• About
  • Policies
  • What is open access
  • Library
  • Contact
Advanced search
      View Item 
      •   BUIR Home
      • University Library
      • Bilkent Theses
      • Theses - Department of Electrical and Electronics Engineering
      • Dept. of Electrical and Electronics Engineering - Master's degree
      • View Item
      •   BUIR Home
      • University Library
      • Bilkent Theses
      • Theses - Department of Electrical and Electronics Engineering
      • Dept. of Electrical and Electronics Engineering - Master's degree
      • View Item
      JavaScript is disabled for your browser. Some features of this site may not work without it.

      Radius of curvature and location estimation of cylindrical objects with sonar using a multi-sensor configuration

      Thumbnail
      View / Download
      9.3 Mb
      Author(s)
      Sekmen, Ali Şafak
      Advisor
      Barshan, Billur
      Date
      1997
      Publisher
      Bilkent University
      Language
      English
      Type
      Thesis
      Item Usage Stats
      159
      views
      80
      downloads
      Abstract
      Despite their limitations, sonar sensors are very popular in time-of-flight measuring systems since they are inexpensive and convenient. One of the most important limitations of sonar is its low angular resolution. An adjustable multi-sonar configuration consisting of three transmitter/receiver ultrasonic transducers is used to improve the resolution. The radius of curvature estimation of cylindrical objects is accomplished with this configuration. Two different ways of rotating the transducers are considered. First, the sensors are rotated around their joints. Second, the sensors are rotated around their centers. Also, two methods of tirne-of-flight estimation are implemented which are thresholding and curve-fitting. Sensitivity analysis of the radius of curvature with respect to some important parameters is made. The bias-variance combinations of both estimators are compared to the Cramer-Rao lower bound. Theory and simulations are verified by experimental data from real sonar systems. Data is smoothed by extended Kalman filtering. Rotating around the center works better than rotating around the joint. Curve-fitting method is shown to be better than thresholding method both in the absence and presence of noise. The best results are obtained w'hen the sensors are rotated around their centers and the curve-fitting method is used to estimate the time- of-flight. There is about 30% improvement in the absence of noise and 50% improvement in the presence of noise.
      Permalink
      http://hdl.handle.net/11693/17967
      Collections
      • Dept. of Electrical and Electronics Engineering - Master's degree 655
      Show full item record

      Browse

      All of BUIRCommunities & CollectionsTitlesAuthorsAdvisorsBy Issue DateKeywordsTypeDepartmentsCoursesThis CollectionTitlesAuthorsAdvisorsBy Issue DateKeywordsTypeDepartmentsCourses

      My Account

      Login

      Statistics

      View Usage StatisticsView Google Analytics Statistics

      Bilkent University

      If you have trouble accessing this page and need to request an alternate format, contact the site administrator. Phone: (312) 290 2976
      © Bilkent University - Library IT

      Contact Us | Send Feedback | Off-Campus Access | Admin | Privacy