阅读说明：本技术 一种惯性测量的冗余系统及标定方法 (Redundancy system and calibration method for inertial measurement ) 是由 邵志浩 丁波 杜鹏 宋长哲 何健伟 胡华峰 许卫国 徐娅 王佳丽 石妙 于 2021-08-09 设计创作，主要内容包括：本发明公开了一种惯性测量冗余系统及标定方法,涉及惯性测量技术领域。其包括以下步骤：通过并排设置两套带有转位机构和敏感组件的三自惯性组件；并通过两位置系统标定,确定两套惯组相对位置关系；将其中一套惯组敏感组件旋转至预设角度斜置并锁紧；得到用于冗余判断或重构的敏感信息。本发明采用带有转位机构的三自惯组,其适用性较强,不需要再对惯组进行定制化,可进行批量化生产,降低了成本；且本发明方案不需要实施复杂的标定流程,而仅仅通过简单的两位置系统标定即可确定两套惯组之间的关系。且本发明方案,可实现敏感组件任意精确角度的斜置,为惯性测量系统故障检测提供所需的敏感信息。(The invention discloses an inertial measurement redundancy system and a calibration method, and relates to the technical field of inertial measurement. Which comprises the following steps: two sets of three self-inertia assemblies with indexing mechanisms and sensitive assemblies are arranged side by side; calibrating through a two-position system, and determining the relative position relation of the two sets of inertial measurement units; rotating one set of inertial measurement unit sensitive assemblies to a preset angle, obliquely placing the set of inertial measurement unit sensitive assemblies and locking the set of inertial measurement unit sensitive assemblies; sensitive information for redundant judgment or reconstruction is obtained. The three-self inertial set with the indexing mechanism is adopted, so that the applicability is strong, the inertial set does not need to be customized, batch production can be carried out, and the cost is reduced; in addition, the scheme of the invention can determine the relationship between the two sets of inertial units only by simple two-position system calibration without implementing a complex calibration process. The scheme of the invention can realize the inclined arrangement of the sensitive component at any accurate angle and provide required sensitive information for the fault detection of the inertial measurement system.)

1. A calibration method of an inertial measurement redundancy system is characterized by comprising the following steps:

arranging a redundant inertial measurement unit suite, wherein the redundant inertial measurement unit suite comprises a first inertial measurement unit (1) and a second inertial measurement unit (2) which are arranged side by side, the second inertial measurement unit (2) is provided with a transposition mechanism and a sensitive component, and the transposition mechanism comprises an inner frame shaft and an outer frame shaft;

initializing and resetting the first inertial set (1) and the second inertial set (2), acquiring a basic coordinate system of the first inertial set (1) and the second inertial set (2), and reading a first set of sensitive data of the first inertial set (1) and the second inertial set (2), wherein the first set of sensitive data comprises: an included angle Ax1 between an X axis and a horizontal plane in a basic coordinate system of the first inertial set (1), an included angle Az1 between a Z axis and the horizontal plane in the basic coordinate system of the first inertial set (1), an included angle Bx1 between the X axis and the horizontal plane in a basic coordinate system of the second inertial set (2) and an included angle Bz1 between the Z axis and the horizontal plane in the basic coordinate system of the second inertial set (2);

simultaneously overturning the first inertial unit (1) and the second inertial unit (2), reading the measurement data of the first inertial unit (1) and the second inertial unit (2) again, and obtaining a second group of sensitive data, wherein the second group of sensitive data comprises: the horizontal angles Ax2, Ay2 of the first inertia set (1), and the horizontal angles Bx2, By2 of the second inertia set (2);

rotating the sensitive assembly of the second inertial measurement unit (2) to enable the sensitive assembly to rotate and lock according to a first preset angle, wherein the first preset angle comprises: the outer frame shaft rotation angle theta and the inner frame shaft rotation angle phi of the second inertia unit (2);

and obtaining the relative relation between the first inertial set (1) and the second inertial set (2) according to the first set of sensitive data, the second set of sensitive data and the first preset angle.

2. The calibration method according to claim 1, characterized in that: the obtaining of the relative relationship between the first inertial set (1) and the second inertial set (2) according to the first set of sensitive data, the second set of sensitive data and the first preset angle includes:

according to the formula:

Δz＝Bx2-Ax2

Δy＝Bx1-Ax1

Δx＝(Az1-Bz1+Ay2-By2)/2

obtaining a rotation quantity delta Z of the second inertial set (2) relative to the first inertial set (1) around a Z axis, a rotation quantity delta Y of the second inertial set (2) relative to the first inertial set (1) around a Y axis, and a rotation quantity delta X of the second inertial set (2) relative to the first inertial set (1) around an X axis;

according to the formula:

obtaining the relative position relation of the first inertial unit (1) and the second inertial unit (2) after the first inertial unit (1) and the second inertial unit (2) are simultaneously overturnedWhereinThe relative position relation of the first inertial unit (1) and the second inertial unit (2) before the rotation and locking of the indexing mechanism is obtained;is the relative position relation before and after the rotation of the second inertia unit (2)

3. The calibration method according to claim 2, wherein the deriving the relative relationship between the first inertial set (1) and the second inertial set (2) according to the first set of sensitive data, the second set of sensitive data, and the first preset angle further comprises:

by the formula:

N_A/K_A＝K_0A+K_AxyzAccl

obtaining the apparent acceleration vector Acc1 measured by the first inertial set (1) and the apparent acceleration vector Acc2 measured by the second inertial set (2), wherein N is_AOutputting a number of pulses, K, for the accelerometer of the first inertial unit (1)_AAccelerometer equivalent, N, of the first inertial mass (1)_BOutputting a pulse number, K, for the accelerometer of the second inertial unit (2)_BIs the accelerometer equivalent, K, of the first inertial mass (1)_0AIs the accelerometer zero position, K, of the first inertial unit (1)_0BIs the accelerometer zero position, K, of the second inertial unit (2)_AxyzIs the mounting error matrix, K, of the first inertial unit (1)_BxyzIs the installation error matrix of the second inertial set (2).

4. The calibration method according to claim 1, wherein the first inertial set (1) and the second inertial set (2) perform an initialization reset and acquire a base coordinate system of the first inertial set (1) and the second inertial set (2), and the reading of the first set of sensitive data of the first inertial set (1) and the second inertial set (2) comprises:

resetting the first inertial unit (1) and the second inertial unit (2) and acquiring a basic coordinate system of the first inertial unit and the second inertial unit;

the first inertial set (1) and the second inertial set (2) are hung on a rolling and loading frame vehicle (4), and the first inertial set (1) and the second inertial set (2) are leveled for the first time by taking the basic coordinate system as a reference;

and after the first leveling, reading a first group of sensitive data of the first inertial set (1) and the second inertial set (2).

5. The calibration method according to claim 4, wherein the step of simultaneously flipping the first inertial set (1) and the second inertial set (2), and reading the measurement data of the first inertial set (1) and the second inertial set (2) again to obtain a second set of sensitive data comprises:

turning over the first inertial set (1) and the second inertial set (2) at a second preset angle, and leveling the roll-on rack truck (4) and the cabin section for the second time by taking the basic coordinate system as a reference; and after the second leveling is finished, measuring and recording a second group of sensitive data of the first inertial set (1) and the second inertial set (2).

6. The inertial measurement system redundancy measurement method of claim 5, wherein:

in the first leveling, the leveling precision of the first inertial unit (1) and the second inertial unit (2) is better than 10' on an X axis and a Z axis of a basic coordinate system;

in the second leveling, the leveling precision of the first inertia set (1) and the second inertia set (2) is better than 10' on an X axis and a Y axis.

7. The inertial measurement system redundancy measurement method according to claim 5, wherein said flipping said first inertial set (1) and said second inertial set (2) by a second preset angle comprises:

and simultaneously turning the first inertia set (1) and the second inertia set (2) by 90 degrees anticlockwise.

8. A redundant system of inertial measurements, comprising:

the system comprises two sets of redundant inertial sets, a first detection unit and a second detection unit, wherein the two sets of redundant inertial sets are arranged in a device to be detected and arranged side by side, and each set of redundant inertial set comprises a transposition mechanism and a sensitive component;

the indexing mechanism comprises an outer frame shaft and an inner frame shaft, wherein two ends of the inner frame shaft are movably connected with the outer frame shaft, and the inner frame shaft can rotate around the outer frame shaft;

the sensitive component is movably connected with the inner frame shaft, and the sensitive component can rotate around the inner frame shaft and can also rotate around the outer frame shaft.

9. The redundancy system of claim 8, wherein:

the indexing accuracy of the inner frame shaft and the outer frame shaft of the indexing mechanism is not more than 12'.

10. The redundancy system of claim 8, wherein:

the two sets of redundant inertial measurement units are arranged in parallel in the cabin section (3) of the equipment to be tested.

Technical Field

The invention relates to the technical field of inertia measurement, in particular to a redundancy system and a calibration method for inertia measurement.

Background

In recent years, an inertial measurement unit has become a core device in high-precision fields such as aircraft, rockets and the like, generally comprises a gyroscope, an accelerometer and a related processing circuit, and is provided with a function of measuring the apparent acceleration of a carrier rocket along three rocket axes and the angular velocity around the rocket axis in real time, outputting the measurement results to an rocket-mounted computer for navigation and attitude calculation, and realizing guidance and stable control of the carrier rocket.

Under the influence of vibration, impact and other using environments, the inertia device is easy to have the conditions of reliability reduction, even failure and the like, and the flight reliability of the carrier rocket is directly influenced. Due to the limitations of the production process level of the inertial device, a redundancy design is generally adopted to improve the reliability of the inertial measurement combination. The redundancy method is a design for judging that a sensor fails and accurately finding out the failed sensor when a certain sensor fails, and acquiring correct information from normal sensor output. Generally, sensitive components of the measurement system need to be mounted in a three-axis orthogonal manner to form a complete right-hand coordinate system, and the redundancy design is in terms of redundancy levels, including component-level redundancy and system-level redundancy. The redundancy of the component level is to increase the number of inertia devices, and the redundancy comprises a multi-meter inertial set such as an eight meter, a ten meter and the like; the redundant skew configuration is outside the orthogonal triaxial sensitive assembly, and one or more gyros/accelerometers are tilted to measure the angular velocity/acceleration of rotation. This redundant approach uses multiple devices to redundantly measure the same shaft angular velocity/acceleration. The system level redundancy is realized by adopting two or more sets of strapdown or platform inertia measurement combinations. The multi-meter inertial measurement unit adopted by component level redundancy is complex in structure, expensive in cost, limited in application occasions and incapable of forming mass production. The system level redundancy generally adopts two or more sets of inertial measurement units to be placed side by side, and the measurement data of a single inertial measurement unit is taken as a basic unit for redundancy judgment, so that the reliability of the system cannot be improved by more effectively utilizing the information of the inertial measurement units.

In addition, due to the limited space for installing the inertial measurement system, the two redundant designs require a customized fixed design for the inertial measurement device, and the inertial measurement system needs to be calibrated on the ground periodically, which means that the measurement system needs to undergo disassembly-calibration-reinstallation, and the operation flow is complicated and the period is long, which brings inconvenience to practitioners.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a redundant system and a calibration method for inertial measurement, and mainly solves the problems of complicated and complicated calibration procedures in the related technology.

Accordingly, the present invention provides a method of redundancy for an inertial measurement system, comprising the steps of:

arranging a redundant inertial measurement unit suite, wherein the redundant inertial measurement unit suite comprises a first inertial measurement unit and a second inertial measurement unit which are arranged side by side, the second inertial measurement unit is provided with a transposition mechanism and a sensitive component, and the transposition mechanism comprises an inner frame shaft and an outer frame shaft;

initializing and resetting the first inertial measurement unit and the second inertial measurement unit, acquiring a basic coordinate system of the first inertial measurement unit and the second inertial measurement unit, and reading a first set of sensitive data of the first inertial measurement unit and the second inertial measurement unit, wherein the first set of sensitive data comprises: an included angle Ax1 between an X axis and a horizontal plane in the first inertial set basic coordinate system, an included angle Az1 between a Z axis and the horizontal plane in the first inertial set basic coordinate system, an included angle Bx1 between the X axis and the horizontal plane in the second inertial set basic coordinate system and an included angle Bz1 between the Z axis and the horizontal plane in the second inertial set basic coordinate system;

and simultaneously overturning the first inertial measurement unit and the second inertial measurement unit, reading the measurement data of the first inertial measurement unit and the second inertial measurement unit again, and obtaining a second group of sensitive data, wherein the second group of sensitive data comprises: the horizontal angles Ax2, Ay2 of the first inertial set, and the horizontal angles Bx2, By2 of the second inertial set;

rotating the sensitive assembly of the second inertial measurement unit, so that the sensitive assembly rotates and is locked according to a first preset angle, wherein the first preset angle comprises: the outer frame shaft rotation angle theta and the inner frame shaft rotation angle phi of the second inertial unit;

and obtaining the relative relation between the first inertial measurement unit and the second inertial measurement unit according to the first group of sensitive data, the second group of sensitive data and the first preset angle.

In some embodiments, the deriving the relative relationship between the first inertial set and the second inertial set according to the first set of sensitive data, the second set of sensitive data, and the first preset angle includes:

according to the formula:

Δz＝Bx2-Ax2

Δy＝Bx1-Ax1

Δx＝(Az1-Bz1+Ay2-By2)/2

obtaining a rotation quantity delta Z of the second inertial set relative to the first inertial set around the Z axis, a rotation quantity delta Y of the second inertial set relative to the first inertial set around the Y axis, and a rotation quantity delta X of the second inertial set relative to the first inertial set around the X axis;

according to the formula:

obtaining the relative position relationship between the first inertial measurement unit and the second inertial measurement unit after the first inertial measurement unit and the second inertial measurement unit are simultaneously overturnedWhereinThe relative position relation of the first inertial unit and the second inertial unit before the rotation and locking of the indexing mechanism is obtained;is the relative position relationship before and after the rotation of the second inertial unit

In some embodiments, the deriving the relative relationship between the first inertial set and the second inertial set according to the first set of sensitive data, the second set of sensitive data, and the first preset angle further includes:

by the formula:

N_A/K_A＝K_0A+K_AxyzAcc1

obtaining the apparent acceleration vector Acc1 of the first inertial set measurement and the apparent acceleration vector Acc2 of the second inertial set, wherein N_AOutputting a number of pulses, K, for the accelerometer of the first inertial measurement unit_AAccelerometer equivalent of the first inertial measurement unit, N_BOutputting a number of pulses, K, for the accelerometer of the second inertial measurement unit_BAccelerometer equivalent, K, of the first inertial measurement unit_0AIs the accelerometer zero position, K, of the first inertial unit_0BIs the accelerometer zero position, K, of the second inertial unit_AxyzIs the mounting error matrix, K, of the first inertial unit_BxyzAnd the mounting error matrix of the second inertial measurement unit.

In some embodiments, the initializing and resetting the first inertial measurement unit and the second inertial measurement unit, acquiring a base coordinate system of the first inertial measurement unit and the second inertial measurement unit, and reading a first set of sensitive data of the first inertial measurement unit and the second inertial measurement unit includes:

resetting the first inertial measurement unit and the second inertial measurement unit and acquiring a basic coordinate system of the first inertial measurement unit and the second inertial measurement unit;

the first inertial set and the second inertial set are hung on a roll-on rack vehicle, and the first inertial set and the second inertial set are leveled for the first time by taking the basic coordinate system as a reference;

and after the first leveling, reading a first group of sensitive data of the first inertial measurement unit and the second inertial measurement unit.

In some embodiments, the simultaneously flipping the first inertial measurement unit and the second inertial measurement unit, and reading the measurement data of the first inertial measurement unit and the second inertial measurement unit again to obtain a second set of sensitive data includes:

turning over the first inertial unit and the second inertial unit at a second preset angle, and leveling the roll-on rack vehicle and the cabin section for the second time by taking the basic coordinate system as a reference; and after the second leveling is finished, measuring and recording a second group of sensitive data of the first inertial set and the second inertial set.

In some embodiments, in the first leveling, the leveling accuracy of the first inertial set and the second inertial set is better than 10' in the X axis and the Z axis of the basic coordinate system;

in the second leveling, the leveling precision of the first inertial unit and the second inertial unit is better than 10' on an X axis and a Y axis.

In some embodiments, the flipping the first inertial set and the second inertial set at a second preset angle includes:

and simultaneously turning the first inertial set and the second inertial set by 90 degrees anticlockwise.

In another aspect, a redundant system for inertial measurement is provided, comprising:

the system comprises two sets of redundant inertial sets, a first detection unit and a second detection unit, wherein the two sets of redundant inertial sets are arranged in a device to be detected and arranged side by side, and each set of redundant inertial set comprises a transposition mechanism and a sensitive component;

the indexing mechanism comprises an outer frame shaft and an inner frame shaft, wherein two ends of the inner frame shaft are movably connected with the outer frame shaft, and the inner frame shaft can rotate around the outer frame shaft;

the sensitive component is movably connected with the inner frame shaft, and the sensitive component can rotate around the inner frame shaft and can also rotate around the outer frame shaft.

In some embodiments, the indexing accuracy of both the inner frame shaft and the outer frame shaft of the indexing mechanism is no greater than 12 ".

In some embodiments, the two sets of redundant inertial measurement units are arranged side by side in the cabin section of the device under test.

Compared with the prior art, the invention has the following advantages:

(1) the inertial unit is designed redundantly, and any accurate angle inclined arrangement of the sensitive assembly can be realized by adopting two sets of inertial assemblies with the indexing mechanisms, so that a measuring system does not need to be designed in a customized manner, the calibration efficiency is improved, and the cost is reduced.

(2) The relation between the two sets of inertial measurement units can be determined only by simple two-position system calibration without depending on precise calibration equipment;

(3) the invention provides a reliable platform for fault separation and detection of the sensitive device through the sensitive information output by the two sets of inertial measurement units for determining the position relation.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of an inertial measurement system according to an embodiment of the invention;

FIG. 2 is a schematic diagram illustrating calibration of relative positions of two inertial measurement units according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a ground measurement procedure of a redundant inertial measurement system in an embodiment of the present invention;

FIG. 4 is a method for calibrating a redundant inertial measurement system according to an embodiment of the present invention.

In the figure: 1. a first inertial unit; 2. a second inertial unit; 3. a cabin section; 4. and (4) rolling and mounting the rack vehicle.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

The redundant design of the inertia measurement system can be used for main bodies of aircrafts, naval vessels, missiles and the like which need navigation information, and inertia components can be arranged in the cabin sections 3 of the devices.

Referring to fig. 1, an inertial measurement system is provided in an embodiment of the present application, including:

two sets of three self-inertia units are adopted as redundant inertia unit kits: the first inertial unit 1 and the second inertial unit 2 are installed side by side according to the installation structure of the cabin section 3. The three-self-inertia unit is an inertia measurement assembly with self-calibration, self-diagnosis and self-alignment functions, and is widely applied to the field of inertia measurement. The three-self inertial unit generally comprises an indexing mechanism and an inertia sensitive assembly, and compared with the traditional inertial unit, the three-self inertial unit has the indexing mechanism, so that the inertia sensitive assembly of the three-self inertial unit can stay at different positions including a certain inclined angle according to the requirement. Of course, the redundant inertial assembly can also be arranged at other parts of the equipment, generally in the cabin section 3. The sensitive assembly comprises: one or more gyros or one or more accelerometers.

Specifically, the second inertial set 2 in the present invention is a three-self inertial set, including: a second indexing mechanism and a second sensitive assembly. The second indexing mechanism also comprises an inner frame shaft and an outer frame shaft, and the second sensitive component can rotate around the inner frame shaft in the structure and can also rotate around the outer frame shaft under the driving of the inner frame. The second sensitive assembly is arranged with reference to the orientation shown in fig. 2, in which common instruments such as accelerometers and gyroscopes are located. The indexing accuracy of the inner frame shaft and the outer frame shaft of the indexing mechanism is not more than 12'.

Referring to fig. 1 and 2, the first inertial set 1 can be a universal three-self inertial set similar to the second inertial set 2. Specifically, the universal three-self inertial unit generally comprises an indexing mechanism with a locking function, a sensitive component and a shell. Wherein the indexing mechanism includes: the outer frame shaft on the shell, the outer frame of the shell and the inner frame shaft on the inner frame of the shell. The sensitive component is arranged at one end of the inner frame shaft, and can rotate around the inner frame shaft or the outer frame shaft under the driving of the inner frame.

It can be understood that the first sensitive assembly of the first inertial set 1 and the second sensitive assembly of the second inertial set 2 are arranged as shown in the direction of fig. 2.

It should be noted that, before the inertial measurement system of the present invention is used, preset data in the sensitive components of two sets of three-self inertial measurement units need to be predetermined, which includes: outputting equivalent weight by the two inertial measurement units of accelerometers, zero positions of the accelerometers and an installation error matrix of the accelerometers; and a gyro zero position, a gyro output equivalent and a plurality of gyro mounting error matrixes in the sensitive component.

As shown in fig. 3 and 4, the present invention provides a specific embodiment of a calibration method for an inertial measurement redundancy system:

s1, arranging two sets of three self-inertia units in a cabin section 3 side by side: the first inertial set 1 and the second inertial set 2 are initialized and reset, and a basic coordinate system X of the first inertial set 1 is obtained₁Y₁Z₁And the base coordinate system X of the second inertial unit 2₂Y₂Z₂. The inerter is then de-energized and the capsule section 3 is suspended to the top of the roll frame 4.

It should be noted that the top of the roll-off rack wagon 4 is provided with a part which can roll in the rolling direction shown in fig. 3. Which can drive the cabin section on the roll-on rack truck 4 to turn over.

S2, overturning the cabin section 3, and measuring output data of two positions before and after the inertia measurement system is overturned to obtain first output data and second output data.

Specifically, see fig. 3 for a representation: before the step of turning the cabin 3 is performed, in some embodiments, the inertial unit needs to be powered off, and then the cabin 3 is hung on the rolling frame 4. Wherein the rolling trolley 4 can roll according to the rolling direction shown in fig. 3. And then, supplying power to the two sets of three self-inertia units through ground test equipment, leveling for the first time, and measuring and collecting the two sets of inertia units after the leveling for the first time is finished to obtain first output data, wherein the first output data comprises horizontal angles Ax1 and Az1 of the first inertia unit 1 and horizontal angles Bx1 and Bz1 of the second inertia unit 2.

It is worth noting that the first leveling is the previously recorded base coordinate system position X of the corresponding inertial set₁Y₁Z₁And X₂Y₂Z₂The two inertial sets are adjusted for reference. The leveling process may be adjusting the height or other aspects of the roll-off rack cart 4 to bring the sensitive components in both inertial units back to the initialized zero angle position.

Specifically, the rolling and loading trolley 4 drives the cabin section 3 to turn over according to a second preset angle, leveling is carried out again, and the second leveling is the basic coordinate system position X of the corresponding inertial measurement unit recorded before₁Y₁Z₁And X₂Y₂Z₂And adjusting the two inertial measurement units for reference to enable the two inertial measurement units to return to the initialized zero-angle position. After the second leveling is finished, the two sets of inertial measurement units are measured and collected to obtain first output data, the first output data comprise an included angle Ax1 between an X axis and a horizontal plane in a first inertial measurement unit 1 basic coordinate system, an included angle Az1 between a Z axis and the horizontal plane in the first inertial measurement unit 1 basic coordinate system, an included angle Bx1 between the X axis and the horizontal plane in a second inertial measurement unit 2 basic coordinate system and an included angle Bz1 between the Z axis and the horizontal plane in the second inertial measurement unit 2 basic coordinate system. The second leveling is the same as the first leveling.

Preferably, the roll-on rack truck 4 drives the cabin section 3 to roll 90 degrees anticlockwise for turning, and the rotation of the angle is convenient for calculation.

It can be understood that the leveling accuracy of the first inertial set 1 and the second inertial set 2 is better than 10' in the X axis and the Z axis; the leveling accuracy of the first inertial set 1 and the second inertial set 2 is better than 10' on the X axis and the Y axis. Under the precision, the position deviation of the two sets of inertial units is small after the position of the two sets of inertial units is changed for many times.

S3, rotating a second sensitive assembly to a first preset angle through a second transposition mechanism of the second inertial measurement unit (2) and locking the second sensitive assembly; obtaining a relative position relation of the first inertial measurement unit 1 and the second inertial measurement unit 2 according to the first output data, the second output data and the rotation angle of the second inertial measurement unit;

it is worth mentioning that the dual inertial set calibration result can be calculated by the existing first output data and the second output data:

first, by

Δy＝Bx1-Ax1

Δz＝Bx2-Ax2

Obtaining: the rotation quantity delta X of the second inertial set 2 relative to the first inertial set 1 around the X axis; the rotation quantity delta Y of the second inertia set 2 relative to the first inertia set 1 around the Y axis; and the polarity of the data of the three rotation quantities is positive according to the right-hand rule relative to the rotation quantity delta Z of the second inertia set 2 around the Z axis of the first inertia set 1.

Then, the relative relationship between the first inertial set 1 and the second inertial set 2 before the second inertial set 2 is obliquely arranged is obtained through the rotation quantities Δ x, Δ y, Δ z in the three directions as follows:

next, the second inertial unit 2 is rotated by a first preset angle, in order to make the second sensitive component of the second inertial unit 2 reach a preset position, the inner frame shaft and the outer frame shaft in the second indexing mechanism are required to be rotated by a certain angle, wherein the rotation angle of the outer frame shaft is θ, and the rotation angle of the inner frame shaft is θ

From this equation (1) and the rotation angle data described above, equation (2) is obtained:

in the formulaFor the relative relationship between the second inertial set 2 before and after rotation, the final relative relationship between the two sets of inertial sets after the second inertial set 2 is inclined is obtained through the formula (3)

Rotating the second sensitive assembly to a first preset angle through a second indexing mechanism of the second inertial measurement unit 2 and locking the second sensitive assembly;

then, obtaining a relative position relationship between the first inertial set 1 and the second inertial set 2 according to the first output data, the second output data and the rotation angle of the second indexing mechanism:

and S4, obtaining an accelerometer output model and a gyroscope output model according to the relative position relationship between the first inertial measurement unit 1 and the second inertial measurement unit 2, the measurement data and the existing data.

Specifically, as shown in formula (4) and formula (5):

N_A/K_A＝K_0A+K_AxyzAcc1 (4)

wherein Acc1 is the apparent acceleration vector Acc1 and Acc2 measured by the first inertial set 1, N is the apparent acceleration vector of the second inertial set 2_A/K_A、N_B/K_BOutputs the pulse number (N) for the two inertial measurement units_AAnd N_B) And equivalent (K)_AAnd K_B) The ratio, wherein the output pulse number of the two inertial measurement units is the measured value of the equipment, and the equivalent value is a preset value; k_0A、K_0BThe set accelerometer zero position. K_Axyz、K_BxyzInstalling an error matrix for the measured additional table; wherein Acc1 and Acc2 are inertia measurement redundanciesThe acceleration vector of the residual system is only measured by Acc1 from the first inertial set 1, and Acc2 is measured by the second inertial set. And obtaining an accelerometer output model according to the two acceleration vectors Acc1 and Acc2 for redundancy judgment.

Likewise, the following formula (6) and formula (7) can be used:

NG_A/E_A＝D_0A+E_Axyzω1 (6)

obtaining the angular velocity vector ω 1 measured by the first inertial group 1 and the angular velocity vector ω 2, NG measured by the second inertial group 2_A/E_A、NG_B/E_BOutputting pulse Number (NG) for inertial group gyro_AAnd NG_B) Equivalent weight (E) to the inertial group_AAnd E_B) A ratio; d_0A、D_0BIs a pre-known gyroscope null; e_Axyz、E_BxyzInstalling an error matrix for a previously known gyroscope; and both omega 1 and omega 2 are angular velocity vectors of the inertial measurement redundancy system, except that omega 1 is measured by the first inertial measurement unit 1, and omega 2 is measured by the second inertial measurement unit. And a gyroscope output model obtained according to the two angular velocity vectors ω 1 and ω 2 is used for redundancy judgment.

And finally, the ground test equipment binds the model to other control single machines on the rocket, and the single machine on the rocket carries out fault detection and isolation on the sensitive data output by the two inertial units by methods such as generalized likelihood ratio fault detection and the like, and provides navigation solution.

In summary, in the inertial measurement system redundancy method in the embodiment of the present invention, two three self-inertial units are provided, and the indexing mechanism of the three self-inertial units can be used to tilt the sensitive component at any angle. The measurement system need not be subject to a limited space for custom design. Therefore, the invention is beneficial to improving the batch manufacturing and reducing the cost. Meanwhile, the invention determines the relation between two sets of inertial units by a relatively simple two-position system calibration method, so that the invention does not need to rely on precise calibration equipment and complex steps of complex disassembly-calibration-reinstallation. On the other hand, a reliable information measuring and collecting platform can be provided for the fault separation and detection of the sensitive device of the high-altitude flight device by determining the redundant information output by the two sets of inertial measurement units with the position relation.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.