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Tool for Sampling Permafrost on a Remote Planet

A report discusses the robotic arm tool for rapidly acquiring permafrost (RATRAP), which is being developed for acquiring samples of permafrost on Mars or another remote planet and immediately delivering the samples to adjacent instruments for analysis. The prototype RATRAP includes a rasp that protrudes through a hole in the bottom of a container that is placed in contact with the permafrost surface. Moving at high speed, the rasp cuts into the surface and loads many of the resulting small particles of permafrost through the hole into the container. The prototype RATRAP has been shown to be capable of acquiring many grams of permafrost simulants in times of the order of seconds. In contrast, a current permafrost-sampling system that the RATRAP is intended to supplant works by scraping with tines followed by picking up the scrapings in a scoop, sometimes taking hours to acquire a few grams. Also, because the RATRAP inherently pulverizes the sampled material, it is an attractive alternative to other sampling apparatuses that generate core or chunk samples that must be further processed by a crushing apparatus to make the sample particles small enough for analysis by some instruments.

Posted in: Machinery & Automation, Briefs, TSP

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Special Semaphore Scheme for UHF Spacecraft Communications

A semaphore scheme has been devised to satisfy a requirement to enable ultrahigh- frequency (UHF) radio communication between a spacecraft descending from orbit to a landing on Mars and a spacecraft, in orbit about Mars, that relays communications between Earth and the lander spacecraft. There are also two subsidiary requirements: (1) to use UHF transceivers, built and qualified for operation aboard the spacecraft that operate with residual-carrier binary phase-shift-keying (BPSK) modulation at a selectable data rate of 8, 32, 128, or 256 kb/s; and (2) to enable low-rate signaling even when received signals become so weak as to prevent communication at the minimum BPSK rate of 8 kHz. The scheme involves exploitation of Manchester encoding, which is used in conjunction with residual-carrier modulation to aid the carrier-tracking loop. By choosing various sequences of 1s, 0s, or 1s alternating with 0s to be fed to the residual- carrier modulator, one would cause the modulator to generate sidebands at a fundamental frequency of 4 or 8 kHz and harmonics thereof. These sidebands would constitute the desired semaphores. In reception, the semaphores would be detected by a software demodulator.

Posted in: Briefs, TSP

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Achieving Positioning Accuracy Goals

The task of choosing the correct mix of motion control components for a successful servo positioning system involves a combination of art, science, and experience. It also includes a little luck, but luck is not needed when you fully comprehend the principle of operation, accuracy, resolution, and repeatability of each component in the system.

Posted in: Features, Articles

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CNC Wood Routers Use Drive for Precision Control

The woodworking industry is as advanced and under pressure to deliver high-quality goods quickly as any. One of the most versatile tools devised to quicken production with flat panels of wood is the wood router, used to rout (hollow out) an area in the face of a piece of wood, and used for 3D design, cabinets, sign making, molds, and general material cutting. The table-like device, similar to a metal mill, consists of a broad-based wooden hand plane with a narrow gantry-carried cutting implement projecting beyond its base plate. To guide its computer numerical controlled (CNC) ATC wood routers, WartHog CNC (Soddy-Daisy, TN) turned to YET US’s (Manchester, NH) XtraDrive servo drive system, integrating it into the routers’ precision and power controls.

Posted in: Applications, Application Briefs

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Drive Utilized in Filament Respooler

Optical fiber, now the mainstay of telecommunications as well as sensor, illumination, and imaging systems, is made by first pulling a large-diameter preform into a long, filimentous fiber. Then divided into bunches, a resin cladding is applied to keep the transmital of light uncontamintated. The finished product is then wound onto large spools to await shipment to customers. Showmark (Downingtown, PA) developed the automatic UniSpooler to customize the amount of cable a customer gets based on need, and uses the Kinemax KI3-15-5 linear drive from Amacoil/Uhling (Aston, PA) to help guide filaments from the supply spool to smaller takeup spool with the desired amount of fiber or wire.

Posted in: Applications, Application Briefs

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Guide Used in Leak-Testing System or Plastic Bottles

Container leaks can range from mildly annoying to potentially dangerous. To avoid faulty containers from ever leaving the production line, producers have installed testing devices as part of the bottle production process to ensure integrity. As many bottle/container manufacturing systems were pre-existing, a unit able to integrate itself into the existing production line without necessitating a long shutdown or costly re-design was seen as ideal. When Air Logic Power Systems Inc, (ALPS, Milwaukee, MI) developed such a unit, the RS-100 Plastic Container Integrity Tester, it chose the PDU2 linear transmission unit from HepcoMotion (Tiverton, UK) and distributed by Bishop-Wisecarver (Pittsburg, CA). Using the PDU2 eliminated many of the bottle handling issues that could potentially slow production by its ability to move in synch with an existing production line.

Posted in: Applications, Application Briefs

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Brushless Motor Drive

Intelligent Motion Systems (IMS, Marlborough, CT) released the MDrivePlus motion control system for brushless motor applications. The unit features 20 microstep resolutions to 51,200 (full step, degrees, metric, and arc minutes), a motion control system-on-a-chip, electronic gearing, 6,385 bytes of program storage, and analog input to 10 VDC. Drive voltage ranges include +12 to +75 VDC and 120 and 240 VAC. The housing is chemical resistant and the unit has a cast aluminum heat sink. Outputs are configured for sourcing or sinking, and the unit features an auxiliary logic power input.

Posted in: Products, Products

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