What is 16 feet long, 10 feet high, weighs 6,000 pounds, has six legs, and can sprint at 8 mph and step over a 4 foot wall? The Adaptive Suspension Vehicle (ASV) described in this book. Machines That Walk provides the first in depth treatment of the "statically stable walking machine" theory employed in the design of the ASV, the most sophisticated, self contained, and practical walking machine being developed today. Under construction at Ohio State University, the automatically terrain adaptive ASV has one human operator, can carry a 500 pound payload and is expected to have better fuel economy and mobility than that of conventional wheeled and tracked vehicles in rough terrain. The development of the ASV is a milestone in robotics research, and Machines That Walk provides a wealth of research results in mobility, gait, static stability, leg design, and vertical geometry design. The authors' treatment of statically stable gait theory and actuator coordination is by far the most complete available.