The Tactical Hazardous Operations Robot (THOR) is a 33 degree of freedom robot capable of compliant, force controlled walking. THOR was originally built for the Office of Naval Research’s Shipboard Autonomous Firefighting Robot (SAFFiR) program, and then was the original entrant of Team VALOR for the DARPA Robotics Challenge. THOR has been noted as the first bipedal in the world to extinguish a fire. This represented the final challenge of Phase I of the SAFFiR program.
Designed by a team of TREC engineers, THOR was manufactured almost entirely in TREC’s in house machine shop. Building off the prototype legs, the twelve degrees of freedom in the legs are actuated entirely by custom linear series elastic actuators. This allows THOR to use custom impedance control algorithms in each of these actuators to achieve compliant force-controlled motion. These algorithms are implemented on custom dual axis motor controllers designed in house. By using an inverted Hoeckens Linkage in the knees and hip pitches and parallelly actuated hip roll-yaws and ankle pitch-rolls, THOR is capable of super human ranges of motion, making it a versatile platform, capable of many human-like tasks.
Using a control architecture designed and written in house, THOR represents one of the few humanoids in the world capable of whole-body task-space control. This allows THOR to robustly achieve multiple motion tasks, such as maintaining balance, remaining upright, and handle a fire hose. By combining whole-body momentum control with impedance controlled joints, THOR is also capable of walking across a variety of unknown terrains, including grass, gravel, and brick. Videos of some of the few THOR is capable of can be found on our YouTube channel!