| Many modern robotic systems could benefit from high force actuators and controllers with good reliability and low cost. In this dissertation, control algorithms for a pneumatically actuated hopping robot, and a novel damping device for seismic protection of structures, are designed and tested experimentally.; The hopping robot is similar in structure to the Acrobot, which is a double inverted pendulum that has a single actuator located at the second joint. We study the Acrobot for its potential as a hopping robot. By allowing the base to translate in the vertical plane, we show that stable periodic hopping motions are possible. In order to achieve a successful hardware design, we address the need for a light and powerful actuator, the need for tilt sensing at high bandwidths, and the need to control the open-loop instability of the periodic hopping motions.; Toward this end, a robust control approach is developed to handle measurement noise, low actuator bandwidth, and varying set points for the balance control problem of the Acrobot. The approach is implemented in hardware and is demonstrated experimentally. A low cost solution to the problem of tilt sensing is developed, along with an approach for state estimation that can be used for general purpose robot manipulators. A realistic model of the hopping robot is developed, and the feedback control problem for periodic hopping gaits is explored.; Additionally, a novel vibration damper capable of 20,000 pounds of force output is designed from hydraulic components. The damper uses a closed hydraulic cylinder filled with high pressure nitrogen gas. The exchange of gas from one side of the cylinder to the other is controlled by a high performance servovalve. All sensory data is local to the device, and a control law is presented that allows the damper to act on a building in various configurations, including base isolation. The device is tested experimentally on a compact model of a full scale single story building. It is systematically compared to other competing actuators and control approaches, and is shown to have superior performance under many load conditions. |
