[Ben Katz] is building a running robot from hobby level brushless motors, all on his blog under the tag, “HobbyKing Cheetah.”
One of the features of fancy modern industrial motor and controller sets is the ability for the motor to act as a mass-spring-damper. For example, let’s say you want a robot to hold an egg. You could have it move to the closed position, but tell the controller you only want to use so much force to do it. It will hold the egg as if there was a spring at its joint.
Another way you could use this is in the application of a robot leg. You tell the controller what kind of spring and shock absorber (damper) combination it is and it will behave as if those parts have been added to the mechanism. This is important if you want a mechanical leg to behave like a biological leg.
[Ben] had worked on a more formal project which used some very expensive geared motors to build a little running robot. It looks absolutely ridiculous, as you can see in the following video, but it gives an idea of where he’s going with this line of research. He wanted to see if he could replace all those giant geared motors with the cheap and ubiquitous high performance brushless DC motors for sale now. Especially given his experience with them.
So far he’s done a very impressive amount of work. He’s built a control board. He’s characterized different motors for the application. He’s written a lot of cool software; he can even change the stiffness and damping settings on the fly. He has a single leg that can jump. It’s cool. He’s taking a hiatus from the project, but he’ll be right back at it soon. We’re excited for the updates!
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.
Continue reading “MIT’s Robotic Cheetah is Getting Even Scarier”
[Boston Dynamics] has been just full of videos over the last few days. They’ve dropped updates on Atlas and LS3 in addition to the WildCat update we already featured.
This video shows updates to the Atlas robot. This is to be a simplified version of the atlas, as compared to the robots sent off to competitors in the DARPA robotics challenge. Arms have been replaced with weights. It appears that this update focuses on Atlas’ balancing and handling on rough terrain. Atlas walks gingerly, over some crushed cinder blocks – possibly the same ones we saw BigDog throwing around recently. There are a few tense moments, but Atlas manages to get through unscathed.
The real scary part (for us) is watching Atlas get hit with a weighted ball. We’re assuming the 20 on the ball indicates pounds. Imagine getting hit from the side with a 20lb swinging weight. Would you be able to stand up? Did we mention Atlas did this all while standing on one foot? Atlas takes it in stride though – waving its arms to maintain balance in a very human manner. Notable is the balance system. Atlas never lifts its foot off the ground. This is slightly different from the bouncing/hopping system of balance we’ve come to know and love in [Boston Dynamics’] other robots. Continue reading “Atlas Survives the Wrecking Ball”
[Boston Dynamics] has released a video of their latest robot, which means it’s time to go hide in bed before this thing comes to get us. The new video features WildCat, which is apparently the evolution of the Cheetah robot we saw last year. Cheetah was an indoor cat, tethered by power, data, and hydraulic lines while running on a treadmill. WildCat has been released to
terrorize people explore the great outdoors
Reminiscent of the early videos of BigDog, WildCat is currently powered by an internal combustion engine. The engine drives a hydraulic system, which then actuates the robot’s legs and front/rear pods. The beauty of a system like this is that switching to an electric motor is simple – just replace the IC engine. While we’re sure this would make a much more stealthy cat, weight and run time could be issues. Moving the power system onboard has also slowed down WildCat a bit. Cheetah was able to reach 28 MPH while WildCat can only muster 16 MPH.
WildCat is part of DARPA’s maximum mobility and manipulation program. The research appears to be focused on improving the gaits the robot uses to move at various speeds. The video highlights both bounding and galloping. Slo-mo sections show all four of WildCat’s legs leaving the ground, which is the suspension phase of a classic gallop gait. Control isn’t perfect yet, as WildCat tumbles at one point in the video. It gets right back up though – ready for more.
Continue reading “Boston Dynamics Takes WildCat Outside”
It’s a blur, but you really don’t want to seen this thing coming for you anyway. It’s the latest look at what the folks at Boston Dynamics have been working on under a DARPA contract. They call it the Cheetah robot as it’s the fastest four-legged bot ever developed. The clip after the break shows it breaking the world record over 100 meters… for a human. This isn’t really legitimate since the run is done on a treadmill and the robot is tethered. But it’s still
The Cheetah is a relative of BigDog, another Boston Dynamics robot which we’ve seen several times in the past. BigDog specializes in lifting heavy loads and traversing rough terrain. We don’t think it will be too long before both traits can be “bred” into one device. A lot of times when we feature these robots there are comments about how they invoke images from The Terminator movies. For us this is more along [Michael Bay’s] vision of robots from the Transformers series. It certainly not small enough or fast enough to be seen as an early version of the Rat Thing.
Continue reading “Cheetah robot can run down even the fastest of us”