MIT's latest addition to their cheetah robot line is the new mini cheetah robot. This new lightweight model weighs only 20 pounds making it springy and light on its feet. Built to be "virtually indestructible" the robot can easily right itself when it falls. It can even perform a backflip from standing.
“The rate at which it can change forces on the ground is really fast,” says Benjamin Katz, technical associate in MIT's Department of Mechanical Engineering. “When it’s running, its feet are only on the ground for something like 150 milliseconds at a time, during which a computer tells it to increase the force on the foot, then change it to balance, and then decrease that force really fast to lift up. So it can do really dynamic stuff, like jump in the air with every step, or run with two feet on the ground at a time. Most robots aren’t capable of doing this, so move much slower.”
From the MIT article: "Each of the robot’s 12 motors is about the size of a Mason jar lid, and consists of: a stator, or set of coils, that generates a rotating magnetic field; a small controller that conveys the amount of current the stator should produce; a rotor, lined with magnets, that rotates with the stator’s field, producing torque to lift or rotate a limb; a gearbox that provides a 6:1 gear reduction, enabling the rotor to provide six times the torque that it normally would; and a position sensor that measures the angle and orientation of the motor and associated limb.
Each leg is powered by three motors, to give it three degrees of freedom and a huge range of motion. The lightweight, high-torque, low-inertia design enables the robot to execute fast, dynamic maneuvers and make high-force impacts on the ground without breaking gearboxes or limbs."
Read more about the backflipping mini cheetah robot at MIT.