The invention discloses a three-axis turntable axis perpendicularity detection method based on laser gyro strap-down inertial navigation, comprising a laser gyro strap-down inertial navigation system, a three-axis turntable, a three-axis turntable attitude acquisition system, an inertial navigation system output attitude acquisition system, and a data processing computer. The laser gyro strap-down inertial navigation system is fixedly installed on the table board of the detected three-axis turntable. Axis perpendicularity detection of the three-axis turntable is completed by acquiring angular attitude output of the three-axis turntable and attitude measurement information of the laser gyro strap-down inertial navigation system and based on the principle that the rotation vector increment of a fixedly-connected rigid body is not affected by the measurement point. The method can be used to detect the axis perpendicularity of any two axes of a three-axis turntable, and has the advantages of high detection precision, simple system composition and operation, a wide scope of application, and the like.

Three-axis turntable axis perpendicularity detection method based on laser gyro strap-down inertial navigation

The invention belongs to the technical field of inertial navigation and measuring equipment. A basic mechanical device, namely an external geneva mechanism which has the kinetic characteristic of periodic intermittent rotation is used to achieve the indexing mechanism for north-seeking measuring, wherein 90-degree transposition among the four positions with one another is achieved. A driving element with suitable revolving speed is selected, the mode of computer control is adopted, an initial position is used as a standard, the four-position indexing mechanism of a north-seeking device is enabled to achieve 90-degree transposition among the four positions with one another through rotation and cease for a circle, measurement of earth rotation related fraction is completed by a gyroscope, and then an azimuthal angle which is relative to north is calculated.

Indexing method and mechanism used for four-position north-seeking measuring in north-seeking system

The invention relates to a three-axis integral or combinational laser gyro two-way constant-speed frequency offset method, belonging to the technical field of inertial navigation equipment. A three-axis integral laser gyro is installed on a two-way constant-speed frequency offset rotary table rotating around a vertical axis, each sensitive axis of the three-axis integral laser gyro deviates from the rotating axis of the frequency offset rotary table by an angle beta, and the angle beta is equal to 54.73561 DEG. The three-axis integral laser gyro is driven to rotate by the rotary table, and the component (alpha& cos beta) of the angular velocity of rotation (alpha&) on the sensitive axes of the laser gyro moves the working area of the laser gyro out of a latchup area, thus the constant-speed frequency offset of the laser gyro and the error rotation modulation of the laser gyro are carried out simultaneously. In the invention, the two-way constant-speed frequency offset technology is adopted in the three-axis integral or combinational laser gyro, errors caused by the latchup effect of the laser gyro are completely eliminated, and the laser gyro can work uninterruptedly. Therefore, an ultrahigh-precision strapdown inertial system can be manufactured.

Three-axis integral or combinational laser gyro two-way constant-speed frequency offset method and two-way constant-speed frequency offset three-axis integral or combinational laser gyro group

The invention provides a high-reliability inertia bearing keeping system which comprises a rotary transformer, an accelerometer sensor, a tilt angle sensor, a gyroscope I, a gyroscope II, an accelerometer I, an accelerometer II, a bearing ring, a longitudinal swing ring, an angle collector, two AD (analog/digital) collectors, a resolver, two DA (digital/analog) compensators, a horizontal motor and a bearing motor, wherein the rotary transformer, the accelerometer sensor and the tilt angle sensor are fixed on a carrier; a platform is fixed in the longitudinal swing ring; the two gyroscopes and the two accelerometers are fixed on the platform; acceleration signals of the two gyroscopes and three angle signals are acquired and output to the resolver for resolving, and the signals are output to drive the bearing ring and the longitudinal swing ring to rotate, so that a rotary axis of the gyroscope I is always directed to the geographical north; and when subsystems have faults, the resolver can still perform correction computation according to the input signals so as to obtain an accurate bearing angle, and thus the rotary axis of the gyroscope I is still directed to the geographical north The system has the characteristics of high reliability, low cost and compact structure

High-reliability inertia bearing keeping system

Laser gyro combined offset frequency method and combined device for inertial measurement of laser gyro

The invention relates to a two-way constant speed frequency-offset laser gyro north finder, and belongs to the technical field of inertial navigation equipment. The laser gyro north finder is provided with a two-way constant speed frequency-offset rotary table rotating around a vertical axis; the rotary table is provided with a laser gyro and an accelerometer; the sensing axis of the laser gyro deviates the rotary plane of the rotary table by a beta angle; and the input axis of the accelerometer is parallel to the rotary plane of the frequency-offset rotary table and is parallel to a projection of the sensing axis of the laser gyro on the rotary plane of the frequency-offset rotary table. The laser gyro north finder applies two-way constant speed frequency-offset technology, thoroughly eliminates influence of latchup effect on precision of the laser gyro, and performs rotation error modulation and filtering on the errors produced by the laser gyro due to other reasons to ensure that the precision of the laser gyro is greatly improved than that of other conventional frequency-offset technology so as to manufacture the arc-second high-precision laser gyro north finder.

Ling Xie

Papers

Two-way constant speed frequency-offset laser gyro north finding method and two-way constant speed frequency-offset laser gyro north finder

Three-axis integral or combinational laser gyro two-way constant-speed frequency offset method and two-way constant-speed frequency offset three-axis integral or combinational laser gyro group

Laser gyro combined offset frequency method and combined device for inertial measurement of laser gyro