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.

Reduced-order Kalman filter for RLG SINS initial alignment

Abstract: A closed-loop reduced-order Kalman filter is utilized to perform initial alignment of ring laser gyroscope strapdown inertial navigation system. The observability of the system with different measurement models were analyzed in detail. Navigation algorithm in alignment is modified to feedback continuously for the closed-loop system. The feasibility of this solution is verified through simulation and experiments. It is shown that the initial covariance of Kalman filter can influence the speed of initial alignment significantly because the covariance can not reflect the true state of the azimuth very well. At the beginning of alignment, Kalman filter must make a very conservative guess at the initial value of azimuth angle. If not, initial alignment will be accomplished at a low speed.

A new systematic calibration method of ring laser gyroscope inertial navigation system

Abstract: Inertial navigation system has been the core component of both military and civil navigation systems. Before the INS is put into application, it is supposed to be calibrated in the laboratory in order to compensate repeatability error caused by manufacturing. Discrete calibration method cannot fulfill requirements of high-accurate calibration of the mechanically dithered ring laser gyroscope navigation system with shock absorbers. This paper has analyzed theories of error inspiration and separation in detail and presented a new systematic calibration method for ring laser gyroscope inertial navigation system. Error models and equations of calibrated Inertial Measurement Unit are given. Then proper rotation arrangement orders are depicted in order to establish the linear relationships between the change of velocity errors and calibrated parameter errors. Experiments have been set up to compare the systematic errors calculated by filtering calibration result with those obtained by discrete calibration result. The largest position error and velocity error of filtering calibration result are only 0.18 miles and 0.26m/s compared with 2 miles and 1.46m/s of discrete calibration result. These results have validated the new systematic calibration method and proved its importance for optimal design and accuracy improvement of calibration of mechanically dithered ring laser gyroscope inertial navigation system.

Method for calibrating a rotational angle sensor by means of a laser gyroscope

Abstract: The invention describes a method for calibrating a rotational angle sensor having a rotor (12) which is coupled to a rotating shaft (10) in a manner which is faithful to the rotational angle, a stator (16), and a scanning means (14) which is arranged on the stator (16). The scanning means (14) scans a material measure of the rotor (12) and generates measured angle values associated with the rotational angle position of the rotor (12). A laser gyroscope (18) measures the angular velocity of the shaft (10). The signals from the laser gyroscope (18) which are dependent on the angular velocity of the shaft (10) are integrated over time with respect to the rotational angle, as a result of which each rotational angle position is associated with, as reference angle values, the signals from the laser gyroscope (18) which have been integrated as far as this rotational angle position. The measured angle values from the scanning means (14) are compared with these reference angle values, correction variables associated with the respective measured angle values being formed from the differences. The measured angle values and their respective associated correction variables are stored in the form of a correction table in a non-volatile memory. During measurement of the rotational angle, the measured angle values are corrected using the correction variable which is associated with the respective measured angle value and is stored in the correction table.

Singlemode fibre frequency-modulated continuous-wave Sagnac gyroscope

Abstract: A singlemode fibre frequency-modulated continuous-wave Sagnac gyroscope is described. The rotation speed of the fibre coil can be determined simultaneously by detecting the phase shift of the beat signal produced by two counter-propagating laser beams in a singlemode fibre coil. A resolution of 0.02°/s with a 100 m fibre coil has been observed.

Laser gyro light path control system

Abstract: This invention discloses a laser gyroscope light path time and frequency division system, wherein, the time division control system receives distance control component adjustable light path of control signal Z drive control lens generated by the light intensity high-frequency signal input light distance long signal measurement and control unit; the light intensity low frequency signal input light path bias signal measurement unit generates light path revise signal an and small-shake low frequency modulating signal S. The difference of the frequency division system lies in the following: the light intensity low frequency signal is input to each different frequency light path bias signal measurement and control unit to generate light path control signal which simultaneously input relative light path control part adjustable light path to the best.