Abstract: A first optical fiber, a second optical fiber, and a prism are used to turn light through 180° in a small space. The prism can be a discrete microprism or a custom prism specially made using precision molding techniques or by specially machining a section of coreless optical fiber using precision machining techniques. A precision holder or substrate can be used to facilitate molding of a prism and/or assembly of the overall apparatus.

Abstract: An optical fiber is bent to form a discontinuous curve through which light can be injected into the fiber or extracted from the fiber. The bend can be formed by securing a portion of the optical fiber in a fixture and laterally displacing a portion of the fiber outside the fixture using a depressor. The depressor can be an integral part of the securing fixture or a separate device. The securing fixture can be adjustable so that the degree and location of the bend can be varied. Injected light can be sourced from a second optical fiber, and extracted light can be supplied to a second optical fiber which can have a lens at its free end.

Abstract: Control system for electromechanical arrangements having open-loop instability. The system is built around a control unit that processes sensing signals and provides control signals to maintain a movable member, such as a rotor or shaft, in the desired position. The control unit according to the invention includes a specially designed compensation filter, which isolates the open-loop instability so that the shaft is treated as a pure mass. In magnetic bearings, the open-loop instability is manifested as negative stiffness. The invention isolates the negative stiffness thus providing for better positive stiffness and improved bandwidth. Various filters, summers, and other operators required to carry out the invention are preferably implemented on a programmed processing platform such as a digital signal processor (DSP) or an arrangement of multiple digital signal processors.

Abstract: Two neural networks are used to control adaptively a vibration and noise-producing plant. The first neural network, the emulator, models the complex, nonlinear output of the plant with respect to certain controls and stimuli applied to the plant. The second neural network, the controller, calculates a control signal which affects the vibration and noise producing characteristics of the plant. By using the emulator model to calculate the nonlinear plant gradient, the controller matrix coefficients can be adapted by backpropagation of the plant gradient to produce a control signal which results in the minimum vibration and noise possible, given the current operating characteristics of the plant.

Abstract: A motor has a rotor for controlling a parameter of an instrumentality, such as a blade or a blade flap. The rotor is positioned about the drive shaft of the instrumentality and rotates at the same average angular velocity of the drive shaft. The instrumentality is controlled by applying to the instrumentality a physical displacement signal that is generated by the phase relationship of the rotor of the motor with respect to the angular position of the drive shaft. A plurality of permanent magnets proximate the periphery of the rotor cooperate with a plurality of stator polepieces and electromagnetic coils. The current flowing through the coils is reversed each time that the rotor advances by the angular space of one permanent magnetic pole. The strength and polarity of the current flowing through the coils controls the direction and displacement of the rotor with respect to a neutral phasing of the rotor with respect to the drive shaft.

Abstract: An adaptive controller is used to adaptively generate vibration cancellation signals driving a controlled device which effects an associated vibration and noise-producing plant. The adaptive controller has multiple control paths to generate the control signal. In a vibration attenuation control path(s), an adaptive control signal is generated by plant compensation and adaptive filtering techniques to cancel vibrations. In a position control, saturation prevention path, the available operational extents of the controlled device are monitored and compensation signals are generated which direct the movement of the controlled device in such a manner as to prevent the controlled device from reaching the extents of control. The control signals from the multiple paths are then combined and transmitted to the controlled device which alters in some fashion the noise and vibration being generated or transmitted by the associated vibrating plant.

Abstract: A pressure vessel is provided for housing electronic components in an underwater environment and permitting connection of the components to signal transmission elements of a signal cable. The pressure vessel comprises a hollow steel shell defining an interior chamber adapted to house the electronic components. A layer of thermal-sprayed aluminum covers the shell. The shell has an opening adapted to pass the signal transmission elements into the interior chamber. A seal adapted to sealingly surround the transmission elements is disposed in the opening in the shell so that an outer peripheral surface of the seal contacts an inner peripheral surface of the opening in the shell for preventing moisture penetration into the interior chamber. The seal may be formed of epoxy and the outer peripheral surface have a plurality of compressible o-rings disposed in axially-spaced circumferential grooves for contacting the inner peripheral surface of the opening in the shell.

Abstract: Multiple function bandwidth management systems. Bandwidth-management systems for an optical network are easily assembled by concatenating a plurality of intelligent, miniaturized, bandwidth-management modules (BMM's) together. The BMM's subdivide the wide available spectrum into narrow band segments. Each individual BMM is designed to overcome loss and optimize dispersion, gain, and power or gain equalization for a few channels at a time. Each device includes optical connectors and filters, as well as any other components necessary to direct the band of optical channels through the device's optical path while passing other optical channels within the spectrum to additional devices which can be connected without disturbing existing bandwidth-management modules. Each BMM also includes a digital control module that operates the BMM in any one of a plurality of selectable operating modes.

Abstract: Adjustable optical fiber grating dispersion compensators. The invention provides a fully tunable dispersion compensator with a wide dynamic range. Dispersion compensators according to the invention are based on uniform fiber Bragg grating technology. Individual gratings are tuned so that the gratings, which normally operate in reflection mode, operate in transmission mode with the frequency of interest falling just outside a reflection band edge. Gratings are combined to provide broadband, or multiple-wavelength dispersion. Tuning is provided via transducers coupled to the gratings. A control system can be connected to the transducers to provide a control signal so that the frequencies of the gratings can be dynamically tuned. The control system operates by measuring signals from opto-electronic detectors. The signals are used to determine a fractional spectral power transmitted through a filter. The fractional spectral power is related to the amount of dispersion present in the optical path of the network.

Abstract: A shock and acoustic mount for reducing transmission of forces between two relatively moveable members such as a mounted component and a supporting structure, providing a compressible fluid spring with large allowable relative movement of the mounted component and support structure. The mount comprises a casing, a piston shell with one end disposed in the casing and another end extending outside of the casing, and a piston housed in the piston shell, all relatively moveable in response to external axial forces. In one embodiment, the mount is filled with a compressible fluid, such as air, providing an air spring. The piston is sealingly bonded to the inner surface of the piston shell, the bond accommodating acoustic and vibration forces by deformation of the bond material. An annular seal between the piston shell and the casing accommodates large and shock forces.

Abstract: A cable seal and method for sealing a cable termination is provided for sealing the passage of a cable into a cable-receiving structure. The seal includes a first plurality of o-rings disposed along a length of the cable adjacent the cable-receiving structure and a first length of heat-shrinkable tube which fits over the cable and o-rings for compressive engagement with the cable and o-rings to prevent moisture penetration between an inner surface of the first tube and the outer surface of the cable. A second plurality of o-rings is disposed over the first heat-shrinkable tube adjacent the first plurality of o-rings.

Abstract: Adjustable optical fiber grating dispersion compensators. The invention provides a fully tunable dispersion compensator with a wide dynamic range. Dispersion compensators according to the invention are based on uniform fiber Bragg grating technology. Individual gratings are tuned so that the gratings, which normally operate in reflection mode, operate in transmission mode with the frequency of interest falling just outside a reflection band edge. Gratings are combined to provide broadband, or multiple-wavelength dispersion. Tuning is provided via transducers coupled to the gratings. A control system can be connected to the transducers to provide a control signal so that the frequencies of the gratings can be dynamically tuned. The control system operates by measuring signals from opto-electronic detectors. The signals are used to determine a fractional spectral power transmitted through a filter. The fractional spectral power is related to the amount of dispersion present in the optical path of the network.

Abstract: In many uses of electrical motors, the interaction of a tool being powered, e.g., a milling machine, and the workpiece being worked on by the motor induces mechanical vibrations which adversely affect the functioning of the tool as well as inducing wear producing vibrations in the motor rotor shaft. Damping of such vibrations is achieved by deliberately inducing internal unbalanced forces on the motor rotor shaft for counteracting the externally induced vibrations. Such internal unbalanced forces are produced by the use of additional currents in the main stator coils for generating additional, unbalanced force generating magnetic fields. A mathematical analysis of the process is provided.

Abstract: A method and apparatus are provided for stabilizing at least one element of a mechanical system against echo-like responses to mechanical disturbances. One or more error signals are provided by sensing the motion of the system at one or more points. At least one adaptive filter is operated in response to the error signal or signals, and in response to at least one non-advanced reference signal that is directly related to some motion of the system. The adaptive filter produces a corrective signal for driving a mechanical actuator, thereby to apply to the element a stabilizing generalized force. By non-advanced is meant that there is a zero or negative time-delay between the presence of a given signal at the reference-sensing location and the arrival of the same, or a similar, signal at the error-sensing location. In particular embodiments of the invention, the reference-sensing location is the same as the error-sensing location.

Abstract: A stream of gas contaminated with particulate material is wetted by a liquid spray in a scrubber manifold. Positioned downstream of the liquid spray in the manifold is a bed of wire filaments extending transversely across the manifold and cocurrent with the liquid and gas flow through the manifold in a fan-shaped arrangement. The liquid spray impacts the filaments to fold a liquid film on the filaments. The particulate laden gas stream impacts the filaments and becomes entrained in the liquid on the filaments. The scrubbing liquid on the filament forms a particle collection surface which strips the solid contaminant particles from the gas along the filaments. The liquid and entrained particles flows by gravity down the filaments where the liquid drains with the contaminate as a film. The gas flow exits the manifold substantially free of particulate matter.

Abstract: A joystick controller for utilizing omnidirectional pivoting manual displacement by an operator to operate transducers for producing control signals comprises a mounting plate defining an opening therethrough and gimbal mounting means secured to the mounting plate for pivotally mounting a joystick shaft extending through the opening. The joystick shaft has an operator knob on one end, and a gauge plate on the other end, the gauge plate having a first straight edge and a second straight edge perpendicular thereto. First and second lever arms are pivotally mounted and biased against the first and second straight edges of the gauge plate, whereby displacement of the joystick knob causes displacement of the gauge plate and pivots the lever arms biased thereagainst. Follower rods extend from the lever arms to engage the gauge plate. First and second transducers are respectively operated by the pivoting lever arms.

Abstract: A mobile platform in an underground mine supports an electric motor that operates a compressor to supply air under pressure to one or more hoppers containing abrasive particles which are held in suspension and pressurized within the hopper. The electric motor is drivingly connected to a hydraulic pump that supplies water under pressure in a range of 3000 to 4000 p.s.i. through a conduit to the water inlet of a nozzle assembly. A second conduit conveys the pressurized abrasive particles to the nozzle assembly for admixture with the water. The flow of abrasive particles is maintained by the compressed air at a constant flow rate to enhance the output velocity of the water encapsulated particles from the nozzle assembly. The abrasive stream impinges on the surface of a gas well casing to sever the casing as the nozzle assembly is rotated around the casing. In this manner a pipe or gas well casing obstructing a mining operation is removed without generating sparks in the hazardous mine atmosphere.