Authors' current addresses: A.C. Sanderson, Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180; M.A. Peshkin, Department of Mechanical Engineering, The Technological Institute, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60201; L.S. Homem de Mello, Robotics Institute, Department of Electrical and Computer Engineering, Camegi...
