Motion Control

Researchers Equip Robot with Novel Tactile Sensor

Researchers at MIT and Northeastern University have equipped a robot with a novel tactile sensor that lets it grasp a USB cable draped freely over a hook and insert it into a USB port.The sensor is an adaptation of a technology called GelSight, which was developed by the lab of Edward Adelson, the John and Dorothy Wilson Professor of Vision Science at MIT, and first described in 2009. The new sensor isn’t as sensitive as the original GelSight sensor, which could resolve details on the micrometer scale. But it’s smaller — small enough to fit on a robot’s gripper — and its processing algorithm is faster, so it can give the robot feedback in real time.A GelSight sensor — both the original and the new, robot-mounted version — consists of a slab of transparent, synthetic rubber coated on one side with a metallic paint. The rubber conforms to any object it’s pressed against, and the metallic paint evens out the light-reflective properties of diverse materials, making it much easier to make precise optical measurements.In the new device, the gel is mounted in a cubic plastic housing, with just the paint-covered face exposed. The four walls of the cube adjacent to the sensor face are translucent, and each conducts a different color of light — red, green, blue, or white — emitted by light-emitting diodes at the opposite end of the cube. When the gel is deformed, light bounces off of the metallic paint and is captured by a camera mounted on the same cube face as the diodes.From the different intensities of the different-colored light, the algorithms developed by Adelson’s team can infer the three-dimensional structure of ridges or depressions of the surface against which the sensor is pressed. Source Read other Sensors tech briefs.

Posted in: Photonics, Optics, Materials, Motion Control, Sensors, Lighting, LEDs, Machinery & Automation, Robotics, News

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New Algorithm Lets Cheetah Robot Run

Speed and agility are hallmarks of the cheetah: The big predator is the fastest land animal on Earth, able to accelerate to 60 mph in just a few seconds. As it ramps up to top speed, a cheetah pumps its legs in tandem, bounding until it reaches a full gallop.Now MIT researchers have developed an algorithm for bounding that they’ve successfully implemented in a robotic cheetah — a sleek, four-legged assemblage of gears, batteries, and electric motors that weighs about as much as its feline counterpart. The team recently took the robot for a test run on MIT’s Killian Court, where it bounded across the grass at a steady clip. In experiments on an indoor track, the robot sprinted up to 10 mph, even continuing to run after clearing a hurdle. The MIT researchers estimate that the current version of the robot may eventually reach speeds of up to 30 mph.The key to the bounding algorithm is in programming each of the robot’s legs to exert a certain amount of force in the split second during which it hits the ground, in order to maintain a given speed: In general, the faster the desired speed, the more force must be applied to propel the robot forward. In experiments, the team ran the robot at progressively smaller duty cycles, finding that, following the algorithm’s force prescriptions, the robot was able to run at higher speeds without falling. Sangbae Kim, an associate professor of mechanical engineering at MIT, says the team’s algorithm enables precise control over the forces a robot can exert while running. SourceAlso: Learn about Hall Thrusters for Robotic Solar System Exploration.

Posted in: Motion Control, Motors & Drives, Software, Machinery & Automation, Robotics, News

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Untethered Soft Robot Walks Through Flames

Developers from Harvard’s School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering have produced the first untethered soft robot — a quadruped that can stand up and walk away from its designers.The researchers were able to scale up earlier soft-robot designs, enabling a single robot to carry on its back all the equipment it needs to operate — micro-compressors, control systems, and batteries.Compared with earlier soft robots, which were typically no larger than a steno pad, the system is huge, measuring more than a half-meter in length and capable of carrying as much as 7½ pounds on its back.Giving the untethered robot the strength needed to carry mechanical components meant air pressures as high as 16 pounds per square inch, more than double the seven psi used by many earlier robot designs. To deal with the increased pressure, the robot had to be made of tougher stuff.The material settled on was a “composite” silicone rubber made from stiff rubber impregnated with hollow glass microspheres to reduce the robot’s weight. The robot’s bottom was made from Kevlar fabric to ensure it was tough and lightweight. The result was a robot that can stand up to a host of extreme conditions.SourceAlso: Learn about a Field-Reconfigurable Manipulator for Rovers.

Posted in: Materials, Composites, Mechanical Components, Motion Control, Motors & Drives, Machinery & Automation, Robotics, News

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NASA Tests Robot Swarms for Autonomous Movement

NASA engineers and interns are testing a group of robots and related software that will show whether it's possible for autonomous machines to scurry about an alien world such as the Moon, searching for and gathering resources just as an ant colony does.

Posted in: Electronics & Computers, Motion Control, Software, Communications, Wireless, Machinery & Automation, Robotics, RF & Microwave Electronics, Antennas, News

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NASA Begins Engine Test of Space Launch System Rocket

Engineers are preparing to test parts of NASA's Space Launch System (SLS) rocket that will send humans to space. They installed an RS-25 engine on the A-1 Test Stand at Stennis Space Center. The Stennis team will perform developmental and flight certification testing of the RS-25 engine, a modified version of the space shuttle main engine. The SLS's core stage will be powered by a configuration of four RS-25 engines.

Posted in: Motion Control, Motors & Drives, Power Transmission, Test & Measurement, Aerospace, Aviation, News

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Students Learn On-the-Fly Engineering in Solar Car Competition

Nine teams of solar powered model cars competed during the inaugural Junior Solar Sprint (JSS) competition held at the STEM Education and Outreach Center at Aberdeen Proving Ground, MD. The JSS is a nationwide competition funded by the Army Educational Outreach Program, which challenges teams of students from elementary and middle school to design, construct, and race small model cars powered entirely by solar energy.

Posted in: Motion Control, Motors & Drives, Solar Power, Renewable Energy, Energy, News, Automotive

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'Active' Surfaces Control How Particles Move

Researchers at MIT and in Saudi Arabia have developed a new way of making surfaces that can actively control how fluids or particles move across them. The work might enable new kinds of biomedical or microfluidic devices, or solar panels that could automatically clean themselves of dust and grit.The system makes use of a microtextured surface, with bumps or ridges just a few micrometers across, that is then impregnated with a fluid that can be manipulated — for example, an oil infused with tiny magnetic particles, or ferrofluid, which can be pushed and pulled by applying a magnetic field to the surface. When droplets of water or tiny particles are placed on the surface, a thin coating of the fluid covers them, forming a magnetic cloak.The thin magnetized cloak can then actually pull the droplet or particle along as the layer itself is drawn magnetically across the surface. Tiny ferromagnetic particles, approximately 10 nanometers in diameter, in the ferrofluid could allow precision control when it’s needed — such as in a microfluidic device used to test biological or chemical samples by mixing them with a variety of reagents. Unlike the fixed channels of conventional microfluidics, such surfaces could have “virtual” channels that could be reconfigured at will.The new approach could be useful for a range of applications: For example, solar panels and the mirrors used in solar-concentrating systems can quickly lose a significant percentage of their efficiency when dust, moisture, or other materials accumulate on their surfaces. But if coated with such an active surface material, a brief magnetic pulse could be used to sweep the material away.Source Also: Read more Materials tech briefs.

Posted in: Motion Control, Fluid Handling, Medical, Drug Delivery & Fluid Handling, Solar Power, Renewable Energy, Energy, News

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