A Multi-Instrument Hybrid Redundant Inertial Measurement Unit

Abstract

The invention relates to a multi-instrument hybrid redundant inertial measurement unit, comprising a body and five gyroscopes mounted on the body; wherein the aluminum alloy body provides five gyroscope mounting reference surfaces, each of which is mounted with a gyroscope, and the reference surfaces are respectively recorded as a first gyroscope mounting reference surface GX, a second gyroscope mounting reference surface GY, a third gyroscope mounting reference surface GZ, a fourth gyroscope mounting reference surface GS, and a fifth gyroscope mounting reference surface GT; wherein the first gyroscope mounting reference surface GX, the second gyroscope mounting reference surface GY, and the third gyroscope mounting reference surface GZ are mutually orthogonal, and are provided with mechanical interfaces and electrical interfaces compatible with a 70-type integrated laser gyroscope and a 98-type optical fiber gyroscope, and are used for mounting the 70-type laser gyroscope or the 98-type optical fiber gyroscope; and the fourth gyroscope mounting reference surface GS and the fifth gyroscope mounting reference surface GT are provided with mechanical interfaces and electrical interfaces compatible with a 70-type and a 50-type machine-shaking laser gyroscope, and are used for mounting the 70-type or 50-type machine-shaking laser gyroscope.

Description

Technical Field

[0001] The invention relates to an inertial measurement unit (IMU) of an optical gyro strapdown inertial navigation system, in particular to a multi-table redundant IMU in which multiple types of laser gyros and optical fiber gyros are mixed and optionally matched, and belongs to the technical field of inertial navigation. Background Art

[0002] As one of the main control system equipment, the strapdown inertial navigation system based on optical gyroscope has the characteristics of simple structure, long working life, strong adaptability to mechanical environment, and higher reliability. It has become the core guidance and control equipment of spacecraft such as space launch vehicles, aircraft, and satellites. There are two main types of optical gyroscopes commonly used in engineering, namely organic dither laser gyroscopes and fiber optic gyroscopes. Among them, laser gyroscopes have higher dynamic accuracy and can meet the application requirements of medium and high precision; fiber optic gyroscopes have slightly lower dynamic accuracy and are generally used in medium and low precision occasions, but fiber optic gyroscopes have greater advantages in weight and cost. Multi-meter redundancy design improves the reliability of the strapdown inertial navigation system by adopting inertial instrument redundancy. Compared with the system redundancy using multiple system backups, it has the advantages of higher reliability and relatively lower hardware cost under the same number of instruments, and can improve system accuracy through data fusion technology. It is a common means of reliability design of strapdown inertial navigation system.

[0003] With the development of aerospace technology and the rise of civil aerospace applications and needs, on the one hand, the requirements for strapdown inertial navigation systems are becoming more and more diverse, and on the other hand, due to cost constraints, the requirements for the versatility of strapdown inertial navigation systems are becoming higher and higher. At present, in the development of a new generation of rockets, in order to adapt to the different requirements of different launch missions for rocket carrying capacity, the design and manufacturing costs of rockets are mainly reduced by improving the versatility of the control system. As for the control system, since different launch missions have different requirements for orbital accuracy and launch costs, in order to increase the range of launch missions that can be undertaken by the same carrier rocket, higher requirements are also placed on the task diversity of the control system. In summary, the traditional IMU design with a single instrument type and specification can no longer meet the current control system's requirements for the task diversity and versatility of inertial navigation equipment. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a multi-instrument hybrid redundant inertial measurement unit, to flexibly select instruments of different types and precisions according to task requirements to realize an optical gyro strapdown inertial navigation system, to provide a way to realize the universalization of inertial navigation equipment and control systems, to improve the task diversity of the control system, and to reduce the design and use costs.

[0005] The technical solution of the present invention is: a multi-instrument hybrid redundant inertial measurement unit, the measurement unit includes a body and five gyroscopes installed on the body;

[0006] Among them, the aluminum alloy body provides five gyroscope installation reference surfaces, and a gyroscope is installed on each reference surface, which are respectively recorded as the first gyroscope installation reference surface GX, the second gyroscope installation reference surface GY, the third gyroscope installation reference surface GZ, the fourth gyroscope installation reference surface GS, and the fifth gyroscope installation reference surface GT. The first gyroscope installation reference surface GX, the second gyroscope installation reference surface GY, and the third gyroscope installation reference surface GZ are orthogonal to each other, and are provided with mechanical interfaces and electrical interfaces compatible with the 70-type integrated laser gyroscope and the 98-type fiber optic gyroscope, which are used to install the 70-type laser gyroscope or the 98-type fiber optic gyroscope; the fourth gyroscope installation reference surface GS and the fifth gyroscope installation reference surface GT are provided with mechanical interfaces and electrical interfaces compatible with the 70-type and 50-type machine-shaked laser gyroscopes, which are used to install the 70-type or 50-type machine-shaked laser gyroscopes.

[0007] When the gyroscopes installed on the fourth gyroscope installation reference plane GS and the fifth gyroscope installation reference plane GT are both type 50 integrated laser gyroscopes, the jitter frequency of the type 50 integrated laser gyroscope is between 500 Hz and 580 Hz, and the frequency difference is not less than 20 Hz.

[0008] When the 70-type integrated laser gyroscopes are installed on the first gyroscope installation reference plane GX, the second gyroscope installation reference plane GY, and the third gyroscope installation reference plane GZ, the jitter frequencies of the two 70-type integrated laser gyroscopes are between 350Hz and 450Hz, and the frequency difference is not less than 20Hz.

[0009] The flatness of the gyro installation reference surface is not less than 0.01 mm, and the verticality between the orthogonal installation reference surfaces is not less than 0.02 mm.

[0010] The multi-instrument hybrid redundant inertial measurement unit further includes an add-meter assembly 4, which includes an add-meter body and five accelerometers mounted on the add-meter body;

[0011] The meter body provides five meter installation reference surfaces, each of which is equipped with an accelerometer, which are respectively recorded as the first meter installation reference surface AX, the second meter installation reference surface AY, the third meter installation reference surface GZ, the fourth meter installation reference surface AS, and the fifth meter installation reference surface AT, wherein the first meter installation reference surface AX, the second meter installation reference surface AY, and the third meter installation reference surface AZ are orthogonal to each other.

[0012] The flatness of each mounting reference surface of the meter must be no less than 0.01mm, and the verticality between the orthogonal mounting reference surfaces must be no less than 0.02mm.

[0013] The main body also provides a gyroscope assembly installation reference surface AA, which is used for the gyroscope assembly, and the gyroscope assembly installation reference surface AA is parallel to the third gyroscope installation reference surface GZ.

[0014] The parallelism between the mounting reference plane AA of the added-meter assembly and the mounting reference plane GZ of the third gyroscope is not less than 0.02 mm.

[0015] There are multiple wiring holes and weight-reducing grooves on the main body, and the IMU main body structural modal is not less than 1200Hz under load.

[0016] The meter-adding assembly also includes a ceramic gasket, which is made of a machinable ceramic material with a high thermal conductivity and is installed on the installation reference plane of the meter-adding assembly to improve the thermal insulation performance between the meter-adding assembly and the meter-adding assembly installation reference plane AA.

[0017] The beneficial effects of the present invention compared with the prior art are:

[0018] (1) The present invention solves the problem of fixed design accuracy, weight, hardware cost and other indicators of traditional IMU and relatively single mission capability through the interchangeable design of two types of laser gyroscopes and two types of fiber optic gyroscopes, unified standardized definition of gyroscope electrical interfaces and mechanical interfaces compatible with requirements of various types of gyroscopes. It can meet the different requirements of IMU accuracy and hardware cost for different launch missions, and improve the versatility and mission diversity of IMU.

[0019] (2) The present invention solves the problem of reduced accuracy of the fiber optic gyro due to the jitter interference of the laser gyro when the fiber optic gyro and the machine-shake laser gyro are installed on the same IMU through IMU structure design, frequency configuration, and design and optimization of the fiber optic gyro filter, thereby effectively suppressing the accuracy loss of the fiber optic gyro.

[0020] (3) The present invention solves the laser gyro jitter coupling problem through IMU structural design and frequency configuration, effectively suppresses the gyro jitter coupling error, and ensures the gyro accuracy.

[0021] (4) The IMU of the present invention is designed with a motherboard circuit, which, on the one hand, realizes electrical connection with various instruments through cables to achieve electrical integration of the IMU; on the other hand, it realizes external input and output of the IMU.

[0022] (5) The present invention provides a unified and standardized definition of the electrical interface of the four-type laser and fiber optic gyroscope, and uses a 422 serial port to transmit gyroscope data. The communication protocol is unified, and the gyroscope can be replaced and used immediately.

[0023] (6) In order to avoid the jitter coupling problem between laser gyroscopes, especially in the full laser gyroscope state, the present invention optimizes the design of the IMU body from the topological structure to the local size, improves the body stiffness, reduces the structural weight, and at the same time clearly requires the range of applicable gyroscope jitter frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of a multi-instrument hybrid redundant IMU in an embodiment of the present invention;

[0025] Figure 2 This is a back view of a multi-instrument hybrid redundant IMU in an embodiment of the present invention;

[0026] Figure 3 It is a front view of the aluminum alloy body of the multi-instrument hybrid redundant IMU in an embodiment of the present invention;

[0027] Figure 4 It is a back view of the aluminum alloy body of the multi-instrument hybrid redundant IMU in an embodiment of the present invention;

[0028] Figure 5 It is a diagram of a combined body with a table in an embodiment of the present invention;

[0029] Figure 6 It is a diagram showing the main body in the embodiment of the present invention;

[0030] Figure 7 A diagram of a shock absorber in an embodiment of the present invention;

[0031] Figure 8 This is a diagram of the main motherboard in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the embodiments.

[0033] The typical form of an optical gyro strapdown inertial navigation IMU is: inertial instruments (optical gyroscopes and accelerometers) are installed on an aluminum alloy body, and some functional circuits are matched to form an IMU. In order to reduce the impact of size effect on the accelerometer output, the accelerometer is usually integrated and installed on an add-on meter body. The strapdown inertial navigation system generally adopts a soft strapdown method with internal vibration reduction. Therefore, the IMU is equipped with several vibration absorbers and 5 gyroscopes installed on the body 1, an add-on meter assembly 4, a circuit motherboard 5, an optical fiber gyroscope data filter, and 6 IF circuit modules 6; wherein, the add-on meter assembly 4 includes an add-on meter body 9 and five accelerometers 10 installed on the add-on meter body 9.

[0034] Among them, the aluminum alloy body 1 provides five gyroscope installation reference surfaces, each of which is equipped with a gyroscope, which are respectively recorded as the first gyroscope installation reference surface GX, the second gyroscope installation reference surface GY, the third gyroscope installation reference surface GZ, the fourth gyroscope installation reference surface GS, and the fifth gyroscope installation reference surface GT. The first gyroscope installation reference surface GX, the second gyroscope installation reference surface GY, and the third gyroscope installation reference surface GZ are orthogonal to each other, and are provided with mechanical interfaces and electrical interfaces compatible with the 70-type integrated laser gyroscope and the 98-type fiber optic gyroscope, which are used to install the 70-type laser gyroscope or the 98-type fiber optic gyroscope; the fourth gyroscope installation reference surface GS and the fifth gyroscope installation reference surface GT are provided with mechanical interfaces and electrical interfaces compatible with the 70-type and 50-type machine-shaked laser gyroscopes, which are used to install the 70-type or 50-type machine-shaked laser gyroscopes.

[0035] When the gyroscopes installed on the fourth gyroscope installation reference plane GS and the fifth gyroscope installation reference plane GT are both type 50 integrated laser gyroscopes, the jitter frequency of the type 50 integrated laser gyroscope is between 500 Hz and 580 Hz, and the frequency difference is not less than 20 Hz.

[0036] When the 70-type integrated laser gyroscopes are installed on the first gyroscope installation reference plane GX, the second gyroscope installation reference plane GY, and the third gyroscope installation reference plane GZ, the jitter frequencies of the two 70-type integrated laser gyroscopes are between 350Hz and 450Hz, and the frequency difference is not less than 20Hz.

[0037] The flatness of the gyro installation reference surface is not less than 0.01 mm, and the verticality between the orthogonal installation reference surfaces is not less than 0.02 mm.

[0038] The meter body 9 provides five meter installation reference surfaces, each of which is equipped with an accelerometer, which are respectively recorded as the first meter installation reference surface AX, the second meter installation reference surface AY, the third meter installation reference surface GZ, the fourth meter installation reference surface AS, and the fifth meter installation reference surface AT, wherein the first meter installation reference surface AX, the second meter installation reference surface AY, and the third meter installation reference surface AZ are orthogonal to each other.

[0039] Preferably, the flatness of each mounting reference surface of the meter is required to be no less than 0.01 mm, and the verticality between the orthogonal mounting reference surfaces of the meter is required to be no less than 0.02 mm.

[0040] The main body 1 also provides a gyroscope assembly installation reference surface AA, which is used for the gyroscope assembly 4, and the gyroscope assembly installation reference surface AA is parallel to the third gyroscope installation reference surface GZ.

[0041] Preferably, the parallelism between the mounting reference plane AA of the gyroscope assembly and the mounting reference plane GZ of the third gyroscope is not less than 0.02 mm.

[0042] Preferably, the body 1 is an integrated body structure, and the material is cast aluminum alloy.

[0043] Preferably, the watch body 9 is an integrated body structure, and the material is cast aluminum alloy.

[0044] Preferably, the main body 1 has a plurality of wiring holes and weight-reducing grooves, and the IMU main body structural modal under load is not less than 1200 Hz.

[0045] Preferably, the meter-adding assembly further comprises a ceramic gasket 11, which is made of a machinable ceramic material with geothermal conductivity and is installed on the installation reference plane of the meter-adding assembly to improve the thermal insulation performance between the meter-adding assembly and the meter-adding assembly installation reference plane AA.

[0046] Preferably, the flatness of the ceramic gasket 11 after installation is not less than 0.02 mm.

[0047] Preferably, the circuit motherboard 5 is directly mounted on the main body to complete the electrical relationship summary of the gyroscope and the accelerometer, as well as the electrical connection between the inertial measurement unit and the inertial navigation computer and the power supply circuit.

[0048] Preferably, the main body 1 and the watch body 9 are connected as a whole through a polymer damping rubber material.

[0049] Preferably, the IF circuit module is directly installed on the IMU body. The five IF modules are divided into two groups, three of which are installed in the -Y direction of the IMU body, and the other two are installed in the +X direction of the IMU body. The IF circuit module converts the current signal (I) originally output by the accelerometer into a frequency signal (F), thereby realizing AD conversion while ensuring the accuracy of the conversion.

[0050] Preferably, the above-mentioned multi-instrument hybrid redundant inertial measurement unit also includes a vibration reduction system composed of 8 vibration absorbers, which are directly installed on the IMU body. The linear vibration frequency of the vibration reduction system along the three directions of the arrow body coordinate system is not higher than 100 Hz, the three-way angular vibration frequency is not higher than 160 Hz, and the linear vibration amplification factor is not higher than 3.5.

[0051] Fiber optic gyro data filter, the fiber optic gyro data filter is burned into the main body motherboard, and the basic requirements are: (1) the filter order is not higher than 12th order, (2) the filter cutoff frequency is not lower than 100 Hz; the specific filter parameters need to be designed and adjusted according to the noise spectrum of the laser gyro and the fiber optic gyro.

[0052] Example:

[0053] like Figure 1 and Figure 2As shown, the present invention provides a multi-instrument hybrid redundant IMU, which is a ten-instrument redundant IMU with five gyroscopes and five accelerometers, three of the five instruments (gyroscopes or accelerometers) are mutually orthogonal, and the other two are inclined. The multi-instrument hybrid redundant IMU comprises: an aluminum alloy body 1 ( Figure 1 Marking), three large gyroscopes 2 ( Figure 2 Marking), two small gyroscopes 3 ( Figure 1 Marking), plus table combination 4 ( Figure 1 Marking), motherboard circuit 5 ( Figure 1 Mark), five IF conversion circuit modules 6 ( Figure 1 and Figure 2 Marking), eight shock absorbers 7 ( Figure 1 Marking), and two gyro adapter plates 8 ( Figure 2 mark).

[0054] The three orthogonal gyros can be installed with a 70-type laser gyro or a 98-type fiber gyro, and the two oblique gyros can be installed with a 50-type laser gyro or a 60-type fiber gyro. The IMU structural design needs to meet the mechanical requirements of both the laser gyro and the fiber gyro, and solve the jitter coupling of the five laser gyros, as well as the problem of gyro accuracy loss caused by the jitter interference of the laser gyro when the fiber gyro and the laser gyro are mixed.

[0055] In order to meet the requirements of IMU accuracy, weight and cost for different tasks, the IMU design of the present invention is compatible with two types of integrated fiber optic gyroscopes, 98 and 60, and 70 and 50 integrated machine-shaking laser gyroscopes. Among them, the 98-type fiber optic gyroscope and the 70-type laser gyroscope have higher accuracy and can be installed interchangeably; the 60-type fiber optic gyroscope and the 50-type laser gyroscope have slightly lower accuracy and can be installed interchangeably.

[0056] The measurement matrix of the multi-instrument hybrid redundant IMU instrument (gyroscope or additional meter) is:

[0057]

[0058] The measurement matrix and installation orientation of the instrument can be determined by the following method: O-X1Y1Z1 is the rocket body coordinate system, where OX1 is the longitudinal axis, OY1 is the normal axis, and OZ1 is the transverse axis; O-XsYsZs is the measurement coordinate system of the main body component, the measurement axis of the inclined S gyro or the meter is the OS axis, and the positive direction has an angle of 127.0°, 46.6°, and 66° with the positive direction of the OXs, OYs, and OZs axes, respectively; the measurement axis of the inclined T gyro or the meter is the OT axis, and the positive direction has an angle of 46.5°, 71.0°, and 49.6° with the positive direction of the OXs, OYs, and OZs axes, respectively; the main body component needs to be tilted relative to the rocket body coordinate system as a whole, and the relationship between the main body component measurement coordinate system O-XsYsZs and the rocket body coordinate system O-X1Y1Z1 is as follows:

[0059]

[0060] The aluminum alloy body 1 is as follows Figure 3 , Figure 4 As shown. It is an integrated body structure, made of cast aluminum alloy, produced by precision casting and precision machining. The aluminum alloy body 1 provides GX, GY, GZ, GS, GT and AA, a total of 6 installation reference surfaces, which are used to install 5 gyroscopes and 1 plus meter assembly. Among them, the surface normal directions of GX, GY, GZ, GS and GT meet the constraints of the measurement matrix of the above-mentioned multi-instrument hybrid redundant IMU instrument (gyroscope or plus meter), AA is parallel to GZ, and GX, GY and GZ are mutually orthogonal. The flatness of each installation reference surface is not less than 0.01mm, the verticality between orthogonal installation reference surfaces is not less than 0.02mm, and the parallelism between parallel installation reference surfaces is not less than 0.02mm. There are multiple wiring holes and weight reduction grooves on the aluminum alloy body. The design of the IMU body is the basis for realizing gyro jitter decoupling and suppressing the noise interference of the laser gyro on the fiber optic gyroscope. It requires light weight, high structural stiffness, and the IMU body structure mode under load is not less than 1200Hz, and the rotational inertia of the IMU is increased as much as possible. Based on finite element simulation, the topological structure of the main body and some sensitive local dimensions were optimized in the design. The overall structure of the main body is frame-type, and there are multiple inclined ribs for instrument installation and reinforcement inside the structure. The position, local dimensions and weight-reducing hole dimensions of the ribs were optimized and adjusted according to the simulation results, which reduced the weight of the structure and improved the rigidity of the mechanism.

[0061] The large gyroscope 2 can be a 70-type integrated laser gyroscope or a 98-type integrated fiber optic gyroscope, which is fastened by three M5 hexagon socket head screws (with spring washers and flat washers) or four M5 slotted pan head screws (with spring washers and flat washers) and installed on the aluminum alloy body 1 ( Figure 1 The three 70-type integrated laser gyros are required to have a vibration frequency between 300Hz and 450Hz, and a frequency difference of no less than 20Hz.

[0062] The small gyroscope 3 can be a 50-type integrated laser gyroscope or a 60-type integrated fiber optic gyroscope, mounted on the aluminum alloy body 1 ( Figure 1 The 50-type integrated laser gyro is fastened by four M4 slotted pan head screws, and the 60-type integrated fiber optic gyro is first fixed to the gyro transition base plate 8 by four M4 hexagon socket head screws, and then fastened by four M4 slotted pan head screws. The jitter frequency of the two 50-type integrated laser gyros is required to be between 500Hz and 580Hz, and the frequency difference is not less than 20Hz.

[0063] The structure of the added table combination is as follows Figure 5 As shown, it consists of an add-on meter body 9, five accelerometers 10, two temperature sensors 12 and three ceramic gaskets 11, which are directly installed on the IMU body through three M4 screws (with spring washers and flat washers). Among them, the two temperature sensors are installed near the center of the add-on meter assembly to provide temperature feedback for the temperature compensation system; the ceramic gasket 11 is made of machinable ceramic material with geothermal conductivity and is installed on the installation reference plane of the add-on meter assembly, which helps to improve the thermal insulation performance between the add-on meter assembly and the IMU. The accelerometer 9 add-on meter is fastened to the five reference planes AX, AY, AZ, AS and AT of the add-on meter body through three M3 screws (with spring washers and flat washers), and the add-on meter assembly. The ceramic gasket 11 needs to be ground after installation to ensure that the overall flatness is not less than 0.02mm.

[0064] The added table entity is as follows Figure 6 As shown, it is made of aluminum alloy and precision machined. The main body of the meter provides five reference planes: AX, AY, AZ, AS and AT. The normal of the surface in the meter system satisfies the measurement matrix shown in the following formula, so as to ensure that the measurement axes of the corresponding gyroscope and accelerometer on the IMU are parallel. The flatness of each installation reference surface is required to be no less than 0.01mm, and the verticality between the orthogonal installation reference surfaces is required to be no less than 0.02mm.

[0065]

[0066] The shock absorber is as follows Figure 7 As shown in the figure, two aluminum alloy structural parts are connected as a whole by polymer damping rubber material. The rubber material determines the stiffness coefficient and damping coefficient of the shock absorber, and is generally reflected in the first-order resonance frequency and amplification factor of the vibration reduction system. The eight shock absorbers are fastened to the IMU body by two M4 screws, and loosened with anti-loosening glue to form the eight-point vibration reduction system of the IMU. It is required that the linear vibration frequency of the vibration reduction system along the three directions of the arrow body coordinate system is not higher than 100Hz, the angular vibration frequency is not higher than 160Hz, and the linear vibration amplification factor is not higher than 3.5.

[0067] The main body motherboard is as follows Figure 8 As shown in the figure, the electrical relationship between the gyro, accelerometer and functional circuit is summarized, the filtering of the gyro output is processed, and the electrical connection with the inertial navigation computer, power supply circuit, etc. is completed. It is directly installed on the IMU body through 5 M3 screws (with spring washers and flat washers).

[0068] The IF circuit module is directly mounted on the IMU body through four M2.5 screws (with spring washers and flat washers). The five IF modules are divided into two groups, three of which are installed in the -Y direction of the IMU body, such as Figure 1 As shown; the other two are installed in the +X direction of the IMU body, below the motherboard of the body, as shown Figure 2 shown.

[0069] The fiber optic gyro data filter described above: The theoretical design of the filter is completed based on the laser gyro jitter noise spectrum and the dynamic characteristics of the fiber optic gyro, and then a static navigation test is carried out on the laser gyro and the fiber optic gyro installed on the same base to obtain the actual noise spectrum of the fiber optic gyro, and finally the filter parameters are adjusted to achieve effective suppression of the laser gyro jitter noise and avoid the accuracy loss of the fiber optic gyro. The general requirements of the filter are: (1) the filter order is not higher than 12th order, and (2) the filter cutoff frequency is not lower than 100Hz. The filter transfer function is shown in the following formula.

[0070]

[0071] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A multi-instrument hybrid redundant inertial measurement unit, characterized in that It comprises a main body (1) and five gyroscopes mounted on the main body (1); and also comprises a watch assembly (4); The aluminum alloy body (1) provides five gyro installation reference surfaces, each of which is used to install a gyro, and they are respectively denoted as a first gyro installation reference surface GX, a second gyro installation reference surface GY, a third gyro installation reference surface GZ, a fourth gyro installation reference surface GS, and a fifth gyro installation reference surface GT. The first gyro installation reference surface GX, the second gyro installation reference surface GY, and the third gyro installation reference surface GZ are orthogonal to each other, and are provided with mechanical interfaces and electrical interfaces compatible with a 70-type integrated laser gyro and a 98-type fiber optic gyro, and are used to install a 70-type laser gyro or a 98-type fiber optic gyro. The fourth gyro installation reference surface GS and the fifth gyro installation reference surface GT are provided with mechanical interfaces and electrical interfaces compatible with a 70-type and a 50-type machine-shaking laser gyro, and are used to install a 70-type or a 50-type machine-shaking laser gyro. The measurement matrix and installation orientation of the instrument can be determined as follows: O-X1Y1Z1 is the arrow body coordinate system, where OX1 is the longitudinal axis, OY1 is the normal axis, and OZ1 is the transverse axis; O-XsYsZs is the measurement coordinate system of the body component, where OXs is the longitudinal axis, OYs is the normal axis, and OZs is the transverse axis; the positive direction of the measurement axis OS axis of the inclined fourth gyroscope has an angle with the positive directions of OXs, OYs, and OZs axes; the positive direction of the measurement axis OT axis of the inclined fifth gyroscope has an angle with the positive directions of OXs, OYs, and OZs axes; The meter assembly (4) comprises a meter body (9) and five accelerometers (10) mounted on the meter body (9); The meter body (9) provides five meter installation reference surfaces, each of which is equipped with an accelerometer, and they are respectively denoted as the first meter installation reference surface AX, the second meter installation reference surface AY, the third meter installation reference surface GZ, the fourth meter installation reference surface AS, and the fifth meter installation reference surface AT, wherein the first meter installation reference surface AX, the second meter installation reference surface AY, and the third meter installation reference surface AZ are orthogonal to each other; The measurement matrix of the multi-instrument hybrid redundant inertial measurement unit is: The measurement matrix and installation orientation of the instrument can be determined by the following method: O-X1Y1Z1 is the arrow body coordinate system, in which OX1 is the longitudinal axis, OY1 is the normal axis, and OZ1 is the transverse axis; O-XsYsZs is the measurement coordinate system of the body component, the measurement axis of the inclined S gyro or the meter is the OS axis, and the positive direction has an angle of 127.0°, 46.6°, and 66° with the positive direction of the OXs, OYs, and OZs axes, respectively; the measurement axis of the inclined T gyro or the meter is the OT axis, and the positive direction has an angle of 46.5°, 71.0°, and 49.6° with the positive direction of the OXs, OYs, and OZs axes, respectively; The main body component is tilted as a whole relative to the rocket body coordinate system. The relationship between the main body component measurement coordinate system O-XsYsZs and the rocket body coordinate system O-X1Y1Z1 is as follows: When the gyroscopes installed on the fourth gyroscope installation reference plane GS and the fifth gyroscope installation reference plane GT are both type 50 integrated laser gyroscopes, the jitter frequency of the type 50 integrated laser gyroscope is between 500Hz and 580Hz, and the frequency difference is not less than 20Hz; When the first gyro installation reference plane GX, the second gyro installation reference plane GY, and the third gyro installation reference plane GZ are all 70-type integrated laser gyros, the jitter frequencies of the two 70-type integrated laser gyros are between 300Hz and 450Hz, and the frequency difference is not less than 20Hz; Fiber optic gyro data filter, the fiber optic gyro data filter is burned into the main body motherboard, the basic requirements are: (1) the filter order is not higher than 12th order, (2) the filter cutoff frequency is not lower than 100Hz.

2. A multi-instrument hybrid redundant inertial measurement unit according to claim 1, characterized in that The flatness of the gyro installation reference surface is not less than 0.01 mm, and the verticality between the orthogonal installation reference surfaces is not less than 0.02 mm.

3. A multi-instrument hybrid redundant inertial measurement unit according to claim 1, characterized in that The flatness of each mounting reference surface of the meter must be no less than 0.01mm, and the verticality between the orthogonal mounting reference surfaces must be no less than 0.02mm.

4. A multi-instrument hybrid redundant inertial measurement unit according to claim 1, characterized in that The main body (1) also provides a meter assembly installation reference surface AA, which is used for the meter assembly body (4), and the meter assembly installation reference surface AA is parallel to the third gyroscope installation reference surface GZ.

5. A multi-instrument hybrid redundant inertial measurement unit according to claim 4, characterized in that The parallelism between the mounting reference plane AA of the added-meter assembly and the mounting reference plane GZ of the third gyroscope is not less than 0.02 mm.

6. A multi-instrument hybrid redundant inertial measurement unit according to claim 1, characterized in that The main body (1) has a plurality of wiring holes and weight-reducing grooves, and the IMU main body structural modal under load is not less than 1200 Hz.

7. A multi-instrument hybrid redundant inertial measurement unit according to claim 4, characterized in that The meter adding assembly also includes a ceramic gasket (11), which is made of a machinable ceramic material with a low thermal conductivity and is installed on the meter adding assembly installation reference plane to improve the thermal insulation performance between the meter adding assembly and the meter adding assembly installation reference plane AA.

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