A Rate Integrating Fiber Optic Gyro

Abstract

In the past, fiber optic gyros have generally been viewed as angular rate sensors. However, for inertial navigation purposes, a "rate integrating" gyro characteristic is desired. The distinction is subtle, but important. A rate gyro's output represents an estimate of instantaneous angular rate. The system attitude is determined by sampling the rate and integrating numerically to angular displacement. On the other hand, a rate integrating gyro provides the change in rotation angle rather than instantaneous rate. The system accumulates the angular increments obtained from the gyro to determine rotation angle and, hence, attitude. A ring laser gyro is a good example of a rate integrating sensor. Its output consists of pulses that represent fixed angle increments. It is shown that an interferometric fiber optic gyro can also be configured as a rate integrating gyro. The paper discusses the theory and application of this concept.

Nonclassical quaternions and pentanions in problems of inertial orientation

“…An additional analysis showed advantages of algorithm 3 also in speed of operation. Optimal conical algorithm 6 exceeds in exactness even the four-step algorithm Litton [7], and his calculable complication is equal to calculable complication of algorithm 4.…”

“…In Table II the values of constant of speed of calculable drift of algorithms are showed for comparison (at the conical vibrations of block of gyroscopes SIOS with conditions [6]: corner of nutation -1 deg., frequency of conical vibrations -10 Hz, step of calculations -0,01 s), got within the hundredth stakes of percent at a computer design by the method of parallel account [1, p. 218]. As seen in Table II, algorithm 3 substantially excels at exactness other algorithms (except for new algorithm 6) and is, essentially, a conical [7] algorithm (actually of the sixth order of exactness). An additional analysis showed advantages of algorithm 3 also in speed of operation.…”

An accurate calibration method for accelerometer nonlinear scale factor on a low-cost three-axis turntable

“…The true geographic frame c frame The computed geographic frame p frame The platform frame were estimated independently of the accelerometer errors by a special path, then accelerometer errors were estimated by another special path following gyroscope error compensation [5]. Two sets of rotation sequences were designed by Savage. Comparing the specific force before rotation with the specific force after rotation, the gyroscope and accelerometer errors can be obtained [6].…”

A unified scheme for rotation modulation and self-calibration of dual-axis rotating SINS

“…Two sets of calibration rotation schemes were designed in [17], which calculated the horizontal and vertical components of the specific force before and after rotation, and estimated the various calibration parameters through the fitting method. A conclusion was drew in [18] that the gyro error parameters are related to the rotation paths and the accelerometer error parameters are only related to the final position. Based on this, a calibration rotation scheme was designed to realize the separation and decoupling between the gyro and accelerometer error parameters.…”