CN103604431A - Strapdown compass system based on triaxial integrated high-precision optic fiber gyroscope - Google Patents

Abstract

A strapdown compass system based on a three-axis integrated high-precision fiber optic gyroscope, which is composed of three parts: the box, the fiber optic gyro IMU component and the system circuit component; the box is composed of a bottom plate and an outer cover, and the bottom plate is divided into an inertial group area and the circuit area, respectively hold the fiber optic gyroscope IMU components and system circuit components. The fiber optic gyroscope IMU components and system circuit components are electrically connected through electrical connectors. The present invention adopts a modularized integrated design, focuses on improving the adaptability and engineering performance of the system, and successfully overcomes the problems of poor system performance caused by the large volume, heavy weight, poor temperature performance, poor consistency, and complex structure of the platform compass. , and by optimizing the strapdown compass algorithm, the accuracy of the system is improved. The invention has better practical value and broad application prospect in the inertial technical field.

Description

A strapdown compass system based on three-axis integrated high-precision fiber optic gyroscope

Technical field:

The invention relates to a strapdown compass system based on a three-axis integrated high-precision optical fiber gyroscope, which belongs to the technical field of inertial navigation. the

Background technique:

The compass system is a sophisticated and complex navigation instrument, which can not only provide accurate heading and horizontal reference information for the navigation, armament, and command systems of large and medium-sized surface and underwater ships, but also display the ship's attitude angle and calculate the ship's position . The platform compass is generally equipped with two two-degree-of-freedom gyroscopes or three single-degree-of-freedom gyroscopes, and two electromagnetic pendulums or two accelerometers to form a leveling and north-finding circuit, and establish a three-axis space stable platform to track the geographic coordinates of the northeast sky Tie. Due to the mechanical platform structure, the platform compass system has problems such as complex structure, large volume, heavy weight, high price, and difficulty in further improving reliability. the

Three-axis integrated fiber optic gyroscope is a fiber optic gyroscope that integrates the gyroscopes in three orthogonal directions during inertial navigation. At the same time, the optical path, circuit and structure are comprehensively designed, which not only saves equipment volume, but also reduces costs. It has a simple structure. , Easy processing, low cost, small size, light weight, quick start, strong impact resistance, large dynamic range, etc. the

The strapdown compass system installs the inertial sensitive components (gyroscope, accelerometer) directly on the carrier, and the gyroscope is no longer isolated from the rotational motion of the carrier through the platform frame, but moves completely synchronously with the carrier. The function of the navigation platform is realized by using the direction cosine matrix in the computer, and the physical mechanical platform in the conventional platform compass system is replaced by the "mathematical platform". Since the complex electromechanical navigation platform is omitted, many shortcomings of the platform compass system are overcome. the

Therefore, the strapdown compass system based on fiber optic gyro has the advantages of high dynamic accuracy, automatic alignment, short stabilization time, high reliability, compact structure, light weight, low power consumption, and no maintenance, etc. It is an important aspect of ship navigation technology. research direction. the

Invention content:

(1. Purpose:

The purpose of the present invention is to provide a strapdown compass system based on a three-axis integrated high-precision fiber optic gyro, which uses a three-axis integrated high-precision fiber optic gyro as an inertial sensitive element, and overcomes the large volume, complex structure, and shock resistance of the platform compass. Weak capacity, high cost and other problems focus on improving the system's environmental adaptability and actual performance, reducing the system start-up time, simplifying the assembly and production process, and ensuring the reliability and maintainability of the system. The invention improves the initial alignment algorithm of the strapdown compass system, realizes fast and accurate alignment in different states such as carrier mooring state, anchoring state, and maneuvering state; designs and realizes timely switching between compass state and inertial navigation state, shortens The initial alignment time is improved, and the horizontal error and heading error of the compass system are reduced. the

(2) Technical solution:

The present invention is a strapdown compass system based on a three-axis integrated high-precision fiber optic gyroscope, as shown in Figure 1, which is composed of three parts: a box body, a fiber optic gyroscope IMU component and a system circuit component. The position connection relationship between them is: the box is used to hold and protect the fiber optic gyroscope IMU components and system circuit components, and is divided into inertial group area and circuit area. Among them, the inertial group area is used to place the fiber optic gyroscope IMU components, including three-axis integrated fiber optic gyroscope, accelerometer, IMU table body, light source pre-amplifier components, etc.; the circuit area is used to place system circuit components, including secondary power boards, accelerometers I/F processing circuit boards, navigation computing boards, gyro processing circuit boards, motherboards, etc. There are three external electrical connectors on the front of the box, which are used for power supply and communication of the compass system. The electrical connection between the inertial group area and the circuit area is completed through an external electrical connector, and the box is completely closed by the upper cover of the box and the connecting bolts. the

The box body, as shown in Fig. 2(a) and Fig. 2(b), is divided into two parts, the bottom plate and the outer cover. The bottom plate of the box is a long rectangular plate structure, which can minimize the difficulty of processing, and is used to install the fiber optic gyro IMU components and system circuit components, as well as the entire compass system. The upper surface of the bottom plate is processed with mounting bosses and screw holes for installing circuit brackets, fiber optic gyroscope IMU system components, motherboards, etc., and four box mounting flanges are evenly distributed on the lower long edge of the bottom plate, which provides the level of the entire compass system. The installation datum provides two side contact surfaces of the box on the lower short edge of the bottom plate, which constitutes the orientation datum of the entire compass system. The box cover is a rectangular box structure, which is processed and formed by welding. There are 3 mounting holes for through-wall sockets processed on the front of the cover, and an inner flange is provided on the joint surface with the bottom plate, which improves the rigidity of the entire cover on the one hand, and also provides processing positions for fixing screws, which is also conducive to sealing . Three external electrical connectors are installed on the front of the cover, the models are: YMA27S4M1D40, YMA27S12M1D40 and YMA27S26M1D40, and the disc end is located outside the cover for power supply and communication. Considering the electromagnetic interference between the system circuit and the gyroscope, the circuit area is placed on the front of the bottom plate. The circuit area is provided with a circuit bracket mounting surface and a motherboard mounting surface, which are used to install the circuit bracket and the system motherboard respectively. The rear part of the bottom plate is the inertial group area, which is equipped with IMU mounting surface, IMU resting surface, and light source front component fixing holes. The IMU mounting surface and the IMU resting surface provide horizontal and vertical installation references for installing the fiber optic gyroscope IMU components, and the component fixing holes are placed in front of the light source so that the light source can be locked and fixed on the chassis. There are mounting flanges evenly distributed around the box body, and positioning pins and mounting holes are arranged on the mounting flanges. Sealing grooves are processed on the front and top of the box for placing sealing rings. After the front panel and top cover are installed, it can achieve a good sealing effect. The inertial group area and the circuit area are connected by electrical connectors, all of which are electrically connected, which simplifies the system production and assembly process, and improves the system reliability and maintainability. the

The system circuit components refer to the navigation solving board, the accelerometer I/F processing circuit board, the gyro processing circuit board, the mother board and the secondary power supply board installed in the circuit area. The position connection relationship between them is: the navigation calculation board, the accelerometer I/F processing circuit board, and the gyro processing circuit board are electrically connected to the CMI96ZJN socket on the motherboard through the CMI96TKW curved rectangular electrical connector and fixedly arranged on the The motherboard at the bottom of the box is connected for easy assembly and maintenance. The navigation calculation board, accelerometer I/F processing circuit board, and gyro processing circuit board have uniform dimensions, structure and installation interface, are covered with a heat conduction box, and are fixed on the circuit bracket with side locking strips. Take the gyro processing circuit as an example, as shown in Figure 3, including the gyro processing circuit board, heat conduction box, locking strip, and CMI96TKW curved rectangular electrical connector. The mother board is fixed on the mounting boss on the bottom plate, and the side close to the fiber optic gyroscope IMU system components is welded with in-line sockets J30J-31ZKNP5 and J30J-37ZKNP5 for electrical connection with the fiber optic gyroscope IMU system components; The side close to the external electrical connector provides pads for soldering the cabin plugs YMA27T4K1P40, YMA27T12K1P40 and YMA27T26K1P40. The circuit bracket is a box-shaped frame structure, which is fixed on the bottom plate through the fixing holes at the bottom and the mounting flange. There are slide grooves processed inside it to fix the above-mentioned system circuit components, and at the same time conduct the heat of the circuit to the external environment. Its basic shape is shown in Figure 4. Starting from the front end, the circuit boards are the secondary power supply board, navigation calculation board, accelerometer I/F processing circuit board, and gyroscope processing circuit board in sequence. This layout is conducive to system assembly and avoids the heat generated by the secondary power supply board. The impact on the fiber optic gyro sensitive ring and the accelerometer head. the

The fiber optic gyro IMU assembly, as shown in Figure 5 (a) and (b), adopts a three-axis integrated high-precision light and small fiber optic gyro, including an IMU table body, three fiber optic gyro sensitive rings, three accelerometer heads and a fixed Place the assembly in front of the light source on the base plate. The three optical fiber gyroscope sensitive rings share the same light source and are wound with Φ80μm thin-diameter optical fiber, which reduces the weight and volume of the compass system. The gyro light source is fixed on the side wall of the chassis by locking strips, which facilitates heat dissipation and weakens the influence of light source heat on the optical fiber gyro sensitive ring and the accelerometer head. The IMU component of the fiber optic gyroscope adopts a double-layer magnetic shielding design, and the IMU body with a space-diagonal vibration-reduction layout effectively ensures that the IMU component of the fiber optic gyroscope has good isotropic dynamic response characteristics under vibration and impact conditions, and improves the vibration of the system. performance. (The fiber optic gyro IMU component has previously been patented separately, and will not be described in detail here). the

Principle of work of the present invention and work flow brief introduction are as follows:

The three-axis integrated fiber optic gyro processing circuit board, accelerometer I/F processing circuit board, navigation solving board, and secondary power supply board in the circuit area are connected through the motherboard to complete electrical signal exchange. The above circuit boards and the fiber optic gyroscope on the IMU body The electrical signal exchange between the sensitive unit (including the front board), the light source module (including the drive circuit), the accelerometer, the temperature sensor (18B20), etc. is realized through two electrical connectors on the motherboard and the IMU body. The power supply and data communication of the system are realized through three external electrical connectors on the motherboard. The three-axis fiber optic gyro sensitive carrier perceives the angular motion of the system, and the angular velocity information is output by the RS422 serial port through the gyro main board according to the protocol. The sensitive carrier of the three-axis quartz flexible accelerometer perceives system acceleration information, and its output is proportional to the system acceleration, which is collected and processed by the accelerometer I/F processing circuit board and outputs three pulse signals. The accelerometer has a built-in temperature sensor, and the measured temperature signal output is a digital serial code composed of 0/1, which can be directly collected by the digital interface circuit. The navigation calculation board completes the collection of gyroscope information, accelerometer information and temperature information, so as to perform functions such as temperature compensation, navigation calculation, integrated navigation and communication. The secondary power board converts the external input power into various forms of voltage required by the system, and also performs functions such as filtering, voltage stabilization, and overcurrent protection. the

(3) Advantages and effects:

The present invention is a strapdown compass system based on a three-axis integrated high-precision fiber optic gyroscope, which changes the traditional design method, and overcomes many shortcomings of the platform compass through the integrated modularization and comprehensive integration of inertial devices and systems; improves the compass The system's processing circuit and optimized compass algorithm improve the heading and horizontal accuracy of the compass system while reducing the body and weight, and reduce the start-up time and shorten the alignment time. Specifically, the following advantages are achieved:

1. The overall layout of the system has been optimized to achieve a fully fixed connection, light and small design, and reduce the size and weight of the compass system. the

2. The idea of modularization is adopted to ensure high interchangeability of modules, simplify system assembly and production process, and improve system reliability and maintainability. the

3. The reasonable layout of the circuit part reduces the interference of thermal and magnetic shocks to the system; the improved algorithm makes the compass system heading angle accuracy 10'secΦ, pitch angle accuracy 0.02°, roll angle error 0.02°, mooring state The initial alignment time is less than 30 minutes, the initial alignment time is less than 60 minutes in the anchored state, and the start-up time is less than 30 seconds. the

Description of drawings:

Fig. 1 is the perspective view of the front half cutaway of the present invention

Fig. 2 (a) is the bottom plate of casing of the present invention

Fig. 2 (b) is the outer cover of casing of the present invention

Fig. 3 is the structure schematic diagram of the gyroscope processing circuit of the present invention

Fig. 4 is the basic structural diagram of the circuit support of the present invention

Figure 5 (a) is a perspective view of the fiber optic gyroscope IMU assembly of the present invention

Figure 5 (b) is a perspective view of the fiber optic gyroscope IMU assembly of the present invention

The symbols in the figure are explained as follows:

1. Box body 2. Outer cover 3. Bottom plate

4. Circuit bracket 5. Motherboard 6. Accelerometer

7. Light source pre-amplifier components 8. Fiber optic gyro IMU components 9. Fiber optic gyro sensitive ring

10. System circuit components 11. Accelerometer I/F processing circuit 12. Navigation solving board

Road board

13. Secondary power board 14. External electrical connector 15. Cabinet mounting flange

16. Motherboard installation surface 17. Cabinet side surface 18. IMU surface

19. Fixing holes for components placed in front of the light source 20. IMU mounting surface 21. Circuit bracket mounting surface

22. Mounting hole for through-wall socket 23 Inner flange

301. CMI96TKW curved plug rectangular electric connector 302. Locking bar 303. Gyro processing circuit board

Connector

304. Heat conduction box

401. Fixing hole 402. Mounting flange 403. Chute

501.IMU body mounting hole 502.IMU body

Detailed ways:

As shown in Fig. 1, the present invention is a strapdown compass system based on a three-axis integrated high-precision fiber optic gyroscope, which is composed of three parts: a box body 1 (outer cover 2 and a bottom plate 3), a fiber optic gyroscope IMU component 8 and a system circuit component 10 . The position connection relationship between them is: the fiber optic gyroscope IMU assembly 8 is placed in the inertial group area of the base plate 3, the system circuit assembly 10 is placed in the circuit area of the base plate 3, and the fiber optic gyroscope IMU assembly 8 and the system circuit assembly 10 are electrically connected by an electrical connector. connect. The front part of the outer cover 2 has a wall socket installation hole 22 for placing the external electrical connector 14, and the outer cover 2 is installed on the bottom plate 3 by screws. the

The box body 1 is divided into two parts, a bottom plate 2 and an outer cover 3, as shown in Fig. 2(a) and Fig. 2(b). The maximum shape of the compass system is 384.5×204×162mm. The size of the cabinet excluding the external electrical connector 14 and the cabinet installation flange 15 is 365×170×162mm. Through the four Φ9 channels on the cabinet installation flange 15 Holes, use four M8 screws for fixing, the spacing between the mounting holes is 205×188mm, and the box body 1 is in the shape of a cuboid. The bottom plate 3 is divided into two areas, the inertial group area and the circuit area, all of which are electrically connected, which simplifies the system production and assembly process, and improves the system reliability and maintainability. The circuit area is processed with 2 rectangular circuit support mounting surfaces 21 and 6 motherboard mounting surfaces 16, and the circuit support 4 is fastened on the circuit support mounting surface 21 by screws; the motherboard mounting surface 16 is used to install the motherboard 5, for It provides a horizontal reference. The inertial group area is processed with an IMU installation surface 20, an IMU support surface 18, and a light source front component fixing hole 19. The four IMU installation surfaces 20 are distributed in a diagonal form to provide a horizontal reference for the fiber optic gyroscope IMU assembly 8; the IMU support surface 18 is The fiber optic gyro IMU component provides a vertical reference; the light source pre-amplifier assembly fixing hole 19 is used to lock the gyro light source pre-amplifier assembly 7 on the bottom plate, reducing the impact of light source heat on inertial sensitive components. In addition, the bottom plate 3 is processed with a box installation flange 15 and a side surface 17 of the box, which ensures the installation strength and locks the compass system tightly. the

The system circuit assembly 10 includes a secondary power supply board 13, a navigation solving board 12, an accelerometer I/F processing circuit board 11, a gyroscope processing circuit board 303, a mother board 5 and a circuit bracket 4 for fixing each circuit board. Wherein, the secondary power supply board 13, the navigation solving board 12, the accelerometer I/F processing circuit board 11 and the gyro processing circuit board 303 have a unified external dimension, structural form and installation interface, and are installed on the circuit bracket through the locking bar 302. 4, and then fasten the mounting flange 402 on the circuit support mounting surface 21 of the bottom plate 3 by screws. The motherboard 5 is placed at the bottom of the circuit support 4, and the motherboard 5 electrically connects each circuit board through an electrical connector to realize power supply and communication. Take the gyro processing circuit board 303 in Figure 3 as an example. The front side of the circuit board is covered with a heat conduction box 304 to facilitate heat dissipation, and the back side is fixed to the side wall of the circuit bracket 4 by a locking strip 302. The lower part is installed with a CMI96TKW curved plug rectangular electrical connection The device 301 is electrically connected to the motherboard 5 . The fiber optic gyroscope circuit is divided into two parts, the sensitive ring preamplifier circuit and the gyroscope processing circuit board 303 . The sensitive ring pre-amplifier circuit board is integrated in the fiber optic gyroscope IMU assembly 8 and placed in the inertial group area to separate the optical path from the circuit, reduce electromagnetic interference, and improve system reliability and maintainability. Considering the problem of heating, the gyro processing circuit board 303 is placed in the circuit area to avoid the influence of the heat generated by it on the optical fiber gyro sensitive ring 9 and the head of the accelerometer 6 . The secondary power board 13 is arranged at the front end of the circuit support 4, and is packaged with a power cover to prevent the secondary power board 13 from interfering with other processing circuits, and being close to the circuit support 4 is conducive to the heat dissipation generated by the secondary power board 13 to the external environment. Fig. 4 is the basic structural diagram of circuit support 4, and this circuit support 4 is a box-shaped frame structure, and is fixed on the base plate 3 through the fixing hole 401 of the bottom and mounting flange 402, and its inside is processed with chute 403, is used for The system circuit assembly 10 is secured while conducting heat from the circuit to the external environment. the

The fiber optic gyro IMU assembly 8, as shown in Figure 5(a) and Figure 5(b), is a three-axis integrated high-precision light fiber optic gyro, including an IMU table body 502, three fiber optic gyro sensitive rings 9, and three accelerometers 6, and a light source front assembly 7 fixed on the base plate 3, the fiber optic gyroscope IMU assembly 8 is fixed on the base plate 3 with screws through the mounting hole 501 of the IMU table body. The three optical fiber gyroscope sensitive rings 9 share one light source and are wound with Φ80 μm thin-diameter optical fibers, which effectively reduces the weight and volume of the system. The front assembly 7 of the light source is fixed close to the bottom plate 3, which accelerates the heat dissipation of the light source and reduces the influence of the heat generated by the light source on the optical fiber gyroscope sensitive ring 9 and the accelerometer 6. The fiber optic gyro IMU component 8 adopts a double-layer magnetic shielding design, that is, the magnetic shielding of the fiber optic gyro sensitive ring combined with the overall magnetic shielding of the inertial group area, which effectively improves the performance of the system. the

Claims (1)

1. the strapdown compass system based on three-axis integrative high precision fiber optic gyro, is characterized in that: it is comprised of casing, optical fibre gyro IMU assembly and circuit system assembly three parts; Casing, for splendid attire and protection optical fibre gyro IMU assembly and circuit system assembly, is divided into Guan Zu district and circuit region; Wherein ，Guan Zu district is used for placing optical fibre gyro IMU assembly, comprises three-axis integrative optical fibre gyro, and accelerometer is put assembly before IMU stage body and light source; Circuit region, for place system circuit unit, comprises Universal Power, accelerometer I/F treatment circuit plate, navigation calculation plate, gyro treatment circuit plate and motherboard; Casing front end has three outside electric connectors, for this compass system power supply and communication; Between Guan Zu district and circuit region, by outside electric connector, complete electrical connection, upper cover and coupling bolt by casing all seal casing;

Described casing, is divided into base plate and outer cover two parts; This base plate is long rectangular flat structure, and it at utmost reduces the difficulty of processing, for installing optical fibres gyro IMU assembly and circuit system assembly and whole compass system is installed; The upper surface of base plate is processed with installation base and the screw hole for mounting circuit support, optical fibre gyro IMU system component, motherboard, uniform four the casing mounting flanges in lower long edge of base plate, the horizontal reference for installation of whole compass system is provided, lower minor face edge at base plate provides two casing sides by face, has formed the directed benchmark of whole compass system; This outer cover is the structure of rectangular box body, welding manner machine-shaping; In the front portion of outer cover, be processed with 3 socket mounting holes through walls, at the position, composition surface with base plate, be provided with inner flange, improve on the one hand the rigidity of whole outer cover, the machining position of gib screw is also provided in addition, be conducive to sealing simultaneously; Outer cover is anterior installs three outside electric connectors, model respectively: YMA27S4M1D40, YMA27S12M1D40 and YMA27S26M1D40, its disk end is positioned at the outside of outer cover, for power supply and communication; Consider the electromagnetic interference (EMI) phenomenon between circuit system and gyro, circuit region is placed on base plate front portion, and this circuit region is provided with circuit carriers installed surface and motherboard installed surface, is respectively used to mounting circuit support and system board; Shi Guanzu district, base plate rear portion, is provided with IMU installed surface, IMU and puts assembly fixed orifice before by face and light source; IMU installed surface and IMU provide horizontal and vertical reference for installation by face for installing optical fibres gyro IMU assembly, put assembly fixed orifice light source is locked on cabinet before light source; Casing surrounding is evenly equipped with mounting flange, configures register pin and mounting hole on mounting flange; Before casing, all processed seal groove above, for placing O-ring seal, after front panel and top cover install, play good sealing effectiveness; Between Guan Zu district and circuit region, adopt electric connector to be connected, all electrical connection, has simplified system production, assembly technology, has improved system reliability and maintenanceability;

Described circuit system assembly, refers to the navigation calculation plate, accelerometer I/F treatment circuit plate, gyro treatment circuit plate, motherboard and the Universal Power that are arranged in circuit region; Navigation calculation plate, accelerometer I/F treatment circuit plate, gyro treatment circuit plate are realized electrical connection and are connected with the motherboard that is fixedly installed on bottom half with the CMI96ZJN socket on motherboard by CMI96TKW bend cutting rectangular electric connector, are convenient to assembling and maintenance; Navigation calculation plate, accelerometer I/F treatment circuit plate, gyro treatment circuit plate have unified physical dimension, version and mounting interface, cover heat conduction box outward, utilize the locking strip of side to be fixed in circuit carriers; Take gyro treatment circuit as example, comprised gyro treatment circuit plate, heat conduction box, locking strip, CMI96TKW bend cutting rectangular electric connector; Motherboard is fixed on the installation base on base plate, and its side near optical fibre gyro IMU system component is welded direct insertion socket J30J-31ZKNP5 and J30J-37ZKNP5, for realizing the electrical connection with optical fibre gyro IMU system component; Motherboard provides pad near a side of outside electric connector, welding habitat female connector YMA27T4K1P40, YMA27T12K1P40 and YMA27T26K1P40; This circuit carriers is the framed structure of a box, and fixed orifice and mounting flange by bottom are fixed on base plate, and its inside is processed with chute, for fixing said system circuit unit, the heating of circuit is transmitted to external environment condition simultaneously; From front end, each circuit board is followed successively by Universal Power, navigation calculation plate, accelerometer I/F treatment circuit plate, gyro treatment circuit plate, be furnished with like this assembling of the system of being beneficial to, avoided the impact on optical fibre gyro sensing ring and accelerometer gauge outfit of heat that Universal Power produces;

Described optical fibre gyro IMU assembly, adopts the small-sized optical fibre gyro of three-axis integrative high precision, comprises an IMU stage body, and three optical fibre gyro sensing rings, put assembly before three accelerometer gauge outfits and a light source being fixed on base plate; Three optical fibre gyro sensing rings share same light source, adopt the Φ 80 thin footpath of μ m optical fiber coilings, have reduced the weight and volume of compass system; Gyro light source is fixed on cabinet sidewall by locking strip, and convenient heat radiation, has weakened the impact of heat of light source on optical fibre gyro sensing ring and accelerometer gauge outfit; Optical fibre gyro IMU assembly adopts double-deck magnetic shielding design, adopts the IMU stage body of diagonal angle, space vibration damping layout effectively to guarantee that optical fibre gyro IMU assembly has good isotropy dynamic response feature under vibration, impact condition, has improved the vibration performance of system.

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