Subdivision layout inertial measurement unit, star sensor and detector initial attitude reference acquisition method

Abstract

The invention discloses a subdivision layout inertial measurement unit, star sensor and detector initial attitude reference acquisition method, which comprises the following steps: according to detection information of a star sensor aiming at a star simulator, detection information of an optical detector aiming at an optical simulator, inertial measurement unit self-alignment information and light aiming information of the star simulator and a reference mirror on the optical simulator; initial attitude references of the inertial measurement unit, the star sensor and the detector are obtained through calculation; according to the invention, the problem of initial attitude reference acquisition among an inertial measurement unit, a star sensor and an optical detector which are installed in different cabins and cannot be intervisible is solved; the problems that a reference mirror cannot be installed on an optical detector and a star sensor pair under a compact layout, and a measurement coordinate system of the optical detector and the star sensor cannot establish a relation with a geographic coordinate system are solved.

Description

Technical Field

[0001] The invention relates to the field of flight control, in particular to a method for acquiring initial attitude references of an inertial group, a star sensor and a detector in a compartment layout. Background Art

[0002] In order to achieve high-precision flight control, the aircraft needs to obtain the relative initial attitude reference of the inertial group, star sensor, and optical detector during testing and bind it to the flight control software. In an aircraft with a compact compartment layout, the inertial group, star sensor, and optical detector are installed in different cabins, and there is no optical path between the individual units. That is, it is impossible to install a reference mirror on a single unit, calibrate the conversion matrix between the reference mirror and the measurement coordinate system of the single unit, and obtain the initial attitude reference of the inertial group, star sensor, and optical detector by aiming at the reference mirror. Therefore, it is necessary to study the initial attitude reference acquisition method of the inertial group, star sensor, and detector suitable for a compact compartment layout under the above constraints. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a method for obtaining the initial attitude reference of an inertial group, a star sensor and a detector in a compartment layout, so as to solve the problem of obtaining the initial attitude reference between the inertial group, the star sensor and the optical detector installed in different compartments and unable to see each other.

[0004] The technical solution of the present invention is to provide a method for obtaining the initial attitude reference of the inertial group, star sensor and detector in a compartment layout, which is applicable to the situation where the inertial group, star sensor and optical detector are installed in different compartments and there is no visual light path between the three. The method specifically includes the following steps:

[0005] (1) Calculate the transformation matrix between the inertial measurement coordinate system and the geographic coordinate system

[0006] (2) Calibrate the vector representation of two different point source targets simulated by the optical simulator in the optical simulator reference mirror coordinate system And the vector representation of two different star targets simulated by the star simulator in the star simulator reference mirror coordinate system

[0007] (3) Obtain the measurement value of the optical detector on the point source target, and calculate the vector representation of two different point source targets in the optical detector measurement coordinate system Obtain the measurement value of the star sensor for the star target, and calculate the vector representation of two different star targets in the star sensor measurement coordinate system.

[0008] (4) Calculate the transformation matrix between the optical simulator reference mirror coordinate system and the geographic coordinate system And the conversion matrix between the star simulator reference mirror coordinate system and the geographic coordinate system

[0009] (5) Using vector representation and the transformation matrix Calculate the vector representation of two different point source targets in the geographic coordinate system Using vector representation The transformation matrix of Calculate the vector representation of two different star targets in the geographic coordinate system

[0010] (6) Using vector representation Construct a rectangular coordinate system with three orthogonal axes Using vector representation Construct a rectangular coordinate system with three orthogonal axes Using vector representation Construct a rectangular coordinate system with three orthogonal axes Using vector representation Construct a rectangular coordinate system with three orthogonal axes

[0011] (7) Through the three-axis orthogonal rectangular coordinate system and the transformation matrix Calculate the transformation matrix between the inertial measurement coordinate system and the optical detector measurement coordinate system Through the three-axis orthogonal rectangular coordinate system and the transformation matrix Calculate the transformation matrix between the inertial measurement coordinate system and the star sensor measurement coordinate system That is to complete the acquisition of the initial attitude benchmark of the inertial group, star sensor, and optical detector.

[0012] Furthermore, in step (1), the transformation matrix between the inertial measurement coordinate system and the geographic coordinate system is calculated by using the azimuth output by the inertial group self-alignment and the two-axis non-horizontal degree: Specifically:

[0013] The inertial group is powered on to perform self-alignment and output the Y-axis azimuth angle amv y Unlevelness of Y and Z axis emv y 、emv z ;

[0014] The conversion matrix between the inertial measurement coordinate system and the celestial north-west geographic coordinate system is calculated according to the following formula

[0015] y m =-amv y

[0016] p m =-emvy

[0017] r m =arcsin(sin(emv z ) / cos(emv y ))

[0018]

[0019] Furthermore, in step (3), the measurement value of the optical detector on the point source target is obtained, and the vector representation of two different point source targets in the optical detector measurement coordinate system is calculated. The specific method is:

[0020] Record the horizontal angles (H) of the two point source targets output by the optical detector in the optical detector measurement coordinate system. R1 , T R1 ) and pitch angle (H R2 , T R2 ), we get [tanH R1 ,1,tanT R1 ]、[tanH R2 ,1,tanT R2 ], after normalization, the vector representation of two different point source targets in the optical detector measurement coordinate system is obtained

[0021] Furthermore, in step (3), the measurement value of the star sensor on the star target is obtained, and the vector representation of two different star targets in the star sensor measurement coordinate system is calculated. The specific method is:

[0022] Record the horizontal angles (θ) of the two star targets output by the star sensor in the star sensor measurement coordinate system. ys1 ,θ zs1 ) and pitch angle (θ ys2 ,θ zs2 ), we get [1, -tanθ ys1 ,-tanθ zs1 ], [1, -tanθ ys2 ,-tanθ zs2 ], after normalization, the vector representation of two different star targets in the star sensor measurement coordinate system is obtained

[0023] Furthermore, in step (4), by setting up an electronic theodolite and a gyro north finder, aiming at the reference mirror on the optical simulator, obtaining the two-axis non-horizontal degree and north angle of the optical simulator reference mirror coordinate system, and calculating the conversion matrix between the optical simulator reference mirror coordinate system and the geographic coordinate system Aim at the reference mirror on the star simulator, obtain the two-axis non-horizontal degree and north angle of the star simulator reference mirror coordinate system, and calculate the conversion matrix between the star simulator reference mirror coordinate system and the geographic coordinate system

[0024] Furthermore, the Y-axis and Z-axis non-horizontal degrees emc of the optical simulator reference mirror coordinate system are obtained. y 、emc z And the angle between the Z axis and the north direction is amc z ;

[0025] Calculate the conversion matrix between the optical simulator reference mirror coordinate system and the celestial north-west geographic coordinate system according to the following formula:

[0026] y c =-amc z

[0027] p c =emc z

[0028] r c = -arcsin(sin(emc y ) / cos(emc z ))

[0029]

[0030] Similarly, calculate the transformation matrix between the star simulator reference mirror coordinate system and the celestial north-west geographic coordinate system

[0031] Further, in step (5), the vector representation is calculated The specific method is:

[0032]

[0033] Furthermore, in step (6), a three-axis orthogonal rectangular coordinate system is constructed. The specific method is:

[0034]

[0035] Similarly, construct a rectangular coordinate system with three orthogonal axes

[0036] Further, in step (7),

[0037] Calculate the transformation matrix between the inertial measurement coordinate system and the optical detector measurement coordinate system The specific method is:

[0038]

[0039] Calculate the transformation matrix between the inertial measurement coordinate system and the star sensor measurement coordinate system The specific method is:

[0040]

[0041] The advantages of the present invention compared with the prior art are:

[0042] (1) The present invention solves the problem of difficulty in obtaining the initial attitude reference between the inertial group, star sensor, and optical detector that are installed in different cabins and cannot see each other by transferring the simulator measurement coordinate system and the geographic coordinate system without adding equipment;

[0043] (2) The present invention uses an optical detector to calculate the measurement value of the point source target and a star sensor to calculate the measurement value of the star target, thereby solving the problem that the optical detector and the star sensor cannot be installed with a reference mirror in a compact layout;

[0044] (3) The present invention sets up an electronic theodolite and a gyro north finder, aims at a reference mirror, obtains the two-axis non-levelness and north angle of the reference mirror coordinate system, and solves the problem that the coordinate system measured by an optical detector or star sensor cannot be linked to the geographic coordinate system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0046] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0047] First, the technical terms involved in this embodiment are explained as follows:

[0048] Inertial measurement coordinate system O m X m Y m Z m , origin O m is the intersection point of the three-axis accelerometer, O m X m With A x Accelerometer positive alignment, O m Y m In A x , A yThe accelerometer is in the plane determined by the positive direction and is m X m Vertical, O m Z m With O m X m , O m Y m The axes are perpendicular and form a right-handed coordinate system.

[0049] Optical simulator measurement coordinate system O cr X cr Y cr Z cr , origin O cr is the imaging center point of the optical simulator, O cr Y cr Pointing to the direction of the optical axis of the optical simulator, when the optical axis of the optical simulator (i.e. cr Y cr When the axis is placed horizontally, O cr X cr In the longitudinal plane with O cr Y cr Pointing vertically upward, O cr Z cr With O cr X cr , O cr Y cr The axes are perpendicular and form a right-handed coordinate system.

[0050] Star simulator measurement coordinate system, O cs X cs Y cs Z cs is the star simulator measurement coordinate system, with the origin O cs is the center of the focal plane of the star simulator, O cs X cs The direction of the optical axis of the star sensor when measuring along the outward direction of the optical axis, O cs Y cs The reference prism mounting surface is approximately vertically pointed to the outside of the star simulator, O cs Z cs With O cs X cs , O cs Y cs The axes are perpendicular and form a right-handed coordinate system.

[0051] The optical simulator reference mirror coordinate system and the star simulator collimator mirror coordinate system: The optical simulator and the star simulator are each equipped with a reference mirror. The reference mirror coordinate systems on the optical simulator and the star simulator are defined to be approximately consistent with their respective measurement coordinate systems.

[0052] like Figure 1As shown, the method for obtaining the initial attitude reference of the inertial group, star sensor and detector in the cabin layout proposed by the present invention specifically includes the following steps:

[0053] (1) Calculate the transformation matrix between the inertial measurement coordinate system and the geographic coordinate system

[0054] The conversion matrix between the inertial group measurement coordinate system and the geographic coordinate system is calculated through the azimuth output by the inertial group self-alignment and the two-axis non-horizontal degree. In this embodiment, the celestial north-west geographic coordinate system is used.

[0055] The specific method is:

[0056] The inertial group is powered on to perform self-alignment and output the Y-axis azimuth angle amv y Unlevelness of Y and Z axis emv y 、emv z ;

[0057] The conversion matrix between the inertial measurement coordinate system and the celestial north-west geographic coordinate system is calculated according to the following formula

[0058] y m =-amv y

[0059] p m =-emv y

[0060] r m =arcsin(sin(emv z ) / cos(emv y ))

[0061]

[0062] (2) Calibrate the vector representation of the point source target and star target simulated by the optical simulator and star simulator in the optical simulator reference mirror coordinate system and the star simulator reference mirror coordinate system

[0063] The optical simulator is used to simulate the imaging of point source targets, and the star simulator is used to simulate the imaging of star-shaped targets.

[0064] The vector representation of two different point source targets simulated by the optical simulator in the optical simulator reference mirror coordinate system is obtained by calibration. And the vector representation of two different star targets simulated by the star simulator in the star simulator reference mirror coordinate system

[0065] (3) Record the measurement values ​​of the optical detector for the point source target and the star sensor for the star target, and calculate the vector representation of the point source target and the star target in their respective measurement coordinate systems.

[0066] Obtain the measurement value of the optical detector for the point source target, and calculate the vector representation of two different point source targets in the optical detector measurement coordinate system

[0067] The specific method is:

[0068] The optical detector collects the point source target image output by the optical simulator and records the horizontal angle (H) of the two point source targets output by the optical detector in the optical detector measurement coordinate system. R1 , T R1 ) and pitch angle (H R2 , T R2 ), we get [tanH R1 ,1,tanT R1 ]、[tanH R2 ,1,tanT R2 ], after normalization, the vector representation of two different point source targets in the optical detector measurement coordinate system is obtained

[0069] Obtain the measurement value of the star sensor for the star target, and calculate the vector representation of two different star targets in the star sensor measurement coordinate system

[0070] The specific method is:

[0071] The star sensor collects the arrow target image output by the star simulator and records the horizontal angle (θ ys1 ,θ zs1 ) and pitch angle (θ ys2 ,θ zs2 ), we get [1, -tanθ ys1 ,-tanθ zs1 ], [1, -tanθ ys2 ,-tanθ zs2 ], after normalization, the vector representation of two different star targets in the star sensor measurement coordinate system is obtained

[0072] (4) Aim to obtain the conversion matrix of the optical simulator reference mirror coordinate system, the star simulator reference mirror coordinate system and the geographic coordinate system respectively

[0073] By setting up an electronic theodolite and a gyro north finder, aiming at the reference mirror on the optical simulator, the two-axis non-horizontal degree and north angle of the optical simulator reference mirror coordinate system are obtained to calculate the conversion matrix between the optical simulator reference mirror coordinate system and the geographic coordinate system. Aim at the reference mirror on the star simulator, obtain the two-axis non-horizontal degree and north angle of the star simulator reference mirror coordinate system, and calculate the conversion matrix between the star simulator reference mirror coordinate system and the geographic coordinate system

[0074] Taking the reference mirror on the optical simulator as an example, the Y-axis and Z-axis non-horizontal degree emc of the optical simulator reference mirror coordinate system is obtained. y 、emc z And the angle between the Z axis and the north direction is amc z ;

[0075] Calculate the conversion matrix between the optical simulator reference mirror coordinate system and the celestial north-west geographic coordinate system according to the following formula:

[0076] y c =-amc z

[0077] p c =emc z

[0078] r c = -arcsin(sin(emc y ) / cos(emc z ))

[0079]

[0080] Similarly, the conversion matrix between the star simulator reference mirror coordinate system and the celestial north-west geographic coordinate system can be calculated:

[0081] (5) Calculate the vector representation of point source targets and star targets in the geographic coordinate system

[0082] Calculate the vector representation of two different point source targets in the geographic coordinate system And the vector representation of two different star targets in the geographic coordinate system

[0083]

[0084] (6) Constructing a three-axis orthogonal rectangular coordinate system

[0085] According to the following calculation method, the vector representation of two different point source targets in the geographic coordinate system is used. Construct a rectangular coordinate system with three orthogonal axes Vector representation of two different point source targets in the optical detector measurement coordinate system Construct a rectangular coordinate system with three orthogonal axes

[0086]

[0087]

[0088] Similarly, using vector representation Construct a rectangular coordinate system with three orthogonal axes Using vector representation Construct a rectangular coordinate system with three orthogonal axes

[0089] (7) Obtain the transformation matrix between the inertial measurement coordinate system and the optical detector measurement coordinate system, and the transformation matrix between the inertial measurement coordinate system and the star sensor measurement coordinate system through coordinate transformation.

[0090] Calculate the transformation matrix between the inertial measurement coordinate system and the optical detector measurement coordinate system

[0091]

[0092] Calculate the transformation matrix between the inertial measurement coordinate system and the star sensor measurement coordinate system

[0093]

[0094] Completing the above steps means acquiring the initial attitude reference of the inertial group, star sensor and optical detector.

[0095] It is to be understood that the present invention is described by way of embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and embodiments that can fall within the scope of the claims of this application all fall within the scope protected by the present invention.

[0096] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for obtaining the initial attitude reference of an inertial group, a star sensor, and a detector in a sub-module layout, characterized in that: It is applicable to the situation where the inertial group, star sensor, and optical detector are installed in different cabins and there is no line of sight between the three. The specific steps include: Calculate the transformation matrix between the inertial measurement coordinate system and the geographic coordinate system The vector representation of two different point source targets simulated by the optical simulator in the optical simulator reference mirror coordinate system is obtained by calibration. And the vector representation of two different star targets simulated by the star simulator in the star simulator reference mirror coordinate system Obtain the measurement value of the optical detector on the point source target, and calculate the vector representation of two different point source targets in the optical detector measurement coordinate system Obtain the measurement value of the star sensor for the star target, and calculate the vector representation V of two different star targets in the star sensor measurement coordinate system. s g1 、V s g2 ; Computational Optical Simulator Reference Mirror Coordinate System and Geographic Coordinate System Conversion Matrix And the conversion matrix between the star simulator reference mirror coordinate system and the geographic coordinate system Using vector representation and the transformation matrix Calculate the vector representation of two different point source targets in the geographic coordinate system Using vector representation The transformation matrix of Calculate the vector representation of two different star targets in the geographic coordinate system Using vector representation Construct a rectangular coordinate system with three orthogonal axes Using vector representation V r g1 、V r g2 , construct a rectangular coordinate system with three orthogonal axes Using vector representation Construct a rectangular coordinate system with three orthogonal axes Using vector representation V s g1 、V s g2 , construct a rectangular coordinate system with three orthogonal axes Through the three-axis orthogonal rectangular coordinate system and the transformation matrix Calculate the transformation matrix between the inertial measurement coordinate system and the optical detector measurement coordinate system Through the three-axis orthogonal rectangular coordinate system and the transformation matrix Calculate the transformation matrix between the inertial measurement coordinate system and the star sensor measurement coordinate system That is to complete the acquisition of the initial attitude benchmark of the inertial group, star sensor, and optical detector.

2. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 1 is characterized by: The transformation matrix between the inertial group measurement coordinate system and the geographic coordinate system is calculated through the azimuth output by the inertial group self-alignment and the two-axis non-horizontal degree. Specifically: The inertial group is powered on to perform self-alignment and output the Y-axis azimuth angle amv y Unlevelness of Y and Z axis emv y 、emv z ; The conversion matrix between the inertial measurement coordinate system and the celestial north-west geographic coordinate system is calculated according to the following formula y m =-amv y p m =-emv y r m =arcsin(sin(emv z ) / cos(emv y )) 3. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 2 is characterized by: The measurement value of the optical detector on the point source target is obtained, and the vector representation V of two different point source targets in the optical detector measurement coordinate system is calculated. r g1 、V r g2 , the specific method is: Record the horizontal angles (H) of the two point source targets output by the optical detector in the optical detector measurement coordinate system. R1 , T R1 ) and pitch angle (H R2 , T R2 ), we get [tanH R1 ,1,tanT R1 ]、[tanH R2 ,1,tanT R2 ], after normalization, the vector representation V of two different point source targets in the optical detector measurement coordinate system is obtained r g1 、V r g2 .

4. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 3 is characterized in that: The measurement value of the star sensor on the star target is obtained, and the vector representation V of two different star targets in the star sensor measurement coordinate system is calculated. s g1 、V s g2 , the specific method is: Record the horizontal angles (θ) of the two star targets output by the star sensor in the star sensor measurement coordinate system. ys1 ,θ zs1 ) and pitch angle (θ ys2 ,θ zs2 ), we get [1, -tanθ ys1 ,-tanθ zs1 ], [1, -tanθ ys2 ,-tanθ zs2 ], after normalization, we get the vector representation V of two different star targets in the star sensor measurement coordinate system. s g1 、V s g2 .

5. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 4 is characterized in that: By setting up an electronic theodolite and a gyro north finder, aiming at the reference mirror on the optical simulator, the two-axis non-horizontal degree and north angle of the optical simulator reference mirror coordinate system are obtained to calculate the conversion matrix between the optical simulator reference mirror coordinate system and the geographic coordinate system. Aim at the reference mirror on the star simulator, obtain the two-axis non-horizontal degree and north angle of the star simulator reference mirror coordinate system, and calculate the conversion matrix between the star simulator reference mirror coordinate system and the geographic coordinate system 6. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 5 is characterized in that: Obtain the Y-axis and Z-axis non-horizontal degree emc of the optical simulator reference mirror coordinate system y 、emc z And the angle between the Z axis and the north direction is amc z ; Calculate the conversion matrix between the optical simulator reference mirror coordinate system and the celestial north-west geographic coordinate system according to the following formula: y c =-amc z p c =emc z r c =-arcsin(sin(emc y ) / cos(emc z )) Similarly, calculate the transformation matrix between the star simulator reference mirror coordinate system and the celestial north-west geographic coordinate system 7. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 6 is characterized by: Computing vector representation The specific method is:

8. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 7 is characterized in that: Construct a rectangular coordinate system with three orthogonal axes The specific method is: Similarly, construct a rectangular coordinate system with three orthogonal axes 9. The method for obtaining the initial attitude reference of the inertial group, star sensor and detector of the sub-module layout according to claim 8 is characterized in that: Calculate the transformation matrix between the inertial measurement coordinate system and the optical detector measurement coordinate system The specific method is: Calculate the transformation matrix between the inertial measurement coordinate system and the star sensor measurement coordinate system The specific method is:

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