Engineering topics

Lilley, R. W.

Publications and source records attributed to Lilley, R. W..

25 records · Page 2

NASA NTRS1976

Simulation analysis of a microcomputer-based, low-cost Omega navigation system

The current status of research on a proposed micro-computer-based, low-cost Omega Navigation System (ONS) is described. The design approach emphasizes minimum hardware, maximum software, and the use of a low-cost, commercially-available microcomputer. Currently under investigation is the implementation of a low-cost navigation processor and its interface with an omega sensor to complete the hardware-based ONS. Sensor processor functions are simulated to determine how many of the sensor processor functions can be handled by innovative software. An input data base of live Omega ground and flight test data was created. The Omega sensor and microcomputer interface modules used to collect the data are functionally described. Automatic synchronization to the Omega transmission pattern is described as an example of the algorithms developed using this data base.

Lilley, R. W.↗

NASA NTRS1976

Small-aircraft flight evaluation of Rustrak chart recorder

It was found that the RUSTRAK recorder was only slightly hampered by aircraft vibration while in level cruising flight or while taxiing, regardless of light turbulence or particular mounting configuration. No one mounting configuration was better than the other. There is some (approximately 1/4 inch) vibration error during climbs, descents, and touchdowns in choppy weather. However, it was found that improved performance resulted from setting the recorder on carpet rather than the metal floor plate. This suggests that padding the recorder with some cushioning, shock-damping material might reduce the engine vibration and wind chop effects.

Salter, R. J., Jr.↗

NASA NTRS1976

Simulation analysis of a microcomputer-based, low-cost omega navigation system

A status report is presented on a proposed low-cost Omega Navigation System (ONS) based on a microcomputer (Available commercially). Minimum hardware and maximum software are designed for. Electronic subsystems are discussed in detail, with block diagrams of the receiver and microcomputer interface modules, and a flowchart of the automatic synchronization process. The system is designed as a precision navaid for general aviation in the $1000 price range.

Lilley, R. W.↗

NASA NTRS1974

Omega flight-test data reduction sequence

Computer programs for Omega data conversion, summary, and preparation for distribution are presented. Program logic and sample data formats are included, along with operational instructions for each program. Flight data (or data collected in flight format in the laboratory) is provided by the Ohio University Omega receiver base in the form of 6-bit binary words representing the phase of an Omega station with respect to the receiver's local clock. All eight Omega stations are measured in each 10-second Omega time frame. In addition, an event-marker bit and a time-slot D synchronizing bit are recorded. Program FDCON is used to remove data from the flight recorder tape and place it on data-processing cards for later use. Program FDSUM provides for computer plotting of selected LOP's, for single-station phase plots, and for printout of basic signal statistics for each Omega channel. Mean phase and standard deviation are printed, along with data from which a phase distribution can be plotted for each Omega station. Program DACOP simply copies the Omega data deck a controlled number of times, for distribution to users.

Lilley, R. W.↗

NASA NTRS1974

Flight evaluation: Ohio University omega receiver base

A flight evaluation is presented of the Ohio University Omega Receiver Base, developed under the NASA Tri-University Program in Air Transportation, to provide a vehicle for the transfer of flight-test data to NASA and to other participants in the Tri-University program. Chart recordings of flight data are given, along with chronological listings of significant events which occurred during the flight. Digital data was prepared in data-processing card form for distribution. Data include phase measurements from all eight Omega time-slots for the duration of the flight, plus event marks which serve to correlate the phase data with flight-path documentation.

Chamberlin, K. A.↗

NASA NTRS1974

Low cost omega navigation receiver

The development of a low cost Omega navigation receiver is discussed. Emphasis is placed on the completion and testing of a modular, multipurpose Omega receiver which utilizes a digital memory-aided, phase-locked loop to provide phase measurement data to a variety of applications interfaces. The functional units contained in the prototype device are described. The receiver is capable of receiving and storing phase measurements for up to eight Omega signals and computes two switch-selectable lines of position, displaying this navigation data in chart-recorded form.

Lilley, R. W.↗

NASA NTRS1974

Binary processing and display concepts for low-cost Omega receivers

A description is given of concepts related to plans for developing a low-cost, all-digital Omega receiver capable of offering to the small-aircraft pilot a reliable and accurate navigation aid. The receiver base considered includes a receiver front-end module, a receiver control module, a memory-aided phase-locked loop module, a housekeeping timer module, and a synthesizer module.

Lilley, R. W.↗