Phase-coherent and comma-free biorthogonal telemetry system.
Logical design for phase-coherent and comma-free biorthogonal telemetry system less RF carrier
DIGITAL COMMUNICATIONS SYSTEM↗
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Results for “Logic Design”
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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Digital techniques used in the steering apparatus of the GPO steerable aerial at Goonhilly Downs
A discription of the logic design for the digital control equipment is followed by further descriptions of items of particular interest. The means of applying off-sets to the demanded aerial position for over-coming possible inaccuracy of the predicted orbit; and to demand accuratly determined velocities manually; means of conversion from pure binary form to provide displays in terms of angles, and the derivation of analogue voltages for the for the servo-amplifiers are discussed in detail. A critical analysis of the equipment in the light of operational experience concludes the paper.
TRACKING STATION↗
A study of the data commutation problems in a self-repairable multiprocessor.
Network logic design for data commutation functions in self repairable computer multiprocessor
Goldberg, J.↗
Special purpose computer provides programmable digital filter for sampled-data control systems
Generalized digital filter is a special purpose computer. The term digital filter is an algorithm which accepts an input sequence of numbers and transforms it into an output number sequence. The organization of the computer, the logical design and synthesis, and experimentaion with the computer in two sampled data control systems is discussed.
Carroll, C. C.↗
Monolithic parallel processor Progress report, 28 Jun. - 27 Dec. 1968
Breadboard models and logic design of monolithic parallel processor
Source record↗
Negative radix conversion
Negative radix conversion results applied to logical design of serial converter
Zohar, S.↗
Digital realization of pulmonary screening and motivating device Final technical report, 22 Jun. - 28 Aug. 1970
Digital logic design for spirometer
Charo, I. F.↗
Washout circuit design for multi-degrees-of-freedom moving base simulators.
A mathematical framework is presented for designing logic to accept motion-dependent parameters from a simulation, attenuating them ('washing them out'), and generating appropriately limited drive signals. This framework is sufficiently general to encompass six-degree-of-freedom simulators with large motion capability. Emphasis is placed on preserving certain motion cue relations (such as those that would be observed in coordinated flight). Strategies for simulating side forces via tilts are shown. Finally, several specific circuits are shown. These circuits have proven to be readily adaptable to a variety of moving-base simulators.
Conrad, B.↗
Digital adaptive flight controller development
The development of a digital adaptive flight control algorithm is described that combines a weighted least squares estimator with optimal linear regulator control logic designed to minimize a quadratic model following performance index. Very promising results for a typical fighter aircraft's trajectory over six distinct flight conditions are reported.
Kaufman, H.↗
A Kalman filter for the Stoland system
A simple Kalman filter for potential use in STOL navigation systems is described. The mathematical formulation of all the elements of the filter, its initialization and overall operation are presented. Simulation results show that a typical approach flight to landing, the Kalman filter has much smaller errors during navigation on TACAN data and during transition from TACAN to MODILS data than a complementary filter. Summary type flow charts of the Kalman filter logic designed for the Sperry 1819A computer are presented. Also, the memory and real time requirements of the Kalman filter and complementary filter are described. The Kalman filter is shown to gain its superior performance at the expense of real time and memory required in the onboard computer.
Schmidt, S. F.↗
Apollo experience report: Guidance and control systems: Automated control system for unmanned mission AS-201
The Apollo command module heat shield and Apollo command and service module/Saturn launch vehicle structural integrity were evaluated in an unmanned test flight. An automated control system was developed to provide the mission event sequencing, the real-time ground control interface, and the backup attitude reference system for the unmanned flight. The required mission events, the design logic, the redundancy concept, and the ground-support-equipment concept are described and some development problem areas are discussed. The mission event time line and the real-time ground command list are included to provide an outline of the control system capabilities and requirements. The mission was accomplished with the automated control system, which functioned without flight anomalies.
Holloway, G. F.↗
An advanced combustor analytical design procedure and its application in the design and development testing of a premix/prevaporized combustion system
Due to the protracted time and relatively high monetary expenditures associated with empirical design procedures, AiResearch has placed considerable emphasis on the development and use of combustor analytical models to augment the existing design techniques. A brief account of the semi-empirical design procedure is given, followed by the description of six analytical computer models. An advanced combustor design logic based upon these models is presented. A brief description of a premix/prevaporized combustion system and correlation with the models is given.
Reynolds, R. S.↗
CADAT place-and-routine in two dimensions
CADAT place-and-route-in-two dimensions program (PR2D) is standard-cell automatic-layout program for generating large-scale-integrated/metal-oxidesemiconductor (LSI/MOS) arrays. PR2D translates logic designer's cell interconnection requirements into physically-defined MOS chip. PR2D reads input data, searches pin data file for data on each pattern type, generates placement of patterns, and interconnects patterns. As output, it generates artwork for layouts.
Source record↗
Wide field of view laser beacon system for three-dimensional aircraft position measurement
This paper presents a new wide field of view laser beacon system for measurement, in three dimensions, of aircraft or other remote objects. The system is developed for aircraft collision hazard warning independent of ground-based hardware, as well as for flight research, helicopter-assisted construction and rescue, and robotic manipulation applications. Accurate information describing the relative range, elevation, and azimuth of the aircraft are generated by the sweep of a low-power fan-shaped rotating laser beacon past an array of optical detectors. The system achieves a wide angle of acceptance of laser beacon light through use of compound parabolic concentrators, which collimate the light for spectral filtering to minimize solar interference. An on-board microprocessor system converts the pulse sequence to aircraft position in real time. System reliability and performance are enhanced through narrow pass filtering of the pulse signals, digital logic design to mask spurious signals, and adaptive modulation of trigger threshold levels.
Sweet, L. M.↗
Programmable controller system for wind tunnel diversion vanes
A programmable controller (PC) system automatic sequence control, which acts as a supervisory controller for the servos, selects the proper drives, and automatically sequences the vanes, was developed for use in a subsonic wind tunnel. Tunnel modifications include a new second test section (80 ft x 100 ft with a maximum air speed capability of 110 knots) and an increase in maximum velocity flow from 200 knots to 300 knots. A completely automatic sequence control is necessary in order to allow intricate motion of the 14 triangularly arranged vanes which can be as large as 70 ft high x 35 ft wide and which require precise acceleration and deceleration control. Rate servos on each drive aid in this control, and servo cost was minimized by using four silicon controlled rectifier controllers to control the 20 dc drives. The PC has a programming capacity which facilitated the implementation of extensive logic design. A series of diagrams sequencing the vanes and a block diagram of the system are included.
King, R. F.↗
An interactive wire-wrap board layout program
An interactive computer-graphics-based tool for specifying the placement of electronic parts on a wire-wrap circuit board is presented. Input is a data file (currently produced by a commercial logic design system) which describes the parts used and their interconnections. Output includes printed reports describing the parts and wire paths, parts counts, placement lists, board drawing, and a tape to send to the wire-wrap vendor. The program should reduce the engineer's layout time by a factor of 3 to 5 as compared to manual methods.
Schlutsmeyer, A.↗
Shortcomings in ground testing, environment simulations, and performance predictions for space applications
This paper addresses the issues involved in radiation testing of devices and subsystems to obtain the data that are required to predict the performance and survivability of satellite systems for extended missions in space. The problems associated with space environmental simulations, or the lack thereof, in experiments intended to produce information to describe the degradation and behavior of parts and systems are discussed. Several types of radiation effects in semiconductor components are presented, as for example: ionization dose effects, heavy ion and proton induced Single Event Upsets (SEUs), and Single Event Transient Upsets (SETUs). Examples and illustrations of data relating to these ground testing issues are provided. The primary objective of this presentation is to alert the reader to the shortcomings, pitfalls, variabilities, and uncertainties in acquiring information to logically design electronic subsystems for use in satellites or space stations with long mission lifetimes, and to point out the weaknesses and deficiencies in the methods and procedures by which that information is obtained.
Stassinopoulos, E. G.↗
Reactive system verification case study: Fault-tolerant transputer communication
A reactive program is one which engages in an ongoing interaction with its environment. A system which is controlled by an embedded reactive program is called a reactive system. Examples of reactive systems are aircraft flight management systems, bank automatic teller machine (ATM) networks, airline reservation systems, and computer operating systems. Reactive systems are often naturally modeled (for logical design purposes) as a composition of autonomous processes which progress concurrently and which communicate to share information and/or to coordinate activities. Formal (i.e., mathematical) frameworks for system verification are tools used to increase the users' confidence that a system design satisfies its specification. A framework for reactive system verification includes formal languages for system modeling and for behavior specification and decision procedures and/or proof-systems for verifying that the system model satisfies the system specifications. Using the Ostroff framework for reactive system verification, an approach to achieving fault-tolerant communication between transputers was shown to be effective. The key components of the design, the decoupler processes, may be viewed as discrete-event-controllers introduced to constrain system behavior such that system specifications are satisfied. The Ostroff framework was also effective. The expressiveness of the modeling language permitted construction of a faithful model of the transputer network. The relevant specifications were readily expressed in the specification language. The set of decision procedures provided was adequate to verify the specifications of interest. The need for improved support for system behavior visualization is emphasized.
Crane, D. Francis↗