Automatic north-seeking navigation device

Abstract

The utility model provides an automatic north-seeking navigation device. The automatic north-seeking navigation device comprises a north-seeking module which comprises a single-axis fiber-optic gyroscope and two accelerometers and is used for transmitting obtained course angle information to a data processing module; the MEMS inertial navigation unit comprises three MEMS gyroscopes and three MEMS angular velocimeters, and the MEMS inertial navigation unit is used for transmitting the obtained attitude information of the automatic north-seeking navigation device to the data processing module; and the data processing module is used for calculating a north direction included angle and an attitude angle of the automatic north-seeking navigation device according to the received course angle information and attitude information. According to the utility model, the north-seeking module with a simple structure is combined with the MEMS IMU, so that the problem that the MEMS IMU cannot realize north seeking and navigation at any time is solved; in addition, the MEMS in the MEMS IMU is corrected through a fiber-optic gyroscope in the north-seeking module, so that the drift of the MEMS IMU is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of navigation, in particular to a north-seeking navigation device. Background Art

[0002] MEMS is the abbreviation of Micro Electro Mechanical System sensor, which is a combination of electronic and mechanical hardware in the form of a chip. It consists of micro silicon structures, which are placed in a silicon wafer through a special etching process similar to the microfabrication technology of integrated circuit batch processing, and can be made into MEMS gyroscopes, and can achieve inertial navigation performance similar to that of pure mechanical gyroscopes, laser gyroscopes and quartz accelerometers. The cost of MEMS gyroscopes is only one-hundredth to one-thousandth of that of traditional pure mechanical navigation gyroscopes or laser gyroscopes, and the cost of MEMS accelerometers is only one-tenth of that of quartz accelerometers. Moreover, MEMS also has the advantages of small size and light weight, and the characteristic length of MEMS devices ranges from 1 millimeter to 1 micron. In addition, the size of a MEMS inertial measurement unit (IMU) composed of three MEMS gyroscopes and three MEMS accelerometers can already be made as small as an ordinary chip.

[0003] Due to the limitations of the size of MEMS gyroscopes and related manufacturing processes, the accuracy of current MEMS gyroscopes is still not comparable to that of pure mechanical navigation gyroscopes or laser gyroscopes, and is still at a relatively poor level. Therefore, the MEMS IMU system composed of three MEMS gyroscopes and three MEMS accelerometers currently still has the disadvantages of being unable to achieve north-seeking and fast navigation drift. A commonly used solution is to additionally add a high-precision inertial navigation system. After providing accurate heading angle and other angle information to the MEMS IMU, the MEMS IMU can achieve north-seeking and navigation functions. Since accurate angle information needs to be provided by a high-precision inertial navigation system, the MEMS IMU cannot meet the requirements of north-seeking and navigation at any time and anywhere; at the same time, since the MEMS IMU and the high-precision inertial navigation system are usually not strongly correlated systems, the high-precision inertial navigation system cannot be used to solve the problem of fast navigation drift of the MEMS IMU. Moreover, the cost of the high-precision inertial navigation system is also relatively high, offsetting the low-cost advantage of MEMS gyroscopes. Therefore, there is a lack of an effective and low-cost north-seeking and navigation MEMS IMU. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the utility model provides a north-seeking navigation device, which solves the problem of the lack of an effective and low-cost MEMS IMU in the prior art.

[0005] According to an embodiment of the present invention, a north-seeking navigation device is provided, including: a north-seeking module, including a single-axis fiber optic gyroscope and two accelerometers, and the north-seeking module is configured to transmit the obtained heading angle information to a data processing module; a microelectromechanical system (MEMS) inertial navigation unit, including three MEMS gyroscopes and three MEMS angular velocity sensors, and the MEMS inertial navigation unit is configured to transmit the obtained attitude information of the north-seeking navigation device to the data processing module; a data processing module, configured to calculate a northward included angle and an attitude angle of the north-seeking navigation device based on the received heading angle information and attitude information.

[0006] According to an embodiment of the present invention, the north-seeking navigation device further includes a turntable. Among them, one of the two accelerometers is horizontally arranged on the turntable, and the other accelerometer and the single-axis fiber optic gyroscope among the two accelerometers are vertically arranged on the turntable.

[0007] According to an embodiment of the present invention, the north-seeking navigation device further includes an optical encoder. Among them, the rotating shaft of the optical encoder is fixedly connected to the rotating shaft of the turntable through a structural member.

[0008] According to an embodiment of the present invention, the upper surface and the lower surface of the north-seeking navigation device are used for the installation of the turntable, the optical encoder, and the MEMS inertial navigation unit.

[0009] According to an embodiment of the present invention, the position of the single-axis fiber optic gyroscope is set such that its first position and second position are the same as the X-axis and Y-axis of the MEMS inertial navigation unit.

[0010] According to an embodiment of the present invention, the north-seeking navigation device further includes a motor, a driving gear, and a driven gear to cooperate with the rotation of the turntable.

[0011] According to an embodiment of the present invention, the data processing module further calculates the northward included angle and the attitude angle of the north-seeking navigation device based on the data of the optical encoder.

[0012] According to an embodiment of the present invention, the calculation of the northward included angle and the attitude angle adopts a four-position calculation method.

[0013] According to an embodiment of the present invention, in the calculation, considering the installation error between the single-axis fiber optic gyroscope and the MEMS inertial navigation unit during installation, the first position and the second position of the single-axis fiber optic gyroscope are used to correct the X-axis and Y-axis of the MEMS inertial navigation unit.

[0014] The technical principle of the present utility model is as follows: By integrating a north-seeking module with a simple structure into a MEMS IMU, the problem that the MEMS IMU cannot achieve north-seeking and navigation at any time is solved; in addition, the MEMS in the MEMS IMU is corrected by the fiber optic gyro in the north-seeking module, reducing the drift of the MEMS IMU. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the self-north-seeking navigation device according to an embodiment of the present utility model.

[0016] Figure 2 It is an internal view of the self-north-seeking navigation device according to an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solutions in the present utility model will be further described below with reference to the accompanying drawings and embodiments.

[0018] As Figure 1 and Figure 2 shown, an embodiment of the present utility model provides a self-north-seeking navigation device, including: a north-seeking module, including a single-axis fiber optic gyro 5 and two accelerometers 7, and the north-seeking module is used to transmit the obtained heading angle information to the data processing module 1; a microelectromechanical system (MEMS) inertial navigation unit 2, including three MEMS gyros and three MEMS angular velocity meters, and the MEMS inertial navigation unit 2 is used to transmit the obtained attitude information of the self-north-seeking navigation device to the data processing module 1; a data processing module 1, used to calculate the northward included angle and attitude angle of the self-north-seeking navigation device based on the received heading angle information and attitude information. Due to the adoption of a north-seeking module with a simple structure, the self-north-seeking navigation device can achieve north-seeking and navigation at low cost at any time.

[0019] In addition, according to an embodiment of the present utility model, the self-north-seeking navigation device further includes a turntable 6. Among them, one of the two accelerometers 7 is horizontally arranged on the turntable 6, and the other accelerometer 7 and the single-axis fiber optic gyro 5 among the two accelerometers 7 are vertically arranged on the turntable 6. Among them, the vertically arranged accelerometer 7 and fiber optic gyro 5 are respectively used to measure the local gravitational acceleration and the horizontal component of the earth's rotation.

[0020] According to an embodiment of the present utility model, the self-north-seeking navigation device further includes an optical encoder 3. Among them, the rotating shaft of the optical encoder 3 is fixedly connected to the rotating shaft of the turntable 6 through a structural member to ensure the orthogonality of the four measurement positions of the turntable 6.

[0021] Referring again to Figure 1, according to an embodiment of the present invention, the upper and lower surfaces of the north-seeking navigation device are used for the installation of the turntable 6, the photoelectric encoder 3, and the MEMS inertial navigation unit 2. In addition, the front and rear surfaces are respectively used for the installation and fixation of the power supply and the motor drive board 4, and the data processing module 1. Moreover, the position of the single-axis fiber optic gyro is set such that its first position and second position are the same as the X-axis and Y-axis of the MEMS inertial navigation unit 2. Meanwhile, the power supply and the motor drive board 4 are also responsible for supplying the power required for operation to the accelerometer 7, the fiber optic gyro 5, the data processing module 1, the photoelectric encoder 3, and the MEMS inertial navigation unit 2.

[0022] In addition, referring again to Figure 2 , according to an embodiment of the present invention, the north-seeking navigation device further includes a motor, a driving gear 9, and a driven gear 10 to cooperate with the rotation of the turntable 6.

[0023] According to an embodiment of the present invention, the data processing module also calculates the northward included angle and the attitude angle of the north-seeking navigation device based on the data of the photoelectric encoder. In addition, the calculation of the northward included angle and the attitude angle adopts the four-position calculation method. Additionally, in the calculation, considering the installation error between the single-axis fiber optic gyro and the MEMS inertial navigation unit 2 during installation, the first position and the second position of the single-axis fiber optic gyro are used to correct the X-axis and Y-axis of the MEMS inertial navigation unit 2.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. 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 self-seeking north navigation device, characterized in that: include: A north-seeking module, comprising a single-axis fiber optic gyroscope and two accelerometers, wherein the north-seeking module is used to transmit the obtained heading angle information to the data processing module; A micro-electromechanical system (MEMS) inertial navigation unit, comprising three MEMS gyroscopes and three MEMS angular velocity meters, wherein the MEMS inertial navigation unit is used to transmit the obtained attitude information of the self-seeking north navigation device to a data processing module; The data processing module is used to calculate the north angle and attitude angle of the self-seeking north navigation device based on the received heading angle information and attitude information.

2. The self-seeking north navigation device according to claim 1, characterized in that: A turntable is also included, wherein one of the two accelerometers is disposed transversely on the turntable, and the other of the two accelerometers and the single-axis fiber optic gyroscope are disposed longitudinally on the turntable.

3. A self-seeking north navigation device as claimed in claim 2, characterized in that: It also includes a photoelectric encoder, wherein the rotating shaft of the photoelectric encoder is fixedly connected to the rotating shaft of the turntable through a structural member.

4. The self-seeking north navigation device according to claim 3, characterized in that: The upper surface and the lower surface of the self-seeking north navigation device are used for installing the turntable, the photoelectric encoder and the MEMS inertial navigation unit.

5. The self-seeking north navigation device according to claim 4, characterized in that: The position of the single-axis fiber optic gyroscope is set so that its first position and second position are the same as the X-axis and Y-axis of the MEMS inertial navigation unit.

6. The self-seeking north navigation device according to claim 5, characterized in that: It also includes a motor, a driving gear and a driven gear to cooperate with the rotation of the turntable.

7. The self-seeking north navigation device according to claim 6, characterized in that: The data processing module also calculates the north angle and attitude angle of the self-seeking north navigation device based on the data of the photoelectric encoder.

8. The self-seeking north navigation device according to claim 7, characterized in that: The north angle and the attitude angle are calculated using a four-position calculation method.

9. The self-seeking north navigation device according to claim 7, characterized in that: In the calculation, the installation error between the single-axis fiber optic gyroscope and the MEMS inertial navigation unit is taken into account, and the X-axis and Y-axis of the MEMS inertial navigation unit are corrected using the first position and the second position of the single-axis fiber optic gyroscope.

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