A prism calibration method for inertial orientation equipment

Abstract

The present invention discloses a prism calibration method for an inertial orientation device, comprising: starting a north-seeking process, recording the azimuth, pitch angle and roll angle of an inertial navigation north-seeking, and obtaining an external aiming azimuth of a prism; introducing an imaginary horizontal coordinate system, using a direction cosine matrix to obtain a prism coordinate system represented by an inertial navigation coordinate system as a base vector, and using inverse sine and cosine operations to obtain the pitch angle and roll angle of an orientation output axis in the prism coordinate system relative to the horizontal coordinate system, further combining the azimuth and pitch angle of the inertial navigation north-seeking, using a compensation formula to obtain the azimuth of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, and further combining the external aiming azimuth of the prism, the pitch angle and roll angle of the inertial navigation north-seeking to obtain the compensation amount of the prism output of the inertial orientation device. The present invention only needs to obtain the north-seeking result and the external aiming azimuth of the prism, and then completes the calibration of the prism of the inertial orientation device through simple calculation, so the operation is simpler and the calibration efficiency is higher.

Description

Technical Field

[0001] The present invention relates to the field of calibration testing technology, and more specifically, to a prism calibration method for an inertial orientation device. Background Art

[0002] In the vehicle-mounted inertial orientation equipment, in order to transmit the north-seeking (azimuth alignment) results of the inertial navigation to other systems for calculation and use through the method of optical aiming transmission, it is necessary to install a right-angle prism on the inertial navigation, and the prism coordinate system is generally recorded as the L system. Generally, the output result of the strapdown inertial navigation (i.e., the strapdown inertial navigation system, which is an inertial navigation system that directly connects the inertial instrument to the carrier and uses a computer to complete the navigation platform function) is one of the three sensitive axes of X, Y, and Z. The result includes a set of three data, namely azimuth, pitch angle, and roll angle. The inertial navigation coordinate system is generally recorded as the G system. The purpose of prism calibration is to establish a mathematical model and obtain the positional relationship between the prism coordinate system L and the inertial navigation coordinate system G by collecting inertial navigation data and right-angle prism external aiming results.

[0003] The north-seeking accuracy of inertial navigation depends on the accuracy of inertial devices and the quality of algorithms, while the accuracy of inertial orientation equipment depends on the calibration accuracy of the positional relationship between the prism coordinate system and the inertial navigation coordinate system. Therefore, how to construct an efficient and easy-to-operate prism calibration method has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of the technical problems faced by the prior art mentioned above, the present invention proposes a prism calibration method for an inertial orientation device, so as to solve the problem of how to construct an inertial orientation device prism calibration method that is efficient and easy to operate.

[0005] To achieve the above object, the present invention provides a prism calibration method for an inertial orientation device, comprising the steps of:

[0006] Start the north-seeking process. After the inertial orientation equipment is finished working, record the inertial navigation north-seeking azimuth, inertial navigation north-seeking pitch angle and inertial navigation north-seeking roll angle, and obtain the external aiming azimuth of the prism;

[0007] An imaginary horizontal coordinate system is introduced, and the relationship between the inertial navigation coordinate system and the prism coordinate system is established using the direction cosine matrix, so as to obtain the first matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the base vector;

[0008] Based on the first matrix vector, using inverse sine and cosine operations to obtain a pitch angle and a roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system;

[0009] Based on the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the inertial navigation north-seeking azimuth angle and the inertial navigation north-seeking pitch angle, a compensation formula is used to obtain the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system;

[0010] A compensation amount of an inertial orientation device prism output is obtained based on the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the external aiming azimuth angle of the prism, the inertial navigation north-seeking pitch angle and the inertial navigation north-seeking roll angle.

[0011] Furthermore, the introduction of the imaginary horizontal coordinate system, the use of the direction cosine matrix to establish the relationship between the inertial navigation coordinate system and the prism coordinate system, and the formula for obtaining the first matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the basis vector specifically include:

[0012]

[0013] Wherein, G represents the inertial navigation coordinate system, L represents the prism coordinate system, and P represents the imaginary horizontal coordinate system. The first matrix vector representing the prism coordinate system with the inertial navigation coordinate system as the basis vector, The matrix vector representing the horizontal coordinate system with the inertial navigation coordinate system as the basis vector, A matrix vector representing the horizontal coordinate system represented by the prism coordinate system as the basis vector.

[0014] Furthermore, the formula for obtaining the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system by using inverse sine and cosine operations based on the first matrix vector specifically includes:

[0015]

[0016]

[0017] Among them, β L represents the pitch angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, γ L represents the roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, represents the element of the 3rd row and 2nd column of the first matrix vector, represents the element of the 3rd row and 1st column of the first matrix vector, Represents the element of the 3rd row and 3rd column of the first matrix vector.

[0018] Further, the formula for obtaining the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system using a compensation formula based on the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the inertial navigation north-seeking azimuth angle, and the inertial navigation north-seeking pitch angle specifically includes:

[0019] S′=α xb +π-γ L *tan(β xb +β L );

[0020] Where S′ represents the azimuth angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, α xb represents the north-seeking azimuth of the inertial navigation system, β xb Indicates the inertial navigation north-seeking pitch angle.

[0021] Further, the formula for obtaining the compensation amount of the inertial orientation device prism output based on the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the prism external aiming azimuth angle, the inertial navigation north-seeking pitch angle and the inertial navigation north-seeking roll angle specifically includes:

[0022] α bc =S 0 -S;

[0023] β bc =β xb ;

[0024] γ bc =γ xb ;

[0025] Among them, α bc , β bc and γ bc They represent the azimuth compensation, pitch compensation and roll compensation output by the prism of the inertial orientation device respectively; S 0 represents the external aiming azimuth of the prism; S represents the theoretical azimuth of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, which is equal to S′ modulo 2π; γ xb It represents the north-seeking roll angle of the inertial navigation.

[0026] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0027] The present invention only needs to obtain the north-finding result and the external aiming azimuth of the prism, and then calibrate the positional relationship between the installation position of the inertial device and the azimuth output prism through simple calculation, and compensate the output result of the inertial orientation device to meet the relevant accuracy requirements. Compared with the prior art, the prism calibration method is simpler to operate and has higher calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of a flow chart of a prism calibration method for an inertial orientation device provided in an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of a prism external aiming azimuth angle measurement system provided by an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of the coordinate system relationship provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] The terms "first", "second" or "third" etc. in the specification, claims or drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0034] like Figure 1 As shown, in one embodiment, a prism calibration method for an inertial orientation device mainly includes the following steps S1-S5.

[0035] S1. Start the north-seeking process. After the inertial orientation device is finished working, record the inertial navigation north-seeking azimuth, inertial navigation north-seeking pitch angle and inertial navigation north-seeking roll angle, and obtain the external aiming azimuth of the prism.

[0036] Specifically, after checking the status of the product and equipment, start the north-seeking process through the tester or the host computer. After the inertial orientation equipment is completed, record the inertial navigation north-seeking result. xb (azimuth), β xb (pitch angle), γ xb (roll angle or tumble angle or roll angle), the results are all angle values ​​relative to the horizontal coordinate system P (which is an imaginary coordinate system), and the external aiming azimuth S of the right-angle prism is obtained through the theodolite and the external reference 0 , the schematic diagram of the prism external aiming azimuth angle measurement system is as follows Figure 2 shown.

[0037] S2. Introduce an imaginary horizontal coordinate system, use the direction cosine matrix to establish the relationship between the inertial navigation coordinate system and the prism coordinate system, and obtain the matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the basis vector.

[0038] A mathematical model is established, and the relationship between the G system (inertial navigation coordinate system) and the L system (prism coordinate system) is established using the direction cosine matrix. During the conversion process, an imaginary horizontal coordinate system needs to be introduced, which is called the horizontal coordinate system P system. The relationship diagram between several coordinate systems can be found in Figure 3 Then we get the matrix vector of the L system represented by the G system as the basis vector. The specific formula is:

[0039]

[0040] in, represents the matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the basis vector, The matrix vector representing the horizontal coordinate system with the inertial navigation coordinate system as the basis vector, The matrix vector representing the horizontal coordinate system with the prism coordinate system as the basis vector realizes the relational transformation between the G system and the L system by introducing an imaginary horizontal coordinate system.

[0041] S3, matrix vector based on the prism coordinate system represented by the inertial navigation coordinate system as the basis vector Use the inverse sine and cosine operations to obtain the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system. The specific formula is as follows:

[0042]

[0043]

[0044] Among them, βL It represents the pitch angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, γ L It represents the roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system. The element of the 3rd row and 2nd column of the matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the basis vector, and Same reason.

[0045] S4. Based on the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the inertial navigation north-seeking azimuth angle and the inertial navigation north-seeking pitch angle, a compensation formula is used to obtain the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system. The specific calculation formula is:

[0046] S′=α xb +π-γ L *tan(β xb +β L ) (4)

[0047] Where S′ represents the azimuth angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, α xb represents the inertial navigation north azimuth, β xb Indicates the inertial navigation north-seeking pitch angle.

[0048] S5. Obtain the compensation amount of the prism output of the inertial orientation device based on the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the prism external aiming azimuth angle, the inertial navigation north-seeking pitch angle, and the inertial navigation north-seeking roll angle.

[0049] Specifically, the azimuth compensation α bc Equal to the prism's external aiming azimuth S 0 Subtract the horizontal azimuth of the output axis calculated in the L system (i.e., the theoretical azimuth of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system) S, which is equal to S' modulo 2π. The specific formula is:

[0050] α bc =S 0 -S (5)

[0051] like Figure 3 As shown in the figure, the L system is obtained by rotating the P system by a small angle, and they are approximately coincident. At the same time, the pitch angle and roll angle are used to compensate when calculating the azimuth angle. From formula (4), it can be seen that when the angle is smaller than 5°, it is not necessary to use compensation, but the β in the inertial group north-seeking result can be directly used. xb , γ xb As the calibration result, the pitch angle compensation β bcIt is approximately equal to the pitch angle of the inertial group azimuth output axis, which is the formula:

[0052] β bc =β xb (6)

[0053] Roll angle compensation γ bc It is approximately equal to the roll angle of the inertial group azimuth output axis, which is the formula:

[0054] γ bc =γ xb (7)

[0055] By adopting this prism calibration method, the compensation amount of the azimuth prism output of the inertial orientation device can be effectively obtained. At the same time, during the calibration process, this calibration method only needs to send instructions to the inertial orientation device to start finding the north to obtain the result, and obtain the external aiming angle of the azimuth output prism through the theodolite for benchmark transfer, and then perform a series of calculations to complete the calibration, and compensate the output result of the inertial orientation device to meet the relevant accuracy requirements. Compared with the existing technology, this prism calibration method is simpler to operate and has higher calibration efficiency.

[0056] It should be noted that the flowcharts or block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, a program segment or a part of a code, and the above-mentioned module, a program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the accompanying drawings. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0057] Those skilled in the art will appreciate that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, and all of these combinations and / or combinations fall within the scope of the present disclosure.

[0058] Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, it should be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

1. A prism calibration method for an inertial orientation device, It is characterized in that Includes steps: Start the north-seeking process. After the inertial orientation equipment is finished working, record the inertial navigation north-seeking azimuth, inertial navigation north-seeking pitch angle and inertial navigation north-seeking roll angle, and obtain the external aiming azimuth of the prism; An imaginary horizontal coordinate system is introduced, and the relationship between the inertial navigation coordinate system and the prism coordinate system is established using the direction cosine matrix, so as to obtain the first matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the base vector; Based on the first matrix vector, using inverse sine and cosine operations to obtain a pitch angle and a roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system; Based on the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, the inertial navigation north-seeking azimuth angle and the inertial navigation north-seeking pitch angle, a compensation formula is used to obtain the azimuth angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, and the formula specifically includes: S′=α xb +π-γ L *tan(β xb +b L ); Where S′ represents the azimuth angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, α xb represents the north-seeking azimuth of the inertial navigation system, β xb represents the pitch angle of the inertial navigation north-seeking, β L represents the pitch angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, γ L represents the roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system; Based on the azimuth angle of the prism output axis relative to the horizontal coordinate system in the prism coordinate system, the prism external aiming azimuth angle, the inertial navigation north-seeking pitch angle and the inertial navigation north-seeking roll angle, the compensation amount of the inertial orientation device prism output is obtained, and the formula specifically includes: a bc =S 0 -S; β bc ＝β xb ； cb c =c x b; Among them, α bc , β bc and γ bc They represent the azimuth compensation, pitch compensation and roll compensation output by the prism of the inertial orientation device respectively; S 0 represents the external aiming azimuth of the prism; S represents the theoretical azimuth of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, which is equal to S′ modulo 2π; γ xb It represents the north-seeking roll angle of the inertial navigation.

2. The prism calibration method of an inertial orientation device as claimed in claim 1, It is characterized in that The formula for introducing an imaginary horizontal coordinate system, establishing the relationship between the inertial navigation coordinate system and the prism coordinate system using the direction cosine matrix, and obtaining the first matrix vector of the prism coordinate system represented by the inertial navigation coordinate system as the base vector specifically includes: Wherein, G represents the inertial navigation coordinate system, L represents the prism coordinate system, and P represents the imaginary horizontal coordinate system. The first matrix vector representing the prism coordinate system with the inertial navigation coordinate system as the basis vector, The matrix vector representing the horizontal coordinate system with the inertial navigation coordinate system as the basis vector, A matrix vector representing the horizontal coordinate system represented by the prism coordinate system as the basis vector.

3. The prism calibration method of an inertial orientation device as claimed in claim 2, It is characterized in that The formula for obtaining the pitch angle and roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system by using the inverse sine and cosine operations based on the first matrix vector specifically includes: Among them, β L represents the pitch angle of the azimuth output axis in the prism coordinate system relative to the horizontal coordinate system, γ L represents the roll angle of the orientation output axis in the prism coordinate system relative to the horizontal coordinate system, Represents a matrix vector The element at row 3 and column 2 of Represents a matrix vector The element at row 3 and column 1 of Represents a matrix vector The element at row 3 and column 3 of .

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