Masters Theses

Date of Award

5-2001

Degree Type

Thesis

Degree Name

Master of Science

Major

Aviation Systems

Major Professor

William Lewis

Committee Members

U. Peter Solies, Fred Stellar

Abstract

The objective of this research project was to design and construct a system to evaluate the effectiveness of diverse types of flight instrument symbology in transmitting information to the pilot. A structured systems engineering approach was used to select system components given the requirements to minimize cost and modifications to the test aircraft and maximize display flexibility while providing enough information to execute instrument flight tasks.

The system is composed of three major elements: flight data collection, data processing, and the display. Each of these elements was analyzed individually to establish requirements and implementation options. The options were compared using a weighted-array analysis to select the most appropriate solution. The final system configuration combined a three-axis inertial measurement unit from Watson Industries, a Motorola pressure sensor, a Pentium III laptop computer running custom software written in Microsoft Visual Basic, and an Earth Technologies 8.4 inch color liquid crystal display. The software was developed using an iterative process to design, test, and refine instrument appearance and function in a simulated, flight environment.

During early testing, significant IMU deficiencies were noted and partially compensated for by the addition of a pressure sensor for direct altitude measurement and a variable velocity input circuit. Despite these enhancements, IMU performance remained poor and resulted in a significant number of aborted test points.

Three display layouts were used to conduct a limited evaluation of the potential of the system to meet the requirements. The first display was designed to closely replicate the standard GA aircraft 'instrument-T": The second consisted of a gyroscope the size of the entire display with digital readouts of other flight parameters superimposed upon it. The third display was designed to look similar to an F-16 heads up display. Three pilots were chosen from diverse backgrounds and were tasked with performing a simulated precision instrument approach while their performance was recorded. Error analysis was then conducted using commercial data analysis and plotting tools. Pilot performance varied widely between displays, with the "instrument-T" display producing the worst average performance.

This proof-of-principle evaluation was successful, but the basic system architecture should be refined one more time before conducting further symbology testing. The most significant recommendation is to replace the IMU with a more reliable data collection system, preferably one based upon the Global Positioning System. Also, before a rigorous symbology evaluation can be conducted, more detail needs to be added to the instrument types already implemented and new instruments, such as a horizontal situation indicator and turn-and-slip instrument, must be added. Then a sponsor should be sought to finance continuing display research projects.

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