1. Dynamic Systems and Control Laboratory, Department of Mechanical Engineering, San Diego State University, San Diego, CA 92115 e-mails: ;
2. Professor Director of Center for Nonlinear Dynamics and Control, Department of Mechanical Engineering, Villanova University, Villanova, PA 19085 e-mail:
3. Dynamic Systems and Control Laboratory, Department of Mechanical Engineering, San Diego State University, San Diego, CA 92115 e-mail: