Motion Control

Supersonic Laser-Propelled Rockets Could Help Aircraft Exceed Mach 10

A new method for improving the thrust generated by laser-propulsion systems may bring them one step closer to practical use. The method, developed by physicists Yuri Rezunkov of the Institute of Optoelectronic Instrument Engineering, Russia, and Alexander Schmidt of the Ioffe Physical Technical Institute in Saint Petersburg, Russia, integrates a laser‑ablation propulsion system with the gas‑blasting nozzles of a spacecraft. Combining the two systems can increase the speed of the gas flow out of the system to supersonic speeds, while reducing the amount of burned fuel.

Posted in: Photonics, Lasers & Laser Systems, Motion Control, Power Transmission, Aerospace, Aviation, News

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Ocean Gliders Measure Melting Polar Ice

The rapidly melting ice sheets on the coast of West Antarctica are a potentially major contributor to rising ocean levels worldwide. Although warm water near the coast is thought to be the main factor causing the ice to melt, the process by which this water ends up near the cold continent is not well understood. Using robotic ocean gliders, Caltech researchers have now found that swirling ocean eddies, similar to atmospheric storms, play an important role in transporting these warm waters to the Antarctic coast—a discovery that will help the scientific community determine how rapidly the ice is melting and, as a result, how quickly ocean levels will rise. "When you have a melting slab of ice, it can either melt from above because the atmosphere is getting warmer or it can melt from below because the ocean is warm," explains lead author Andrew Thompson, assistant professor of environmental science and engineering. "All of our evidence points to ocean warming as the most important factor affecting these ice shelves, so we wanted to understand the physics of how the heat gets there." Because the gliders are small—only about six feet long—and are very energy efficient, they can sample the ocean for much longer periods than large ships can. When the glider surfaces every few hours, it "calls" the researchers via a mobile phone–like device located on the tail. The communication allows the researchers to almost immediately access the information the glider has collected. Like airborne gliders, the bullet-shaped ocean gliders have no propeller; instead they use batteries to power a pump that changes the glider's buoyancy. When the pump pushes fluid into a compartment inside the glider, the glider becomes denser than seawater and less buoyant, thus causing it to sink. If the fluid is pumped instead into a bladder on the outside of the glider, the glider becomes less dense than seawater—and therefore more buoyant—ultimately rising to the surface. Like airborne gliders, wings convert this vertical lift into horizontal motion. Source Also: Learn about Remote Sensing of Ice Sheets and Snow.

Posted in: Batteries, Electronics & Computers, Environmental Monitoring, Green Design & Manufacturing, Motion Control, Test & Measurement, Measuring Instruments, Monitoring, Communications, Machinery & Automation, Robotics, News

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Engineers Harvest and Print Parts for New Breed of Aircraft

Student interns and engineers at NASA's Ames Research Center rapidly prototyped and redesigned aircraft using 3D-printed parts. The aircraft was custom-built by repurposing surplus Unmanned Aerial Vehicles (UAVs). By lengthening the wings, the team was able to improve aerodynamic efficiency and help extend the flight time of small, lightweight electric aircraft. The prototype aircraft are constructed using components from Aerovironment RQ-14 Dragon Eye UAVs that NASA acquired from the United States Marine Corps via the General Services Administration's San Francisco office. Unmodified, these small electric aircraft weigh 5.9 pounds, have a 3.75-foot wingspan and twin electric motors, and can carry a one-pound instrument payload for up to an hour. After finalizing designs that featured longer and more slender wings and dual fuselages, the teams printed new parts including wing sections, nose cones, winglets, control surfaces, wing ribs and even propellers using the NASA Ames SpaceShop. The 3-D printed wing sections were reinforced using carbon fiber tubing or aluminum rods to give them extra strength without adding significant weight.Flying as high as 12,500 feet above sea level, multiple small converted Dragon Eye UAVs, including the specialized and highly modified “FrankenEye” platform, will study the chemistry of the eruption plume emissions from Turrialba volcano, near San Jose, Costa Rica. The goal of the activity is to improve satellite data research products, such as computer models of the concentration and distribution of volcanic gases, and transport-pathway models of volcanic plumes. Some volcanic plumes can reach miles above a summit vent, and drift hundreds to thousands of miles from an eruption site and can pose a severe public heath risk, as well as a potent threat to aircraft.SourceAlso: Learn about Real-Time Minimization of Tracking Error for Aircraft Systems.

Posted in: Manufacturing & Prototyping, Rapid Prototyping & Tooling, Motion Control, Motors & Drives, Aerospace, Aviation, News

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2-in-1 Motor Increases Range of Electric Cars

Scientists from Nanyang Technological University (NTU) and German Aerospace Centre (DLR) have invented a 2-in-1 electric motor that increases the range of electric vehicles. The engine integrates the traditional electric motor with the air-conditioning compressor, typically two separate units. This novel, space-saving design allows the use of bigger batteries, which can increase the range of electric vehicles by an additional 15 to 20 percent.

Posted in: Manufacturing & Prototyping, Motion Control, Motors & Drives, Energy Efficiency, Energy, Transportation, Automotive, News

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Pulley Mechanism Improves Hand Function After Surgery

Engineers at Oregon State University have developed and successfully demonstrated a simple pulley mechanism to improve hand function after surgery. The device is one of the first instruments ever created that could improve the transmission of mechanical forces and movement while implanted inside the body.

Posted in: Mechanical Components, Motion Control, Rehabilitation & Physical Therapy, Medical, News

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Underwater Robot Skims for Port Security

MIT researchers unveiled an oval-shaped submersible robot, a little smaller than a football, with a flattened panel on one side that it can slide along an underwater surface to perform ultrasound scans.Originally designed to look for cracks in nuclear reactors’ water tanks, the robot could also inspect ships for the false hulls and propeller shafts that smugglers frequently use to hide contraband. Because of its small size and unique propulsion mechanism — which leaves no visible wake — the robots could, in theory, be concealed in clumps of algae or other camouflage. Fleets of them could swarm over ships at port without alerting smugglers and giving them the chance to jettison their cargo.Sampriti Bhattacharyya, a graduate student in mechanical engineering, built the main structural components of the robot using a 3-D printer. Half of the robot — the half with the flattened panel — is waterproof and houses the electronics. The other half is permeable and houses the propulsion system, which consists of six pumps that expel water through rubber tubes.Two of those tubes vent on the side of the robot opposite the flattened panel, so they can keep it pressed against whatever surface the robot is inspecting. The other four tubes vent in pairs at opposite ends of the robot’s long axis and control its locomotion.SourceAlso: Learn about Underwater Localization for Transit and Reconnaissance Autonomy.

Posted in: Imaging, Manufacturing & Prototyping, Rapid Prototyping & Tooling, Motion Control, Power Transmission, Machinery & Automation, Robotics, News

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Robotic Fabric Moves and Contracts

Researchers are developing a robotic, sensor-embedded fabric that moves and contracts. Such an elastic technology could enable a new class of soft robots, stretchable garments, "g-suits" for pilots or astronauts to counteract acceleration effects, and lightweight, versatile robots to roam alien landscapes during space missions.The robotic fabric is a cotton material containing sensors made of a flexible polymer and threadlike strands of a shape-memory alloy. The strands return to a coiled shape when heated, causing the fabric to move."We have integrated both actuation and sensing, whereas most robotic fabrics currently in development feature only sensing or other electronic components that utilize conductive thread," said Rebecca Kramer, an assistant professor of mechanical engineering at Purdue University. "We also use standard sewing techniques to introduce the thread-like actuators and sensors into the fabric, so they could conceivably be integrated into the existing textile manufacturing infrastructure."SourceAlso: See other Sensors tech briefs.

Posted in: Materials, Plastics, Motion Control, Sensors, Aerospace, Machinery & Automation, Robotics, News

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