Tag Archives: robot
#441400 Ostrich-Inspired Robot Gives Its Neck a ...
Birds are able to do a lot thanks to their highly flexible necks, whether it be turning their heads around to groom their backs, looking in many different directions during flight, or accessing hard-to-reach nooks and crannies along the ground or in trees. Among all avian species, the ostrich stands out as one bird with a particularly sturdy and dexterous neck—qualities that are also appealing for robotic manipulators.
Using an accurate blueprint of the muscles and tendons in an ostrich’s neck, researchers in Japan have created a novel robotic manipulator called RobOstrich. They describe the device in a study published 6 April in IEEE Robotics and Automation Letters.
Researchers are interested in creating soft and flexible robotic manipulators that could easily bend into hard-to-reach places, but this comes with challenges. “From a robotics perspective, it is difficult to control such a structure,” explains Kazashi Nakano, a doctoral student at the Graduate School of Information Science and Technology at the University of Tokyo. “We focused on the ostrich neck because of the possibility of discovering something new.”
His team first dissected the neck of an ostrich to understand the underlying network of tendons, muscle, and bone that helps manipulate such a long and heavy body part, which weighs in at a hefty 3 kilograms. Whereas a human has seven vertebrae in the neck, an ostrich has more that double that. What’s more, each cervical vertebra bends in two directions, resulting in extremely high degrees of freedom.
Using this anatomical data, the researchers set about creating their RobOstrich manipulator by 3-D printing 17 vertebrae, which they connected with bearings. Bundles of piano wires were used to mimic the biological muscles between an ostrich’s vertebrae (intervertebral muscles), and rubber bands were used as ligaments at the base of the manipulator to provide tension. An electric motor then reels in the wires, generating tension to “flex” the manipulator’s muscles. In a series of experiments, RobOstrich was able to complete various reaching tasks, where it had to achieve different configurations in order to come into contact with an object.
IEEE Spectrum RobOstrich v3
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Just like a real ostrich neck, the RobOstrich manipulator achieved a “rolling pattern,” where adjacent joints move in sequence while the head remains level with the ground. Nakano says he was surprised to find that this movement pattern can be achieved simply by adding tension to wires on just the underside of the neck alone, while the length of the wire on the backside remains constant—that is, it doesn’t need to be pulled. In this way, the manipulator can achieve complex configurations with minimal effort.
“The flexible structure is difficult to control, but the advantage is that dexterous reaching movements can be achieved by introducing muscle arrangements and joint ranges of motion based on the ostrich’s anatomy,” says Nakano.
As currently configured, RobOstrich can only move forward on a 2D plane, but the researchers hope to achieve 3D movement in the future.
“We aim to develop a controller that can perform reaching movements in an unstructured environment while colliding gently with it,” says Nakano.
Meanwhile, RobOstrich is not the only ostrich-inspired robot making headlines. Ostriches can also run at astounding speeds—covering 100 meters in just 5 seconds. Inspired by this feat, researchers at Oregon State University created Cassie, a two-legged speedster. Last September, Cassie set new records for the fastest bipedal robot; you can watch the video here. Continue reading
Posted in Human Robots
#441388 Robot Hand Manipulates Complex Objects ...
In terms of human features that robots are probably the most jealous of, fingers have to be right up there with eyeballs and brains. Our fleshy little digits have a crazy amount of dexterity relative to their size, and so many sensors packed into them that allow you to manipulate complex objects sight unseen. Obviously, these are capabilities that would be really nice to have in a robot , especially if we want them to be useful outside of factories and warehouses.
There are two parts to this problem: The first is having fingers that can perform like human fingers (or as close to human fingers as is reasonable to expect); the second is having the intelligence necessary to do something useful with those fingers.
“Once we also add visual feedback into the mix along with touch, we hope to be able to achieve even more dexterity, and one day start approaching the replication of the human hand.”
–Matei Ciocarlie, Columbia University
In a paper just accepted to the Robotics: Science and Systems 2023 conference, researchers from Columbia University have shown how to train robotic fingers to perform dexterous in-hand manipulation of complex objects without dropping them. What’s more, the manipulation is done entirely by touch—no vision required.
Robotic fingers manipulate random objects¸ a level of dexterity humans master by the time they’re toddlers.Columbia University
Those slightly chunky fingers have a lot going on inside of them to help make this kind of manipulation possible. Underneath the skin of each finger is a flexible reflective membrane, and under that membrane is an array of LEDs along with an array of photodiodes. Each LED is cycled on and off for a fraction of a millisecond, and the photodiodes record how the light from each LED reflects off of the inner membrane of the finger. The pattern of that reflection changes when the membrane flexes, which is what happens if the finger is contacting something. A trained model can correlate that light pattern with the location and amplitude of finger contacts.
So now that you have fingers that know what they’re touching, they also need to know how to touch something in order to manipulate it the way you want them to without dropping it. There are some objects that are robot-friendly when it comes to manipulation, and some that are robot-hostile, like objects with complex shapes and concavities (L or U shapes, for example). And with a limited number of fingers, doing in-hand manipulation is often at odds with making sure that the object remains in a stable grip. This is a skill called “finger gaiting,” and it takes practice. Or, in this case, it takes reinforcement learning (which, I guess, is arguably the same thing). The trick that the researchers use is to combine sampling-based methods (which find trajectories between known start and end states) with reinforcement learning to develop a control policy trained on the entire state space.
While this method works well, the whole nonvision thing is somewhat of an artificial constraint. This isn’t to say that the ability to manipulate objects in darkness or clutter isn’t super important, it’s just that there’s even more potential with vision, says Columbia’s Matei Ciocarlie: “Once we also add visual feedback into the mix along with touch, we hope to be able to achieve even more dexterity, and one day start approaching the replication of the human hand.”
“Sampling-based Exploration for Reinforcement Learning of Dexterous Manipulation,” by Gagan Khandate, Siqi Shang, Eric T. Chang, Tristan Luca Saidi, Johnson Adams, and Matei Ciocarlie from Columbia University, is accepted to RSS 2023. Continue reading
Posted in Human Robots
#441370 Augmented listening: A cocktail party of ...
Imagine a cocktail party full of 3D-printed, humanoid robots listening and talking to each other. That seemingly sci-fi scene is the goal of the Augmented Listening Laboratory at the University of Illinois Urbana-Champaign. Realistic talking (and listening) heads are crucial for investigating how humans receive sound and developing audio technology. Continue reading
Posted in Human Robots
#441358 Robots are everywhere—improving how ...
Robots are machines that can sense the environment and use that information to perform an action. You can find them nearly everywhere in industrialized societies today. There are household robots that vacuum floors and warehouse robots that pack and ship goods. Lab robots test hundreds of clinical samples a day. Education robots support teachers by acting as one-on-one tutors, assistants and discussion facilitators. And medical robotics composed of prosthetic limbs can enable someone to grasp and pick up objects with their thoughts. Continue reading
Posted in Human Robots
#441308 Robot caterpillar demonstrates new ...
Researchers at North Carolina State University have demonstrated a caterpillar-like soft robot that can move forward, backward and dip under narrow spaces. The caterpillar-bot's movement is driven by a novel pattern of silver nanowires that use heat to control the way the robot bends, allowing users to steer the robot in either direction. Continue reading
Posted in Human Robots