Disclosure of Invention
The application provides a combined navigation system, which solves the technical problem that the GNSS/INS combined navigation technology in the prior art is not suitable for all engineering scenes.
In view of the above, the present application provides a combined navigation system, including: the system comprises a data acquisition module, an image identification module, a decision module and a calculation module;
the data acquisition module is assembled on a carrier to be positioned and used for acquiring sky images, GNSS data and inertial data required by navigation of the carrier;
the image identification module is used for judging whether a satellite in the sky image is shielded or not after the sky image exposure detection is successful, and obtaining a judgment result;
the decision module is used for selecting a data processing mode for navigation according to the judgment result and the GNSS data;
and the calculation module is used for navigating the carrier according to the GNSS data, the inertial data, the sky image and the data processing mode to obtain a navigation result.
Optionally, the data acquisition module specifically includes:
the shooting module is used for shooting a sky image;
a GNSS module for collecting GNSS data, wherein the GNSS data comprises: satellite observation values and satellite ephemeris;
an inertial measurement module configured to collect the inertial data, wherein the inertial data includes: three-axis acceleration and three-axis angular velocity measurements.
Optionally, the image recognition module specifically includes:
the exposure detection module is used for carrying out exposure detection on the sky image to obtain a corresponding detection result;
the segmentation module is used for segmenting the sky image by using a preset segmentation algorithm to obtain a sky area and a sheltered area when the detection result is that the detection is successful;
the judging module is used for judging whether the satellite in the sky image is shielded or not according to the position of the satellite in the sky image, the sky area and the shielding area to obtain a judging result.
Optionally, the determining module specifically includes:
the first submodule is used for obtaining the position of the satellite in the sky image according to satellite information and system parameters corresponding to the satellite;
and the second submodule is used for judging whether the satellite in the sky image is blocked or not according to the position of the satellite in the sky image, the sky area and the blocking area to obtain a judgment result.
Optionally, the method further comprises: a preprocessing module;
the preprocessing module is used for acquiring satellite preliminary information and carrier preliminary information;
correspondingly, the decision module is configured to select a data processing mode for navigation according to the satellite preliminary information, the carrier preliminary information, and the determination result.
Optionally, the decision module is specifically configured to, when the determination result is that the satellite in the sky image is occluded, select a positioning mode of the visual odometer-assisted GNSS/INS compact combination module; and the GNSS/INS tight combination module is further used for selecting the GNSS/INS tight combination module when the judgment result shows that the satellite in the sky image is not shielded.
Optionally, the decision module is further configured to, when it is determined that the carrier preliminary information meets a preset condition, use the carrier preliminary information as a calculation preliminary value of the calculation module.
Optionally, the data acquisition module is fixedly connected to the carrier, and a relative spatial relationship between modules included in the data acquisition module is unchanged.
Optionally, the method further comprises: a calibration module;
and the calibration module is used for calibrating the data acquisition module.
According to the technical scheme, the method has the following advantages:
the application provides a combined navigation system, comprising: the system comprises a data acquisition module, an image identification module, a decision module and a calculation module; the data acquisition module is assembled on a carrier to be positioned and used for acquiring sky images, GNSS data and inertial data required by carrier navigation; the image identification module is used for judging whether the satellite in the sky image is shielded or not after the sky image exposure detection is successful to obtain a judgment result; the decision-making module is used for selecting a data processing mode for navigation according to the judgment result and the GNSS data; and the calculation module is used for navigating the carrier according to the GNSS data, the inertial data, the sky image and the data processing mode to obtain a navigation result. According to the method and the device, the sky image is shielded and judged through the image identification module, the judgment results are utilized for motion calculation, the visual environment perception function is exerted to the maximum extent, the stability of the system is improved, and the technical problem that the GNSS/INS combined navigation technology in the prior art is not suitable for all engineering scenes is solved.
Detailed Description
The embodiment of the application provides a combined navigation system, and solves the technical problem that the GNSS/INS combined navigation technology in the prior art is not suitable for all engineering scenes.
In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
For ease of understanding, the terms in this embodiment are first explained as follows:
the visual odometer is an odometer which estimates the position, the posture and the speed by using a series of time continuous pictures shot by a camera.
GNSS, Global Navigation Satellite System.
Referring to fig. 1, a first embodiment of a combined navigation system in the embodiment of the present application is a schematic structural diagram.
A combined navigation system in this embodiment includes: the system comprises a data acquisition module 1, an image identification module 2, a decision module 3 and a calculation module 4; the data acquisition module 1 is assembled on a carrier to be positioned and used for acquiring sky images, GNSS data and inertial data required by carrier navigation; the image identification module 2 is used for judging whether the satellite in the sky image is shielded or not after the sky image exposure detection is successful, and obtaining a judgment result; the decision module 3 is used for selecting a data processing mode for navigation according to the judgment result and the GNSS data; and the calculation module 4 is used for navigating the carrier according to the GNSS data, the inertial data, the sky image and the data processing mode to obtain a navigation result.
It can be understood that the navigation result in the present embodiment includes: position information, attitude information and velocity information, i.e. the position, attitude and velocity of the corresponding carrier.
The integrated navigation system of the embodiment comprises: the system comprises a data acquisition module 1, an image identification module 2, a decision module 3 and a calculation module 4; the data acquisition module 1 is assembled on a carrier to be positioned and used for acquiring sky images, GNSS data and inertial data required by carrier navigation; the image identification module 2 is used for judging whether the satellite in the sky image is shielded or not after the sky image exposure detection is successful, and obtaining a judgment result; the decision module 3 is used for selecting a data processing mode for navigation according to the judgment result and the GNSS data; and the calculation module 4 is used for navigating the carrier according to the GNSS data, the inertial data, the sky image and the data processing mode to obtain a navigation result. In the application, the sky image is shielded and judged through the image identification module 2, and the judgment results are utilized for motion calculation, so that the visual environment perception function is exerted to the maximum extent, the stability of the system is improved, and the technical problem that the GNSS/INS combined navigation technology in the prior art is not suitable for all engineering scenes is solved.
The above is a first embodiment of a combined navigation system provided in the embodiments of the present application, and the following is a second embodiment of a combined navigation system provided in the embodiments of the present application.
Referring to fig. 1, a schematic structural diagram of a second embodiment of a combined navigation system in an embodiment of the present application is shown.
A combined navigation system in this embodiment includes: the system comprises a data acquisition module 1, an image identification module 2, a decision module 3 and a calculation module 4; the data acquisition module 1 is assembled on a carrier to be positioned and used for acquiring sky images, GNSS data and inertial data required by carrier navigation; the image identification module 2 is used for judging whether the satellite in the sky image is shielded or not after the sky image exposure detection is successful, and obtaining a judgment result; the decision module 3 is used for selecting a data processing mode for navigation according to the judgment result and the GNSS data; and the calculation module 4 is used for navigating the carrier according to the GNSS data, the inertial data, the sky image and the data processing mode to obtain a navigation result.
Specifically, the data acquisition module 1 specifically includes:
the shooting module is used for shooting a sky image;
the GNSS module is used for acquiring GNSS data, wherein the GNSS data comprises: satellite observation values and satellite ephemeris;
the inertia measurement module is used for collecting inertia data, wherein the inertia data comprises: three-axis acceleration and three-axis angular velocity measurements.
Specifically, the image recognition module 2 specifically includes:
the exposure detection module is used for carrying out exposure detection on the sky image to obtain a corresponding detection result;
the segmentation module is used for segmenting the sky image by using a preset segmentation algorithm to obtain a sky area and a sheltered area when the detection result is that the detection is successful;
and the judging module is used for judging whether the satellite in the sky image is shielded according to the position of the satellite in the sky image, the sky area and the shielding area to obtain a judging result.
The image recognition module 2 firstly performs exposure detection, and if it is detected that the pixel brightness of an area exceeding a certain proportion in the sky image exceeds a set exposure threshold, the picture is considered to be overexposed or all the areas are sky areas, that is, the detection is unsuccessful, and at this moment, the visual odometer is unavailable. If exposure detection is performed (detection is successful), image recognition is performed, a sky area and an occlusion area are distinguished by using a semantic segmentation technology or an image segmentation technology, and the position of the satellite in the sky image (as shown in fig. 2 specifically) can be obtained by means of the satellite preliminary information transmitted by the data preprocessing module 5 and the system parameters transmitted by the calibration module 6, so that the satellite occlusion condition is judged.
Correspondingly, the judging module specifically comprises:
the first submodule is used for obtaining the position of the satellite in the sky image according to the satellite information and the system parameters corresponding to the satellite;
and the second submodule is used for judging whether the satellite in the sky image is shielded according to the position of the satellite in the sky image, the sky area and the shielded area to obtain a judgment result.
The integrated navigation system in this embodiment further includes: a preprocessing module 5;
the preprocessing module 5 is used for acquiring satellite preliminary information and carrier preliminary information;
correspondingly, the decision module 3 is configured to select a data processing mode for navigation according to the satellite preliminary information, the carrier preliminary information, and the determination result.
Specifically, the data preprocessing module 5 in this embodiment is responsible for preprocessing the original measurement data to obtain measurement data, carrier preliminary information, and satellite preliminary information that can be used for back-end calculation. The module can perform gross error detection and cycle slip detection on satellite data and screen unqualified satellite measurement values. And performing error compensation on inertial navigation (namely data acquired through the INS inertial navigation) data, wherein the error compensation comprises zero offset compensation, scale factor compensation and the like. And matching and tracking the sky image, namely extracting a series of characteristic points from a new frame of sky image, matching the series of characteristic points with the previous frame of sky image, and if the matching is successful, successfully tracking the characteristic points and selecting the characteristic points as visual measurement values. The characteristic point of the scheme adopts ORB, and the ORB has better scale invariance and rotation invariance and is a more stable characteristic point. And obtaining the initial information of the carrier at the latest moment and the initial information of the satellite by using the latest observation information.
It can be understood that the decision module 3 is specifically configured to, when the determination result is that the satellite in the sky image is blocked, select a positioning mode of the visual odometer-assisted GNSS/INS compact combination module; and the GNSS/INS tight combination module is also used for selecting the GNSS/INS tight combination module when the judgment result is that the satellite in the sky image is not blocked.
Further, the decision module 3 is further configured to, when it is determined that the carrier preliminary information meets the preset condition, use the carrier preliminary information as a calculation preliminary value of the calculation module 4. The initial calculation value is the initial calculation value of the calculation module 4.
It should be noted that the decision module 3 in this embodiment is responsible for processing selection of the combination system. And selecting an optimal data processing mode according to the measurement data, the carrier preliminary information and the satellite preliminary information from the data preprocessing module 5 and the judgment result from the image identification module 2. Firstly, the initial value of the system at the current moment is selected, if the initial information of the carrier is superior to the information obtained by the calculation module 4 at the previous moment, the initial value obtained by the preprocessing module 5 is selected, and otherwise, the information obtained by the calculation module 4 is delayed.
Specifically, when the calculation module 4 calculates the navigation result, the carrier is navigated according to the GNSS data, the inertial data, the satellite information in the sky image, and the data processing mode, so as to obtain the navigation result. Specifically, if the image overexposure or the sky area exceeds a certain threshold value, all satellites are available, otherwise, the shielded satellites are removed or the weight of the shielded satellite measurement value is reduced, and a GNSS/INS tight combination module is used; and if the shielded area exceeds a certain threshold value, starting the visual odometer, and assisting the GNSS/INS fastening combination module by using the visual measurement information of the visual odometer.
It can be understood that, as shown in fig. 3, the data acquisition module 1 and the carrier are fixedly connected, and the relative spatial relationship between the modules included in the data acquisition module 1 is not changed. That is, the antenna, the camera module, the inertial measurement module and the carrier of the GNSS module in this embodiment are fixedly connected, so as to form a stable rigid body.
Specifically, the integrated navigation system in this embodiment further includes: a calibration module 6; and the calibration module 6 is used for calibrating the data acquisition module 1. That is, the calibration module 6 in this embodiment belongs to a pre-processing module, and calibrates system parameters of the device before the integrated navigation system operates, where the system parameters include, but are not limited to, internal and external parameters of a camera module (camera), an inertial navigation boom arm, a GNSS antenna inertial navigation boom arm, an inertial navigation gyroscope zero offset and an accelerometer zero offset, an angle random walk and a velocity random walk, an angular rate random walk and an acceleration random walk, and zero offset instability.
The integrated navigation system of the embodiment comprises: the system comprises a data acquisition module 1, an image identification module 2, a decision module 3 and a calculation module 4; the data acquisition module 1 is assembled on a carrier to be positioned and used for acquiring sky images, GNSS data and inertial data required by carrier navigation; the image identification module 2 is used for judging whether the satellite in the sky image is shielded or not after the sky image exposure detection is successful, and obtaining a judgment result; the decision module 3 is used for selecting a data processing mode for navigation according to the judgment result and the GNSS data; and the calculation module 4 is used for navigating the carrier according to the GNSS data, the inertial data, the sky image and the data processing mode to obtain a navigation result. In the application, the sky image is shielded and judged through the image identification module 2, and the judgment results are utilized for motion calculation, so that the visual environment perception function is exerted to the maximum extent, the stability of the system is improved, and the technical problem that the GNSS/INS combined navigation technology in the prior art is not suitable for all engineering scenes is solved.
In the several embodiments provided in the present application, it should be understood that the disclosed system or unit may also be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical functional division, and other divisions may be implemented, for example, a plurality of units or components may be combined or integrated into another grid network to be installed, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to the needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.