New Visualization Applications In 3-Dimensional Highway Design, Sight Distance Measurement, And Military Path Planning
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Date
2012
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Civil Engineering
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Doctor of Engineering
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This item is made available by Morgan State University for personal, educational, and research purposes in accordance with Title 17 of the U.S. Copyright Law. Other uses may require permission from the copyright owner.
Abstract
This dissertation develops new visualization techniques in the following three areas: (i) 3-dimensional (3D) highway design; (ii) 3D sight distance measurement; and (iii) military path planning. Traditionally, geometric design of roadways is a two-stage process in which the horizontal alignment is designed first followed by the design of an appropriate vertical alignment. The traditional two-stage road design may lead to critical design errors, such as a section of the road with a vertical sag curve and a sharp horizontal curve together will lead to an illusion of a comfortable horizontal curve when driving. This is due to the fact that the vertical curve may be overlooked as it cannot be traced by the traditional two-stage design process. This can lead to a compromise in the safe operation of traffic. One can thus see that this two-stage process is cumbersome and subject to errors. From literature, it is evident that this error-prone and cumbersome process can be improved by visualizing roads three dimensionally in a single stage. In this dissertation, a method is proposed in which the traditional two-stage design process can be reduced to a single-stage design process by developing a 3D roadway using new visualization techniques. The design involves identifying control points on a given terrain, through which the roadway passes and finding suitable 3D lines and/or splines that connect those control points. Mathematical formulations to calculate the 3D lines and splines are presented. The second area in which the new visualization techniques are applied is 3D sight distance measurement. Sufficiency of sight distance throughout a highway is considered as a major safety check. The traditional process of checking for adequate sight distance ahead of a driver is manual as it is performed by checking along the horizontal and vertical roadway alignments separately. The two stage checks may lead to inaccurate sight distance calculations along the roadway. A new visualization-based technique for calculating the sight distance is proposed in which the sight distance is measured using a a rectangular plane of variable length (width of the rectangle is fixed). Two breadth edges of the rectangle are placed at a height `h' from the road surface. One breadth edge of the rectangular plane is fixed at a station and other breadth edge would be moved along the roadway at regular intervals until the plane touches the road surface or is intercepted by roadside features. When touched or intercepted, the entire length of the road surface between the two breadth edges is then measured to obtain the sight distance. Given the 3D road centerline, a method is described to establish the road surface and combine it with a terrain surface having roadside features. Mathematical formulations to prepare the 3D surface and measure the sight distance with some case studies are presented. The third area in which the new visualization techniques are applied is military path planning in combat situations. A Military Path Planning Algorithm (MPPA) is proposed for a robot to plan a path from an origin to a destination without being detected by enemies. In a combat military environment, the only information the robot has is the digital terrain on which it moves. The robot does not know the enemy location until it is at a certain distance from the enemy. The objective would be to reach the destination point from the origin in a safe (by maintaining a certain distance from enemies) and efficient manner. The robot while moving forward performs two types of scanning, namely radar and visual scanning. Radar scanning techniques are not dealt within this dissertation. Visual scanning uses a modified version of the sight distance algorithm discussed in the previous paragraph, which is specifically designed for robotic movement. A Dynamic-GIS is used for the information storage, retrieval of terrain and visualization of robot movement. The MPPA is tested rigorously for different site locations, enemy locations and number of enemies and the results are presented.