Cheetah 3 Is Learning To Move Blindly Before Learning To See

Stand up right now and walk around for a minute. We’re pretty sure you didn’t see everywhere you stepped nor did you plan each step meticulously according to visual input. So why should robots do the same? Wouldn’t your robot be more versatile if it could use its vision to plan a path, but leave most of the walking to the legs with the help of various sensors and knowledge of joint positions?

That’s the approach [Sangbae Kim] and a team of researchers at MIT are taking with their Cheetah 3. They’ve given it cameras but aren’t using them yet. Instead, they’re making sure it can move around blind first. So far they have it walking, running, jumping and even going up stairs cluttered with loose blocks and rolls of tape.

Cheetah 3 jumping 30 inches onto a desk
Jumping 30 inches onto a desk

Two algorithms are at the heart of its being able to move around blind.

The first is a contact detection algorithm which decides if the legs should transition between a swing or a step based on knowledge of the joint positions and data from gyroscopes and accelerometers. If it tilted unexpectedly due to stepping on a loose block then this is the algorithm which decides what the legs should do.

The second is a model-predictive algorithm. This predicts what force a leg should apply once the decision has been made to take a step. It does this by calculating the multiplicative positions of the robot’s body and legs a half second into the future. These calculations are done 20 times a second. They’re what help it handle situations such as when someone shoves it or tugs it on a leash. The calculations enabled it to regain its balance or continue in the direction it was headed.

There are a number of other awesome features of this quadruped robot which we haven’t seen in others such as Boston Dynamics’ SpotMini like invertible knee joints and walking on three legs. Check out those features and more in the video below.

Of course, SpotMini has a whole set of neat features of its own. Let’s just say that while they look very similar, they’re on two different evolutionary paths. And the Cheetah certainly has evolved since we last looked at it a few years ago.

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MIT’s Robotic Cheetah Is Getting Even Scarier

Researchers over at MIT are hard at work upgrading their Robotic Cheetah. They are developing an algorithm for bounding movement, after researching how real cheetahs run in the wild.

Mach 2 is fully electric and battery-powered, can currently run at speeds of 10MPH (however they’re predicting it will be able to reach 30MPH in the future), and can even jump over obstacles 33cm tall.

We originally saw the first robotic Cheetah from Boston Dynamics in cooperation with DARPA two years ago — it could run faster than any human alive (28.3MPH) but in its tests it was tethered to its hydraulic power pack and running on a treadmill. It’s unclear if MIT’s Cheetah is a direct descendant from that one, but they are both supported by DARPA.

The technology in this project is nothing short of amazing — its electric motors are actually a custom part designed by one of the professors of Electrical Engineering at MIT, [Jeffrey Lang]. In order for the robot to run smoothly, its bounding algorithm is sending commands to each leg to exert a very precise amount of force during each footstep, just to ensure it maintains the set speed.

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