CN218994371U

CN218994371U - Miniaturized instrument assembly

Info

Publication number: CN218994371U
Application number: CN202223534919.8U
Authority: CN
Inventors: 郭建刚; 黄世涛; 王鹏; 陈硕; 刘凯
Original assignee: Beijing Aerospace Era Laser Navigation Technology Co ltd
Current assignee: Beijing Aerospace Era Laser Navigation Technology Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-05-09
Anticipated expiration: 2032-12-29

Abstract

The utility model discloses a miniaturized instrument assembly, wherein a meter adding assembly and a digital acquisition circuit are directly arranged on an aluminum alloy body; the gyro shielding shell is embedded into the aluminum alloy body in an adhesive manner, the gyro shielding cover is fixedly connected with the aluminum alloy body, and a cavity for accommodating the laser gyro is formed inside the gyro shielding cover and the gyro shielding shell; the circuit support vapor chamber is arranged on the outer side of the gyro shielding cover, and the integrated gyro control circuit is fixedly arranged on the outer side of the circuit support vapor chamber; the vibration dampers are four, wherein two vibration dampers are mounted on a first side surface of the aluminum alloy body and are arranged along a diagonal line of the side surface, and the other two vibration dampers are mounted on a second side surface of the aluminum alloy body and are arranged along a diagonal line of the side surface. The utility model realizes the remarkable miniaturization of the instrument assembly, and simultaneously avoids the gyro precision loss caused by jitter coupling, circuit thermal influence and the like.

Description

Miniaturized instrument assembly

Technical Field

The utility model relates to a miniaturized instrument assembly, in particular to an instrument assembly of a laser gyro strapdown inertial navigation system in a miniaturized body structure, and belongs to the technical field of inertial navigation.

Background

The main working principle of the laser strapdown inertial navigation system (hereinafter referred to as laser inertial navigation) is that a laser gyroscope and a quartz accelerometer are used as inertial sensitive components to measure information such as carrier speed, attitude and the like in real time, so that a basis is provided for navigation calculation of the control system. The strapdown inertial navigation system has the characteristics of simple structure, long service life, strong mechanical environment adaptability, higher reliability and the like. The laser gyro and the laser strapdown inertial navigation system formed by the laser gyro represent the development direction of an inertial measurement device with high precision and high reliability in the future, and become the core guidance control equipment of international space carrier rocket, space plane, spacecraft, interstar detection, space station and other systems.

Along with the development of the laser inertial navigation technology, the miniaturization requirement of the control system on the inertial navigation system is higher and higher, and particularly in the fields of small rockets, novel high-maneuvering anti-collision warheads and wide unmanned vehicles represented by unmanned aerial vehicles. All inertial instruments, functional circuits and the like are integrally installed on the inertial navigation instrument assembly, the inertial navigation instrument assembly is a core assembly of an inertial navigation system, and the realization of miniaturization of the instrument assembly is the basis and key of the miniaturized design of inertial navigation. A typical laser inertial navigation instrument assembly comprises the following components: and 3 mechanically-tremble laser gyroscopes, 3 accelerometers, an instrument function circuit, a digital acquisition circuit and other components are integrally arranged on the aluminum alloy body. The inertial instrument and the functional circuit complete motion information measurement, and the digital acquisition circuit completes data summarization, other analog acquisition and external electrical connection. The weight of the body structure of the laser strapdown inertial measurement unit of various types is generally between 5Kg and 10Kg, and the miniaturization requirement cannot be met.

Disclosure of Invention

The utility model aims to overcome the defects and provide a miniaturized instrument assembly, which solves the technical problem that the traditional instrument assembly cannot meet the miniaturization requirement.

In order to achieve the above purpose, the present utility model provides the following technical solutions:

a miniaturized instrument assembly comprises an aluminum alloy body, a laser gyro, a digital acquisition circuit, an integrated gyro control circuit, a circuit support vapor chamber, a gyro shielding cover, a gyro shielding shell, a meter adding assembly and a shock absorber;

the meter adding assembly and the digital acquisition circuit are directly arranged on the aluminum alloy body;

the gyro shielding shell is embedded into the aluminum alloy body in an adhesive manner, the gyro shielding cover is fixedly connected with the aluminum alloy body, and a cavity for accommodating the laser gyro is formed inside the gyro shielding cover and the gyro shielding shell;

the circuit support vapor chamber is arranged on the outer side of the gyro shielding cover, and the integrated gyro control circuit is fixedly arranged on the outer side of the circuit support vapor chamber;

the vibration dampers are four, wherein two vibration dampers are arranged on a first side surface of the aluminum alloy body and are arranged along the diagonal line of the side surface, the other two vibration dampers are arranged on a second side surface of the aluminum alloy body and are arranged along the diagonal line of the side surface, the first side surface is opposite to the second side surface, and the diagonal lines of the vibration dampers are arranged on the first side surface and the second side surface and are mutually perpendicular.

Further, the gap between the laser gyro and the gyro shielding cover is 1.5-2.5 mm.

Further, the rotation inertia ratio of the meter adding assembly and the laser gyro is not lower than 80;

the laser gyro is a 50 type or 55 type laser gyro.

Further, in the aluminum alloy body, reinforcing ribs are respectively adopted for reinforcing and reducing weight for the weak part and the part with structural allowance; and the structurally weak part and the part with the structural allowance are determined according to the simulation result.

Further, the miniature instrument assembly further comprises a counterweight, the overall elastic center of the four dampers is recorded as A, the overall mass center of the miniature instrument assembly comprising the counterweight is recorded as B, and the position deviation between the A and the B is less than or equal to 0.5mm.

Further, the linear vibration frequency of the vibration damping system formed by the four vibration dampers is 50 Hz-100 Hz, the three-way deviation is smaller than 10Hz, the angular vibration frequency is 100-180 Hz, and the three-way deviation is smaller than 10Hz.

Further, the aluminum alloy body is provided with a laser gyro installation reference surface, a shock absorber installation reference surface and a meter adding combination installation reference surface;

the laser gyro installation reference surface, the shock absorber installation reference surface and the meter adding assembly installation reference surface are respectively used for fixedly installing the laser gyro, the shock absorber and the meter adding assembly;

the flatness of the laser gyro mounting reference surface is better than 0.005, and the roughness is better than 1.6;

the flatness of the installation datum plane of the shock absorber and the installation datum plane of the meter-adding combination body is better than 0.01;

the parallelism or verticality among the laser gyro installation reference surface, the shock absorber installation reference surface and the meter-adding assembly installation reference surface is better than 0.02.

Further, the circuit support vapor chamber is of a sandwich structure, wherein the middle interlayer material is graphite aluminum with a heat conduction coefficient of 500-600W/mK.

Further, the thickness of the top shielding cover and the top shielding shell is 0.5mm;

the structural mode of the aluminum alloy body is higher than 1200Hz, and the weight is less than 1000g.

Further, the aluminum alloy body is reserved with a plurality of mounting interfaces for matching with the polytype integrated gyro control circuit and the digital acquisition circuit.

Compared with the prior art, the utility model has at least one of the following beneficial effects:

(1) The utility model realizes the remarkable miniaturization of the instrument assembly, reduces the weight of the assembly to 2.5 Kg-2.6 Kg (matches different circuit states), and simultaneously avoids the gyro precision loss caused by jitter coupling, circuit heat influence and the like, and the gyro precision reaches 0.006 DEG/h.

(2) The utility model improves the universality, the body combination of the utility model is compatible with 50 and 55 laser gyroscopes, and the gyro functional circuits and the acquisition circuits with different specifications, the actual product states are up to 4, the individual state performance is stable, the universality of the body combination is effectively realized, and the performance requirements of different models are met.

Drawings

FIG. 1 is a schematic view of a miniaturized laser gyro instrument assembly according to the present utility model;

FIG. 2 is an exploded front view of a miniaturized laser gyro meter assembly according to the present utility model;

FIG. 3 is an exploded rear view of a miniaturized laser gyro meter assembly according to the present utility model;

FIG. 4 is a front view of a miniaturized laser gyro meter assembly without gyro circuitry, circuit support plate and shielding cover according to the present utility model;

FIG. 5 is a rear view of a miniaturized laser gyro meter assembly without gyro circuitry, circuit support plate and shielding cover according to the present utility model;

FIG. 6 is a schematic view of an aluminum alloy body according to the present utility model.

Detailed Description

The features and advantages of the present utility model will become more apparent and clear from the following detailed description of the utility model.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In the existing laser strapdown inertial navigation system, the closed-loop locking area of the mechanically-tremble laser gyro is eliminated by adopting a tremble frequency-bias technology, and the natural frequency of the mechanically-tremble laser gyro continuously trembles during working. Therefore, when a plurality of laser gyroscopes are integrally arranged on the same body, shake coupling among the gyroscopes is easy to generate, and the precision of the gyroscopes is lost. Theoretical analysis and experimental results show that the higher the moment of inertia, the larger the size, the higher the combined rigidity and modal frequency of the instrument assembly, the smaller the jitter coupling. Therefore, the method for restraining precision loss caused by jitter coupling and realizing gyro jitter decoupling is a key in structural design of a laser gyro instrument assembly, in particular in miniaturization design.

Meanwhile, the miniaturization leads the integration level of the instrument assembly to be higher, the heat power density to be obviously improved, and the heat capacity of the instrument assembly to be reduced and the heat inertia to be smaller, so that the instrument assembly heat design needs to be optimized in the miniaturization design process.

The utility model overcomes the defects of the prior art, provides the miniaturized inertial measurement unit instrument assembly of the laser gyro, integrates the three laser gyroscopes and the three accelerometers (the meter adding assembly) of the laser inertial measurement unit well, and realizes miniaturization and high precision. The utility model can obviously reduce the size and weight of the laser inertial instrument assembly; the gyro shake decoupling is realized, so that the gyro shake coupling caused by the reduction of the size and the weight of the combined body is avoided, and further, the precision loss is caused; according to the utility model, the thermal design of the instrument combination is optimized, and the gyro precision loss or excessive temperature drift caused by thermal influence is avoided; the universality is improved, and the multi-type gyroscope, the gyroscope functional circuit and the digital acquisition circuit can be compatible.

The utility model adopts a bare gyroscope installation scheme for reducing the size and weight of an instrument assembly. By directly mounting and electrically mounting the bare gyroscope and its functional accessories on the aluminum alloy body, the overall size and weight of the combination are significantly reduced. Through optimizing aluminum alloy body structure, improve structural rigidity when reducing weight, optimize the aggregate body and distribute, improve shake inertia ratio, realized the top shake decoupling. The circuit installation substrate of the gyroscope is designed, so that the stiffness of the body is further enhanced while the installation of the gyroscope is realized, and meanwhile, the heat dissipation of the circuit is optimized, and the direct thermal shock to the gyroscope is reduced. The reserved multiple mounting interfaces can be matched with the multi-type gyro functional circuit and the digital acquisition circuit, and meanwhile, certain productization is carried out on the gyro circuit and the acquisition circuit.

Examples:

as shown in FIG. 1, the miniaturized instrument assembly adopts a conventional orthogonal arrangement scheme of a 3-gyroscope and a 3-accelerometer to collect angular movement and linear movement information in three orthogonal directions (X, Y, Z), and comprises the following components: the laser gyro comprises an aluminum alloy body 1, three 50-type or 55-type laser gyroscopes 15, a digital acquisition circuit 3, three integrated gyro control circuits 5, three circuit support vapor chamber (6, 7, 8), three gyro shielding covers (9, 10, 11), three gyro shielding shells (12, 13, 14), a meter adding combination body 2 and four vibration absorbers 4. As shown in fig. 2 and 3, three gyro shield cases (12, 13, 14) are first bonded to the aluminum alloy body 1 using GD414, respectively. The laser gyro 15 is directly mounted on the aluminum alloy body 1 through 3M 3 screws (with spring washers and flat washers). As shown in fig. 4 and 5, the gyro shield covers (9, 10, 11) and the circuit support soaking plates (6, 7, 8) are fastened and mounted on the aluminum alloy body 1 together by 10M 2 screws (anti-loose glue) passing through the gyro shield cases (12, 13, 14). Three integrated gyro control circuits 5 are fastened and installed on circuit support vapor chamber (6, 7, 8) through 4M 2.5 screws (with spring washers and flat pads). The gauge-adding assembly 2 is directly mounted to the aluminum alloy body 1 by 3M 3 screws (with spring washers, flat pads). The digital acquisition board 3 is directly mounted to the aluminium alloy body 1 by means of 5M 2.5 screws (with spring washers, flat pads). The damper 4 is fastened by 2M 4 screws and loosened using a locking glue.

The aluminum alloy body 1 is an integrated body structure as shown in fig. 6, and is made of cast aluminum alloy and is produced by precision casting and precision machining. The aluminum alloy body 1 is used as a core supporting structural member of the instrument assembly, and is a key for realizing the miniaturized design of the instrument assembly. The main measures adopted in the design of the aluminum alloy body 1 are as follows:

(1) Scheme for direct installation by using bare gyroscope

In order to replace the packaging scheme of the integrated gyroscope, parts such as a gyroscope box and the like are omitted, and the bare gyroscope is used for direct installation, so that the overall weight and the enveloping size of the instrument assembly are effectively reduced. The gap between the top and bottom surfaces of the gyroscope and the shield is designed to be 1.5 mm-2.5 mm.

(2) Optimizing component layout, reducing envelope and improving moment of inertia

On the basis of the bare gyroscope scheme, the layout of the instrument and the circuit assembly is optimized, so that the overall envelope size is minimized. And the layout of large-mass components such as gyroscopes is close to the periphery of the components, so that the rotational inertia of the components is guaranteed, and the large reduction of the rotational inertia of the components due to miniaturization is avoided. And finally, the rotation inertia ratio of the instrument assembly and the laser gyro is not lower than 80.

(3) Optimizing aluminum alloy body design, reducing weight and improving rigidity

The structural design of the aluminum alloy body is optimized based on simulation, and the weight reduction is carried out by adopting the design of a weight reduction groove and a reinforcing rib in a large amount while the structural rigidity of the whole force transmission path of the 'shock absorber-gyroscope mounting base' is ensured. And reinforcing the weak part of the structure according to the simulation result, and carrying out weight reduction treatment on the part with larger structural margin to finally meet the design requirements of low weight and high rigidity. The final simulation result shows that the structural mode on the aluminum alloy body in the assembled state is higher than 1200Hz, and the weight of the aluminum alloy body is only about 940g.

(4) Most balancing is completed by means of component layout, and weight design is reduced

The instrument assembly has higher requirements on trimming precision. In order to reduce the counter weight and the overall weight of the combination, the balancing of the combination is considered when the top, the meter, the circuit component and the shock absorber are arranged, and two cores are close to the balancing state by means of the component arrangement: on one hand, the mass center of the combined body in a non-counterweight state is finely adjusted by properly adjusting the position of the component; on the other hand, by properly adjusting the damper position, the elastic center of the damper system is finely adjusted. Balancing is performed by designing the balance weight, the final balance weight is only about 40g, and the deviation between the mass center and the elastic center is not higher than 0.5mm.

(5) Layout scheme of space four-point shock absorber

By adopting a space-crossing four-piece vibration damper layout scheme, the space of the instrument assembly is saved, the coupling is restrained, and the dynamic performance is better. The four vibration dampers are distributed on four opposite angles of the instrument assembly, compared with a traditional eight-point vibration damping mode, the number of vibration dampers is halved, the occupied space is smaller, meanwhile, the mode distribution of line angles of the vibration damping system is unchanged, and the vibration damping system has excellent line angle decoupling property and dynamic environment adaptability. The vibration frequency of the vibration damping system line is designed to be 50 Hz-100 Hz, and the three-way deviation is smaller than 10Hz; the angular vibration frequency is 100-180 Hz, and the three-way deviation is less than 10Hz.

The aluminum alloy body is used as a core structural member of the instrument assembly, and provides more installation reference surfaces, and the installation reference surfaces comprise 3 gyro installation reference surfaces, 2 vibration damper installation reference surfaces and 1 meter-adding assembly installation reference surface. The flatness requirement of the gyro installation reference surface is better than 0.005, the roughness is better than 1.6, and the flatness requirement of the installation reference surface of the damper and meter-adding combination is better than 0.01; parallelism and verticality between the reference surfaces are better than 0.02.

The gyro shielding shell and the gyro shielding cover are made of high magnetic conduction material plates, are formed through processes such as sheet metal forming and welding, and are subjected to full heat treatment. The thickness of the metal plate is generally 0.5mm, and the metal plate needs to be rechecked when the electromagnetic environment has special requirements.

The gyro supports the vapor chamber, and the vapor chamber adopts a high heat conduction aluminum matrix composite prefabricated plate. The plate is of a sandwich structure, the middle interlayer material is graphite aluminum, and the heat conductivity coefficient reaches 500-600W/(mK). The prefabricated plate is integrally formed, and the structural rigidity and strength meet the design requirements. Through the high heat conductivity of graphite aluminium, the heat impact of functional circuit is dispersed to the body structure fast, realizes the samming function, reduces the direct temperature impact to the instrument.

The integrated gyro control circuit and the digital acquisition circuit are respectively made of model spectrum products, and can realize universal exchange of a plurality of circuit models by replacing and supporting the vapor chamber and the like in order to improve the universality of the products.

The utility model has been described in detail in connection with the specific embodiments and exemplary examples thereof, but such description is not to be construed as limiting the utility model. It will be understood by those skilled in the art that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present utility model and its embodiments without departing from the spirit and scope of the present utility model, and these fall within the scope of the present utility model. The scope of the utility model is defined by the appended claims.

What is not described in detail in the present specification is a well known technology to those skilled in the art.

Claims

1. The miniaturized instrument assembly is characterized by comprising an aluminum alloy body (1), a laser gyro (15), a digital acquisition circuit (3), an integrated gyro control circuit (5), a circuit support vapor chamber, a gyro shielding cover, a gyro shielding shell, a meter adding assembly (2) and a shock absorber (4);

the meter adding assembly (2) and the digital acquisition circuit (3) are directly arranged on the aluminum alloy body (1);

the gyro shielding shell is embedded into the aluminum alloy body (1) in an adhesive mode, the gyro shielding cover is fixedly connected with the aluminum alloy body (1), and a cavity for accommodating the laser gyro (15) is formed inside the gyro shielding cover and the gyro shielding shell;

the circuit support vapor chamber is arranged at the outer side of the gyro shielding cover, and the integrated gyro control circuit (5) is fixedly arranged at the outer side of the circuit support vapor chamber;

the number of the vibration dampers (4) is four, wherein two vibration dampers (4) are arranged on a first side surface of the aluminum alloy body (1) along the diagonal line of the side surface, the other two vibration dampers (4) are arranged on a second side surface of the aluminum alloy body (1) along the diagonal line of the side surface, the first side surface is opposite to the second side surface, and the diagonal lines of the vibration dampers (4) are arranged on the first side surface and the second side surface and are mutually perpendicular.

2. A miniaturized instrument package according to claim 1, characterized in that the gap between the laser gyro (15) and the gyro shielding cover is 1.5-2.5 mm.

3. The miniaturized meter combination according to claim 1, wherein the moment of inertia ratio of the meter combination (2) to the laser gyro (15) is not lower than 80;

the laser gyro (15) is a 50 type or 55 type laser gyro.

4. A miniaturized instrument assembly according to claim 1, characterized in that in the aluminium alloy body (1), reinforcing ribs are used for reinforcing and reducing weight respectively for the parts with weak structure and the parts with structural allowance; and the structurally weak part and the part with the structural allowance are determined according to the simulation result.

5. The miniaturized instrument assembly according to claim 1, further comprising a counterweight, wherein the overall elastic center of the four vibration dampers (4) is denoted as a, the overall centroid of the miniaturized instrument assembly comprising the counterweight is denoted as B, and the positional deviation between a and B is less than or equal to 0.5mm.

6. A miniaturized instrument package according to claim 1, characterized in that the vibration damping system of four vibration dampers (4) has a linear vibration frequency of 50 Hz-100 Hz and a three-way deviation of less than 10Hz, and an angular vibration frequency of 100-180 Hz and a three-way deviation of less than 10Hz.

7. A miniaturized instrument package according to claim 1, characterized in that the aluminium alloy body (1) is provided with a laser gyro mounting reference surface, a shock absorber mounting reference surface and a meter-adding package mounting reference surface;

the laser gyro installation reference surface, the shock absorber installation reference surface and the meter adding combination installation reference surface are respectively used for fixedly installing a laser gyro (15), a shock absorber (4) and a meter adding combination (2);

8. The miniaturized meter combination of claim 1, wherein the circuit support vapor chamber is of a sandwich construction, and wherein the intermediate interlayer material is graphite aluminum having a thermal conductivity of 500-600W/mK.

9. The miniaturized instrument package of claim 1 wherein the top shield cover and top shield shell have a thickness of 0.5mm;

the structural mode of the aluminum alloy body (1) is higher than 1200Hz, and the weight is less than 1000g.

10. A miniaturized instrument package according to claim 1, characterized in that the aluminium alloy body (1) is reserved with a plurality of mounting interfaces for matching with a multi-type integrated gyro control circuit (5) and a digital acquisition circuit (3).