May 21 - The cheetah is not only the world's fastest land animal, it is also one of the most energy efficient, expending only what it needs to survive. It's that efficiency that engineers at MIT are working to emulate in a robotic cheetah, already clocked as the second fast robot ever developed. Ben Gruber reports.
It takes this robot a while to get going - but once it does - it's very fast - the second fastest running robot ever developed. According to its creator Sangbae Kim, what this robotic cheetah lacks in speed it makes up for in efficiency. Driven by custom designed electric motors, Kim's robot can reach speeds of 22 kms, or 13.6 miles per hour. He says it's almost as energy efficient as a real cheetah - a new feat for a running robot. SANGBAE KIM, ASSISTANT PROFESSOR OF MECHANICAL ENGINEERING, MIT, SAYING: "We designed the motor in a way that minimized the gear ratio, so we can be more interactive with the environment." Kim says the motors acts like muscles, providing torque and speed with only a fraction of the energy required by hydraulic systems. Boston Dynamics robotic cheetah can run more than twice as fast as the MIT robot, but it needs to be powered by a tethered hydraulic pump. According to Kim his cheetah uses less power that comes from batteries on its robot frame. Kim also fitted his cheetah with regenerative motor drives which act like the breaking system in hybrid cars to add another layer of efficiency. And he's fairly certain his cheetah can run even faster. SANGBAE KIM, ASSISTANT PROFESSOR OF MECHANICAL ENGINEERING, MIT, SAYING: "We can simulate faster speeds. We've simulated up to 33 miles per hour which is about 15 metres per second and our power estimation is about two kilowatts which is actually lower than animal level." And while the real cheetah is capable of reaching speeds of up to 70 miles per hour.. Kim and his team are focusing on its energy efficiency rather than its speed for their next prototype. He says that within the next five years he wants to build a hybrid robot with increased functionality. SANGBAE KIM, ASSISTANT PROFESSOR OF MECHANICAL ENGINEERING, MIT, SAYING: "We are planning to build a slightly different version of the robot which will be more like a monkey or an ape. Which means it has similar architecture, but the front legs will have a manipulator, will have hands. So you can walk on the four legs but when you reach a door or an obstacle you can stand up and use the front legs to manipulate obstacles." Kim says his cheetah/monkey hybrid will be the ideal tool for search and rescue missions in places where it's too dangerous to send humans. But he admits the research is still in its infancy and the machine has to learn to walk before it can run.