US 6,208,414 B1 · Modular laser gyro

Abstract

A modular laser gyro incorporating a laser gyro with a digital control processor. The digital control processor safely and quickly starts the laser gyro. The microprocessor also executes tests on the gyro and provides a health signal. Optional start-up operations may be performed including the calibration of volts per mode and system configuration. Various information including gyro parameter load commands, gyro control commands, gyro status commands, and gyro calibration and diagnostic commands may be provided to an inertial navigation system. A high voltage start circuit includes a high voltage start module and high voltage pulse generator apparatus. The high voltage start circuit is contained within a modular laser gyro housing. A direct digital dither drive for a dither motor controls the dithering of the gyro to prevent lock in of the laser beams. A dither stripper controls the stripping of the dither signal. A bias drift rate improvement system, as well as a random drift rate improvement system reduces errors. A lifetime prediction mechanism incorporates a memory model that stores worst case performance parameters and evaluates them against predetermined failure criteria. An active current control controls lasing current to prolong life and enhance performance. A single transformer power supply powers the modular gyro.

Claims29

Dependent claims

A modular sensor apparatus for measuring at least one inertial property, the modular sensor apparatus comprising:

an inertial sensor means for sensing at least one inertial property, wherein the inertial sensor means has at least one sensor control input and a measured inertial property output that varies in response to the at least one sensor control input;
a digital control means for controlling the inertial sensor means, wherein the digital control means has at least one control output connected to the at least one sensor control input;
and
a self test means for performing a built in test of the modular sensor apparatus, wherein the self test means is connected to the digital control means.

1 more element

A modular laser gyro having a laser within a cavity within a gyro block, a photodiode means connected to the gyro block to detect the laser, a dither drive motor connected to the gyro block to drive the gyro block, a dither pickoff connected to the gyro block to sense motion of the gyro block, and a cathode and a first and a second anode for maintaining the laser within the cavity, wherein the modular laser gyro further comprises:

(a) a microcontroller connected to control the laser gyro having an A/D converter wherein the A/D converter is integral to the microcontroller and wherein the microcontroller has an active current control output to control cathode and anode current and a pulse width modulated output;
(b) a direct digital dither drive connected to drive the dither drive motor and to receive the pulse width modulated output from the microcontroller;
(c) a path length control connected to control a PLC transducer means and connected to receive input from a PLC pickoff located on the gyro block and used for sensing laser path length wherein the path length control further has an A/D converter output used by the microcontroller to process laser path length data;
(d) an active current control means connected to the laser gyro to maintain the laser within the gyro block having a microcontroller input, a first active current control output connected to the cathode, a second active current control output connected to the first anode, and a third active current control output connected to the second anode;
and
(e) means for high voltage start-up contained within a gyro housing and connected to the active current control means to allow for laser gyro start-up.

3 more elements

Dependencies are inferred from the claim text.

Modular laser gyro

Life of this patent

Modular laser gyro

Life of this patent

Abstract

Claims29