Tag Archives: steel
#437800 Malleable Structure Makes Robot Arm More ...
The majority of robot arms are built out of some combination of long straight tubes and actuated joints. This isn’t surprising, since our limbs are built the same way, which was a clever and efficient bit of design. By adding more tubes and joints (or degrees of freedom), you can increase the versatility of your robot arm, but the tradeoff is that complexity, weight, and cost will increase, too.
At ICRA, researchers from Imperial College London’s REDS Lab, headed by Nicolas Rojas, introduced a design for a robot that’s built around a malleable structure rather than a rigid one, allowing you to improve how versatile the arm is without having to add extra degrees of freedom. The idea is that you’re no longer constrained to static tubes and joints but can instead reconfigure your robot to set it up exactly the way you want and easily change it whenever you feel like.
Inside of that bendable section of arm are layers and layers of mylar sheets, cut into flaps and stacked on top of one another so that each flap is overlapping or overlapped by at least 11 other flaps. The mylar is slippery enough that under most circumstances, the flaps can move smoothly against each other, letting you adjust the shape of the arm. The flaps are sealed up between latex membranes, and when air is pumped out from between the membranes, they press down on each other and turn the whole structure rigid, locking itself in whatever shape you’ve put it in.
Image: Imperial College London
The malleable part of the robot consists of layers of mylar sheets, cut into flaps that can move smoothly against each other, letting you adjust the shape of the arm. The flaps are sealed up between latex membranes, and when air is pumped out from between the membranes, they press down on each other and turn the whole structure rigid, locking itself in whatever shape you’ve put it in.
The nice thing about this system is that it’s a sort of combination of a soft robot and a rigid robot—you get the flexibility (both physical and metaphorical) of a soft system, without necessarily having to deal with all of the control problems. It’s more mechanically complex than either (as hybrid systems tend to be), but you save on cost, size, and weight, and reduce the number of actuators you need, which tend to be points of failure. You do need to deal with creating and maintaining a vacuum, and the fact that the malleable arm is not totally rigid, but depending on your application, those tradeoffs could easily be worth it.
For more details, we spoke with first author Angus B. Clark via email.
IEEE Spectrum: Where did this idea come from?
Angus Clark: The idea of malleable robots came from the realization that the majority of serial robot arms have 6 or more degrees of freedom (DoF)—usually rotary joints—yet are typically performing tasks that only require 2 or 3 DoF. The idea of a robot arm that achieves flexibility and adaptation to tasks but maintains the simplicity of a low DoF system, along with the rapid development of variable stiffness continuum robots for medical applications, inspired us to develop the malleable robot concept.
What are some ways in which a malleable robot arm could provide unique advantages, and what are some potential applications that could leverage these advantages?
Malleable robots have the ability to complete multiple traditional tasks, such as pick and place or bin picking operations, without the added bulk of extra joints that are not directly used within each task, as the flexibility of the robot arm is provided by a malleable link instead. This results in an overall smaller form factor, including weight and footprint of the robot, as well as a lower power requirement and cost of the robot as fewer joints are needed, without sacrificing adaptability. This makes the robot ideal for scenarios where any of these factors are critical, such as in space robotics—where every kilogram saved is vital—or in rehabilitation robotics, where cost reduction may facilitate adoption, to name two examples. Moreover, the collaborative soft-robot-esque nature of malleable robots also tends towards collaborative robots in factories working safely alongside and with humans.
“The idea of malleable robots came from the realization that the majority of serial robot arms have 6 or more degrees of freedom (DoF), yet are typically performing tasks that only require 2 or 3 DoF”
—Angus B. Clark, Imperial College London
Compared to a conventional rigid link between joints, what are the disadvantages of using a malleable link?
Currently the maximum stiffness of a malleable link is considerably weaker than that of an equivalent solid steel rigid link, and this is one of the key areas we are focusing research on improving as motion precision and accuracy are impacted. We have created the largest existing variable stiffness link at roughly 800 mm length and 50 mm diameter, which suits malleable robots towards small and medium size workspaces. Our current results evaluating this accuracy are good, however achieving a uniform stiffness across the entire malleable link can be problematic due to the production of wrinkles under bending in the encapsulating membrane. As demonstrated by our SCARA topology results, this can produce slight structural variations resulting in reduced accuracy.
Does the robot have any way of knowing its own shape? Potentially, could this system reconfigure itself somehow?
Currently we compute the robot topology using motion tracking, with markers placed on the joints of the robot. Using distance geometry, we are then able to obtain the forward and inverse kinematics of the robot, of which we can use to control the end effector (the gripper) of the robot. Ideally, in the future we would love to develop a system that no longer requires the use of motion tracking cameras.
As for the robot reconfiguring itself, which we call an “intrinsic malleable link,” there are many methods that have been demonstrated for controlling a continuum structure, such as using positive pressure or via tendon wires, however the ability to in real-time determine the curvature of the link, not just the joint positions, is a significant hurdle to solve. However, we hope to see future development on malleable robots work towards solving this problem.
What are you working on next?
For us, refining the kinematics of the robot to enable a robust and complete system for allowing a user to collaboratively reshape the robot, while still achieving the accuracy expected from robotic systems, is our current main goal. Malleable robots are a brand new field we have introduced, and as such provide many opportunities for development and optimization. Over the coming years, we hope to see other researchers work alongside us to solve these problems.
“Design and Workspace Characterization of Malleable Robots,” by Angus B. Clark and Nicolas Rojas from Imperial College London, was presented at ICRA 2020.
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#437735 Robotic Chameleon Tongue Snatches Nearby ...
Chameleons may be slow-moving lizards, but their tongues can accelerate at astounding speeds, snatching insects before they have any chance of fleeing. Inspired by this remarkable skill, researchers in South Korea have developed a robotic tongue that springs forth quickly to snatch up nearby items.
They envision the tool, called Snatcher, being used by drones and robots that need to collect items without getting too close to them. “For example, a quadrotor with this manipulator will be able to snatch distant targets, instead of hovering and picking up,” explains Gwang-Pil Jung, a researcher at Seoul National University of Science and Technology (SeoulTech) who co-designed the new device.
There has been other research into robotic chameleon tongues, but what’s unique about Snatcher is that it packs chameleon-tongue fast snatching performance into a form factor that’s portable—the total size is 12 x 8.5 x 8.5 centimeters and it weighs under 120 grams. Still, it’s able to fast snatch up to 30 grams from 80 centimeters away in under 600 milliseconds.
Image: SeoulTech
The fast snatching deployable arm is powered by a wind-up spring attached to a motor (a series elastic actuator) combined with an active clutch. The clutch is what allows the single spring to drive both the shooting and the retracting.
To create Snatcher, Jung and a colleague at SeoulTech, Dong-Jun Lee, set about developing a spring-like device that’s controlled by an active clutch combined with a single series elastic actuator. Powered by a wind-up spring, a steel tapeline—analogous to a chameleon’s tongue—passes through two geared feeders. The clutch is what allows the single spring unwinding in one direction to drive both the shooting and the retracting, by switching a geared wheel between driving the forward feeder or the backward feeder.
The end result is a lightweight snatching device that can retrieve an object 0.8 meters away within 600 milliseconds. Jung notes that some other, existing devices designed for retrieval are capable of accomplishing the task quicker, at about 300 milliseconds, but these designs tend to be bulky. A more detailed description of Snatcher was published July 21 in IEEE Robotics and Automation Letters.
Photo: Dong-Jun Lee and Gwang-Pil Jung/SeoulTech
Snatcher’s relative small size means that it can be installed on a DJI Phantom drone. The researchers want to find out if their system can help make package delivery or retrieval faster and safer.
“Our final goal is to install the Snatcher to a commercial drone and achieve meaningful work, such as grasping packages,” says Jung. One of the challenges they still need to address is how to power the actuation system more efficiently. “To solve this issue, we are finding materials having high energy density.” Another improvement is designing a chameleon tongue-like gripper, replacing the simple hook that’s currently used to pick up objects. “We are planning to make a bi-stable gripper to passively grasp a target object as soon as the gripper contacts the object,” says Jung.
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#437693 Video Friday: Drone Helps Explore ...
Video Friday is your weekly selection of awesome robotics videos, collected by your Automaton bloggers. We’ll also be posting a weekly calendar of upcoming robotics events for the next few months; here's what we have so far (send us your events!):
ICRES 2020 – September 28-29, 2020 – Taipei, Taiwan
AUVSI EXPONENTIAL 2020 – October 5-8, 2020 – [Online Conference]
IROS 2020 – October 25-29, 2020 – Las Vegas, Nev., USA
CYBATHLON 2020 – November 13-14, 2020 – [Online Event]
ICSR 2020 – November 14-16, 2020 – Golden, Colo., USA
Let us know if you have suggestions for next week, and enjoy today's videos.
Clearpath Robotics and Boston Dynamics were obviously destined to partner up with Spot, because Spot 100 percent stole its color scheme from Clearpath, which has a monopoly on yellow and black robots. But seriously, the news here is that thanks to Clearpath, Spot now works seamlessly with ROS.
[ Clearpath Robotics ]
A new video created by Swisscom Ventures highlights a research expedition sponsored by Moncler to explore the deepest ice caves in the world using Flyability’s Elios drone. […] The expedition was sponsored by apparel company Moncler and took place over two weeks in 2018 on the Greenland ice sheet, the second largest body of ice in the world after Antarctica. Research focused on an area about 80 kilometers east of Kangerlussuaq, where scientists wanted to study the movement of water deep underground to better understand the effects of climate change on the melting ice.
[ Flyability ]
Shane Wighton of the “Stuff Made Here” YouTube channel, whose terrifying haircut machine we featured a few months ago, has improved on his robotic basketball hoop. It’s actually more than an improvement: It’s a complete redesign that nearly drove Wighton insane. But the result is pretty cool. It’s fun to watch him building a highly complicated system while always seeking simple and elegant designs for its components.
[ Stuff Made Here ]
SpaceX rockets are really just giant, explosion-powered drones that go into space sometimes. So let's watch more videos of them! This one is sped up, and puts a flight into just a couple of minutes.
[ SpaceX ]
Neato Robotics makes some solid autonomous vacuums, and these incremental upgrades feature improved battery life and better air filters.
[ Neato Robotics ]
A full-scale engineering model of NASA's Perseverance Mars rover now resides in a garage facing the Mars Yard at NASA's Jet Propulsion Laboratory in Southern California.
This vehicle system test bed rover (VSTB) is also known as OPTIMISM, which stands for Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars. OPTIMISM was built in a warehouselike assembly room near the Mars Yard – an area that simulates the Red Planet's rocky surface. The rover helps the mission test hardware and software before it’s transmitted to the real rover on Mars. OPTIMISM will share the space with the Curiosity rover's twin MAGGIE.
[ JPL ]
Heavy asset industries like shipping, oil and gas, and manufacturing are grounded in repetitive tasks like locating items on large industrial sites — a tedious task that can take as long 45 minutes to find critical items like a forklift in an area that spans the size of multiple football fields. Not only is this work boring, it’s dangerous and inefficient. Robots like Spot, however, love this sort of work.
Spot can provide real-time updates on the location of assets and complete other mundane tasks. In this case, Spot is using software from Cognite to roam the vast shipyard to locate and manage more than 100,000 assets stored across the facility. What used to take humans hours can be managed on an ongoing basis by Spot — leaving employees to focus on more strategic tasks.
[ Cognite ]
The KNEXT Barista system helps high volume premium coffee providers who want to offer artisan coffee specialities in consistent quality.
[ Kuka ]
In this paper, we study this idea of generality in the locomotion domain. We develop a learning framework that can learn sophisticated locomotion behavior for a wide spectrum of legged robots, such as bipeds, tripeds, quadrupeds and hexapods, including wheeled variants. Our learning framework relies on a data-efficient, off-policy multi-task RL algorithm and a small set of reward functions that are semantically identical across robots.
[ DeepMind ]
Thanks Dave!
Even though it seems like the real risk of COVID is catching it from another person, robotics companies are doing what they can with UVC disinfecting systems.
[ BlueBotics ]
Aeditive develop robotic 3D printing solutions for the production of concrete components. At the heart of their production plant are two large robots that cooperate to manufacture the component. The automation technology they build on is a robotic shotcrete process. During this process, they apply concrete layer by layer and thus manufacture complete components. This means that their customers no longer dependent on formwork, which is expensive and time-consuming to create. Instead, their customers can manufacture components directly on a steel pallet without these moulds.
[ Aeditive ]
Something BIG is coming next month from Robotiq!
My guess: an elephant.
[ Robotiq ]
TurtleBot3 is a great little home robot, as long as you have a TurtleBot3-sized home.
[ Robotis ]
How do you calculate the coordinated movements of two robot arms so they can accurately guide a highly flexible tool? ETH researchers have integrated all aspects of the optimisation calculations into an algorithm. The hot-wire cutter will be used, among other things, to develop building blocks for a mortar-free structure.
[ ETH Zurich ]
And now, this.
[ RobotStart ] Continue reading