GOAT (Gear-less Omnidirectional Acceleration Topology)
The GOAT (Gearless Omnidirectional Acceleration Topology) robot is a monoped robot that has 3DOF position control of its foot, as well as high bandwidth proprioceptive force control, meaning that it is capable of both precise foot placement and highly dynamic running gaits. It can achieve high bandwidth, precise, dynamic motion by using three direct-drive electromagnetic actuators connected in a spatial parallel configuration. Direct drive actuation avoids the common problems associated with using gearboxes, including stiction and backlash. These actuators also allow for straightforward implementation of virtual model control on the robot leg, which lets the robot change its stiffness in real time.
Virtual Model Control
High-bandwidth virtual model control implemented at 800 hertz in C++ allows the leg to effectively emulate the behavior of a spring-damper system.
3D balance control was achieved through a LQR controller.
To achieve successful hopping behavior, a raibert-style controller was developed for the GOAT leg.