Adaptive height controller for an agile hopping robot

The controller is first derived for height control of hopping vertically, with no horizontal motion, from an analytical approximation. This is tested in simulation, using a spring-damper model and a more detailed model with a foot mass and compliant ground. The controller is then applied to a hydraulic spring-loaded hopper monoped. An extension allows the control of running on a treadmill, with constant horizontal speed.