Tag Archives: robot
#439316 Tencent’s New Wheeled Robot Flicks Its ...
Ollie (I think its name is Ollie) is a “a novel wheel-legged robot” from Tencent Robotics. The word “novel” is used quite appropriately here, since Ollie sports some unusual planar parallel legs atop driven wheels. It’s also got a multifunctional actuated tail that not only enables some impressive acrobatics, but also allows the robot to transition from biped-ish to triped-ish to stand up extra tall and support a coffee-carrying manipulator.
It’s a little disappointing that the tail only appears to be engaged for specific motions—it doesn’t seem like it’s generally part of the robot’s balancing or motion planning, which feels like a missed opportunity. But this robot is relatively new, and its development is progressing rapidly, which we know because an earlier version of the hardware and software was presented at ICRA 2021 a couple weeks back. Although, to be honest with you, there isn’t a lot of info on the new one besides the above video, so we’ll be learning what we can from the ICRA paper.
The paper is mostly about developing a nonlinear balancing controller for the robot, and they’ve done a bang-up job with it, with the robot remaining steady even while executing sequences of dynamic motions. The jumping and one-legged motions are particularly cool to watch. And, well, that’s pretty much it for the ICRA paper, which (unfortunately) barely addresses the tail at all, except to say that currently the control system assumes that the tail is fixed. We’re guessing that this is just a symptom of the ICRA paper submission deadline being back in October, and that a lot of progress has been made since then.
Seeing the arm and sensor package at the end of the video is a nod to some sort of practical application, and I suppose that the robot’s ability to stand up to reach over that counter is some justification for using it for a delivery task. But it seems like it’s got so much more to offer, you know? Many far more boring platforms robots could be delivering coffee, so let’s find something for this robot to do that involves more backflips.
Balance Control of a Novel Wheel-legged Robot: Design and Experiments, by Shuai Wang, Leilei Cui, Jingfan Zhang, Jie Lai, Dongsheng Zhang, Ke Chen, Yu Zheng, Zhengyou Zhang, and Zhong-Ping Jiang from Tencent Robotics X, was presented at ICRA 2021. Continue reading
Posted in Human Robots
#439313 Study explores the potential of using a ...
Humanoid robots have the potential of assisting humans in a variety of settings, ranging from home environments to malls, schools and healthcare facilities. Some roboticists have been specifically investigating the potential of social robots as tools to offer care and companionship to the elderly population. Continue reading
Posted in Human Robots
#439294 Unitree’s Go1 Robot Dog Looks Pretty ...
In 2017, we first wrote about the Chinese startup Unitree Robotics, which had the goal of “making legged robots as popular and affordable as smartphones and drones.” Relative to the cost of other quadrupedal robots (like Boston Dynamics’ $74,000 Spot), Unitree’s quadrupeds are very affordable, with their A1 costing under $10,000 when it became available in 2020. This hasn’t quite reached the point of consumer electronics that Unitree is aiming for, but they’ve just gotten a lot closer: now available is the Unitree Go1, a totally decent looking small size quadruped that can be yours for an astonishingly low $2700.
Not bad, right? Speedy, good looking gait, robust, and a nifty combination of autonomous human following and obstacle avoidance. As with any product video, it’s important to take everything you see here with a grain of salt, but based on Unitree’s track record we have no particular reason to suspect that there’s much in the way of video trickery going on.
There are three versions of the Go1: the $2700 base model Go1 Air, the $3500 Go1, and the $8500 Go1 Edu. This looks to be the sort of Goldilocks pricing model, where most people are likely to spring for the middle version Go1, which includes better sensing and compute as well as 50% more battery life an an extra m/s of speed (up to 3.5m/s) for a modest premium in cost. The top of the line Edu model offers higher end computing, 2kg more payload (up to 5kg), as well as foot-force sensors, lidar, and a hardware extension interface and API access. More detailed specs are here, although if you’re someone who actually cares about detailed robot specs, what you’ll find on Unitree’s website at the moment will probably be a little bit disappointing.
We’ve reached out to Unitree to ask them about some of the specs that aren’t directly addressed on the website. Battery life is a big question—the video seems to suggest that the Go1 is capable of a three-kilometer, 20-minute jog, and then some grocery shopping and a picnic, all while doing obstacle avoidance and person following and with an occasional payload. If all of that is without any battery swaps, that’s pretty good. We’re also wondering exactly what the “Super Sensory System” is, what kinds of tracking and obstacle avoidance and map making skills the Go1 has, and exactly what capabilities you’ll be required to spring for the fancier (and more expensive) versions of the Go1 to enjoy.
Honestly, though, we’re not sure what Unitree could realistically tell us about the Go1 where we’d be like, “hmm okay maybe this isn’t that great of a deal after all.” Of course the real test will be when some non-Unitree folks get a hold of a Go1 to see what it can actually do (Unitree, please contact me for my mailing address), but even at $3500 for the midrange model, this seems like an impressively cost effective little robot. Continue reading
Posted in Human Robots
#439286 MIT is Building a Dynamic, Acrobatic ...
For a long time, having a bipedal robot that could walk on a flat surface without falling over (and that could also maybe occasionally climb stairs or something) was a really big deal. But we’re more or less past that now. Thanks to the talented folks at companies like Agility Robotics and Boston Dynamics, we now expect bipedal robots to meet or exceed actual human performance for at least a small subset of dynamic tasks. The next step seems to be to find ways of pushing the limits of human performance, which it turns out means acrobatics. We know that IHMC has been developing their own child-size acrobatic humanoid named Nadia, and now it sounds like researchers from Sangbae Kim’s lab at MIT are working on a new acrobatic robot of their own.
We’ve seen a variety of legged robots from MIT’s Biomimetic Robotics Lab, including Cheetah and HERMES. Recently, they’ve been doing a bunch of work with their spunky little Mini Cheetahs (developed with funding and support from Naver Labs), which are designed for some dynamic stuff like gait exploration and some low-key four-legged acrobatics.
In a paper recently posted to arXiv (to be presented at Humanoids 2020 in July), Matthew Chignoli, Donghyun Kim, Elijah Stanger-Jones, and Sangbae Kim describe “a new humanoid robot design, an actuator-aware kino-dynamic motion planner, and a landing controller as part of a practical system design for highly dynamic motion control of the humanoid robot.” So it’s not just the robot itself, but all of the software infrastructure necessary to get it to do what they want it to do.
Image: MIT
MIT Humanoid performing a back flip off of a humanoid robot off of a 0.4 m platform in simulation.
First let’s talk about the hardware that we’ll be looking at once the MIT Humanoid makes it out of simulation. It’s got the appearance of a sort of upright version of Mini Cheetah, but that appearance is deceiving, says MIT’s Matt Chignoli. While the robot’s torso and arms are very similar to Mini Cheetah, the leg design is totally new and features redesigned actuators with higher power and better torque density. “The main focus of the leg design is to enable smooth but dynamic ‘heel-to-toe’ actions that happen in humans’ walking and running, while maintaining low inertia for smooth interactions with ground contacts,” Chignoli told us in an email. “Dynamic ankle actions have been rare in humanoid robots. We hope to develop robust, low inertia and powerful legs that can mimic human leg actions.”
The design strategy matters because the field of humanoid robots is presently dominated by hydraulically actuated robots and robots with series elastic actuators. As we continue to improve the performance of our proprioceptive actuator technology, as we have done for this work, we aim to demonstrate that our unique combination of high torque density, high bandwidth force control, and the ability to mitigate impacts is optimal for highly dynamic locomotion of any legged robot, including humanoids.
-Matt Chignoli
Now, it’s easy to say “oh well pfft that’s just in simulation and you can get anything to work in simulation,” which, yeah, that’s kinda true. But MIT is putting a lot of work into accurately simulating everything that they possibly can—in particular, they’re modeling the detailed physical constraints that the robot operates under as it performs dynamic motions, allowing the planner to take those constraints into account and (hopefully) resulting in motions that match the simulation pretty accurately.
“When it comes to the physical capabilities of the robot, anything we demonstrate in simulation should be feasible on the robot,” Chignoli says. “We include in our simulations detailed models for the robot’s actuators and battery, models that have been validated experimentally. Such detailed models are not frequently included in dynamic simulations for robots.” But simulation is still simulation, of course, and no matter how good your modeling is, that transfer can be tricky, especially when doing highly dynamic motions.
“Despite our confidence in our simulator’s ability to accurately mimic the physical capabilities of our robot with high fidelity, there are aspects of our simulator that remain uncertain as we aim to deploy our acrobatic motions onto hardware,” Chignoli explains. “The main difficulty we see is state estimation. We have been drawing upon research related to state estimation for drones, which makes use of visual odometry. Without having an assembled robot to test these new estimation strategies on, though, it is difficult to judge the simulation to real transfer for these types of things.”
We’re told that the design of the MIT Humanoid is complete, and that the plan is to build it for real over the summer, with the eventual goal of doing parkour over challenging terrains. It’s tempting to fixate on the whole acrobatics and parkour angle of things (and we’re totally looking forward to some awesome videos), but according to Chignoli, the really important contribution here is the framework rather than the robot itself:
The acrobatic motions that we demonstrate on our small-scale humanoid are less about the actual acrobatics and more about what the ability to perform such feats implies for both our hardware as well as our control framework. The motions are important in terms of the robot’s capabilities because we are proving, at least in simulation, that we can replicate the dynamic feats of Boston Dynamics’ ATLAS robot using an entirely different actuation scheme (proprioceptive electromagnetic motors vs. hydraulic actuators, respectively). Verification that proprioceptive actuators can achieve the necessary torque density to perform such motions while retaining the advantages of low mechanical impedance and high-bandwidth torque control is important as people consider how to design the next generation of dynamic humanoid robots. Furthermore, the acrobatic motions demonstrate the ability of our “actuator-aware” motion planner to generate feasible motion plans that push the boundaries of what our robot can do.
The MIT Humanoid Robot: Design, Motion Planning, and Control For Acrobatic Behaviors, by Matthew Chignoli, Donghyun Kim, Elijah Stanger-Jones, and Sangbae Kim from MIT and UMass Amherst, will be presented at Humanoids 2020 this July. You can read a preprint on arXiv here. Continue reading
Posted in Human Robots
#439263 Somehow This Robot Sticks to Ceilings by ...
Just when I think I’ve seen every possible iteration of climbing robot, someone comes up with a new way of getting robots to stick to things. The latest technique comes from the Bioinspired Robotics and Design Lab at UCSD, where they’ve managed to get a robot to stick to smooth surfaces using a vibrating motor attached to a flexible disk. How the heck does it work?
According to a paper just published in Advanced Intelligent Systems, it’s due to “the fluid mediated adhesive force between an oscillatory plate and a surface” rather than black magic. Obviously.
Weird, right? In the paper, the researchers explain that what’s going on here: As the 14cm diameter flexible disk vibrates at 200 Hz, it generates a thin layer of low pressure air in between itself and the surface that it’s vibrating against. Although the layer of low pressure air is less than 1 mm thick, the disk can resist 5 N of force pulling on it. You can sort of think of this as a suction effect, except that it doesn’t require the disk to be constantly sealed against a surface, meaning that the robot can move around without breaking adhesion.
Image: UCSD
The big advantage here is that this is about as simple and cheap as a smooth-surface climbing robot gets, especially at small(ish) scales. There are a couple of downsides too, though. The biggest one could be that 200 Hz is a frequency that’s well within human hearing, which probably explains that soundtrack in the video—the robot is, as the researchers put it, “inherently quite noisy.” And in contrast to some other controllable adhesion techniques, this system must be turned on at all times or it will immediately plunge to its doom.
The robot you’re looking at in the video (with a 14cm disk) seems to be the sweet spot when it comes to size—going smaller means that the motor starts taking up a disproportionate amount of weight, while going larger would likely not scale well either, with the overall system mass increasing faster than the amount of adhesion that you get. The researchers suggest that “it could be advantageous to combine several disk geometries to achieve the desired load capacity and resilience to disturbances,” but that’s one of a number of things that the researchers need to figure out to properly characterize this novel adhesion technique.
Gas-Lubricated Vibration-Based Adhesion for Robotics, by William P. Weston-Dawkes, Iman Adibnazari, Yi-Wen Hu, Michael Everman, Nick Gravish, and Michael T. Tolley, is available here. Continue reading
Posted in Human Robots