Unisys Corporation

Honeywell G.m.b.h.

Honeywell International Inc.

Mark L Wilson

Bernard S Fritz

David Kubisiak

Stanley J Lins

The invention includes a device for measuring the velocity of a target that includes an array of vertical cavity surface emitting lasers having an energy output, a first lens configured to capture the energy output of the array and project it onto the target whose velocity is to be monitored, a second lens configured to capture the energy output reflected from the target, and at least one detector configured to detect the energy transmitted from the second lens, where the energy of the array projected onto the target creates pulses of light from reflectance off of surface imperfections on the target, and the velocity of the target is determined by monitoring the frequency of the pulses of light. The invention also includes a method of measuring the velocity of a target that includes projecting an image of at least one vertical cavity surface emitting laser array onto the target, monitoring the intensity pattern formed from the image reflecting off of the target with at least one light intensity detector to produce an analog signal, converting the analog signal to a digital signal having the same frequency, measuring the frequency of the digital signal with a counter, and processing the frequency with a microprocessor to determine the velocity of the target.

Method and device for measuring the velocity of a moving surface

Signal processing methods are disclosed for processing Laser Doppler Velocimeter (LDV) signals. A true Doppler frequency is extracted from the phase noise frequencies by maintaining a highest frequency value. The highest frequency value is replaced with any measured frequency values that are higher than the current highest frequency value. This is continued for a predetermined lifetime period, after which the highest frequency value is stored and then reinitialized. The highest detected frequency values over a window of lifetimes are then averaged to provide a moving or rolling average value which is indicative of the velocity of a medium.

Laser doppler velocimeter with high immunity to phase noise

A method of driving and sensing a resonant sensor network wherein a least a one resonant sensor is driven by a first light from a first light source at a first frequency, wherein said first light source is modulated by an a.c. source. A second light source at a second frequency is utilized sense the resonant frequency of the at least one resonant sensor. Wherein said at least one resonant sensor modulates said second light source. The modulated light is provided to a photo detector and the first light source is filtered out of said reflected light. The detector ac amplifies the filtered reflected light, thereby detecting said the resonant frequency of the resonant sensor.

Multi-wavelength optical drive/sense readout for resonant microstructures

A light based distance, velocity and acceleration sensor which uses phase difference to determine the desired measurement. A laser signal is modulated by an oscillator signal and reflected off an object to a signal receiver. The reflected laser signal and the oscillator signal then pass through a dual path conditioning circuit, where the path lengths and circuit elements of the two paths are identical to cancel the effects of propagation delays in an output signal. The conditioned signals are passed through a phase comparator, to produce a signal indicative of the phase difference between the oscillator signal and the reflected laser signal. The phase difference is directly proportional to the distance between the sensor and the object.

Laser sensor capable of measuring distance, velocity, and acceleration

A turbidity sensor is provided with a light source and a plurality of light sensitive components which are disposed proximate a conduit to measure the light intensity directly across the conduit from the light source and at an angle therefrom. The conduit is provided with a plurality of protrusions extending radially inward from the walls of the conduit to discourage the passage of air bubbles through the light beam of the sensor. The direct light beam and scattered light are compared to form a relationship that is indicative of the turbidity of the liquid passing through the conduit. The rate of change of turbidity is provided as a monitored variable.

Turbidity sensor with analog to digital conversion capability

An optical switch for coupling one of a plurality of input light sources to one of a plurality of output terminals is comprised of a Bragg cell array acoustically excited in accordance with one or more preselected control frequencies from a selectable source of such frequencies. The beam deflection is proportional to the applied radio frequency. A scan lens is positioned to intercept the deflected beams and to focus the beams into a plane for imaging upon a linear array of optical output fibers. By choice of the control frequency any combination of input and output fiber optic lines may be optically coupled without requiring active sensors. Sufficient diffraction is provided by the Bragg cell in combination with the scan lens to minimize cross-talk and insertion loss.

Multi-position opto-electronic switch

A variable refractive index device, such as a Bragg cell, is temperature stabilized by sensing ray path deviations of a secondary diffracted beam. Two photodetectors with centers offset from the exit position of the central ray of the beam at normal temperature operation receive light energy as a function of the deviation of this ray path from the normal position. Light in each fiber is detected to derive electrical signals that are utilized to establish a correction signal to a voltage controlled oscillator which varies the frequency thereof and compensates for the diffraction deviations caused by temperature variations.

Temperature compensated fiber optic bypass switch

An optical light conducting fiber that has a D-shaped stress sensitive coating of PVF.sub.2 which covers substantially equal length segments of said fiber, so that each of said segments is separated by equal uncoated segments of substantially the same length as said coated segments. The fiber when used in an interferometer provides an antenna that is capable of sensing electromagnetic and other stress-inducting waves in the environment. The optical fiber is polarized by winding it on a specially designed spool, heating it and applying a high intensity electric field in the desired direction.

Traveling wave fiber optic interferometric sensor and method of

An optical read/write system is provided in which a laser diode for supplying read and write beams is mounted at a fixed location on a temperature stabilized platform. A single mode, polarizing-preserving optical fiber is connected between the read head and the diode to reduce the mass of the system. The light beam, which upon leaving the laser diodes is generally elliptical in shape, is passed through a magnifying lens before it impinges upon the receiving end of the optical fiber. This changes the generally elliptical shape of the laser beam to a generally circular shape. After passing through the optical fiber the light beam proceeds through an optical assembly which directs a portion of it onto the storage media. Some of the energy of the incoming laser light is reflected to monitoring diode which is coupled to a power control means that controls the power output of the laser. Reflected light from the storage media is also coupled to a second monitoring photo diode to detect data from the read beam that is reflected from the storage media. The write light beam after passing through a polarizing prism is transmitted through a quarter wavelength plate and a demagnifying lens, which directs the light onto the storage media. The demagnifying lens corrects the cross-sectional area of the beam so that it has a circular shape and is approximately the same size as it was upon leaving the laser diode.

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Vadnais Heights, MN, United States of America

Mark L Wilson