Combined navigation system

Abstract

The utility model provides an integrated navigation system, which comprises a data processing module, an MEMS (Micro Electro Mechanical System) inertial device, a GNSS (Global Navigation Satellite System) satellite module, an external interface and a power supply module, the inertial navigation data processor is respectively connected with the inertial navigation data acquisition module and the combined navigation data processor, the MEMS inertial device and the external interface are both connected with the inertial navigation data acquisition module, and the GNSS satellite module is connected with the combined navigation data processor. The inertial navigation data acquisition module adopts an FPGA chip, the system utilizes the characteristic of parallel processing of the FPGA chip, an SPI channel is adopted to complete I MU data acquisition, inertial data processing and data acquisition and transmission are separated, the real-time performance of data is ensured, a dual-core processor is adopted for data processing, the data resolving efficiency is improved, and the data processing precision is improved. Meanwhile, the FPGA chip is used for expanding the high-speed transmission function of an external interface, and resources and time for processing a navigation algorithm by a processor are not occupied.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of integrated navigation, particularly relates to a kind of integrated navigation system. BACKGROUND

[0002] The integrated navigation system combined with inertial device and satellite positioning is mainly composed of IMU, GNSS, navigation algorithm solving module and data acquisition transmission module.The selection of inertial sensor in IMU, the hardware structure and implementation of navigation algorithm solving module and data acquisition transmission affect the navigation accuracy, system performance and production cost of integrated navigation system.Currently, the IMU combined with optical fiber gyroscope and MEMS accelerometer adopts high-precision optical fiber gyroscope to improve navigation accuracy, but the high cost is not conducive to civilian promotion;In the navigation algorithm solving module, it is mainly divided into inertial navigation algorithm and integrated navigation algorithm, and the algorithm processing efficiency is low and real-time is not high using single ARM core;The implementation of data acquisition transmission needs to adopt high-efficiency mode and can guarantee the navigation accuracy of system.Therefore, a kind of integrated navigation of MEMS inertial device and GNSS is needed to guarantee the optimal navigation accuracy and performance of navigation system. SUMMARY

[0003] The utility model aims at providing a kind of integrated navigation system to solve the problems of low navigation accuracy, low solving efficiency and low data real-time of current navigation system.The specific technical scheme is as follows:

[0004] An integrated navigation system, the system includes data processing module (1), MEMS inertial device (2), GNSS satellite module (4), the data processing module (1) includes inertial navigation data acquisition module (11), inertial navigation data processor (12) and integrated navigation data processor ARM (13), the inertial navigation data processor (12) is connected with the integrated navigation data processor (13) and the inertial navigation data acquisition module (11) respectively, the inertial navigation data acquisition module (11) is connected with the MEMS inertial device (2), the integrated navigation data processor (13) is connected with the GNSS satellite module (4).

[0005] Further, the MEMS inertial device (2) includes multiple MEMS gyroscopes and / or multiple MEMS accelerometers.

[0006] Further, the inertial navigation data acquisition module (11) is connected with the multiple MEMS gyroscopes and / or multiple MEMS accelerometers through multiple SPI channels respectively.

[0007] Further, the MEMS gyroscope and the MEMS accelerometer are both integrated with temperature sensor inside.

[0008] Further, the inertial navigation data acquisition module (11) adopts an FPGA chip, and the inertial navigation data processor (12) and the integrated navigation data processor (13) both adopt ARM chips.

[0009] Further, the GNSS satellite module (4) comprises a clock synchronization PPS device (41), a GNSS Beidou chip (42), a level conversion chip (43) and a Beidou antenna (44), the clock synchronization PPS device (41) and the GNSS Beidou chip (42) are connected with the integrated navigation data processor (13) through the level conversion chip (43).

[0010] Further, the system further comprises an external interface (3), and the external interface (3) comprises at least one of a test host computer serial port, an Ethernet interface, a CAN interface and a UART port.

[0011] Further, the system further comprises a power module (5) for supplying power to the system.

[0012] Further, the inertial navigation data processor (12) and the integrated navigation data processor (13) are connected through a GPIO interface.

[0013] Further, the inertial navigation data processor (12) and the inertial navigation data acquisition module (11) are connected through an AXI bus.

[0014] The combined navigation system has the following beneficial effects:

[0015] 1. The combined navigation system provided by the utility model uses two independent processors, improves the solving efficiency, separates the inertial data processing and data acquisition transmission at the same time, utilizes the parallel processing characteristics of the FPGA chip, adopts 6 SPI channels to complete IMU data acquisition, guarantees the real-time performance of data, and improves the navigation precision.

[0016] 2. The combined navigation system provided by the utility model utilizes the FPGA chip to expand the external interface high-speed transmission function, does not occupy the resources and time of the ARM chip for processing the navigation algorithm, and improves the system performance.

[0017] 3. The combined navigation system provided by the utility model adopts MEMS inertial devices for the data acquisition module, compared with the optical fiber gyroscope, the MEMS is lower in cost and smaller in size, is beneficial to large-area popularization, and is suitable for various fields such as intelligent driving. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a connection schematic diagram of the combined navigation system provided by the utility model. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be described clearly and completely in combination with the drawings provided by the utility model. The advantages and features of the utility model will be more apparent according to the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to facilitate and clarify the purpose of assisting the description of the embodiments of the utility model.

[0020] In the description of the utility model, unless explicitly defined and limited, the terms "connected", "connected" should be interpreted broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship of two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0021] In the description of the utility model, the terms "upper", "lower", "left", "right", "front", "back", "center", "horizontal", "vertical", "top", "bottom", "inner", "outer" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, which is only for the convenience of description and simplification of operation, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore it cannot be understood as a limitation on the utility model.

[0022] Embodiment: the embodiment provides a kind of integrated navigation system, which includes data processing module 1, MEMS inertial device 2, external interface 3, GNSS satellite module 4, power module 5, wherein data processing module 1 includes inertial navigation data acquisition module 11 and two processors, two processors are inertial navigation data processor 12 and integrated navigation data processor 13 respectively.Inertial navigation data acquisition module 11 uses FPGA chip, two processors all use ARM chip, two ARM chips are connected using GPIO interface, inertial navigation data processor 12 and FPGA chip are connected by AXI bus, MEMS inertial device 2 and external interface 3 are connected with FPGA chip, GNSS satellite module 4 is connected with integrated navigation data processor 13, power module 5 is connected with the above-mentioned data processing module 1, MEMS inertial device 2, external interface 3, GNSS satellite module 4.

[0023] The utility model provides a kind of combined navigation system, utilize the characteristics of FPGA parallel processing, adopt SPI channel to carry out the transmission of data, separate inertial data processing and data acquisition transmission, guarantee the real-time of data, data processing adopts dual-core processor ARM, inertial navigation data processor 12 utilizes inertial data to carry out inertial algorithm solution, combined navigation data processor 13 receives the information of GNSS satellite module 4 and 12 solved inertial information, carries out combined navigation algorithm solution, uses two independent ARM processors, improves solution efficiency, simultaneously utilize FPGA chip 11 expansion external interface high-speed transmission function, does not occupy the resource and time of ARM processing navigation algorithm.

[0024] Optionally, the MEMS inertial device 2 is a 6-axis IMU. Generally, a 3-axis IMU is an IMU with only a 3-axis gyroscope. Since there is only one 3-axis gyroscope, the 3-axis IMU can only sense attitude information of a carrier in three degrees of freedom, i.e., roll, pitch and yaw. A 6-axis IMU is an IMU with a 3-axis accelerometer added to a 3-axis IMU. Therefore, the 6-axis IMU can sense acceleration information of a carrier in three degrees of freedom in addition to sensing the attitude of the carrier. The 6-axis IMU uses MEMS sensors, three of which are MEMS accelerometers, and the other three of which are MEMS gyroscopes. The FPGA chip 11 and the MEMS inertial device 2 are connected by six SPI channels, which can respectively collect MEMS accelerometer sampling data and MEMS gyroscope sampling data and transmit them to the FPGA chip 11. Meanwhile, temperature sensors are integrated in the six MEMS sensors, and each temperature sensor and the corresponding MEMS accelerometer and MEMS gyroscope share an SPI channel.

[0025] Optionally, the external interface 3 includes a test host computer serial port, and can also be flexibly expanded to include, but not limited to, an Ethernet interface, a CAN interface and a UART port.

[0026] Optionally, the GNSS satellite module 4 includes a clock synchronization PPS device 41, a GNSS Beidou chip 42, a level conversion chip 43 and a Beidou antenna 44. The clock synchronization PPS device 41 and the GNSS Beidou chip 42 are connected to the combined navigation data processor 13 through the level conversion chip 43.

[0027] The working principle of the system is that: firstly, the FPGA chip 11 obtains the acceleration of the collected MEMS sensor, the angular velocity and the temperature information of the temperature sensor through the SPI channel, the inertial navigation data processor 12 interacts with the FPGA chip through the AXI bus, after the inertial navigation data processor 12 obtains the information of the sensor in the IMU, firstly reads the pre-calibrated gyroscope and accelerometer, temperature compensation model and installation error model in the Flash register, and compensates the IMU sensor information, and then compensates the error of the navigation system caused by the double sample iterative algorithm due to the conical motion, and converts the effective data for high-precision navigation calculation.

[0028] Then, the integrated navigation data processor 13 obtains the high-precision position information of the GNSS satellite module 4 and the PPS time synchronization signal through the level conversion chip 43 using the UART communication protocol, the PPS time synchronization signal is used for time calibration of the inertial navigation information calculated by the inertial navigation data processor 12 and the high-precision position information, the difference between the high-precision position information of the GNSS satellite module 4 and the inertial navigation information calculated by the inertial navigation data processor 12 is used as measurement information, after Kalman fusion processing, the velocity, position, attitude error and sensor zero offset of the moving carrier are estimated, and the estimated results are used for feedback correction of the inertial navigation information and the high-precision position information, for error correction, and then according to the external demand, the corrected navigation information is output through the FPGA chip 11 selecting the appropriate communication interface.

[0029] The combined navigation system of the utility model can be widely applied to the fields of automobile electronics, health detection, military navigation and industrial state monitoring.

[0030] It should be understood by those skilled in the art that the utility model can be realized in many other specific forms without departing from the spirit and scope of the utility model, and all other embodiments obtained by those skilled in the art based on the embodiments in the utility model without creative labor belong to the scope of protection of the utility model.

Claims

1. A combined navigation system characterized by: The system comprises a data processing module (1), a MEMS inertial device (2) and a GNSS satellite module (4), the data processing module (1) comprises an inertial navigation data acquisition module (11), an inertial navigation data processor (12) and a combined navigation data processor (13), the inertial navigation data processor (12) is connected with the combined navigation data processor (13) and the inertial navigation data acquisition module (11) respectively, the inertial navigation data acquisition module (11) is connected with the MEMS inertial device (2), and the combined navigation data processor (13) is connected with the GNSS satellite module (4). The inertial navigation data acquisition module (11) adopts an FPGA chip, and the inertial navigation data processor (12) and the combined navigation data processor (13) both adopt ARM chips.

2. The combined navigation system of claim 1, wherein: The MEMS inertial device (2) comprises a plurality of MEMS gyroscopes and / or a plurality of MEMS accelerometers.

3. The combined navigation system of claim 2, wherein: The inertial navigation data acquisition module (11) is connected with the plurality of MEMS gyroscopes and / or the plurality of MEMS accelerometers through a plurality of SPI channels respectively.

4. The combined navigation system of claim 3, wherein: The MEMS gyroscope and the MEMS accelerometer are both internally integrated with temperature sensors.

5. The combined navigation system of claim 1, wherein: The GNSS satellite module (4) comprises a clock synchronization PPS device (41), a GNSS Beidou chip (42), a level conversion chip (43) and a Beidou antenna (44), the clock synchronization PPS device (41) and the GNSS Beidou chip (42) are connected with the combined navigation data processor (13) through the level conversion chip (43).

6. The combined navigation system of claim 1, wherein: The system further comprises an external interface (3), and the external interface (3) comprises at least one of a test host computer serial port, an Ethernet interface, a CAN interface and a UART port.

7. The combined navigation system of claim 1, wherein: The system further comprises a power module (5) for supplying power to the system.

8. The combined navigation system of claim 1, wherein: The inertial navigation data processor (12) and the combined navigation data processor (13) are connected through a GPIO interface.

9. The combined navigation system of claim 1, wherein: The inertial navigation data processor (12) and the inertial navigation data acquisition module (11) are connected through an AXI bus.

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