Masters Theses

Date of Award

12-1997

Degree Type

Thesis

Degree Name

Master of Science

Major

Engineering Science

Major Professor

Ching Fang Le

Committee Members

Ching Lo, Ted Paludan, Bruce Whitehead

Abstract

Off-line trajectory generation is a method used to compute standard store (any object carried on an aircraft that is designed to be released in flight) separations using wind tunnel data. A six-degree-of-freedom (6-DOF) trajectory generation program (TOP) was originally developed at Arnold Engineering Development Center (AEDC) to control the Captive Trajectory Support (CTS) testing mechanism in aerodynamic tunnels 4T, 16T/S and A. To supplement the six-DOF prediction capability used on-line in the wind tunnels, a family of off-line analysis applications were developed based on the TOP. Variants of the TCP are used to compute standard store separations using wind tunnel data, Multi-Dimensional Interpolation Trajectory Generation Program (MDITGP) and ballistic predictions (BalTGP). The same six-DOF prediction capability is also used in the Helicopter Armament Store Separation Trajectory Generation Program (HassTGP) that analyzes the trajectory from a rotary-wing aircraft. This suite of programs uses similar inputs to run simulations. The input process in the starting version was very extensive and time-consuming and required an experienced analysis engineer. Errors could easily occur and error checking was at a minimum in the old system. The previous file structure was binary direct access and was not portable between hardware platforms. The analysis technical staff has a strong need to transfer files between different hardware systems. This need for portability required writing a conversion program that had to run on each platform to put it into the machine specific binary form. The target computer platforms were the IRIS®, SUN® and PC. The TGP programs run simulations quickly, however, an enormous amount of time was spent in the setup process. This process was chosen as an area that needed vast improvements in efficiency, error checking, quickness and ease of use. The programs and data files are now transportable directly without any software changes or conversion. The improvements to the system were implemented in two phases. Phase one consisted of the determination of an easily transportable file structure. Once the structure had been designed, software was written and tested to use the new file structure in the TGP software. Phase two consisted of the design and implementation of a Graphical User Interface (GUI) that used the new file structure.

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