Thesis (M.S.)--University of British Columbia, 2002. / Includes bibliographical references (leaves 47-50).

Thesis. 1977. B.S. cn--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 85-86. / by Kenneth J. Launie. / B.S.cn

Thesis. 1977. B.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 71-72. / by J. Mark Deric. / B.S.

Animals effectively move and negotiate a variety of environments exemplifying the neuromuscular system's ability to produce complex coordinated movements. Our central thesis is that the nonlinear dynamical properties of muscle play a critical role in power production and stability during such movements. We have developed a closed-loop system that couples an isolated muscle to a physical or computational load, facilitating the study of the interactions between intrinsic muscle properties and external forces. We used this system to determine how elastic elements in the frog semimembranosus can improve power production during a jumping task and how the contractile element automatically manages energy to maintain a stable bouncing gait. Our results reveal that, during ballistic movements (e.g. jumping), series elastic elements stretch and shorten to temporally concentrate energy transfer from the contractile element to the body, amplifying power production. We measured peak instantaneous power greater than twice the maximum power the contractile element could produce alone. Our results show how, during a bouncing gait, the contractile and elastic elements autonomously interact to produce, dissipate, and recycle energy and to maintain dynamic stability without sensory feedback. Our data suggest that muscles can recover over 75% of the kinematic energy from one step and apply it to the next. These results demonstrate the effects and importance of intrinsic muscle properties during movements. Ultimately, this research can guide the development of biomimetic robotic and prosthetic technologies capable of life-like mobility.

Thesis: B.S., Massachusetts Institute of Technology, Department of Biology, 1977 / by Gene Paul Masters. / B.S. / B.S. Massachusetts Institute of Technology, Department of Biology

Thesis. 1977. B.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / B.S.

Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Microfiche copy available in Archives and Engineering. / Bibliography: leaves 95-97. / by David R. Lampe. / M.S.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and (B.S.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1977. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 60-62. / B.S.

Human balance and locomotion control is highly complex and not well understood. To understand how the nervous system controls balance and locomotion works, we test how the body responds to controlled perturbations, the results are analyzed, and control models are developed. However, to recreate this system of control there is a need for a robot with human-like kinematics. Unfortunately, such a robotic testbed does not exist despite the numerous applications such a design would have in mobile robotics, healthcare, and prosthetics. This thesis presents a robotic testbed model of human lower legs. By using MRI and CT scans, I designed joints that require lower force for actuation, are more wear resistant, and are less prone to catastrophic failure than a traditional revolute (or pinned) joints. The result of using this process is the design, construction, and performance analysis of a biologically inspired knee joint for use in bipedal robotics. For the knee joint, the design copies the condylar surfaces of the distal end of the femur and utilizes the same crossed four-bar linkage design the human knee uses. The joint includes a changing center of rotation, a screw-home mechanism, and patella; these are characteristics of the knee that are desirable to copy for bipedal robotics. The design was calculated to have an average sliding to rolling ratio of 0.079, a maximum moment arm of 2.7 inches and a range of motion of 151 degrees. This should reduce joint wear and have kinematics similar to the human knee. I also designed and constructed novel, adjustably-damped hip and ankle joints that use braided pneumatic actuators. These joints provide a wide range of motion and exhibit the same change in stiffness that human joints exhibit as flexion increases, increasing stability, adaptability, and controllability. The theoretical behaviors of the joints make them desirable for use in mobile robotics and should provide a lightweight yet mechanically strong connection that is resistant to unexpected perturbations and catastrophic failure. The joints also bridge the gap between completely soft robotics and completely rigid robotics. These joints will give researchers the ability to test different control schemes and will help to determine how human balance is achieved. They will also lead to robots that are lighter and have lower power requirements while increasing the adaptability of the robot. When applying these design principles to joints used for prosthetics, we reduce the discomfort of the wearer and reduce the effort needed to move. Both of which are serious issues for individuals who need to wear a prosthetic device.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references.