碩士 / 國立交通大學 / 多媒體工程研究所 / 98 / With the progress of development in computer vision technologies, 3D stereo cameras nowadays become more popular than in the past. In this study, a new imaging device and new guidance techniques are proposed to construct an autonomous vehicle for use as a robot guide dog navigating on sidewalks to guide the blind people.
A general formula for designing a new stereo camera consisting of two mirrors and a single conventional projective camera is proposed. People can use the formula to design other stereo cameras easily. Then, a calibration technique based on a so-called pano-mapping technique for this type of camera is proposed. Using an autonomous vehicle to navigate in the environment, the incrementally increasing mechanical error is a big problem in the experiment. A calibration model based on the curve fitting technique is proposed to correct such errors. Also, a 3D data acquisition technique using the proposed two-mirror omni-camera based on the rotational invariance property of the omni-image is proposed. The 3D data can be obtained directly without transforming taken omni-images into panoramic images.
The autonomous vehicle is designed to follow the curb line of the sidewalk using the line following technique. In the path learning procedure, two methods are proposed to extract the curbstone feature points. If there exits no curbstone features or the features are hard to extract, a new human interaction technique using hand pose position detection and encoding is proposed to issue a user’s guidance command to the vehicle. To adapt the adopted image processing operations to the varying light intensity condition in the outdoor environment, two techniques, called dynamic exposure adjustment and dynamic threshold adjustment are proposed. To create a path map, a path planning technique is proposed, which reduces the number of the resulting path nodes in order to save time in path corrections during navigation sessions.
In the navigation procedure after learning, there may exits unexpected obstacles blocking the navigation path. A technique using a concept of virtual node is proposed to design a new path to avoid the obstacle. Finally, to allow the vehicle to guide a blind person to walk smoothly on a sidewalk, a sonar signal processing scheme is proposed for synchronization between the speed of the vehicle and that of the person, which is based on computation of the location of the vehicle with respect to the person using the sonar signals.
A series of experiments were conducted on a sidewalk in the campus of National Chiao Tung University. And the experimental results show the flexibility and feasibility of the proposed methods for the robot guide dog application in the outdoor environment.
| Identifer | oai:union.ndltd.org:TW/098NCTU5641029 |
| Date | January 2010 |
| Creators | Huang, Jheng-Kuei, 黃政揆 |
| Contributors | Tsai, Wen-Hsiang, 蔡文祥 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 113 |
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