American Research Corporation of Virginia

Eastern Repair Fabrication

American Research Corporation of Virginbia

Bruce L Thomas

Russell J Churchill

Lloyd K Loftus

Henry M Bass

Howard P Groger

Martin Weiss

Peter Lo

Roger J Polidoro

A laser-based multi-axis position measurement unit measures position deviations in 5 axes while traversing a 6th linear axis. The apparatus includes three components: 1) a laser-beam unit which emits two parallel laser beams; 2) a sensor unit including at least three laser-position sensors, one of them being transparent; and 3) a microprocessor or computer unit which converts X,Y laser position data from the three sensors to displacements in 5 axes: X (horizontal), Y (vertical), Pitch (angular motion about the X axis), Yaw (angular motion about the Y axis), and Roll (angular motion about the line of travel). Readout of the 6th axis, the line of travel, is provided by means of a separate linear transducer or laser-based ranging system. The device includes an arrangement of three digital sensors on two parallel laser beams to deduce position in 5 axes. Applications for the measurement unit exist in machine tool measurement and calibration, robotics, coordinate measurement machines, optical alignment and other areas where position in multiple axes must be determined. The position information may be directly displayed or used as input for a closed-loop positioning system.

Laser aligned five-axis position measurement device

A precision positioning system is used for resurfacing and repairing rails and guideways of large, heavy machinery at users facilities. The system has new components, an entire machining system, a new alignment system, parallel platforms for tool support and surface scanning. A sectioned, portable monorail frame is held by fixed supports at the locus of a heavy machine requiring guideway straightening. Fixed guides extend along the outer surface of the monorail. Guide wheels and drive wheels contact the guides and support and move an outer tubular beam carriage. An assembly of machining tools is adjustably positioned on the carriage. Laser alignment sources and sensors are connected to the carriage and to heavy machines off-axis and parallel to the monorail. Intelligent controls precisely position the tools for resurfacing the rails and guideways. Scanning and a printout of machine guideway accuracy, before and after the operation, provide written verification of quality improvement. The system increases accuracy and speed of machining, reduces chatter and vibration, eliminates imprecise manual determinations, and returns the equipment to acceptable improved tolerances. The system has applications in any machine tool rebuilder or company with a machine tool in need of requalification. Applications also include rail transport, autonomous vehicles, micro-machining, inspection camera positioning, laser machining, material deposition and other operations such as drilling, heat treating, brazing and welding.

Laser aligned robotic machining system for use in rebuilding heavy

A highly sensitive surface plasmon waveguide sensor monitors the refractive index and thickness of thin adsorbed films. The sensor includes an optical waveguide formed by ion-exchange in a glass substrate, by selective densification of substrate material or by the incorporation of high refractive index materials during deposition of a dielectric layer. Two dielectric thin films are deposited on top of the waveguide. The layer closest to the waveguide has a lower refractive index than the guiding layer to form a buffer layer. The second dielectric layer, or tuning layer, has a higher refractive index. The tuning and buffer layers allow optimization of the resonance wavelength, full-width half maximum of the resonance wavelength range and amplitude of the resonance. The tuning layer is coated with a thin metallic layer, to effect surface plasmon resonance, such as gold, silver, aluminum or one or more semiconducting materials. Alternatively the optical waveguide is coated with the buffer layer and the thin metal layer. The tuning layer and a second buffer layer are deposited on top of the metallic layer. Light is introduced to the waveguide and interaction between the light and the thin metal layer results in attenuation of the TM polarization. The ratio of the TM and TE polarization intensities is monitored by a polarization beam splitter. The relatively unchanged TE polarization intensity serves as an integral reference for the sensor. The sensor has numerous applications in the environmental and biomedical fields.

Chemical detector employing surface plasmon resonance excited using an

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Radford, VA, United States of America

Bruce L Thomas