Dedication

I wish to dedicate this work to my parents, Rita and Pino, as a partial repayment of their sizable investment in Lego pieces 30 years ago, which ultimately led to my interest in robotics; and to my brother Marco, who bore the burden of being my first office mate. I am deeply indebted to my parents as they taught me to ask questions, and to question answers. They are a model of moral integrity and hushed selflessness that I hope I will have the strength to emulate. i Acknowledgments These years at Caltech have been an exciting roller-coaster, which began slowly, went through frenetic ups and downs, and ended much too quickly. I wish I could buy a ticket for another ride. I will always be indebted to my advisor Richard Murray, who was the main reason for this to be a relatively pleasant and fulfilling experience. He has been the last of a long series of people whom I was lucky to meet from high school to grad-uate school, who taught me the value of intellectual honesty, how to respect mysel