Litton Systems, Inc.

Northrop Grumman Systems Corporation

Robert D Curby

George H McCammon

Rodney W Benoist

Masao Yashimoto

Samuel N Fersht

David Y Hsu

Allan J Brockstein

Joseph A Ratkovic

Jeff Becker

Tim Richmond

A projectile guidance system without gyros in which the projectile has an orthogonal body coordinate system. The projectile has a triax of accelerometers providing x, y and z acceleration data measured along the x, y and z axes respectively. A GPS antenna and receiver means provides onboard GPS position and velocity data in earth referenced navigational coordinates. A computer and program means stores and accesses time indexed GPS position and GPS velocity data and transforms x, y and z axis acceleration data from body to navigation coordinates. The program means is responsive to corresponding time indexed acceleration data and to GPS velocity and position data for calculating and outputing an estimated projectile roll, pitch and yaw angle via optimal smoothing techniques with respect to local level for each time index iteration of present position to a flight control system for guiding the projectile to a predetermined location.

Projectile guidance with accelerometers and a GPS receiver

Spurious pulses are eliminated in the output of a comparator performing analog to digital conversion by addition of logic which eliminates pulses having a width less than a selected width from the output of the comparator.

Comparator digital noise filter

The present invention provides for initializing the particular intensity peak selected to operate about, based upon the initial temperature of the gyroscope in order to maintain a selected integer number of wavelengths as the initial cavity path length from start up to start up. In addition, the present invention provides an optimum available movement of the mirrors due to changing the voltage over the available voltage swing for the anticipated range and direction of temperature changes from the start up temperature, over which the gyroscope is expected to operate.

Path length control method for ring laser gyroscope

Apparatus and method for dithering ring laser angular rotation sensors, including a plurality of such sensors with substantially identical natural dither frequencies and having different sensor axes mounted upon a resilient structure; applying energy to dither such sensors; the energy being connected and disconnected from the dithering of each sensor in response to the amplitude of dither of that particular sensor to minimize lock-in; and frequency or phase modulating the energy applied to dithering to avoid continued uni-directional coning effects.

Dither controller for ring laser angular rotation sensor

Pathlength controller for ring laser gyroscope

Growing community of inventors

Thousand Oaks, CA, United States of America

Robert D Curby