published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

M.Ing. (Mechanical Engineering) / The research reported in this thesis describes the design and simulation of a neural controller for a three -degree-of-freedom robot leg for use as an hexapod leg . Biological systems are considered as a motivation to develop the neural control system for hexapod walking on a horizontal surface . Backpropagation training of multilayer perceptrons and a combination of heterogeneous neurons are used to implement several pattern generators with different behaviours. The artificial neurons are simulated and connected together with the pattern generators to form a complete control system . Previous work [48] shows the performance of a two -degree-of-freedom leg controller - this type of controller however cannot compensate for surface irregularities , The control system for the three degree-of-freedom leg is then further extended to compensate for surface irregularities that cannot be traversed by the two -degree-of-freedom leg.

published_or_final_version / abstract / toc / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

No description available.

Robot localization is one of the most important subjects in the Robotics science. It is an interesting and complicated topic. There are many algorithms to solve the problem of localization. Each localization system has its own set of features, and based on them, a solution will be chosen. In my thesis, I want to present a solution to find the best estimate for a robot position in certain space for which a map is available. The thesis started with an elementary introduction to the probability and the Gaussian theories. Simple and advanced practical examples are presented to illustrate each concept related to localization. Extended Kalman Filter is chosen to be the main algorithm to find the best estimate of the robot position. It was presented through two chapters with many examples. All these examples were simulated in Matlab in this thesis in order to give the readers and future students a clear and complete introduction to Kalman Filter. Fortunately, I applied this algorithm on a robot that I have built its base from scratch. MCECS-Bot was a project started in Winter 2012 and it was assigned to me from my adviser, Dr. Marek Perkowski. This robot consists of the base with four Mecanum wheels, the waist based on four linear actuators, an arm, neck and head. The base is equipped with many sensors, which are bumper switches, encoders, sonars, LRF and Kinect. Additional devices can provide extra information as backup sensors, which are a tablet and a camera. The ultimate goal of this thesis is to have the MCECS-Bot as an open source system accessed by many future classes, capstone projects and graduate thesis students for education purposes. A well-known MRPT software system was used to present the results of the Extended Kalman Filter (EKF). These results are simply the robot positions estimated by EKF. They are demonstrated on the base floor of the FAB building of PSU. In parallel, simulated results to all different solutions derived in this thesis are presented using Matlab. A future students will have a ready platform and a good start to continue developing this system.

published_or_final_version / abstract / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

As a result, this dissertation proposes a novel type of tree climbing robot, named Treebot, which has high maneuverability on trees. The design of Treebot was inspired by arboreal animals such as squirrels and inchworms. The applied extendable continuum maneuvering mechanism has large workspace and high degrees of freedom. It allows Treebot to perform various actions, such as moving between trunk and branches. Treebot is able to grip the surface of trees tightly with a wide range of gripping curvature. It enables Treebot to grip from a big tree trunk to small branches. The special gripping mechanism allows zero energy consumption in static gripping. Although Treebot has high maneuverability, it is compact, lightweight, and only five actuators are used in total. By installing proper equipments, Treebot can assist workers to perform forestry tasks such as inspection and maintenance. It can also be used as a mobile surveillance system to observe behaviors of both ground and arboreal animals. / Climbing robots have become a hot research topic in recent decades. Most research in this area focuses on climbing manmade structures, such as vertical walls, glass windows, and structural frames. Little research has been conducted specifically on climbing natural structures such as trees. The nature of trees and manmade structures is very different. For example, trees have an irregular shape and their surface is not smooth. Some types of trees have soft bark that peels off easily. Hence, most of the climbing methods for manmade structures are not applicable to tree climbing. / In addition to presenting the mechanical design of Treebot, this dissertation also proposes several autonomous tree climbing algorithms. Making a robot climb a tree autonomously is a challenging task, as trees are complex and irregular in shape. However, a certain level of autonomous climbing ability is needed to simplify the operational use of Treebot. The proposed works include autonomous climbing on unknown environment and global path planning on known environment. / Preventing trees from failing is important to protect human life and property in urban areas. Most trees in urban areas require regular maintenance. To reach the upper parts of a tree to perform such maintenance, workers need to climb the tree. However, tree climbing is dangerous, the development of a tree climbing robot is important to assist or replace humans works. / Several robots have been designed to climb trees such as WOODY and RiSE. However, these robots are limited to climbing straight tree trunks, and cannot climb trees that are curved or have branches. As branches and curvature are present in almost all trees, the application of these robots is strongly restricted. / Lam, Tin Lun. / Adviser: Yangsheng Xu. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 163-172). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Insects are confronted with the problem of locating food, mates, prey and hosts for their young over long distances, which they often overcome using chemical plume tracking. Tracking a plume of chemical back to its source is made difficult due to the complexity of plume structure. Turbulence and shifts in the wind direction prevail over diffusion in the spreading of an airborne chemical from a point in most cases, producing intricate plumes consisting of filaments of high chemical concentration interspersed with regions of clean air. It has been proposed that insects achieve plume tracking in this environment through variations of anemotaxis, which involves travelling upwind when an attractive chemical is perceived. This study aimed to investigate anemotaxis through the use of a mobile robot to test the efficacy of algorithms which mimic the way insects achieve plume tracking and also to determine whether these algorithms are an effective means of plume tracking for a mobile robot under a range of conditions. To achieve the aims of this study, various plume-tracking algorithms were implemented on a mobile robot built to model a plume-tracking insect and their performance was compared under a range of wind conditions. The algorithms tested were based upon a range of plume-tracking hypotheses. The simplest algorithm was surge anemotaxis, where the robot surged upwind in the presence of an attractive chemical and performed crosswind casting (back and forth motion) in the absence of chemical. The other algorithms tested were the counterturner, where the robot zigzagged upwind, and two bounded search methods. To allow these algorithms to be appropriately implemented, a robot model was constructed that could move in two dimensions and sense the wind velocity and ion level at a point in space. An ion plume was used instead of a chemical plume in each test as it behaves in a similar manner to a chemical plume, but ion sensors have response and recovery times far more rapid than conventional chemical sensors, similar to insects. The plume-tracking robot was tested in three series of tests. Initially, the entire range of plume-tracking algorithms was tested in a wind tunnel with fixed wind direction for a range of wind speeds and release positions. The second series of tests compared the performance of the surge anemotaxis and bounded search algorithms, again in a wind tunnel, but with a wind shift of 20° during some of the tests. The algorithms were tested with and without a direct crosswind surge response to detected wind shifts. The third set of tests examined the performance of the simple and wind shift response algorithms outdoors using natural wind to produce the plume. All algorithms tested achieved successful plume tracking in some conditions. The surge anemotaxis and triangular bounded search algorithms were particularly successful. The tests also showed that the paths obtained from tests undertaken in natural outdoor wind conditions varied greatly from those undertaken in a wind tunnel. This indicates the need to test plume-tracking algorithms in natural environments. This is vital both in the investigation of insect plume-tracking behaviour, as insects navigate in these environments, and in the process of producing plume-tracking robots that are capable of operating effectively in these conditions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1287973 / Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2007

In 2000 the Electrical and Computer Engineering department at Oregon State University began a new and innovative program named TekBots[superscript TM]. This program was created to solve the problems of students in existing undergraduate engineering education not having sufficient skill when graduating in six program educational objectives; Depth, Breadth, Professionalism, Innovation, Community, and Troubleshooting. TekBots uses several core values such as personal ownership, curriculum continuity, contextual teaching, fun, and hands on learning, to encourage students to learn and improve. Since the inception of the program two courses have been greatly refined. An evaluation of the courses supports our indications of improvement our program educational objectives. This thesis presents the TekBots program and the details of the first two TekBots courses. / Graduation date: 2003