CN218545725U

CN218545725U - Digital mixed-state inertia measurement unit

Info

Publication number: CN218545725U
Application number: CN202221923537.1U
Authority: CN
Inventors: 袁斌; 黄海阳
Original assignee: Shenzhen Tianluhai Navigation Equipment Technology Co ltd
Current assignee: Shenzhen Tianluhai Navigation Equipment Technology Co ltd
Priority date: 2022-07-25
Filing date: 2022-07-25
Publication date: 2023-02-28
Anticipated expiration: 2032-07-25

Abstract

The utility model discloses a digital hybrid inertia measurement unit belongs to inertial navigation technical field, including enclosing base and the box body that becomes to seal and hold the chamber, install the digital closed loop unipolar fiber optic gyroscope on the base, the data processing and the communication fishplate bar of installation biax MEMS gyroscope, triaxial MEMS accelerometer and install the power strip in the box body. The digital closed-loop single-axis fiber optic gyroscope is used for measuring angular velocity signals of a Z axis, and the double-axis MEMS gyroscope is used for measuring angular velocity signals of an X axis and a Y axis; the data processing and communication connecting plate is provided with an RS422 interface, an SPI interface, an ARM processor and an external interface; the digital closed-loop uniaxial optical fiber gyroscope is connected with the ARM processor through an RS422 interface, the biaxial MEMS gyroscope and the triaxial MEMS accelerometer are connected with the ARM processor through SPI interfaces, and the ARM processor is provided with an embedded MEMS gyroscope drift compensation model and a Kalman filtering algorithm. The utility model has the advantages of can direct output digital quantity, it is with low costs with the MEMS gyroscope to have fused the fiber optic gyroscope precision height.

Description

Digital mixed-state inertia measurement unit

Technical Field

The utility model relates to an inertial navigation technical field, concretely relates to digit mixed state inertia measurement unit.

Background

An inertial measurement unit, abbreviated as IMU, is a device for measuring the three-axis attitude angle (or angular rate) and acceleration of an object, wherein a gyroscope and an accelerometer are the main elements of the IMU. In general, the IMU includes three single-axis accelerometers and three single-axis gyroscopes, the accelerometers detecting acceleration signals of the object in three independent axes of the carrier coordinate system, and the gyroscopes detecting angular velocity signals of the carrier relative to the navigation coordinate system, measuring the angular velocity and acceleration of the object in three-dimensional space, and calculating the attitude of the object based on the measured angular velocity and acceleration.

In the prior art, chinese patent CN104596513B provides an inertial navigation system and a navigation method in which a fiber-optic gyroscope and a micro-mechanical gyroscope are combined, where the system includes a fiber-optic gyroscope and an MEMS gyroscope which are redundantly arranged with each other; in a normal state, the optical fiber gyroscope measures the angular speed of the azimuth axis direction, when the optical fiber gyroscope breaks down, the MEMS gyroscope is automatically switched to, and the navigation method realizes the error estimation and compensation of gyro drift and accelerometer zero offset through a set motion mode. In the invention patent, the inventive concept that the optical fiber gyroscope and the MEMS gyroscope are redundantly arranged needs to be further optimized.

Disclosure of Invention

The utility model aims at providing a digital mixed state inertia measurement unit has optimized the setting of optic fibre top and MEMS gyroscope among the background art.

In order to achieve the purpose, the utility model adopts the technical proposal that:

a digital mixed state inertia measurement unit comprises a base and a box body which can enclose a closed accommodating cavity, a digital closed-loop single-axis fiber-optic gyroscope, a double-axis MEMS gyroscope, a three-axis MEMS accelerometer, a data processing and communication connecting plate and a power panel; the digital closed-loop single-axis fiber optic gyroscope and the data processing and communication connecting plate are arranged on the base, the double-axis MEMS gyroscope and the three-axis MEMS accelerometer are arranged on the data processing and communication connecting plate, and the power panel is arranged in the box body;

the digital closed-loop single-axis fiber optic gyroscope is used for measuring angular velocity signals of a Z axis, the two-axis MEMS gyroscope is used for measuring angular velocity signals of an X axis and a Y axis, and the three-axis MEMS accelerometer is used for measuring acceleration signals on three orthogonal axes;

the data processing and communication connecting plate is provided with an RS422 interface, an SPI interface, an ARM processor and an external interface; the digital closed-loop single-axis fiber optic gyroscope is connected with the ARM processor through an RS422 interface, and the double-axis MEMS gyroscope and the three-axis MEMS accelerometer are both connected with the ARM processor through SPI interfaces;

the power panel comprises a control circuit for turning on or off a power supply, a filter circuit and a DC/DC conversion circuit, and the power panel supplies power for the digital closed-loop single-axis fiber-optic gyroscope, the double-axis MEMS gyroscope, the three-axis MEMS accelerometer and the data processing and communication connecting plate.

Further, the external interface includes one or more of an RS232 interface, an RS422 interface, an RS485 interface, an SPI interface, and a CAN interface.

Further, the digital closed-loop single-axis fiber optic gyroscope also comprises a temperature sensor, wherein the temperature sensor is arranged inside the digital closed-loop single-axis fiber optic gyroscope.

Further, still include rubber shock pad, rubber shock pad installs in the base, and digital closed loop unipolar fiber optic gyro, biax MEMS gyroscope, triaxial MEMS accelerometer all install on rubber shock pad.

Further, the DC/DC conversion circuit includes a first conversion circuit and a second conversion circuit; the first conversion circuit supplies power to the digital closed-loop uniaxial fiber-optic gyroscope, and the second conversion circuit supplies power to the biaxial MEMS gyroscope and the triaxial MEMS accelerometer.

Furthermore, the side of the box body is provided with an opening matched with the external interface.

Further, the base and the inner wall of box body integrated into one piece have the erection column, and the one end of erection column is equipped with the screw hole.

Furthermore, the base and the box body are made of aluminum alloy, magnesium aluminum alloy or copper alloy.

The utility model provides a digit mixed state inertia measurement unit, as follows for prior art's beneficial effect:

1. angular velocity and acceleration signals on three orthogonal axes can be directly output by digital quantity;

2. the advantages of high precision of the fiber-optic gyroscope and low cost of the MEMS gyroscope are combined.

Drawings

Fig. 1 is a schematic block diagram of the digital mixed-state inertia measurement unit of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. It should be noted that all the directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In the present application, unless expressly stated or limited otherwise, the terms "connected" and "secured" are to be construed broadly, and thus, for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 1, the digital mixed-state inertia measurement unit of the present invention includes a base and a box (not shown) enclosing a closed accommodating cavity, and further includes a digital closed-loop uniaxial fiber-optic gyroscope 10, a biaxial MEMS gyroscope 20, a triaxial MEMS accelerometer 30, a data processing and communication connection board, and a power board; digital closed loop unipolar fiber optic gyroscope 10, data processing and communication fishplate bar are installed on the base, biax MEMS gyroscope 20, triaxial MEMS accelerometer 30 set up on data processing and communication fishplate bar, the power strip is installed in the box body. The digital mixed state inertia measurement unit further comprises a rubber shock pad, the rubber shock pad is installed in the base, and the digital closed-loop single-axis fiber-optic gyroscope 10, the double-axis MEMS gyroscope 20 and the three-axis MEMS accelerometer 30 are all installed on the rubber shock pad. The utility model is suitable for an inertia measurement of carrier under motion or vibration state.

The digital closed-loop uniaxial optical fiber gyroscope 10 adopts digital phase step waves to realize closed loop, adopts square wave signals to perform bias modulation, obtains a digital angular velocity value, converts the digital angular velocity value into digital quantity with a low sampling rate and outputs the digital quantity outwards. The light source of the digital closed-loop uniaxial optical fiber gyroscope 10 adopts a superluminescent light emitting diode in a medium-low precision optical fiber gyroscope, adopts an erbium-doped optical fiber light source in a high-precision optical fiber gyroscope, can be selected according to the requirement in practical application, and is not limited here. The digital closed-loop single-axis fiber optic gyroscope 10 is used for measuring angular velocity signals of a Z axis, the two-axis MEMS gyroscope 20 is used for measuring angular velocity signals of an X axis and a Y axis, and the three-axis MEMS accelerometer 30 is used for measuring acceleration signals of three orthogonal axes. The tri-axial MEMS accelerometer 30 can directly output digital values for system applications.

And the data processing and communication connecting plate is provided with an RS422 interface, an SPI interface, an ARM processor 40 and an external interface 50. The digital closed-loop single-axis fiber optic gyroscope 10 is connected with the ARM processor 40 through an RS422 interface, and the dual-axis MEMS gyroscope 20 and the tri-axis MEMS accelerometer 30 are connected with the ARM processor 40 through SPI interfaces.

The digital mixed-state inertia measurement unit further comprises a temperature sensor, and the temperature sensor is arranged inside the digital closed-loop single-axis fiber-optic gyroscope 10. In this embodiment, the operating temperature range of the digital mixed-state inertia measurement unit is-40 ℃ to 85 ℃.

The power panel comprises a control circuit 60 for turning on or off a power supply, a filter circuit 70 and a DC/DC conversion circuit 80, and the power panel supplies power for the digital closed-loop single-axis fiber-optic gyroscope 10, the double-axis MEMS gyroscope 20, the three-axis MEMS accelerometer 30 and the data processing and communication connecting plate. The input voltage range of the power strip is 9-36VDC, and the nominal input voltage is 12VDC. The DC/DC conversion circuit 80 includes a first conversion circuit and a second conversion circuit; the first conversion circuit converts 12VDC into 5VDC to power the digital closed-loop uniaxial fiber-optic gyroscope 10, and the second conversion circuit converts 5VDC into 3.3VDC to power the two-axis MEMS gyroscope 20 and the three-axis MEMS accelerometer 30.

The mounting column is integrally formed on the inner wall of the base and the inner wall of the box body, and one end of the mounting column is provided with an internal thread; the digital closed-loop single-axis fiber-optic gyroscope 10, the data processing and communication connecting plate and the power panel are provided with screw holes at positions corresponding to the mounting columns, and screws penetrate through the screw holes to be matched with the internal threads of the mounting columns for fixing. The side of box body is equipped with the opening of adaptation external interface 50, external interface 50 includes one or several kinds in RS232 interface, RS422 interface, RS485 interface, SPI interface, the CAN interface. In this embodiment, the base and the box body are made of aluminum alloy, and magnesium aluminum alloy or copper alloy can be adopted in practical application. The base is provided with a screw hole, the box body is provided with an internal thread, and the base and the box body are fixed by screws after being assembled.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Digital mixed state inertia measurement unit, including enclosing base and the box body that becomes to seal and hold the chamber, its characterized in that: the system also comprises a digital closed-loop single-axis fiber optic gyroscope, a double-axis MEMS gyroscope, a three-axis MEMS accelerometer, a data processing and communication connecting plate and a power supply plate; the digital closed-loop single-axis fiber optic gyroscope and the data processing and communication connecting plate are arranged on the base, the double-axis MEMS gyroscope and the three-axis MEMS accelerometer are arranged on the data processing and communication connecting plate, and the power panel is arranged in the box body;

2. The digital mixed-state inertial measurement unit of claim 1, wherein: the external interface comprises one or more of an RS232 interface, an RS422 interface, an RS485 interface, an SPI interface and a CAN interface.

3. The digital mixed-state inertial measurement unit of claim 1, wherein: the digital closed-loop single-shaft fiber optic gyroscope is characterized by further comprising a temperature sensor, wherein the temperature sensor is arranged inside the digital closed-loop single-shaft fiber optic gyroscope.

4. The digital mixed-state inertial measurement unit of claim 1, wherein: still include rubber shock pad, rubber shock pad installs in the base, and digital closed loop unipolar fiber optic gyroscope, biax MEMS gyroscope, triaxial MEMS accelerometer are all installed on the rubber shock pad.

5. The digital mixed-state inertial measurement unit of claim 1, wherein: the DC/DC conversion circuit includes a first conversion circuit and a second conversion circuit; the first conversion circuit supplies power to the digital closed-loop uniaxial fiber-optic gyroscope, and the second conversion circuit supplies power to the biaxial MEMS gyroscope and the triaxial MEMS accelerometer.

6. The digital mixed-state inertial measurement unit of claim 1, wherein: the side of the box body is provided with an opening matched with the external interface.

7. The digital mixed-state inertial measurement unit of claim 1, wherein: the inner wall integrated into one piece of base and box body has the erection column, and the one end of erection column is equipped with the internal thread.

8. The digital mixed-state inertial measurement unit of claim 1, 6 or 7, wherein: the base and the box body are made of aluminum alloy or magnesium aluminum alloy or copper alloy.