O.↗
Design description of the Schuchuli Village photovoltaic power system
A stand alone photovoltaic (PV) power system for the village of Schuchuli (Gunsight), Arizona, on the Papago Indian Reservation is a limited energy, all 120 V (d.c.) system to which loads cannot be arbitrarily added and consists of a 3.5 kW (peak) PV array, 2380 ampere-hours of battery storage, an electrical equipment building, a 120 V (d.c.) electrical distribution network, and equipment and automatic controls to provide control power for pumping water into an existing water system; operating 15 refrigerators, a clothes washing machine, a sewing machine, and lights for each of the homes and communal buildings. A solar hot water heater supplies hot water for the washing machine and communal laundry. Automatic control systems provide voltage control by limiting the number of PV strings supplying power during system operation and battery charging, and load management for operating high priority at the expense of low priority loads as the main battery becomes depleted.
Ratajczak, A. F.↗
The STAR computer - A self-testing-and- repairing computer for spacecraft guidance, control, and automatic maintenance
Successful planetary exploration missions have been completed by unmanned Mariner spacecraft, which were designed at the Jet Propulsion Laboratory. Mariner II completed a 109-day flyby mission to Venus on December 14, 1962. This mission was followed by the flyby of Mars and return of 21 historic photographs of its surface by Mariner IV in July 1965. Further successful missions followed: Mariner V to Venus in 1967, Mariners VI and VII to Mars in 1969. In all of these missions, a Central Computer and Sequencer onboard the spacecraft was used to provide on-board control functions, although complete ground backup was also available.
Algirdas Avizienist↗
Initial design and evaluation of automatic restructurable flight control system concepts
Results of efforts to develop automatic control design procedures for restructurable aircraft control systems is presented. The restructurable aircraft control problem involves designing a fault tolerance control system which can accommodate a wide variety of unanticipated aircraft failure. Under NASA sponsorship, many of the technologies which make such a system possible were developed and tested. Future work will focus on developing a methodology for integrating these technologies and demonstration of a complete system.
Weiss, J. L.↗
The Achievement of Reliability in VTOL AUTOCONTROL Systems
Reliability achievement in VTOL automatic control systems
AUTOMATIC CONTROL↗
Mechanical control of airplanes
Before undertaking a detailed description of an automatic-control mechanism, I will state briefly the fundamental conditions for such devices. These are: 1) it must be sensitive at one or more reference values; 2) it must stop the angular motions of the airplane not produced by the pilot; and 3) it must be possible to switch it off and on by a simple hand lever.
AUTOMATIC PILOTS - BOYKOW↗
Theoretical Study of Automatic Flight Control of Aircraft
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Haus, F.↗
AUTOMATIC STABILIZATION CONTROL SYSTEM CHECKOUT PROCEDURES, CAPSULE 15
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Wykoff, D. B.↗
Automatic frequency control of voltage-controlled oscillators
Optical-capacitive coupling is used for isolation of control voltages, such as the high-voltage level of a klystron control electrode that is not referenced to ground, to serve as error voltages referenced to system ground so that the magnitude and sense of correction may be transferred.
Kolbly, R. B.↗
Automatic quadrature control and measuring system
Quadrature is separated from amplified signal by use of phase detector, with phase shifter providing appropriate reference. Output of phase detector is further amplified and filtered by dc amplifier. Output of dc amplifier provides signal to neutralize quadrature component of transducer signal.
Hamlet, J. F.↗
Separate surfaces for automatic flight controls.
The purpose of this paper is to describe an investigation of separate surface stability augmentation systems for general aviation aircraft. The program objective were twofold: first, a wind tunnel program to determine control effectiveness of separate surfaces in the presence of main surfaces, and hinge moment feedback from separate surfaces via the main surfaces to the pilot; second, a theoretical study to determine the minimum performance of actuators and sensors that can be tolerated, the best slaving gains to be used with separate surfaces, and control authority needed for proper operation under direct pilot control, under autopilot control, and in failure situations. On the basis of the results obtained, it has been concluded that separate surface systems are feasible and advantageous for use in general aviation aircraft.
Roskam, J.↗