Date of Award

4-2014

Document Type

Thesis - Open Access

Degree Name

Master of Science in Mechanical Engineering

Department

Mechanical Engineering

Committee Chair

Patrick Currier, Ph.D.

First Committee Member

Eric Coyle, Ph.D.

Second Committee Member

Charles F. Reinholtz, Ph.D.

Abstract

A 3D simulator is programmed for modeling the Velodyne HDL-32E LIDAR used on the WAM-V vehicle in the marine environment for obstacle detection. The model takes into account sensor integration, sensor error, and error correction. Theoretical analysis includes consideration of atmospheric refraction, time of flight error, UDP packet and timing, calibration parameter errors, depth spread error, field of view, accuracy, angular resolution, and points per second in the environment. The average distance error shows a variance of a 0.0127 m to 0.8128 m depending on the laser and the distance. Test results produce distance correction equations for each laser beam. For presented example Laser 1, the error between the corrected values and the actual distance values ranges from .02%-1.14%, which is reduced from the uncorrected error ranging from 1.32% to 3.42%. For all 32 Lasers, the real-world uncorrected distance readings have a deviation of -1.02E-05 σ to .171σ, where σ= 0.0221 m when the Red Taylor Buoy is at .518 m. The corrected distance readings deviate from 1.43E-07σ to 0.0931σ. The simulated uncorrected distance readings deviate from -0.411σ to 2.77σ, with σ= 0.0208 m. The corrected distance readings in simulation deviate from the standard by -.218σ to 2.24σ. The field of view is measured to be 41 degrees. Reflectivity and intensity profiles are presented. Physical textures are also generated based on these profiles from buoy obstacles used in the marine competition tasks. By color, the increasing order of intensity for obstacles is black, green, red, and then white. The final product consists of data used for simulation of the Velodyne HDL-32E and reporting the accuracy of simulated physical values relative to the real world testing.

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