A strapdown inertial navigation system based on a flexible gyroscope

Abstract

The present invention relates to a strapdown inertial navigation system based on a flexible gyroscope, which includes a chassis. An electrical connector for external connection is provided on the chassis. An IMU assembly is installed inside the chassis. The IMU assembly is electrically connected to a motherboard, and the motherboard is electrically connected to the electrical connector. A power supply board, a fault detection board, and a data processing module are connected to the motherboard. The motherboard is annularly disposed outside the IMU assembly. The data processing module includes a force feedback circuit board and an A / D data acquisition and conversion board. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are arranged at intervals in the circumferential direction of the IMU assembly and are all vertically inserted into the motherboard. In the present invention, each circuit board is arranged at intervals in the circumferential direction around the IMU assembly, and the IMU assembly is surrounded in the middle, which can effectively save space, make the layout compact, reduce the volume and weight, facilitate the heat dissipation of each circuit board, and there is no need to attach a radiator to the circuit board. The good structural arrangement and heat dissipation performance can make the system have better temperature performance and stronger anti-interference ability.

Description

Technical Field

[0001] The present invention belongs to the technical field of navigation in physical measurement, and particularly relates to a strapdown inertial navigation system based on a flexible gyroscope. Background Art

[0002] The inertial navigation system is a main navigation device applied to various vehicles, and can provide accurate attitude and various navigation information, such as the navigation system provided by CN111811537A. According to whether there is an electromechanical entity platform in the system, the inertial navigation system can be divided into two categories: the platform inertial navigation system and the strapdown inertial navigation system.

[0003] Most of the existing marine navigation systems adopt mechanical platform compasses. The platform compass system has problems such as complex structure, large volume, heavy weight, high price, and difficulty in further improving reliability.

[0004] The strapdown inertial navigation system omits the complex electromechanical entity platform, as disclosed in CN103248364A, and adopts a so-called "mathematical platform". In the strapdown inertial navigation system, the inertial instruments are directly fixed to the vehicle. It has many outstanding advantages such as small volume, light weight, compact structure, low power consumption, and high reliability, and is gradually replacing the platform inertial navigation system.

[0005] The gyroscope is a measuring device that senses the angular motion of a moving object relative to inertial space and is applied in many fields. The flexible gyroscope is a new type of two-degree-of-freedom gyroscope that uses a flexible support to suspend the gyro rotor and separates the gyro rotor from the drive motor. Its flexible support's elastic stiffness is compensated by the dynamic effect generated by the support itself. It has the advantages of simple structure, few components, small volume, light weight, high reliability, low power consumption, and low cost, and can refer to CN202304840U. Based on the above advantages of the flexible gyroscope, it has room for development in the strapdown inertial navigation system. The current inertial navigation systems or devices, as disclosed in CN201116875Y and CN203704939U, have a scattered structural layout and are not compact enough, resulting in inconvenient assembly and maintenance, large volume, poor heat dissipation performance, and some even need to add radiators, further increasing the volume, which limits their use on vehicles. Summary of the Invention

[0006] Aiming at the above deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a strapdown inertial navigation system based on a flexible gyroscope, to avoid the problems of non-compact overall structural layout and large volume, and to achieve the effects of reducing volume, facilitating heat dissipation, being convenient for assembly and repair, and having reliable use.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A strapdown inertial navigation system based on a flexible gyroscope, comprising a chassis. An electrical connector for external connection is provided on the chassis. An IMU component and a motherboard are installed inside the chassis. The IMU component is electrically connected to the motherboard, and the motherboard is electrically connected to the electrical connector. A power supply board, a fault detection board, and a data processing module are connected to the motherboard. The motherboard is annularly disposed outside the IMU component. The data processing module includes a force feedback circuit board and an A / D data acquisition and conversion board. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are spaced apart in the circumferential direction of the IMU component and are all vertically inserted into the motherboard.

[0009] To further improve the above technical solution, the chassis is rectangular. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board respectively correspond to the four side plates of the chassis and are located inside the corresponding side plates. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board enclose the IMU component therein.

[0010] Further, the chassis includes a base plate, a top cover plate, and the four side plates. A circular mounting boss is convexly provided upward in the middle of the upper surface of the base plate. The IMU component is detachably connected to the mounting boss. A rectangular mounting side wall is convexly provided upward along the periphery of the base plate. The motherboard is connected to the inner side of the mounting side wall.

[0011] Further, the top cover plate and the four side plates are integrally formed into an upper cover body. The upper cover body is detachably snap-connected to the upper surface of the mounting side wall, and the side plates correspond to the corresponding mounting side walls.

[0012] Further, the electrical connector is provided on the mounting side wall.

[0013] Further, a plurality of mounting lugs are convexly provided on the outer side surface of the mounting side wall.

[0014] Further, the circular mounting boss has at least one lateral through portion, and the lateral through portion is formed as a wire groove.

[0015] Further, connecting portions are respectively convexly provided inward at the four corner positions of the inner wall of the rectangular mounting side wall. The motherboard includes four plug-in bottom plates that are separately provided. One plug-in bottom plate is correspondingly connected between two adjacent connecting portions so that the four plug-in bottom plates are annularly disposed outside the IMU component. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are respectively plugged into one plug-in bottom plate.

[0016] Further, the connecting portion includes a first stepped portion in a stepped shape and a second stepped portion located on the first stepped portion. The end of the plugging bottom plate is detachably connected to the upper surface of the first stepped portion at the corresponding end. A vertical circuit board test plugging bracket is provided on each second stepped portion. The circuit board test plugging bracket has two vertically penetrating circuit board test slots. The two ends of the force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are respectively plugged into the circuit board test slots of the circuit board test plugging bracket at the corresponding end.

[0017] Further, pressing plates are respectively pressed on the upper edges of the force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board. The pressing plates are long strips extending along the corresponding upper edges, and their cross-sections are in an inverted U shape and are clamped downward at the corresponding upper edges through the open ends. The two ends of the pressing plates are respectively detachably connected to the upper surface of the circuit board test plugging bracket at the corresponding end.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. For the strapdown inertial navigation system based on a flexible gyroscope of the present invention, an optimized design is carried out in terms of structure. The circuit boards are arranged circumferentially at intervals around the IMU assembly, and the IMU assembly is surrounded in the middle, which can effectively save space, make the layout compact, reduce the volume of the chassis, facilitate weight reduction, and facilitate the heat dissipation of each circuit board. There is no need to attach a radiator to the circuit board, further reducing the volume of the system. The good structural arrangement and heat dissipation also make the system have better temperature performance and stronger anti-interference ability.

[0020] 2. For the strapdown inertial navigation system based on a flexible gyroscope of the present invention, a modular design is adopted, which is convenient for assembly and later maintenance and repair, simplifies the system production, processing, and assembly processes, and improves the reliability and maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram (exploded view) of a strapdown inertial navigation system based on a flexible gyroscope for a specific embodiment;

[0022] Figure 2 It is a structural schematic diagram of the base plate in a specific embodiment;

[0023] Figure 3 It is a structural schematic diagram of the IMU assembly in a specific embodiment;

[0024] Figure 4 It is a structural schematic diagram of the upper cover body in a specific embodiment;

[0025] Figure 5 It is a structural schematic diagram of the circuit board test plugging bracket in a specific embodiment;

[0026] Figure 6 Schematic diagram of the structure of another perspective of the circuit board testing and inserting bracket (the surface with cross-hatching is the cross-section); Figure 5

[0027] Figure 7 Schematic diagram of the structure of the pressure plate in a specific embodiment;

[0028] Figure 8 Schematic diagram of the structure of another perspective of the pressure plate (the surface with cross-hatching is the cross-section); Figure 7

[0029] Figure 9 Schematic diagram of the printed circuit board that can be used to manufacture the circuit board;

[0030] Figure 10 Schematic diagram of the base plate that can be used to manufacture the plug-in base plate;

[0031] Among them, base plate 1, mounting lug 11, mounting boss 12, wire trough 13, first step portion 14, second step portion 15, groove body 151, mounting side wall 16, electrical connector 161,

[0032] Upper cover body 2, convex edge 21, round hole 22, conductive rubber strip 23, side vertical plate 24, top sealing plate 25,

[0033] IMU assembly 3, mounting support 31, through hole 32, quartz pendulum flexure accelerometer 33, two-degree-of-freedom dynamically tuned flexure gyro 34,

[0034] Circuit board testing and inserting bracket 4, circuit board testing slot 44, lower inner round hole 41, inner side counterbore 42, side inner threaded hole 43, top surface inner threaded hole 45, outer side counterbore 46, lower outer round hole 47,

[0035] Force feedback circuit board 5, A / D data acquisition and conversion board 6, fault detection board 7, power supply board 8,

[0036] Force feedback circuit board base 51, A / D data acquisition and conversion board base 61, fault detection board base 71, power supply board base 81,

[0037] Pressure plate 9, flange surface 91, through hole 92, open end 93,

[0038] Electrical connector plug 101, nameplate 102, electrical connector socket 103, mounting hole 104. Detailed Description of the Invention

[0039] The following further elaborates on the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0040] Please refer to Figure 1 ​​, A strapdown inertial navigation system based on a flexible gyroscope in a specific embodiment. A strapdown inertial navigation system based on a flexible gyroscope includes a chassis. An electrical connector 161 for external connection is provided on the chassis. An IMU assembly 3 (i.e., an inertial measurement unit) and a motherboard are installed inside the chassis. The IMU assembly 3 is electrically connected to the motherboard, and the motherboard is electrically connected to the electrical connector 161. A power supply board 8, a fault detection board 7, and a data processing module are connected to the motherboard. The motherboard is arranged in a ring around the outside of the IMU assembly 3. The data processing module includes a force feedback circuit board 5 and an A / D data acquisition and conversion board 6. The force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 are arranged at intervals in the circumferential direction of the IMU assembly 3 and are all vertically inserted into the motherboard.

[0041] In the strapdown inertial navigation system based on a flexible gyroscope in the embodiment, an optimized design is carried out in terms of structure. The circuit boards are arranged at intervals in the circumferential direction around the IMU assembly 3, and the IMU assembly 3 is surrounded in the middle, which can effectively save space, make the layout compact, reduce the volume of the chassis, and is conducive to the heat dissipation of each circuit board. There is no need to attach a radiator to the circuit board, further reducing the volume of the system.

[0042] Among them, the chassis is rectangular. The force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 respectively correspond to the four side plates 24 of the chassis and are located inside the corresponding side plates 24. The force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 surround the IMU assembly 3 therein.

[0043] In this way, the rectangular shape can comprehensively control the volume size and heat dissipation effect in a better design state.

[0044] Please continue to refer to Figure 2 , among which, the chassis includes a base plate 1, a top sealing plate 25, and the four side plates 24 mentioned above. A circular installation boss 12 protrudes upward in the middle of the upper surface of the base plate 1. The IMU assembly 3 is detachably connected to the installation boss 12. A rectangular installation side wall 16 protrudes upward along the four edges of the base plate 1. The motherboard is connected to the inside of the installation side wall 16.

[0045] In this way, it is convenient for the connection, wiring, and heat dissipation of the IMU assembly 3 and the motherboard, ensuring the reliability of use.

[0046] The IMU assembly 3 is a prior art, and reference can be made to Figure 3, the IMU component 3 adopted in this embodiment is composed of two two-degree-of-freedom dynamically tuned flexible gyros 34 and three quartz pendulous flexible accelerometers 33. They are installed on a high-precision machined mounting bracket 31 to ensure that the input axes of the three accelerometers are spatially orthogonal and the orthogonal coordinate system formed by them is parallel to the gyro coordinate system. They are connected to the internal threaded holes on the upper surface of the mounting boss 12 through screws passing through the through holes 32 on the mounting bracket 31. Among them, the dynamically tuned flexible gyro is a sensor that senses the angular motion information of the carrier, and the quartz pendulous flexible accelerometer 33 is a sensor that senses the linear motion of the carrier. During operation, the quartz pendulous flexible accelerometer 33 is on the hull (carrier), and its input axis is in the same direction as the axis to be measured. Then, the output of the accelerometer reflects the acceleration value of the hull along this axis.

[0047] Please continue to refer to Figure 4 , wherein, the top sealing plate 25 and the four side standing plates 24 are integrated into an integrally formed upper cover body 2. The upper cover body 2 is detachably snap-connected to the upper surface of the mounting side wall 16, and the side standing plates 24 correspond to the corresponding mounting side walls 16 on each side. Specifically, a circle of convex edges 21 are provided around the lower surface of each side standing plate 24, and they are connected to the internal threaded holes on the upper surface of the mounting side wall 16 through screws passing through the round holes 22 at the four corners of the convex edges 21. A conductive rubber strip 23 is also clamped between the lower surface of the side standing plate 24 and the upper surface of the mounting side wall 16. A continuous circle of annular grooves is opened on the lower surface of each side standing plate 24, and the conductive rubber strip 23 falls into the circle of annular grooves; the conductive rubber strip 23 can achieve a good conductive sealing effect after connection.

[0048] In this way, it is convenient for assembly. All components are installed and connected to the plate-shaped base plate 1, and then the upper cover body 2 is buckled; it is also convenient for maintenance and repair. Open the upper cover body 2, and all the components connected to the base plate 1 are clearly visible, which is convenient for implementing repairs.

[0049] Please refer to again Figure 1 、 Figure 2 , wherein, several mounting lugs 11 are protruded outward from the outer side surface of the mounting side wall 16. Vertical through holes are opened on the mounting lugs 11 for use when fixedly connecting to the carrier.

[0050] Among them, the ring-shaped mounting boss 12 has at least one lateral through portion and the lateral through portion is formed as a wire groove 13; the electrical connector 161 is arranged on the mounting side wall 16.

[0051] In this way, it is convenient for wiring connection to ensure the supply of power and the transmission of data.

[0052] Among them, the inner walls of the four corners of the inner wall of the circular rectangular mounting side wall 16 are respectively provided with inwardly protruding connecting parts; the mother board includes four plug-in bottom plates that are separately arranged, and one plug-in bottom plate is correspondingly connected between two adjacent connecting parts so that the four plug-in bottom plates are annularly arranged around the outside of the IMU component 3; the force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 are respectively plugged into one plug-in bottom plate. Specifically, the four plug-in bottom plates are the force feedback circuit board bottom plate 51, the A / D data acquisition and conversion board bottom plate 61, the fault detection board bottom plate 71, and the power supply board bottom plate 81 that are annularly arranged around the outside of the IMU component 3, and the force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 are correspondingly plugged vertically on them.

[0053] Please continue to refer to Figures 5 - 8 , among them, the connecting part includes a stepped first step part 14 and a second step part 15 located on the first step part 14, and the end of the plug-in bottom plate is detachably connected to the upper surface of the first step part 14 at the corresponding end; a vertical circuit board test plugging bracket 4 is provided on each second step part 15, and the circuit board test plugging bracket 4 has two vertically penetrating circuit board test slots 44, and the two ends of the force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 are respectively plugged into the circuit board test slots 44 of the circuit board test plugging bracket 4 at the corresponding end. A groove body 151 corresponding to the two circuit board test slots 44 of the circuit board test plugging bracket 4 on it may also be opened on the second step part 15, and the bottom parts of the two ends of the force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8 are respectively plugged into the groove body 151 on the second step part 15 at the corresponding end.

[0054] Among them, pressing plates 9 are respectively pressed on the upper edges of the force feedback circuit board 5, the A / D data acquisition and conversion board 6, the fault detection board 7, and the power supply board 8. The pressing plate 9 is a long strip extending along the corresponding upper edge, and its cross-section is an inverted U shape and is clamped downward through the open end 93 on the corresponding upper edge. The two ends of the pressing plate 9 are respectively detachably connected to the upper surface of the circuit board test plugging bracket 4 at the corresponding end. Specifically, flanges 91 are connected to the two ends of the pressing plate 9, and screws pass through the through holes 92 on the flanges 91 and are connected to the top inner threaded holes 45 on the upper surface of the circuit board test plugging bracket 4. In this embodiment, the upper surface of the second step part 15 is flush with the upper surface of the mounting side wall 16. The circuit board test plugging bracket 4 is detachably connected to the second step part 15. Specifically, inner and outer sinking platforms 42 and 46 are respectively provided on the inner and outer sides of the circuit board test plugging bracket 4, and vertically penetrating lower inner round holes 41 and lower outer round holes 47 are opened on the lower inner walls of the two sinking platforms, and can be connected to the inner threaded holes on the second step part 15 respectively by screws passing through the lower inner round holes 41 and the lower outer round holes 47. A number of side inner threaded holes 43 for fixing wire routing are also provided on the circuit board test plugging bracket 4.

[0055] In this way, modular design is carried out, which is convenient for maintenance and repair. Only the corresponding pressure plate 9 needs to be removed, and the corresponding circuit board and plug-in base plate are replaced. The use of the circuit board test plug-in bracket 4 can improve the installation stability of each circuit board and ensure the reliable use of the system.

[0056] By carrying out modular design, standard printed boards and plug-in base plates can be used, which is beneficial to reducing costs. For example, Figure 9 、 Figure 10 the printed board with the electrical connector plug 101 and the base plate with the label 102, the electrical connector socket 103 and the mounting holes 104 shown.

[0057] During use, the force feedback circuit board 5 is the servo loop circuit when the gyroscope works in the rate state. It ensures that the gyroscope maintains a high measurement accuracy within a wide dynamic range. The force feedback circuit board completes the electrical signal exchange with the gyroscope in the IMU component through its base plate. The magnitude of the current flowing through the torque motor in the gyroscope in the force feedback loop output reflects the angular velocity of the gyroscope rotor tracking the housing at that time. In order to measure this angular velocity, the current can be converted into a voltage quantity through a standard sampling resistor and then into a digital signal that can be received by a computer through the A / D conversion circuit for navigation and attitude calculation.

[0058] The A / D data acquisition and conversion board 6 is used to convert the angular rate analog signal sensed by the gyroscope and the acceleration signal sensed by the accelerometer into digital signals. In the A / D circuit, a high-performance 16-bit single-chip microcomputer can be used to complete the coordination work of the entire acquisition system, that is, to complete functions such as data processing, data sending, data interface and control. Then it is converted into a digital signal that can be received by a computer through the A / D conversion circuit for navigation and attitude calculation.

[0059] The fault detection board 7 is used to detect the working states of the four-way gyroscope signals, the two-way gyroscope motor power supplies, and the one-way gyroscope excitation power supply. If a fault occurs, a fault alarm flag is issued.

[0060] The power supply board 8 can convert the relatively unified external DC primary power supply into the required secondary power supply through DC / DC conversion, and generate the excitation power supply for the gyroscope to work and the motor drive power supplies for the two gyroscopes (each of the two gyroscopes uses a separate motor power supply and shares one excitation power supply). The primary power supply can be a switching power supply module, and the input is the ship power of 220V and 50Hz.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A strapdown inertial navigation system based on a flexible gyroscope, comprising a chassis, on which there are electrical connectors for external connection. Inside the chassis, an IMU component and a motherboard are installed. The IMU component is electrically connected to the motherboard, and the motherboard is electrically connected to the electrical connectors. A power supply board, a fault detection board, and a data processing module are connected to the motherboard; Characterized in that: The motherboard is annularly arranged outside the IMU component. The data processing module includes a force feedback circuit board and an A / D data acquisition and conversion board. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are arranged at intervals in the circumferential direction of the IMU component and are all vertically inserted into the motherboard; The chassis is rectangular. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board respectively correspond to the four side plates of the chassis and are located inside the corresponding side plates. The force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board enclose the IMU component therein; The chassis includes a base plate, a top cover plate, and the four side plates. In the middle of the upper surface of the base plate, there is a circular installation boss protruding upward. The IMU component is detachably connected to the installation boss. Along the four edges of the base plate, there is a rectangular installation side wall protruding upward. The motherboard is connected to the inner side of the installation side wall; At the four corner positions of the inner wall of the rectangular installation side wall, there are connecting parts protruding inward respectively; the motherboard includes four inserted bottom plates that are separately arranged. Between two adjacent connecting parts, there is a corresponding inserted bottom plate connected so that the four inserted bottom plates are annularly arranged outside the IMU component; the force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are respectively inserted into one inserted bottom plate; The electrical connectors are arranged on the installation side wall.

2. The strapdown inertial navigation system based on a flexible gyroscope according to claim 1, Characterized in that: The top cover plate and the four side plates are integrally formed into an upper cover body, and the upper cover body is detachably buckled and connected to the upper surface of the installation side wall. The side plates correspond to the installation side walls on the corresponding sides.

3. The strapdown inertial navigation system based on a flexible gyroscope according to claim 1, Characterized in that: On the outer side surface of the installation side wall, there are several installation lugs protruding outward.

4. The strapdown inertial navigation system based on a flexible gyroscope according to claim 1, Characterized in that: The circular installation boss has at least one lateral through part, and the lateral through part is formed into a wire trough.

5. The strapdown inertial navigation system based on a flexible gyroscope according to claim 1, Characterized in that: The connecting part includes a stepped first step part and a second step part located on the first step part. The end of the inserted bottom plate is detachably connected to the upper surface of the first step part at the corresponding end; On each second step part, there is a vertical circuit board test insertion bracket. The circuit board test insertion bracket has two vertically penetrating circuit board test slots. The two ends of the force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board, and the power supply board are respectively inserted into the circuit board test slots of the circuit board test insertion bracket at the corresponding ends.

6. A strapdown inertial navigation system based on a flexible gyroscope according to claim 5, characterized in that: Pressure plates are respectively pressed on the upper edges of the force feedback circuit board, the A / D data acquisition and conversion board, the fault detection board and the power supply board. The pressure plates are strip-shaped extending along the corresponding upper edges, and their cross-sections are inverted U-shaped and are clamped to the corresponding upper edges through the open ends downward. The two ends of the pressure plates are respectively detachably connected to the upper surfaces of the circuit board test brackets at the corresponding ends.

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