Ring laser gyroscope

About: Ring laser gyroscope is a research topic. Over the lifetime, 2070 publications have been published within this topic receiving 18609 citations. The topic is also known as: Sagnac interferometer.

A doubly decoupled micromachined vibrating wheel gyroscope

Abstract: In this paper, a doubly decoupled vibrating wheel gyroscope with novel torsional sensing comb capacitors is presented. The doubly decoupled design and symmetrical structure can efficiently suppress the mechanical coupling of the gyroscope. Moreover, the symmetrically distributed proof masses make it immune from the linear accelerations. Both driving and sensing modes of the gyroscope are dominated by slide film air damping, so it can work even at atmospheric environment. The process for this gyroscope is also compatible with z-axis gyroscope, which makes it potential to realize low cost monolithic MIMU (miniature inertial measurement unit) without vacuum packaging. The gyroscope was fabricated and tested at atmosphere. The sensitivity is 3.1mV/o/s while the nonlinearity is 7.68‰ with the full scale of 900o/s. The noise floor is 0.45o/s/Hz1/2.

Inertial Instrument Error Compensation Technology in Laser Gyro Strapdown Inertial Navigation System

Abstract: To improve the navigation precision of laser gyro strapdown inertial navigation system, an error compensation technology was presented, which has an effect on the navigation precision. The system errors mainly result from the inertial instrument errors, which must be eliminated in order to decrease the system errors. This paper emphasized the principle analysis of the inertial instrument errors, and built the exact mathematical models. And a new calibration approach was discussed, through which the models parameters can be exactly acquired. The procedure of the parameters analysis and solution was given. The results of the actual experiments demonstrate both the validity and highprecision of the new calibration approach, so the navigation precison can be improved.

Laser gyro using ring laser

Abstract: PURPOSE:To eliminate the dead region around the angular velocity of a laser gyro omega=0 by detecting a one-way traveling wave ring laser rotating with an input axis which is a detected substance and the output beat frequency of a reference linear laser. CONSTITUTION:The frequency of laser light L2 takes a constant value depending on closed optical path length if a normal passing the center of the closed optical path surface of a one-way traveling wave ring laser URL is regarded as a sensitivity axis. In the angular velocity omega of the sensitivity axis, the frequency varies in directly proportional to omega by Doppler effect. When the modulated light L2 and laser light L3 from a reference linear laser RLL not sensing omega are interfered by combining them as the same directional traveling wave through an output read device ROD, interference fringe is generated by heterodyne effect and the fringe moves by a difference between the frequencies of L2 and L3, namely, by the velosity which is proportional to those beat frequencies. Therefore, the laser gyro recognizes omega by measuring its beat frequency.

Pneumatically dithered laser gyro

Abstract: A dithered ring laser gyro in which the effects of mode locking, or frequency locking, at low rotation rates are reduced by producing an oscillatory flow of the ionized gas in the gain section of the laser. The envelope in which the laser is sealed includes a pair of closed-end bellows. The bellows are extended and retracted in push-pull to pump the gas. There is thus created a dynamically varying pressure differential and oscillatory gas flow along the bore of the gain section of the laser which induces a corresponding oscillatory bias in the gyro output.

Ring laser gyroscope with geometrically induced bias

Abstract: An out of plane ring laser gyroscope comprises a frame and a cavity formed in the frame to provide a non-planar closed optical pattern A gain medium produces two light beams propagating in opposite directions in the cavity A magnetic device applies an axial magnetic field to the gain medium to allow only light of opposite circular polarizations to lase in opposite directions The gain medium and resonant cavity alone will allow left and right circularly polarized modes to lase in both clockwise and anticlockwise directions simultaneously The application of the axial magnetic field to the gain region shifts the center of the gain profile for the clockwise right circularly polarized and anticlockwise left circularly polarized beams with respect to the gain profile center for the anticlockwise right circularly polarized and clockwise left circularly polarized beams The cavity length can then be adjusted so that lasing action in two of the four modes is suppressed leaving only modes of opposite polarization propagating in opposite directions The out of plane geometry of the cavity forces these modes to resonate at greatly different frequencies and hence prevents frequency locking over a very large range of input rotation rates