development of a vision system for ship hull ... - ePrints@USM

LIST OF FIGURESPageFigure 1.1 Example of a Ship Hull 1Figure 2.1 Inspection by horizontal and vertical slices. 11Figure 2.2 Definition of α and β 12Figure 2.3 End plate images taken with DIDSON 12Figure 2.4 6 Degree of Freedom (DOF) for underwater vehicle 14Figure 2.5 Guidance techniques for underwater vehicles 15Figure 2.6 Close loop guide and control a vehicle 17Figure 3.1 Attenuation of the light by the depth water 30Figure 3.2 Change by transmission distance of the laser permeability 31in the turbid waterFigure 3.3 Extinction coefficient of green laser in turbid water 31Figure 3.4 (a) Webcam and laser pointer combined into a handheld 33unit. (b) The camera-to-target distance D can becalculated given the pixel location u, baseline h, andangle θFigure 3.5 Laser precision in measurement with CCD camera, 640 x 34480 pixel resolution.Figure 3.6 Four different shapes of laser spot used for the ranging 38quality investigation of peak detection algorithmsFigure 3.7 Position of laser line in image 40Figure 3.8 Laser ranging system (left) and video image of the pile 41object from vehicle’s camera (right)Figure 3.9 SPSS- Curve Estimation Dialog Box 45Figure 4.1 Circuit box (left) and DC driver inside the box (right) 50Figure 4.2 Initial camera platform designs 51Figure 4.3 Main platform designs 52Figure 4.4 Main platform actual designs 52Figure 4.5 Control architecture of the tracking system 53Figure 4.6a Connection layout of the tracking system 54Figure 4.6bSchematic layout of the circuit.Figure 4.7a The platform 55Figure 4.7b Caster wheel and measuring tape 55Figure 4.7c Roller and nylon string 55Figure 4.7d Optical axis-DC motor 55Figure 4.7e Horizontal axis-DC motor 55Figure 4.8a Flow chart that represents the control flow (1 of 4) 56Figure 4.8b Flow chart that represents the control flow (2 of 4) 57viii