Method for detecting assembly state of target object in aviation cabin based on inertial reference

Abstract

The invention belongs to the technical field of azimuth measurement of assembly parts in an aviation cabin, and provides a method for detecting the assembly state of a target object in the aviation cabin based on inertial benchmark, which comprises the following steps: S1, establishing a correlation conversion equation among an observation coordinate system, a carrier coordinate system and a geographic coordinate system, calculating a deflection angle alpha between the observation coordinate system and the specified direction of the geographic coordinate system; s2, solving a deflection angle gamma between the extravehicular main shaft and a specified direction of a geographic coordinate system according to the characteristic point of the extravehicular main shaft through a rotation matrix; s3, obtaining an included angle beta 2 between the carrier coordinate system and the geographic coordinate system; and S4, detecting whether the assembly angle theta of the target object in the to-be-detected cabin is qualified or not. According to the method, the absolute measurement reference and the observation coordinate system are established for data fusion, unified absolute reference measurement is adopted, the to-be-measured attitudes of the equipment in the narrow space cabin are all concentrated in the geographic coordinate system, the detection preparation process in the aviation cabin is simplified, efficient measurement can be achieved, and the problem that the measurement equipment is limited by the size in the aviation cabin is solved.

Description

Technical Field

[0001] The invention belongs to the field of orientation measurement of assembly parts in an aviation cabin, and in particular relates to an assembly state detection method of a target object in an aviation cabin based on an inertial reference. Background Art

[0002] At present, the following problems exist in the process of large-scale equipment cabin assembly status detection:

[0003] 1) The preliminary preparation work is cumbersome. In order to accurately measure the status of the installed parts in the cabin, it is necessary to complete the confirmation of the measurement benchmark. Usually, the horizontal state of the equipment is selected as the measurement benchmark, and the physical leveling of the large equipment is completed through a level, a large adjustment bracket, a fastening connection device, etc. After confirming that the horizontal state of the equipment to be tested is controllable, the subsequent measurement work can be started. Due to the large size of the equipment to be tested, the preparation process requires a lot of manpower and props, the process is time-consuming, and the operation is complicated.

[0004] 2) Low uniformity of test tooling When measuring the status of in-cabin assemblies, the measurement system is basically built in the internal space of the equipment with the help of laser trackers and theodolites. In this process, due to the complex obstruction environment in the cabin space, various design tooling must be used to structurally lead out the assemblies to be tested, and through adapter tooling of different sizes and shapes, equivalent measurements of the functional parts in the cabin to be tested are completed to solve the problem of limited field of view during the measurement process. The form of tooling changes with the changes in the in-cabin assemblies to be tested. Different cabin parts in the same equipment, as well as different cabin parts in different equipment, require a wide variety of tooling, which is cumbersome to make.

[0005] 3) The size of the cabin is limited. The overall size of the equipment to be measured for the status of the in-cabin assembly parts fluctuates greatly according to different functional requirements. The space size of some equipment in the cabin reaches a certain scale, which can accommodate measurement equipment such as laser trackers and theodolites and ensure that their observation distance can meet the use requirements; the space in the cabin of some equipment is small, and the overall space scale is not enough to provide sufficient use distance guarantee for general high-precision observation equipment. For the second type of equipment, the detection of the assembly status of its in-cabin parts is severely limited at this stage. Therefore, it is necessary to propose a method for detecting the assembly status of target objects in aviation cabins based on inertial reference. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention proposes a method for detecting the assembly status of target objects in an aviation cabin based on an inertial reference. By establishing an absolute measurement reference and an observation coordinate system for data fusion, a unified absolute reference measurement is adopted to concentrate the postures of equipment to be tested in a small cabin space in a geographic coordinate system, thereby simplifying the on-site preparation links for cabin inspection of various large equipment, improving the reuse rate of tooling in the inspection process, and solving the problem of limitations on measurement equipment caused by the cabin dimensions of some equipment to be tested.

[0007] The present invention provides a method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference, which comprises the following steps:

[0008] S1. Measure the coordinate value P of the feature point outside the cabin of the target object of the inertial navigation measurement system through the laser tracker 1 (x 1 ,y 1 ,z 1 ), P 2 (x 2 ,y 2 ,z 2 ), P 3 (x 3 ,y 3 ,z 3 ), using the spatial interaction between the observed feature points and the information feedback target object, establish the associated conversion equation between the observation coordinate system and the carrier coordinate system and the geographic coordinate system, and solve the deflection angle α between the specified direction of the observation coordinate system and the geographic coordinate system, specifically including:

[0009] S11. Construct the target object's extra-cabin feature point vector Q 1 , Q 2 , Q 3 , the associated transformation equation between the observation coordinate system and the geographic coordinate system is:

[0010]

[0011] S12, vector Q in geographic coordinate system s1 , Q s2 , Q s3 , the vector in the observation coordinate system is Q n1 , Q n2 , Q n3 , the coordinate vector is substituted into the transformation equation to obtain:

[0012]

[0013] In the formula, Q s is the vector coordinate matrix in the geographic coordinate system, R is the rotation matrix from the observation coordinate system to the geographic coordinate system, Q n is the vector coordinate matrix in the observation coordinate system;

[0014] Solve the associated transformation equation and calculate the rotation matrix R from the observation coordinate system to the geographic coordinate system;

[0015] S13. According to the obtained rotation matrix R, the translation matrix T of the observation coordinate system to the geographic coordinate system is solved, which is specifically:

[0016]

[0017] Then the spatial relative position relationship between the observation coordinate system and the geographic coordinate system is obtained, so as to calculate the deflection angle α between the observation coordinate system and the specified direction of the geographic coordinate system;

[0018] S2, by measuring the observation value of the feature point of the main axis outside the cabin in the observation coordinate system, and converting the rotation matrix R and the translation matrix T, the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system is solved;

[0019] S3. When measuring outside the cabin through the inertial navigation system, the angle β between the carrier coordinate system and the geographic coordinate system is obtained. 1 When the inertial navigation system is measuring in the cabin, the angle β between the carrier coordinate system and the geographic coordinate system is obtained. 2 ;

[0020] S4. Calculate the assembly angle θ of the target object in the test cabin, θ=|γ-β 2 |, the qualified basis for measuring the orientation of the target object is:

[0021] |Φ-|γ-β 2 ||≤Δ

[0022] Among them, Φ is the required assembly angle of the target object in the cabin, and Δ is the allowable assembly error;

[0023] If |Φ-|γ-β 2 ||≤Δ, the target object is determined to be assembled successfully. If not, the orientation of the target object is adjusted and steps S1 to S4 are executed again until the target object is assembled successfully.

[0024] Preferably, the step S2 includes the following sub-steps:

[0025] S21, measure the coordinates P of the main axis feature point outside the cabin in the observation coordinate system 10 (x 10 ,y 10 ,z 10 ), P 20 (x 20 ,y 20 ,z 20 );

[0026] S22, according to the rotation matrix R and the translation matrix T obtained in step S1, the coordinate value of the main axis feature point outside the cabin converted from the observation coordinate system to the geographic coordinate system is calculated, so as to obtain the coordinate P of the main axis feature point outside the cabin in the geographic coordinate system 10 '(x 10 ',y 10 ',z 10 '),P 20 '(x 20 ',y20 ',z 20 ');

[0027] S23, according to the coordinates P of the main axis feature point outside the cabin in the geographic coordinate system 10 '、P 20 'With the coordinate P in the observation coordinate system 10 , P 20 , obtain the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system.

[0028] Preferably, there are an observation coordinate system, a geographic coordinate system and a carrier coordinate system in the error measurement. The observation coordinate system is a coordinate system formed by self-calibration of the laser tracker. The geographic coordinate system is a coordinate system formed by self-calibration of the inertial navigation measurement system, which is also a standard geographic coordinate system, an absolute coordinate system only related to the state of the earth. The carrier coordinate system is the physical coordinate system of the mobile carrier, and the carrier coordinate system and the geographic coordinate system are pre-associated and calibrated.

[0029] Preferably, the deflection angle α between the observation coordinate system and the specified direction of the geographic coordinate system and the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system remain unchanged during the measurement process.

[0030] Preferably, the inertial navigation measurement system unifies the measurement parameters with the absolute reference of the earth, unifies the attitude of the measured target object in the geographic coordinate system, and measures the spatial attitude of the target to be measured in the absolute reference system of the earth.

[0031] Preferably, the inertial navigation measurement system is arranged on the reference platform, the laser tracker and the reference platform are arranged outside the cabin, the structural features of the carrier coordinate system are extended to four feature points preset on the reference platform, and the direction of the line between the four feature points is the same as the direction of the carrier coordinate system.

[0032] Preferably, the laser tracker observes the characteristic points of the reference platform and the local characteristic points of the envelope cabin at the same time, and the two are used outside the cabin to cooperate to complete the orientation guidance adjustment of the external cabin, realize the pre-adjustment of the correlation calibration of the external observation coordinate system of the cabin to be measured and the carrier coordinate system, and the conversion between the observation coordinate system and the geographic coordinate system.

[0033] Preferably, an external observation coordinate system is established for the cabin, the inertial navigation geographic coordinate system is kept from drifting, the mobile inertial navigation measurement system is placed on the inertial navigation bracket to be measured inside the cabin, the inertial navigation measurement system is started up to run self-calibration, and is integrated with the external observation data to realize the visualization output of the spatial orientation of the inertial navigation bracket to be measured.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1. The inertial reference-based method for detecting the assembly status of target objects in an aviation cabin of the present invention concentrates the postures to be measured of the equipment in a small cabin space in the geographic coordinate system. Through the absolute reference, the customization problem of personalized auxiliary equipment for different measurement targets in different measurement scenarios and the difficulty of equipment layout caused by the small effective space of a small cabin are avoided. Observation and measurement are uniformly performed in the absolute reference coordinate system in various occasions. The method has strong versatility and can carry out efficient measurement in serialized scenarios.

[0036] 2. The inertial reference-based method for detecting the assembly status of target objects in an aviation cabin of the present invention uses absolute reference measurement and pre-adopts a unified measurement reference in the measurement system, thereby avoiding the introduction of a leveling link in the field testing process of traditional equipment to be tested, simplifying the operation process, and improving the efficiency of field measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is an overall schematic diagram of the method for detecting the assembly state of a target object in an aviation cabin of the present invention;

[0038] Figure 2a and Figure 2b It is a schematic diagram of information flow of the method for detecting the assembly status of a target object in an aviation cabin of the present invention;

[0039] Figure 3a and Figure 3b A schematic diagram of coordinate system conversion of a method for detecting assembly status of a target object in an aviation cabin of the present invention;

[0040] Figure 4a and Figure 4b It is a schematic diagram of the external scene test angle space of the method for detecting the assembly state of a target object in an aviation cabin of the present invention;

[0041] Figure 5 It is a schematic diagram of the internal scene test angle space of the method for detecting the assembly status of a target object in an aviation cabin of the present invention.

[0042] Main reference numerals:

[0043] Inertial navigation measurement system 1, laser tracker 2, reference platform 3, inertial navigation bracket 4, placement rack 5, cabin section 6, and extracabin feature points 7. DETAILED DESCRIPTION

[0044] In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

[0045] The device used in the method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference of the present invention is as follows: Figure 1As shown, it includes an inertial navigation measurement system 1, a laser tracker 2, a reference platform 3, an inertial navigation bracket 4, a placement rack 5, a cabin section 6 and an external feature point 7. The information interaction relationship between the functional devices is as follows: Figure 2a and Figure 2b As shown, there are observation coordinate system, geographic coordinate system and carrier coordinate system in error measurement. The observation coordinate system is the coordinate system formed by the self-calibration of laser tracker 2. The geographic coordinate system is the coordinate system formed by the self-calibration of inertial navigation measurement system 1, which is also a standard geographic coordinate system, an absolute coordinate system related only to the state of the earth. The carrier coordinate system is the physical coordinate system of the mobile carrier, and the carrier coordinate system and the geographic coordinate system are pre-associated and calibrated. Inertial navigation measurement system 1 is set on the reference platform 3, laser tracker 2 and reference platform 3 are set outside the cabin, and the structural features of the carrier coordinate system extend to four feature points preset on the reference platform 3, and the direction of the line between the four feature points is the same as that of the carrier coordinate system. Inertial navigation measurement system 1 unifies the measurement parameters with the absolute reference of the earth, unifies the posture of the measured target object in the geographic coordinate system, and measures the spatial posture of the target to be measured in the absolute reference system of the earth.

[0046] The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference comprises the following steps:

[0047] S1, the coordinate value P of the feature point 7 outside the cabin of the target object of the inertial navigation measurement system 1 is measured by the laser tracker 2 1 (x 1 ,y 1 ,z 1 ), P 2 (x 2 ,y 2 ,z 2 ), P 3 (x 3 ,y 3 ,z 3 ),like Figure 3a and Figure 3b As shown, by using the spatial interaction between the observed feature points and the information feedback target object, the associated conversion equations between the observation coordinate system and the carrier coordinate system and the geographic coordinate system are established, and the deflection angle α between the specified direction of the observation coordinate system and the geographic coordinate system is solved, which specifically includes:

[0048] S11. Construct the target object's extra-cabin feature point vector Q 1 , Q 2 , Q 3 , the associated transformation equation between the observation coordinate system and the geographic coordinate system is:

[0049]

[0050] S12, vector Q in geographic coordinate system s1 , Qs2 , Q s3 , the vector in the observation coordinate system is Q n1 , Q n2 , Q n3 , the coordinate vector is substituted into the transformation equation to obtain:

[0051]

[0052] In the formula, Q s is the vector coordinate matrix in the geographic coordinate system, R is the rotation matrix from the observation coordinate system to the geographic coordinate system, Q n is the vector coordinate matrix in the observation coordinate system.

[0053] Solve the associated transformation equation and calculate the rotation matrix R that transforms the observation coordinate system to the geographic coordinate system.

[0054] S13. According to the obtained rotation matrix R, the translation matrix T of the observation coordinate system to the geographic coordinate system is solved, which is specifically:

[0055]

[0056] Then the spatial relative position relationship between the observation coordinate system and the geographic coordinate system is obtained, so as to calculate the deflection angle α between the observation coordinate system and the specified direction of the geographic coordinate system.

[0057] S2, such as Figure 4a and Figure 4b As shown, by measuring the observation value of the feature point of the main axis outside the cabin in the observation coordinate system, the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system is calculated through the transformation of the rotation matrix R and the translation matrix T; step S2 includes the following sub-steps:

[0058] S21, measure the coordinates P of the main axis feature point outside the cabin in the observation coordinate system 10 (x 10 ,y 10 ,z 10 ), P 20 (x 20 ,y 20 ,z 20 ).

[0059] S22, according to the rotation matrix R and translation matrix T obtained in step S1, calculate the coordinate value of the main axis feature point outside the cabin converted from the observation coordinate system to the geographic coordinate system, so as to obtain the coordinate P of the main axis feature point of cabin section 6 in the geographic coordinate system 10 '(x 10 ',y 10 ',z 10 '),P 20 '(x 20 ',y20 ',z 20 ').

[0060] S23, according to the coordinates P of the main axis feature point outside the cabin in the geographic coordinate system 10 '、P 20 'With the coordinate P in the observation coordinate system 10 , P 20 , the deflection angle γ between the main axis of cabin section 6 and the specified direction of the geographic coordinate system is obtained. The deflection angle α between the observation coordinate system and the specified direction of the geographic coordinate system and the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system remain unchanged during the measurement process.

[0061] S3. When measuring outside the cabin through the inertial navigation system, the angle β between the carrier coordinate system and the geographic coordinate system is obtained. 1 ,like Figure 5 As shown in the figure, when the inertial navigation measurement system is measuring in the cabin, the angle β between the carrier coordinate system and the geographic coordinate system is obtained 2 .

[0062] S4. Calculate the assembly angle θ of the target object in the test cabin, θ=|γ-β 2 |, the qualified basis for measuring the orientation of the target object is:

[0063] |Φ-|γ-β 2 ||≤Δ

[0064] Among them, Φ is the required assembly angle of the target object in the cabin, and Δ is the allowable assembly error.

[0065] If |Φ-|γ-β 2 ||≤Δ, the target object is determined to be assembled successfully. If not, the orientation of the target object is adjusted and steps S1 to S4 are executed again until the target object is assembled successfully.

[0066] The laser tracker 2 simultaneously observes the characteristic points of the reference platform and the local characteristic points of the envelope compartment. The two are used outside the compartment to coordinately complete the adjustment of the external orientation of the compartment, and realize the pre-adjustment of the association calibration between the external observation coordinate system of the compartment to be measured and the carrier coordinate system, as well as the conversion between the observation coordinate system and the geographic coordinate system. The external observation coordinate system of the compartment is established to keep the inertial navigation geographic coordinate system from drifting. The mobile inertial navigation measurement system 1 is placed on the inertial navigation bracket 4 to be measured inside the compartment. The inertial navigation measurement system 1 is turned on and self-calibrated, and is integrated with the external observation data to realize the visual output of the spatial orientation of the inertial navigation bracket 4 to be measured.

[0067] The following is a further description of the inertial reference based method for detecting the assembly state of a target object in an aviation cabin of the present invention in conjunction with an embodiment:

[0068] Before the start of the assembly error test in the aviation cabin, the installation and adjustment of the reference platform 3 are completed. The reference platform 3 is a special platform with heavy weight, stable placement and high processing accuracy. Its main functions include the reference extension point and the installation position of the inertial navigation measurement system 1. The physical coordinate system of the inertial navigation measurement system 1 is the carrier coordinate system. By performing internal self-calibration of the instrument before use, the internal correlation calibration between the carrier coordinate system and the geographic coordinate system is completed. After the internal calibration is completed, the reference platform 3 is kept stable and the measurement work is carried out.

[0069] After completing the inventory of the number of various measuring instruments, we began to carry out on-site layout, considering further enhancing the versatility of the absolute test method, getting rid of the constraint of too small effective space inside the test section, and dividing the absolute benchmark test into in-cabin test and out-of-cabin test.

[0070] The extravehicular test scenario requires the participation of the reference platform 3 and the laser tracker 2 in the layout. Among them, the reference platform 3 is an extended reference of the carrier coordinate system structure that provides external observation, and the laser tracker 2 is used to perform external observation of the characteristic points of the reference platform 3 and the characteristic points of the main axis outside the cabin 6. When laying out outside the cabin, first place the laser tracker 2 at a suitable position. The position requirements are: being able to observe no less than three cabin characteristic points at the same time, and the position relationship between the observed cabin characteristic points and the main engine axis is known; being able to observe no less than three reference platform characteristic points at the same time. After completing the placement of the laser tracker 2, within the observable range of the instrument, complete the acquisition of observation data of the characteristic points of the reference platform 3 and the characteristic points of the main axis outside the cabin, complete the establishment of the observation coordinate system, and complete the conversion of the observation coordinate system according to the spatial relationship between the carrier coordinate system and the geographic coordinate system, unify all observation values ​​in the geographic coordinate system, and ensure subsequent observations based on the absolute reference.

[0071] The in-cabin test scenario only requires the inertial navigation measurement system 1 to participate in the layout. The inertial navigation measurement system 1 has a high degree of integration and a small overall size, and can be conveniently placed on the placement rack 5. In addition, the system's external feature structure has high processing accuracy and can be fitted with the bracket surface with high precision. According to the system's external structure, the system is connected and fixed to the pallet to be tested, which can ensure that the system's physical carrier coordinate system is consistent with the spatial posture of the pallet to be tested. The external visible structure of the integrated system includes three major areas: a display screen, an operation panel, and a data interface. Among them, the display screen can interactively display each operation step in the measurement process, and the user can complete each operation step and read the measurement value according to the interface prompts; the operation panel can quickly set some test parameters, as well as various hardware interactive operations; the data interface can be connected to external observation equipment to complete the import and export of various observation data, and ensure data fusion during the measurement data processing process. The system has certain environmental requirements, and vibration and jitter should be avoided as much as possible during layout.

[0072] The inertial reference-based method for detecting the assembly status of target objects in an aviation cabin of the present invention establishes an absolute measurement reference and an observation coordinate system for data fusion, adopts a unified absolute reference measurement, concentrates the postures to be measured of equipment in a small space cabin in a geographic coordinate system, simplifies the aviation cabin detection preparation process, can achieve efficient measurement in serialized scenarios, and solves the problem of limitations of the aviation cabin size on the measurement equipment.

[0073] The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference, characterized in that: It includes the following steps: S1. The coordinate values ​​of the feature points outside the cabin of the target object of the inertial navigation measurement system are measured by a laser tracker. P1 (x1, y1, z1), P2 (x2, y2, z2), and P3 (x3, y3, z3). The spatial interaction between the observed feature points and the information feedback target object is used to establish the associated conversion equations between the observation coordinate system and the carrier coordinate system and the geographic coordinate system, and the deflection angle α between the specified direction of the observation coordinate system and the geographic coordinate system is solved, including: S11, construct the target object's extravehicular feature point vectors Q1, Q2 and Q3, and the associated conversion equation between the observation coordinate system and the geographic coordinate system is: S12, vector Q in geographic coordinate system s1 , Q s2 and Q s3 , the vector in the observation coordinate system is Q n1 , Q n2 and Q n3 , the coordinate vector is substituted into the associated transformation equation to obtain: Q s1 =R·Q n1 ,Q s2 =R·Q n2 ,(Q s3 =R·Q n3 In the formula, Q s is the vector coordinate matrix in the geographic coordinate system, R is the rotation matrix from the observation coordinate system to the geographic coordinate system, Q n is the vector coordinate matrix in the observation coordinate system; Solve the associated transformation equation and calculate the rotation matrix R from the observation coordinate system to the geographic coordinate system; S13. According to the obtained rotation matrix R, the translation matrix T of the observation coordinate system to the geographic coordinate system is solved, which is specifically: Then the spatial relative position relationship between the observation coordinate system and the geographic coordinate system is obtained, so as to calculate the deflection angle α between the observation coordinate system and the specified direction of the geographic coordinate system; S2, by measuring the observation value of the feature point of the main axis outside the cabin in the observation coordinate system, and converting the rotation matrix R and the translation matrix T, the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system is solved; S3, when the inertial navigation measurement system is measured outside the cabin, the angle β1 between the carrier coordinate system and the geographic coordinate system is obtained, and when the inertial navigation measurement system is measured inside the cabin, the angle β2 between the carrier coordinate system and the geographic coordinate system is obtained; S4. Calculate the assembly angle θ of the target object in the test cabin, θ=|γ-β2|, and the qualified basis for measuring the orientation of the target object is: |Φ-|γ-β2||≤Δ Among them, Φ is the required assembly angle of the target object in the cabin, and Δ is the allowable assembly error; If |Φ-|γ-β2||≤Δ, the target object is determined to be assembled properly. If not, the orientation of the target object is adjusted and steps S1 to S4 are re-executed until the target object is assembled properly.

2. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: Step S2 includes the following sub-steps: S21, measure the coordinates P of the main axis feature point outside the cabin in the observation coordinate system 10 (x 10 ,y 10 ,z 10 ), P 20 (x 20 ,y 20 ,z 20 ); S22, according to the rotation matrix R and the translation matrix T obtained in step S1, the coordinate values ​​of the main axis feature point outside the cabin converted from the observation coordinate system to the geographic coordinate system are calculated, so as to obtain the coordinates P of the main axis feature point outside the cabin in the geographic coordinate system 10 '(x 10 ',y 10 ',z 10 '),P 20 '(x 20 ',y 20 ',z 20 '); S23, according to the coordinates P of the main axis feature point outside the cabin in the geographic coordinate system 10 '、P 20 'With the coordinate P in the observation coordinate system 10 , P 20 , obtain the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system.

3. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: Error measurement involves the observation coordinate system, geographic coordinate system and carrier coordinate system. The observation coordinate system is the coordinate system formed by the self-calibration of the laser tracker. The geographic coordinate system is the coordinate system formed by the self-calibration of the inertial navigation measurement system. It is also a standard geographic coordinate system, an absolute coordinate system related only to the state of the earth. The carrier coordinate system is the physical coordinate system of the mobile carrier, and the carrier coordinate system and the geographic coordinate system are pre-associated and calibrated.

4. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: The deflection angle α between the observation coordinate system and the specified direction of the geographic coordinate system, and the deflection angle γ between the main axis outside the cabin and the specified direction of the geographic coordinate system remain unchanged during the measurement process.

5. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: The inertial navigation measurement system unifies the measurement parameters with the absolute reference of the earth, unifies the posture of the target object to be measured in the geographic coordinate system, and realizes the measurement of the spatial posture of the target to be measured.

6. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: The inertial navigation measurement system is set on the reference platform, the laser tracker and the reference platform are set outside the cabin, the structural characteristics of the carrier coordinate system are extended to four feature points preset on the reference platform, and the direction of the connecting line between the four feature points is the same as the direction of the carrier coordinate system.

7. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: The laser tracker simultaneously observes the characteristic points of the reference platform and the local characteristic points of the envelope cabin. The two are used outside the cabin to cooperate to complete the directional adjustment of the external orientation of the cabin, realize the pre-adjustment of the external observation coordinate system of the cabin to be measured and the correlation calibration of the carrier coordinate system, as well as the conversion between the observation coordinate system and the geographic coordinate system.

8. The method for detecting the assembly state of a target object in an aviation cabin based on an inertial reference according to claim 1, characterized in that: An external observation coordinate system is established for the cabin, and the mobile inertial navigation measurement system is placed on the inertial navigation bracket to be measured inside the cabin. The inertial navigation measurement system is started up and self-calibrated, and then integrated with the external observation data to realize the visualization output of the spatial orientation of the target object on the inertial navigation bracket to be measured.

Images