BigDog, a dynamically stable quadruped robot created by Boston Dynamics with Foster-Miller, the NASA Jet Propulsion Laboratory, and the Harvard University Concord Field Station, has now been upgraded with a fifth arm capable of throwing cinder blocks across a room. Continue reading for the video and more information.

BigDog’s unique walking pattern is controlled through four legs, each equipped with four low-friction hydraulic cylinder actuators that power the joints. “The BigDog robot, labelled as a military robot mule, has subsequently proven its potential worth in its ability to reduce load and remove that burden from a soldier’s back.”

Built onto the actuators are sensors for joint position and force, and movement is ultimately controlled through an onboard computer which manages the sensors. Approximately 50 sensors are located on BigDog. These measure the attitude and acceleration of the body, motion and force of joint actuators as well as engine speed, temperature and hydraulic pressure inside the robot’s internal engine. Low-level control, such as position and force of the joints, and high-level control such as velocity and altitude during locomotion, are both controlled through the on-board computer.