Engineering Commons^™

Evaluation Of Collision Properties Of Spheres Using High-Speed Video Analysis, Jian Yu

Theses

Experimental evaluation of the collision properties of spheres is performed using video image analysis techniques. A high-speed Kodak EktaPro1000 video camera is utilized to record a collision sequence between two spheres at 1000 frames/sec, and then the images are analyzed to calculate three dimensional translation and rotation before and after the collision. These quantities are used to compute the collision properties for a pair of one inch nylon spheres, i.e. the coefficient of friction, and the coefficients of normal and tangential restitution. The focus of the thesis is on image analysis techniques that provide high accuracy results even though the …

An Implementation Of A Versatile Camera Calibration Technique For High-Accuracy 3d Machine Vision Metrology Using Off-The-Shelf Tv Camera And Lenses, Bolang Li

Theses

This thesis studies and implements a new versatile camera calibration technique for high-accuracy 3D machine vision metrology using off-the-shelf TV camera and lenses developed by Roger Tsai [1]. This technique builds up a unique relationship from the world coordinate system to the computer image coordinate system of calibration points by using a radial alignment constraint. The technique has advantage in terms of accuracy, speed, and versatility over existing techniques.

The fundamental knowledge for using this technique is presented in this thesis first, followed by an overview of the existing calibration techniques, and a detailed description of the new technique. The …

Automatic Motion Analysis Of Colliding Spheres, John Vijayakumar Caesar

Theses

Motion analysis is useful to compute linear and angular velocities and acceleration of an object from a sequence of images. This thesis is part of an investigation to compute the translation and rotation velocities needed to determine the collision parameters of two colliding spheres. This involves the tracking of the spheres and feature points on the spheres over a time interval. An experimental setup releases two spheres such that they collide and a high speed imaging system, i.e., Kodak Ektapro 1000 is utilised to record the motion of the spheres. The imaging system is capable of recording at a speed …

Computation Of Collision Parameters Of Spheres By Computer Vision, Sumit Sen

Theses

Collision parameter evaluation of rigid spherical particles requires estimation of pre- and post-impact position, velocity and angular velocity vectors of colliding particles. A three dimensional experimental technique is devised where the instantaneous position and orientation of the particles are determined by analyzing frames obtained through high speed video imaging system. Since the image obtained is two dimensional, a mirror setting is designed to capture two orthogonal views of collision in order to estimate motion in depth. The translational velocity vector is determined from the position information extracted through application of available image analysis techniques over two time frames of digitized …

Direct Recovering Of Composite Surface Using Uoff, Zhesheng Huang

Theses

The research work reported in the thesis is motivated by the problem raised in the computer vision area. It utilizes direct method to recover surface structure of objects in 3-D space from a pair of stereo images. The direct method, compared with optical flow-based approach and feature-based approach, is robust and computationally efficient. However it can only recover planar surface structure so far. A new approach to recover structure from a pair of stereo images based on unified optical flow field (UOFF) is developed recently. It can recover curved surface structure.

In this thesis, the problem of recovering surface structure …

3-D Structure Recovery Using Unified Optical Flow Field Approach, Anees Ahmad

Theses

Recovery of the 3-D structure that is characterized by an N^th order factorable and/or non-factorable polynomial equation is studied in this thesis. Analytical tools have been employed to analyze and solve the problem. The solution is based on the direct method, which is derived from the unified optical flow field, which, in turn, is an extension of optical flow to spatial image sequences. Least squares formulation has been employed for optimum estimation. The method used does not require the establishment of point to point correspondence, nor the estimation of the optical flow, as an intermediate step.

The theoretical results …

Automatic Infrared And Visual Inspection Of Solder Joints On Pcbs, Jiang Huang

Theses

This thesis reports the research results of automatic inspection of solder joints on printed circuit boards (PCBs). The previous work on this regard has been advanced significantly in the following three aspects. With the application of some microlens and the principle of geometric optics solder joints of real size are inspected in this work instead of larger simulation solder joints in the previous work. A new set of features is formulated and used for infrared inspection. Consequently, better results have been achieved in this work.

Reasonably good results demonstrate the capability of infrared inspection of solder joints on PCBs. Once …

A Machine Vision System With Remote Host, Chieyeon Jason Chen

Theses

The modem plays an important role in data communication using the Public Swiched Telephone Network. In this thesis, the modem function is merged into a low cost machine vision system based on the Motorola 68HC11. Evalation Board The system comprises the intelligent machine vision con- troller and a remotely located host computer, such as an IBM-PC. It, supports extra long distance communication capability so that the controller and the host can be anywhere in the world where then is a telephone line. Because of the limit of a 2100 bps modem, soft ware data compression is implemented here to save …

Estimating 3-D Motion And Structure Parameters Of A Rigid Planar Object By Establishing Landmark Correspondences, Herman Agustiawan

Theses

The application of a landmark based approach in recognizing 3-D rigid planar objects[3] along with two different motion and structure estimation algorithm [21][23] have been studied to perform motion and structure estimation tasks of moving objects. The recognition algorithm is based on a sphericity value derived from affine transformation that maps feature points in the object under observation from first to second view in the 2-D image space. The motion and structure estimation algorithm is based on a unique mapping given four or more feature point correspondences.

More than ten experiments have been done including small and large rigid motions. …

A Comparative Study Of Edge Detection Techniques, Jaskaran Singh Dhaliwal

Theses

The problem of detecting edges in gray level digital images is considered. A literature survey of the existing methods is presented. Based on the survey, two methods that are well accepted by a majority of investigators are identified. The methods selected are: 1) Laplacian of Gaussian (LoG) operator, and 2) An optimal detector based on maxima in gradient magnitude of a Gaussian-smoothed image. The latter has been proposed by Canny[], and will be referred as Canny's method. The purpose of the thesis is to compare the performance of these popular methods. In order to increase the scope of such comparison, …