MIT researchers have created this beautiful ‘cheetah’ robot weighing in at 70 pounds and able to run without wasting very much energy.
A 70-pound “cheetah” robot designed by MIT researchers may soon outpace its animal counterparts in running efficiency: In treadmill tests, the researchers have found that the robot — about the size and weight of an actual cheetah — wastes very little energy as it trots continuously for up to an hour and a half at 5 mph. The key to the robot’s streamlined stride: lightweight electric motors, set into its shoulders, that produce high torque with very little heat wasted.
The motors can be programmed to quickly adjust the robot’s leg stiffness and damping ratio — or cushioning — in response to outside forces such as a push, or a change in terrain. The researchers will present the efficiency results and design principles for their electric motor at the International Conference on Robotics and Automation in May.
Sangbae Kim, the Esther and Harold E. Edgerton Assistant Professor in MIT’s Department of Mechanical Engineering, says achieving energy-efficiency in legged robots has proven extremely difficult. Robots such as Boston Dynamic’s “Big Dog” carry heavy gasoline engines and hydraulic transmissions, while other electrically powered robots require large battery packs, gears, force sensors and springs to coordinate the joints in a robot’s leg. All this weighty machinery can add up to significant wasted energy, particularly when a robot’s legs need to make frequent contact with the ground in order to trot or gallop.