Formation control of nonholonomic mobile robots using implicit polynomials and elliptic Fourier descriptors

This paper presents a novel method for the formation control of a group of nonholonomic mobile robots using implicit and parametric descriptions of the desired formation shape. The formation control strategy employs implicit polynomial (IP) representations to generate potential fields for achieving the desired formation and the elliptical Fourier descriptors (EFD) to maintain the formation once achieved. Coordination of the robots is modeled by linear springs between each robot and its two nearest neighbors. Advantages of this new method are increased flexibility in the formation shape, scalability to different swarm sizes and easy implementation. The shape formation control is first developed for point particle robots and then extended to nonholonomic mobile robots. Several simulations with robot groups of different sizes are presented to validate our proposed approach

Formation control of multiple mobile robots using parametric and implicit representations

Coordination of autonomous robot groups is an active research area and much recent work has focused on modeling and control issues related to coordination. Robot groups can coordinate in many different ways. Some robot groups may execute coordination in which group members move in a scattered manner like the bees of a beehive or coordination of the group may require a more strict formation like the swallows. The shape formation is very important for the coordination of autonomous mobile robot groups because it increases the capability of a robot group by increasing the competence and the security of the group. The shape formation is applicable in many tasks like formation flight, flocking and schooling, transportation systems, searchand- rescue operations, competitive games, reconnaissance and surveillance. This thesis develops a flexible shape formation control method for autonomous mobile robots. There are different approaches in the literature for shape formation of mobile robots. Proposed method is different from these existing approaches by being applicable to complex formation curves as well as different number of robots and heterogeneous groups. It consists of two phases. In the first phase, shape formation is controlled by using potential fields generated from implicit polynomial representations and in the second phase, the control for keeping the desired shape is designed using elliptical Fourier descriptors. In this shape formation method, coordination between the robots is modeled using virtual linear springs between each robot and its nearest two neighbors. The success of the proposed method is shown through simulations on groups of different numbers of point-particle robots. Proposed method is then extended to non-holonomic mobile robots by using the desired positions in point particle model as references for the non-holonomic robots. The method is also implemented with real non-holonomic robots with a bird-eye-view camera

Formation control of multiple robots using parametric and implicit representations

A novel method is presented for formation control of a group of autonomous mobile robots using parametric and implicit descriptions of the desired formation. Shape formation is controlled by using potential fields generated from Implicit Polynomial (IP) representations and the control for keeping the desired shape is designed using Elliptical Fourier Descriptors (EFD). Coordination of the robots is modeled by linear springs between each robot and its nearest two neighbors. This approach offers more flexibility in the formation shape and scales well to different swarm sizes and to heterogeneous systems. The method is simulated on robot groups with different sizes to form various formation shapes

DESIGN OF A SIX DEGREES OF FREEDOM HAPTIC DEVICE

iii To my brother iv ACKNOWLEDGMENTS First of all, I wish to express my deepest gratitude and appreciation to my advisor Assist. Prof. Dr. Kemalettin Erbatur for all his guidance and assistance not only throughout this thesis but all my graduate study. It has been a pleasure to work with him. I would like to thank Prof. Dr. Asif Şabanoviç who initiated this study and always be patient and tolerant with me. I would also like to acknowledge the members of my defense committee: Assoc. Prof. Dr. Mustafa Unel, Assoc. Prof. Dr. Mahmut Akşit and Assist. Prof. Dr. Erkay Savaş for finding time to serve as my jurors and for their comments on this work. I have to thank İlker Sevgen in addition to his friendship for his efforts in the completion of this thesis and Mehmet Güler for his “ultra-precise ” manufacturing skills. Among my friends who contributed to the success of this thesis in any way, I am glad to mention the following names; Burak Yılmaz who is my part-time roommate and one of the smartest and passionate people I have ever known, Nusrettin Güleç who has been nothing but a real friend for almost seven years now, Özer Ulucay whom I can always count on, Arda Burnaz who supplied foods, drinks and his unconditional friendship, Esra Nur Şahinoğlu whose friendship was precious for me, Onur Özcan who is one of the most sincere person I have known, Deniz Güçlü who was always there fo