Unmanned aerial vehicle navigation method, device, apparatus and computer readable storage medium

Abstract

Embodiments of the present application provide a kind of unmanned plane navigation method, device, equipment and computer readable storage medium, method includes: the inertial navigation information of target unmanned plane, satellite navigation signal and true airspeed are acquired;According to the inertial navigation information and the true airspeed, wind speed information is determined;If the signal strength of the satellite navigation signal is lower than the intensity threshold of pre-set, according to the wind speed information, the inertial navigation information is corrected, and first navigation information is obtained.The unmanned plane navigation method provided in embodiments of the present application, by acquiring the navigation information of unmanned plane and true airspeed, and using navigation information and true airspeed to estimate wind speed information, can be when GNSS signal fails, using the wind speed information estimated to correct the inertial navigation information of unmanned plane, reduce the error accumulation of inertial navigation information, so that the navigation information of unmanned plane is still reliable under the condition of GNSS failure.

Description

Technical Field

[0001] This application relates to the field of positioning and navigation technology, specifically to a drone navigation method, apparatus, device, and computer-readable storage medium. Background Technology

[0002] To better control drones and prevent them from being lost or crashing, navigation is necessary, which involves acquiring real-time flight status information such as position, speed, and attitude. Common navigation methods include GNSS (Global Navigation Satellite System) navigation and IMU (Inertial Measurement Unit) navigation. GNSS navigation provides accurate drone navigation but is susceptible to signal interference, leading to deviations, and also has a certain time delay. IMU navigation can provide accurate navigation for short periods, but over long periods, errors accumulate and cause deviations. Therefore, the current common practice is to primarily use IMU navigation information, periodically correcting it with GNSS navigation information to suppress the accumulation of errors in the IMU navigation data, thus obtaining accurate navigation information in real-time for drone navigation.

[0003] However, under GNSS signal rejection conditions, such as when the signal is affected by external electromagnetic interference, the UAV cannot obtain effective GNSS navigation signals. As a result, it cannot use GNSS navigation information to correct the error accumulation of IMU navigation information, which will cause the accuracy of IMU navigation information to decrease rapidly or even diverge quickly, seriously affecting the navigation performance of the UAV. Summary of the Invention

[0004] This application provides a UAV navigation method, apparatus, device, and computer-readable storage medium, aiming to solve the technical problem that the accuracy of IMU navigation information estimation rapidly decreases when GNSS signals are interfered with in existing UAV navigation methods.

[0005] On one hand, embodiments of this application provide a drone navigation method, including:

[0006] Acquire the target UAV's inertial navigation information, satellite navigation signals, and vacuum speed;

[0007] Wind speed information is determined based on the inertial navigation information and the vacuum speed;

[0008] If the signal strength of the satellite navigation signal is lower than a preset strength threshold, the inertial navigation information is corrected according to the wind speed information to obtain the first navigation information.

[0009] As an optional embodiment of this application, the step of correcting the inertial navigation information based on the wind speed information to obtain the first navigation information includes:

[0010] Based on the wind speed information and the vacuum velocity, the observed ground velocity of the target UAV is determined;

[0011] Based on the observed ground speed and the ground speed information in the inertial navigation information, the inertial navigation information is filtered and corrected to obtain the first navigation information.

[0012] As an optional embodiment of this application, the step of determining the wind speed information based on the inertial navigation information and the vacuum velocity includes:

[0013] The coordinate system rotation matrix is ​​determined based on the attitude information in the inertial navigation information;

[0014] The vacuum velocity is processed according to the coordinate system rotation matrix to obtain the vacuum velocity in the navigation coordinate system;

[0015] The wind speed information in the navigation coordinate system is determined based on the vacuum speed in the navigation coordinate system and the ground speed information in the inertial navigation information.

[0016] As an optional embodiment of this application, the step of determining the wind speed information based on the inertial navigation information and the vacuum velocity includes:

[0017] If the signal strength of the satellite navigation signal is higher than or equal to a preset strength threshold, the inertial navigation information is corrected based on the satellite navigation signal to obtain second navigation information;

[0018] Wind speed information is determined based on the second navigation information and the vacuum speed.

[0019] As an optional embodiment of this application, the step of correcting the inertial navigation information based on the satellite navigation signal to obtain second navigation information includes:

[0020] Obtain the heading angle and flight altitude of the target UAV;

[0021] Target correction information is determined from the satellite navigation signal, the heading angle, and the flight altitude based on the statistical characteristics of the data.

[0022] The inertial navigation information is corrected based on the target correction information to obtain the second navigation information.

[0023] As an optional embodiment of this application, if the signal strength of the satellite navigation signal is lower than a preset strength threshold, the inertial navigation information is corrected according to the wind speed information to obtain first navigation information, including:

[0024] If the signal strength of the satellite navigation signal is lower than a preset strength threshold, then the data statistical characteristics of the vacuum velocity are obtained;

[0025] If the statistical characteristics of the vacuum velocity data are less than a preset characteristic threshold, the inertial navigation information is corrected according to the wind speed information to obtain the first navigation information;

[0026] If the statistical characteristics of the vacuum velocity data are greater than or equal to a preset characteristic threshold, the attitude information in the inertial navigation information is corrected according to the linear acceleration of the target UAV to obtain corrected attitude information, and the corrected attitude information is set as the first navigation information.

[0027] As an optional embodiment of this application, obtaining the inertial navigation information of the target UAV includes:

[0028] Acquire the target UAV's initial position, initial velocity, initial attitude, linear acceleration, and angular velocity;

[0029] Based on the initial velocity information and the acceleration, the target ground speed information of the target UAV is obtained;

[0030] Based on the initial position information and the ground speed information, the target position information of the target UAV is obtained;

[0031] Based on the initial attitude information and the angular velocity, the target attitude information of the target UAV is obtained;

[0032] The target ground speed information, the target position information, and the target attitude information are set as the inertial navigation information of the target UAV.

[0033] On the other hand, embodiments of this application also provide a drone navigation device, including:

[0034] The acquisition module is used to acquire the target UAV's inertial navigation information, satellite navigation signals, and vacuum speed.

[0035] A wind speed calculation module is used to determine wind speed information based on the inertial navigation information and the vacuum speed;

[0036] The navigation correction module is used to correct the inertial navigation information based on the wind speed information if the signal strength of the satellite navigation signal is lower than a preset strength threshold, so as to obtain the first navigation information.

[0037] On the other hand, this application embodiment also provides a drone navigation device, which includes a processor, a memory, and a drone navigation program stored in the memory and executable on the processor. The processor executes the drone navigation program to implement the steps in the drone navigation method described above.

[0038] On the other hand, embodiments of this application also provide a computer-readable storage medium storing a drone navigation program, which is executed by a processor to implement the steps in the drone navigation method described above.

[0039] The UAV navigation method provided in this application obtains the UAV's navigation information and vacuum speed, and uses the navigation information and vacuum speed to estimate wind speed information. Thus, under GNSS signal rejection conditions, that is, when the signal strength of the satellite navigation signal is lower than a preset strength threshold, the estimated wind speed information can be used to correct the UAV's inertial navigation information, reduce the accumulation of errors in the inertial navigation information, and make the UAV's navigation information still reliable in the case of GNSS failure. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram illustrating an implementation scenario of a drone navigation method provided in this application embodiment;

[0042] Figure 2 This is a flowchart illustrating the steps of a drone navigation method provided in an embodiment of this application.

[0043] Figure 3 A flowchart illustrating the steps for correcting inertial navigation information based on wind speed, as provided in this application embodiment;

[0044] Figure 4 A flowchart illustrating the steps for determining wind speed information based on inertial navigation information and vacuum velocity, provided in an embodiment of this application;

[0045] Figure 5A flowchart illustrating another step in determining wind speed information based on inertial navigation information and vacuum velocity, provided in an embodiment of this application.

[0046] Figure 6 A flowchart illustrating the steps for correcting inertial navigation information, provided in an embodiment of this application;

[0047] Figure 7 A schematic flowchart illustrating another step for correcting inertial navigation information provided in an embodiment of this application;

[0048] Figure 8 This application provides a schematic flowchart illustrating the steps for acquiring inertial navigation information in an embodiment of the present application.

[0049] Figure 9 This is a schematic diagram of the structure of a drone navigation device provided in an embodiment of this application;

[0050] Figure 10 This is a schematic diagram of the structure of a drone navigation device provided in an embodiment of this application. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present invention.

[0052] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in the embodiments of this application.

[0053] This application provides a drone navigation method, apparatus, device, and computer-readable storage medium, which will be described in detail below.

[0054] In this embodiment, the UAV navigation method is deployed as a program on the UAV navigation device, which is a processor installed in the UAV navigation equipment. The UAV navigation device is usually installed on the UAV. The UAV navigation device in the UAV navigation equipment is also connected to the data acquisition device installed on the UAV, such as various sensors. After obtaining the corresponding data from the data acquisition device, the program corresponding to the UAV navigation method is run to output the navigation information of the UAV.

[0055] like Figure 1 As shown, Figure 1 This is a schematic diagram illustrating an implementation scenario of a drone navigation method provided in this application embodiment, which can also be understood as a structural schematic diagram of a drone navigation system. The implementation scenario provided in this application embodiment mainly includes a data acquisition device 100 and a drone navigation device 200. The data acquisition device 100 is mainly used to collect various types of data from the drone. For example, the GNSS receiver in the data acquisition device can receive satellite signals from GNSS and parse the drone's satellite navigation information. The inertial measurement unit in the data acquisition device can collect the drone's linear acceleration and angular velocity through a three-axis accelerometer and a three-axis gyroscope, and combine this with the initial navigation information to deduce the drone's current navigation information. Specifically, the navigation information typically includes position, speed, attitude, and other information. Furthermore, to better control the drone, the data acquisition device may also include other sensors, such as an airspeed meter, barometer, magnetometer, etc., to collect the drone's airspeed, flight altitude, and heading angle in real time. After collecting various types of data from the UAV, the data acquisition device 100 transmits them to the UAV navigation device 200. The UAV navigation device 200 processes the data transmitted by the data acquisition device 100 and outputs the navigation information of the UAV.

[0056] It should be noted that, Figure 1 The schematic diagram of the drone navigation implementation scenario shown is merely an example. The drone navigation implementation scenario described in this application embodiment is intended to more clearly illustrate the technical solution of this application embodiment and does not constitute a limitation on the technical solution provided in this application embodiment.

[0057] Based on the above schematic diagram of the implementation scenario of UAV navigation, a specific embodiment of the UAV navigation method is proposed.

[0058] like Figure 2 As shown, Figure 2 This is a flowchart illustrating the steps of a drone navigation method provided in an embodiment of this application. The drone navigation method in this embodiment includes steps 201-203:

[0059] 201. Acquire the target UAV's inertial navigation information, satellite navigation signals, and vacuum speed.

[0060] In this embodiment of the application, in conjunction with the foregoing Figure 1 As shown in the schematic diagram illustrating the implementation scenario of the UAV navigation method, the inertial navigation information of the target UAV is obtained by strapdown recursion of the initial navigation information using linear acceleration and angular velocity acquired by the inertial measurement unit. Specifically, by integrating the acquired linear acceleration, the change in the UAV's velocity can be obtained. Combined with the initial velocity, the real-time velocity of the UAV can be recursively obtained. Furthermore, by integrating the UAV's velocity, the change in the UAV's displacement can be obtained. Combined with the UAV's initial position, the real-time position of the UAV can be recursively obtained. In addition, based on the integration of angular velocity, the change in the UAV's angle in various directions can be obtained, which reflects the change in the UAV's attitude. Therefore, combined with the UAV's initial attitude, the real-time attitude of the UAV can be obtained. For details on the steps to obtain the UAV's inertial navigation information, please refer to the subsequent sections. Figure 8 And its explanations and descriptions.

[0061] Of course, it should be noted that errors are inevitable during data acquisition. As these errors accumulate, the inertial navigation information of the target UAV will gradually deviate from the true value. Therefore, it is often necessary to use other navigation information to correct the inertial navigation information, in order to suppress the accumulation of errors in the strapdown calculation process and thus reduce the deviation of the navigation information. Specifically, in the embodiments of this application, the UAV navigation device receives satellite navigation signals from the satellite navigation system through a GNSS receiver installed on the UAV and calculates the satellite navigation information to obtain the UAV's satellite navigation information. However, when external interference prevents the UAV from receiving satellite navigation signals through the GNSS receiver, or when it receives poor-quality satellite navigation information, the UAV navigation device cannot calculate accurate satellite navigation information and therefore cannot correct the inertial navigation information. This causes the inertial navigation information to diverge rapidly due to the accumulation of errors, resulting in serious navigation deviations.

[0062] Furthermore, to address the aforementioned problem of GNSS failure causing rapid divergence of inertial navigation information and resulting in severe navigation deviations, this application embodiment further utilizes other sensor components installed on the UAV. Specifically, in this application embodiment, the UAV navigation device also obtains the UAV's vacuum speed (air velocity, i.e., the UAV's flight speed relative to the air) through the airspeed meter installed on the UAV, and calculates a relatively accurate wind speed based on the inertial navigation information and vacuum speed. This allows for the reverse deduction of the UAV's real-time speed using relatively stable wind speed information when GNSS interference fails, thereby correcting the inertial navigation information.

[0063] 202. Determine the wind speed information based on the inertial navigation information and the vacuum speed.

[0064] In this embodiment of the application, as described above, inertial navigation information typically includes position information, velocity information, and attitude information. The velocity information in the inertial navigation information usually refers to the flight speed of the UAV relative to the ground, i.e., ground speed. Therefore, based on the velocity information and vacuum speed in the inertial navigation information, real-time wind speed information can be calculated.

[0065] As an optional embodiment of this application, considering that the velocity information in inertial navigation information and the vacuum velocity are usually referenced by different coordinate systems—for example, the velocity information in inertial navigation information is usually referenced by the northeast-northeast ground coordinate system with the UAV's center of gravity as the origin, i.e., the navigation coordinate system—while the vacuum velocity is usually referenced by the front-right-lower coordinate system with the UAV's center of gravity as the origin, i.e., the body coordinate system—therefore, in determining the wind speed information based on the inertial navigation information and the vacuum velocity, it is necessary to consider the transformation between the navigation coordinate system and the body coordinate system, mapping the ground velocity and vacuum velocity to the same coordinate system for calculation. The specific calculation process can be found in the subsequent sections. Figure 4 And its explanations and descriptions.

[0066] Furthermore, considering that the velocity information in inertial navigation information will accumulate errors over time, resulting in inaccurate calculated wind speeds and affecting the effectiveness of subsequent corrections using wind speed information, as another optional embodiment of this application, when the signal strength of the satellite navigation signal is higher than a preset strength threshold, the inertial navigation information is corrected using GNSS navigation information, and the wind speed information is calculated based on the corrected navigation information, updated and stored in real time. Specific implementation schemes can be found in subsequent sections. Figure 5 And its explanations and descriptions.

[0067] 203. If the signal strength of the satellite navigation signal is lower than a preset strength threshold, the inertial navigation information is corrected according to the wind speed information to obtain the first navigation information.

[0068] As described above, the embodiments of this application aim to address the correction of inertial navigation information in the event of GNSS navigation signal failure. Typically, GNSS navigation signal failure can be determined based on the signal strength of the satellite navigation signal. That is, when the received satellite navigation signal strength is lower than a preset strength threshold, the UAV can be considered to be in a GNSS failure state. In this case, inertial navigation information cannot be obtained through GNSS navigation information. Therefore, the speed information of the UAV can be inferred using the aforementioned wind speed and vacuum velocity, and this speed information can be used to correct the inertial navigation information, resulting in corrected navigation information. The specific implementation process of correcting inertial navigation information based on wind speed can be found in the following sections. Figure 3 And its explanations and descriptions.

[0069] Furthermore, when wind speed information is valid, it can be used to correct inertial navigation information. However, when wind speed information becomes invalid due to external interference or other factors, it is impossible to correct the velocity in the navigation information. As an embodiment of this application, the estimation of velocity and position in the navigation information is abandoned, and only the valid output of attitude is retained. For the specific implementation process, please refer to the subsequent sections. Figure 7 And its explanations and descriptions.

[0070] In this embodiment of the application, after obtaining navigation information such as the speed, position, and attitude of the UAV, and further combining it with the location information of the destination, the attitude and speed of the UAV can be controlled to avoid abnormalities such as the UAV flipping over or getting lost.

[0071] The UAV navigation method provided in this application obtains the UAV's navigation information and vacuum speed, and uses the navigation information and vacuum speed to estimate wind speed information. Thus, under GNSS signal rejection conditions, that is, when the signal strength of the satellite navigation signal is lower than a preset strength threshold, the estimated wind speed information can be used to correct the UAV's inertial navigation information, reduce the accumulation of errors in the inertial navigation information, and make the UAV's navigation information still reliable in the case of GNSS failure.

[0072] like Figure 3 As shown, Figure 3 This is a flowchart illustrating a step for correcting inertial navigation information based on wind speed, as provided in an embodiment of this application. Details are as follows.

[0073] In this embodiment of the application, a process for correcting inertial navigation information based on wind speed is provided, including steps 301 to 302:

[0074] 301. Based on the wind speed information and the vacuum speed, determine the observed ground speed of the target UAV.

[0075] In this embodiment, as described above, vacuum velocity describes the speed of the UAV relative to the air. Therefore, subtracting the wind speed from the real-time collected vacuum velocity yields the observed ground velocity of the target UAV. Furthermore, it should be noted that if the wind speed information calculated in the aforementioned steps is not based on the same coordinate system as the vacuum velocity, a coordinate system transformation is required to map the vacuum velocity and wind speed information to the same coordinate system for calculation. Specifically, the formula for calculating the observed ground velocity based on the wind speed information and vacuum velocity is as follows:

[0076]

[0077] in, It is a rotation matrix from the body coordinate system to the navigation coordinate system related to the drone's attitude. It is the vacuum velocity in the body coordinate system directly collected by the airspeed meter. This refers to the wind speed estimated in the navigation coordinate system mentioned above. This refers to the ground speed of the target UAV being observed.

[0078] 302. Based on the observed ground speed and the ground speed information in the inertial navigation information, the inertial navigation information is filtered and corrected to obtain the first navigation information.

[0079] In this embodiment, after obtaining the observed ground speed of the target UAV, the relatively accurate observed ground speed is used as the main observation information to perform Kalman filtering on the ground speed information in the inertial navigation information. This suppresses the accumulation of speed and position errors in the inertial navigation information, corrects the inertial navigation information, and thus obtains the corrected first navigation information.

[0080] like Figure 4 As shown, Figure 4 This is a flowchart illustrating a step for determining wind speed information based on inertial navigation information and vacuum velocity, as provided in an embodiment of this application. Details are as follows.

[0081] In this embodiment of the application, in the process of determining the wind speed, it is necessary to first perform coordinate transformation processing on the inertial navigation information and vacuum velocity, specifically including steps 401 to 403:

[0082] 401. Determine the coordinate system rotation matrix based on the attitude information in the inertial navigation information.

[0083] In this embodiment, as described above, vacuum speed is typically referenced to the body coordinate system, while ground speed information in inertial navigation is typically referenced to the navigation coordinate system. Considering the difference between the body coordinate system and the navigation coordinate system—that the body coordinate system uses the front-right-lower direction of the aircraft as the coordinate direction, while the navigation coordinate system uses the northeast-northeast direction as the coordinate direction—the coordinate system rotation matrix for switching from the body coordinate system to the navigation coordinate system is related to the UAV's heading angle, i.e., the UAV's attitude information. Therefore, the corresponding coordinate system rotation matrix from the body coordinate system to the navigation coordinate system can be determined based on the attitude information in the inertial navigation information.

[0084] 402. The vacuum velocity is processed according to the coordinate system rotation matrix to obtain the vacuum velocity in the navigation coordinate system.

[0085] In this embodiment of the application, by processing the vacuum velocity according to the aforementioned coordinate system rotation matrix, the vacuum velocity in the body coordinate system that is collected in real time can be converted to the vacuum velocity in the navigation coordinate system.

[0086] 403. Determine the wind speed information in the navigation coordinate system based on the vacuum speed in the navigation coordinate system and the ground speed information in the inertial navigation information.

[0087] In this embodiment, the wind speed in the navigation coordinate system can be obtained by subtracting the ground speed (which is also referenced by the navigation coordinate system) from the vacuum speed in the navigation coordinate system.

[0088] Specifically, to more clearly illustrate the calculation process for determining wind speed information based on inertial navigation information and vacuum velocity in the embodiments of this application, the calculation formula is given below:

[0089]

[0090] in, It is the vacuum velocity directly acquired by the airspeed meter, with the aircraft's coordinate system as a reference. It is a rotation matrix from the navigation coordinate system to the body coordinate system related to the drone's attitude. It is the velocity information in the inertial navigation information calculated by the inertial measurement unit, that is, the ground speed of the UAV in the navigation coordinate system. This refers to the wind speed information in the navigation coordinate system to be estimated in this embodiment of the application.

[0091] In this embodiment, by further utilizing the attitude information in the inertial navigation information to determine the transformation matrix related to the attitude of the UAV, the vacuum speed and ground speed in different coordinate systems can be mapped to the same coordinate system, thereby enabling the calculation of a more accurate wind speed, which facilitates the subsequent use of wind speed correction to obtain more accurate navigation information.

[0092] like Figure 5 As shown, Figure 5 This is a schematic flowchart illustrating another step in determining wind speed information based on inertial navigation information and vacuum velocity, as provided in an embodiment of this application. Details are as follows.

[0093] This application embodiment provides a process for correcting navigation information under GNSS conditions to obtain more accurate wind speed information, specifically including steps 501-502:

[0094] 501. If the signal strength of the satellite navigation signal is higher than or equal to a preset strength threshold, the inertial navigation information is corrected according to the satellite navigation signal to obtain the second navigation information.

[0095] In this embodiment of the application, if the signal strength of the satellite navigation signal is higher than or equal to a preset strength threshold, the GNSS of the UAV can be considered to be in an effective working state. At this time, by processing the satellite navigation signal received by the GNSS receiver, the GNSS navigation information of the UAV can be obtained. By using the GNSS navigation information to perform Kalman filtering correction on the inertial navigation information, the accumulated error in the inertial navigation information can be corrected, thereby outputting optimized navigation information.

[0096] Furthermore, as an optional embodiment of this application, in addition to correcting the inertial navigation information based on GNSS satellite navigation signals, data from other sensors deployed on the UAV can also be used to correct the inertial navigation information. Specific implementation schemes can be found in the following sections. Figure 6 And its explanations and descriptions.

[0097] 502, Determine the wind speed information based on the second navigation information and the vacuum speed.

[0098] In this embodiment, compared with the prior art, when GNSS is available, the inertial navigation information is corrected using GNSS navigation information, and after outputting optimized navigation information, the UAV navigation device further calculates the real-time wind speed based on the optimized navigation information, i.e., the second navigation information, and the collected vacuum velocity. The specific process for calculating the wind speed can be the same as described above. Figure 4 The proposed solutions are similar, differing only in that the navigation information used is inertial navigation information corrected from GNSS navigation information. Specifically, the attitude information in the second navigation information is used to determine the corresponding coordinate system rotation matrix. Based on this rotation matrix, the vacuum velocity is transformed to obtain the vacuum velocity in the navigation coordinate system. Then, the ground speed information in the second navigation information is subtracted from the vacuum velocity in the navigation coordinate system to obtain the final wind speed information.

[0099] The method provided in this application, when the GNSS signal is valid, not only corrects the inertial navigation information using GNSS navigation information to obtain optimized inertial navigation information, but also further estimates wind speed information based on the optimized inertial navigation information and the real-time vacuum velocity. Since the wind speed at high altitudes can remain relatively stable for a short period of time, when GNSS fails due to external interference, the latest estimated wind speed before the GNSS failure can be used in conjunction with the real-time vacuum velocity to infer the observed ground speed of the UAV, thereby correcting the inertial navigation information when GNSS fails and improving the navigation effect of the UAV.

[0100] like Figure 6 As shown, Figure 6 This is a flowchart illustrating the steps for correcting inertial navigation information, as provided in an embodiment of this application. Details are as follows.

[0101] This application provides an implementation scheme for correcting inertial navigation information based on data from multiple sensors on a UAV, specifically including steps 601-603:

[0102] 601, Obtain the heading angle and flight altitude of the target UAV.

[0103] In this embodiment of the application, after the magnetic field strength and direction are collected by the magnetometer installed on the UAV, the UAV navigation device can determine the heading angle of the UAV based on the real-time magnetic field strength and direction. Similarly, after the air pressure is collected by the barometer installed on the UAV, the UAV navigation device can calculate the flight altitude of the UAV based on the real-time air pressure value.

[0104] 602. Target correction information is determined from the satellite navigation signal, the heading angle, and the flight altitude based on the statistical characteristics of the data.

[0105] In this embodiment, considering the potential for sensor malfunctions and other anomalies during high-altitude flight of the UAV, it is necessary to assess the effectiveness of the sensors. Specifically, this can be achieved by statistically analyzing the data collected by the sensors to determine if there are any anomalies such as data drift. In other words, based on the statistical characteristics of satellite navigation information, heading angle, and flight altitude, data with higher quality is selected from the satellite navigation signals, heading angle, and flight altitude to serve as target correction information.

[0106] 603. The inertial navigation information is corrected according to the target correction information to obtain the second navigation information.

[0107] In this embodiment, if the satellite navigation signal data quality is optimal, GNSS can be used as the primary observation navigation source to correct the inertial navigation information. If the magnetometer data quality is optimal, the heading angle can be used as the heading observation navigation source to correct the inertial navigation information. If the barometer data quality is optimal, the flight altitude can be used as the vertical channel observation navigation source to correct the inertial navigation information. The specific implementation process of using different observation channels as observation navigation sources to correct the inertial navigation information will not be detailed here.

[0108] like Figure 7 As shown, Figure 7 This is a schematic flowchart illustrating another step in correcting inertial navigation information according to an embodiment of this application. Details are as follows.

[0109] In this embodiment of the application, another implementation scheme for correcting inertial navigation information in the event of GNSS failure is proposed. Specifically, the inertial navigation information is corrected only when the vacuum velocity is valid, that is, when the calculated wind speed information is valid. If the calculated wind speed information is invalid, only the correction of the UAV attitude in the navigation information is retained. Specifically, steps 701 to 703 are included:

[0110] 701. Obtain the statistical characteristics of the vacuum velocity data, and determine whether the statistical characteristics of the vacuum velocity data are less than a preset characteristic threshold. If yes, proceed to step 702; if no, proceed to step 703.

[0111] In this application embodiment, the statistical characteristics of vacuum speed data typically refer to the variance describing the fluctuation of vacuum speed data. Specifically, a large variance indicates that the vacuum speed fluctuates significantly, which may indicate an anomaly in the airspeed meter. In this case, the wind speed calculated using the vacuum speed will also have a large error, making it difficult to correct speed, position, and other information in inertial navigation information when GNSS fails. Conversely, a small variance indicates that the vacuum speed fluctuates less, the airspeed meter is of good quality, and a relatively accurate wind speed can be calculated. Therefore, it can be used to correct speed, position, and other information in inertial navigation information when GNSS fails.

[0112] 702, The inertial navigation information is corrected based on the wind speed information to obtain the first navigation information.

[0113] In this embodiment of the application, when the GNSS fails but the airspeed meter is good, that is, when the wind speed data is accurate, the wind speed information can be used to correct the position, velocity and attitude information in the inertial navigation information to obtain the corrected first navigation information.

[0114] 703. The attitude information in the inertial navigation information is corrected according to the linear acceleration of the target UAV to obtain corrected attitude information, and the corrected attitude information is set as the first navigation information.

[0115] In this embodiment, when GNSS fails and airspeed meter data is poor, accurate wind speed information cannot be estimated, and therefore, the speed and position in the inertial navigation information cannot be effectively corrected. In this situation, the UAV navigation device abandons the estimation of the UAV's speed and position, retaining only the effective attitude output. Specifically, the UAV navigation device calculates the rotation of the UAV's body coordinate system relative to the Earth coordinate system based on accelerometer measurements, thereby inferring the UAV's attitude. That is, it uses only the linear acceleration of the target UAV to correct the attitude information in the inertial navigation information, obtaining the corrected attitude information to control the UAV and avoid attitude anomalies such as rollover.

[0116] like Figure 8 As shown, Figure 8 This is a schematic flowchart illustrating the steps for obtaining inertial navigation information according to an embodiment of this application. Details are as follows.

[0117] This application provides a specific implementation scheme for acquiring inertial navigation information, including steps 801 to 805:

[0118] 801, acquire the target UAV's initial position information, initial velocity information, initial attitude information, linear acceleration, and angular velocity.

[0119] In this embodiment, considering that the UAV's inertial navigation information is obtained through real-time strapdown recursion, the initial position information of the target UAV can be understood as the position information in the previous inertial navigation information, the initial velocity information can be understood as the velocity information in the previous inertial navigation information, and the initial attitude information can be understood as the attitude information in the previous inertial navigation information. The linear acceleration and angular velocity are obtained from the outputs of the three-axis accelerometer and three-axis gyroscope in the inertial measurement unit, respectively.

[0120] 802. Based on the initial velocity information and the acceleration, the target ground speed information of the target UAV is obtained.

[0121] In this embodiment, the change in the drone's velocity can be obtained by integrating the acceleration output from the triaxial accelerometer. Combined with the initial velocity of the target drone at the previous moment, the target velocity of the target drone at the current moment can be calculated. This target velocity is the real-time ground speed of the target drone. Simultaneously, the target velocity at the current moment is also considered as the initial velocity of the target drone at the previous moment for the next moment.

[0122] 803. Based on the initial position information and the ground speed information, the target position information of the target UAV is obtained.

[0123] In this embodiment, similar to the integral of acceleration, the displacement change of the UAV can be obtained by accumulating the ground speed information. Combined with the initial position of the target UAV at the previous moment, the target position of the target UAV at the current moment can be calculated. This target position is the real-time position of the target UAV. Furthermore, the target position at the current moment will also be considered as the initial position information of the target UAV at the previous moment for the next moment.

[0124] 804. Based on the initial attitude information and the angular velocity, the target attitude information of the target UAV is obtained.

[0125] In this embodiment, similarly, by integrating the angular velocities of the UAV measured by the three-axis gyroscope at various angles, the changes in the UAV at each angle can be obtained. Combined with the attitude information of the target UAV at the previous moment, the target attitude of the target UAV at the current moment can be obtained. This target attitude is the real-time attitude information of the target UAV. Furthermore, the target attitude at the current moment will also be considered as the initial attitude information of the target UAV at the previous moment for the next moment.

[0126] 805, set the target ground speed information, the target position information, and the target attitude information as the inertial navigation information of the target UAV.

[0127] In this embodiment, the target ground speed information, target position information, and target attitude information obtained during the aforementioned strapdown recursion process can be understood as the velocity information, position information, and attitude information in the inertial navigation information, respectively. It is also understood that if the initial position information, initial velocity information, and initial attitude information during the strapdown recursion process are relatively accurate, then the linear acceleration and angular velocity measured by the inertial measurement unit can be used to obtain relatively accurate inertial navigation information within a short time. However, over a long period, as the errors in linear acceleration and angular velocity accumulate, the error between the inertial navigation information and the true value will become increasingly larger. Therefore, it is necessary to introduce other navigation information to correct the inertial navigation information.

[0128] To better understand the specific implementation scheme of the UAV navigation method provided in the embodiments of this application, the following will be combined with Figures 1 to 8 The provided embodiments illustrate the complete implementation steps of a UAV navigation method. Details are as follows.

[0129] 1) Real-time acquisition of data from various sensors installed on the UAV, including: output data from the three-axis accelerometer and three-axis gyroscope in the inertial measurement unit, GNSS signals received by the GNSS receiver, barometer output data, magnetometer output data and airspeed meter output data;

[0130] 2) Process the collected data accordingly to obtain the corresponding UAV information, and judge the data quality of the corresponding sensors based on the statistical characteristics of the collected data; for example, perform strapdown recursive calculation on the data collected by the three-axis accelerometer and three-axis gyroscope to obtain the UAV's inertial navigation information, solve the GNSS signal to obtain the UAV's GNSS navigation information, convert the barometer output data to obtain the UAV's flight altitude, convert the magnetometer output data to obtain the UAV's heading angle, and convert the airspeed meter output data to obtain the UAV's vacuum speed;

[0131] 3) By comparing the signal strength of the GNSS signal with the preset strength threshold, the validity of the GNSS navigation information can be determined;

[0132] 4) If the GNSS signal strength is greater than a preset strength threshold, meaning the GNSS navigation information is valid, then the optimal sensor data is selected from the GNSS signal, barometer output data, and magnetometer output data to correct the UAV's inertial navigation information, resulting in corrected inertial navigation information. Specifically, if the GNSS signal is optimal, the GNSS navigation information obtained from the GNSS signal is used as the primary observation navigation source to perform Kalman filtering correction on the UAV's inertial navigation information; if the magnetometer output data quality is optimal, the heading angle obtained from the magnetometer output data is used as the heading observation navigation source to perform Kalman filtering correction on the UAV's inertial navigation information; if the barometer output data quality is optimal, the flight altitude obtained from the barometer output data is used as the vertical channel observation navigation source to perform Kalman filtering correction on the UAV's inertial navigation information.

[0133] 5) After correcting the UAV’s inertial navigation information using the best sensor data, the corrected inertial navigation information is output to control the UAV. At the same time, based on the relationship between airspeed, ground speed and wind speed in different reference coordinate systems, the wind speed information is calculated using the vacuum speed obtained from the airspeed meter output data and the speed information in the corrected inertial navigation information, and stored as real-time wind speed. Then, return to step 1) to continue collecting data from various sensors installed on the UAV.

[0134] 6) If the GNSS signal strength is less than or equal to a preset strength threshold, i.e., the GNSS navigation information is invalid, then the validity of the airspeed indicator output data should be further determined.

[0135] 7) If the airspeed meter is of good quality, that is, when the airspeed meter output data is valid, then extract the real-time wind speed stored in step 5), and calculate the observed ground speed using the real-time wind speed stored in step 5 and the airspeed meter based on the relationship between airspeed, ground speed and wind speed in different reference coordinate systems. Then, use the observed ground speed to perform Kalman filtering correction on the UAV's inertial navigation information to obtain the corrected inertial navigation information, and output it to control the UAV. Then return to step 1) to continue collecting data from various sensors installed on the UAV.

[0136] 8) If the airspeed meter output data also fails, abandon the estimation of speed and position in the navigation information, calculate the rotation of the UAV's body coordinate system relative to the geographic coordinate system using the data collected by the accelerometer, thereby correcting the UAV's attitude information in the navigation information, and output the UAV's attitude information as navigation information to control the UAV's attitude, and then return to step 1) to continue collecting data from various sensors installed on the UAV.

[0137] To better implement the UAV navigation method in the embodiments of this application, a UAV navigation device is also provided in the embodiments of this application, based on the UAV navigation method. For example... Figure 9 As shown, Figure 9 This is a schematic diagram of the structure of a drone navigation device provided in an embodiment of this application. Specifically, the drone navigation device includes:

[0138] The acquisition module 901 is used to acquire the inertial navigation information, satellite navigation signals, and vacuum speed of the target UAV.

[0139] The wind speed calculation module 902 is used to determine wind speed information based on the inertial navigation information and the vacuum speed.

[0140] The navigation correction module 903 is used to correct the inertial navigation information based on the wind speed information to obtain first navigation information if the signal strength of the satellite navigation signal is lower than a preset strength threshold.

[0141] In some embodiments of this application, the navigation correction module includes:

[0142] The ground speed calculation module is used to determine the ground speed of the target UAV based on the wind speed information and the vacuum speed.

[0143] The filtering and correction submodule is used to filter and correct the inertial navigation information based on the observed ground speed and the ground speed information in the inertial navigation information to obtain the first navigation information.

[0144] In some embodiments of this application, the wind speed calculation module includes:

[0145] The rotation matrix determination submodule is used to determine the coordinate system rotation matrix based on the attitude information in the inertial navigation information;

[0146] The vacuum velocity transformation module is used to process the vacuum velocity according to the coordinate system rotation matrix to obtain the vacuum velocity in the navigation coordinate system.

[0147] The wind speed calculation sub-module is used to determine the wind speed information in the navigation coordinate system based on the vacuum speed in the navigation coordinate system and the ground speed information in the inertial navigation information.

[0148] In some embodiments of this application, the wind speed calculation module includes:

[0149] The satellite navigation correction submodule is used to correct the inertial navigation information according to the satellite navigation signal if the signal strength of the satellite navigation signal is higher than or equal to a preset strength threshold, so as to obtain second navigation information.

[0150] The wind speed determination submodule is used to determine wind speed information based on the second navigation information and the vacuum speed.

[0151] In some embodiments of this application, the above-mentioned satellite navigation correction sub-module includes:

[0152] The parameter acquisition unit is used to acquire the heading angle and flight altitude of the target UAV;

[0153] The parameter filtering unit is used to determine target correction information from the satellite navigation signal, the heading angle, and the flight altitude based on the statistical characteristics of the data of the satellite navigation signal, the heading angle, and the flight altitude;

[0154] The navigation correction unit is used to correct the inertial navigation information according to the target correction information to obtain second navigation information.

[0155] In some embodiments of this application, the navigation correction module includes:

[0156] The data statistical feature acquisition sub-module is used to acquire the data statistical features of the vacuum velocity if the signal strength of the satellite navigation signal is lower than a preset strength threshold.

[0157] The first correction module is used to perform the step of correcting the inertial navigation information based on the wind speed information to obtain the first navigation information if the statistical characteristics of the vacuum velocity data are less than a preset characteristic threshold.

[0158] The second correction module is used to correct the attitude information in the inertial navigation information according to the linear acceleration of the target UAV if the statistical characteristics of the vacuum velocity data are greater than or equal to a preset characteristic threshold, so as to obtain corrected attitude information and set the corrected attitude information as the first navigation information.

[0159] In some embodiments of this application, the above-mentioned acquisition module includes:

[0160] The initial navigation information acquisition submodule is used to acquire the target UAV's initial position information, initial velocity information, initial attitude information, linear acceleration, and angular velocity.

[0161] The ground speed calculation sub-module is used to obtain the target ground speed information of the target UAV based on the initial speed information and the acceleration.

[0162] The position calculation sub-module is used to obtain the target position information of the target UAV based on the initial position information and the ground speed information;

[0163] The attitude determination submodule is used to obtain the target attitude information of the target UAV based on the initial attitude information and the angular velocity.

[0164] The inertial navigation information update submodule is used to set the target ground speed information, the target position information, and the target attitude information as the inertial navigation information of the target UAV.

[0165] This application also provides a drone navigation device, such as... Figure 10 As shown, Figure 10 This is a schematic diagram of the structure of a drone navigation device provided in an embodiment of this application.

[0166] The drone navigation device includes a memory, a processor, and a drone navigation program stored in the memory and capable of running on the processor. When the processor executes the drone navigation program, it implements the steps in the drone navigation method provided in any embodiment of this application.

[0167] Specifically, a drone navigation device may include components such as a processor 1001 with one or more processing cores, a memory 1002 with one or more storage media, a power supply 1003, and an input unit 1004. Those skilled in the art will understand that... Figure 10 The structure of the drone navigation device shown does not constitute a limitation on the drone navigation device. It may include more or fewer components than shown, or combine certain components, or have different component arrangements. Wherein:

[0168] The processor 1001 is the control center of the UAV navigation device. It connects various parts of the UAV navigation device via various interfaces and lines. By running or executing software programs and / or modules stored in the memory 1002, and by calling data stored in the memory 1002, it performs various functions and processes data of the UAV navigation device, thereby providing overall monitoring of the UAV navigation device. Optionally, the processor 1001 may include one or more processing cores; preferably, the processor 1001 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operating system, user interface, and applications, and the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into the processor 1001.

[0169] The memory 1002 can be used to store software programs and modules. The processor 1001 executes various functional applications and data processing by running the software programs and modules stored in the memory 1002. The memory 1002 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for at least one function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created based on the use of the UAV navigation device, etc. In addition, the memory 1002 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, the memory 1002 may also include a memory controller to provide the processor 1001 with access to the memory 1002.

[0170] The UAV navigation device also includes a power supply 1003 that supplies power to the various components. Preferably, the power supply 1003 can be logically connected to the processor 1001 through a power management system, thereby enabling functions such as charging, discharging, and power consumption management through the power management system. The power supply 1003 may also include one or more DC or AC power supplies, recharging systems, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components.

[0171] The drone navigation device may also include an input unit 1004, which can be used to receive input digital or character information, and generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function control.

[0172] Although not shown, the UAV navigation device may also include a display unit, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 1001 in the UAV navigation device loads the executable files corresponding to the processes of one or more applications into the memory 1002 according to the following instructions, and the processor 1001 runs the applications stored in the memory 1002, thereby implementing the steps in the UAV navigation method provided in any embodiment of this application.

[0173] Therefore, embodiments of this application provide a computer-readable storage medium, which may include: read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk, etc. The computer-readable storage medium stores a drone navigation program, which, when executed by a processor, implements the steps of the drone navigation method provided in any embodiment of this application.

[0174] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0175] In practice, each of the above units or structures can be implemented as an independent entity or can be arbitrarily combined to be implemented as the same or several entities. For the specific implementation of each of the above units or structures, please refer to the previous method embodiments, which will not be repeated here.

[0176] For details on the implementation of each of the above operations, please refer to the previous examples, which will not be repeated here.

[0177] The above provides a detailed description of a drone navigation method provided by the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A navigation method for unmanned aerial vehicles (UAVs), characterized in that, include: Acquire the target UAV's inertial navigation information, satellite navigation signals, and vacuum speed; Wind speed information is determined based on the inertial navigation information and the vacuum speed; If the signal strength of the satellite navigation signal is lower than a preset strength threshold, the inertial navigation information is corrected according to the wind speed information to obtain the first navigation information; If the signal strength of the satellite navigation signal is lower than a preset strength threshold, the inertial navigation information is corrected based on the wind speed information to obtain first navigation information, including: If the signal strength of the satellite navigation signal is lower than a preset strength threshold, then the data statistical characteristics of the vacuum velocity are obtained; If the statistical characteristics of the vacuum velocity data are less than a preset characteristic threshold, the inertial navigation information is corrected according to the wind speed information to obtain the first navigation information; If the statistical characteristics of the vacuum velocity data are greater than or equal to a preset characteristic threshold, the attitude information in the inertial navigation information is corrected according to the linear acceleration of the target UAV to obtain corrected attitude information, and the corrected attitude information is set as the first navigation information.

2. The UAV navigation method according to claim 1, characterized in that, The step of correcting the inertial navigation information based on the wind speed information to obtain the first navigation information includes: Based on the wind speed information and the vacuum velocity, the observed ground velocity of the target UAV is determined; Based on the observed ground speed and the ground speed information in the inertial navigation information, the inertial navigation information is filtered and corrected to obtain the first navigation information.

3. The UAV navigation method according to claim 1, characterized in that, The step of determining wind speed information based on the inertial navigation information and the vacuum velocity includes: The coordinate system rotation matrix is ​​determined based on the attitude information in the inertial navigation information; The vacuum velocity is processed according to the coordinate system rotation matrix to obtain the vacuum velocity in the navigation coordinate system; The wind speed information in the navigation coordinate system is determined based on the vacuum speed in the navigation coordinate system and the ground speed information in the inertial navigation information.

4. The UAV navigation method according to claim 1, characterized in that, The step of determining wind speed information based on the inertial navigation information and the vacuum velocity includes: If the signal strength of the satellite navigation signal is higher than or equal to a preset strength threshold, the inertial navigation information is corrected based on the satellite navigation signal to obtain second navigation information; Wind speed information is determined based on the second navigation information and the vacuum speed.

5. The UAV navigation method according to claim 4, characterized in that, The step of correcting the inertial navigation information based on the satellite navigation signal to obtain second navigation information includes: Obtain the heading angle and flight altitude of the target UAV; Target correction information is determined from the satellite navigation signal, the heading angle, and the flight altitude based on the statistical characteristics of the data. The inertial navigation information is corrected based on the target correction information to obtain the second navigation information.

6. The UAV navigation method according to any one of claims 1 to 5, characterized in that, The acquisition of the inertial navigation information of the target UAV includes: Acquire the target UAV's initial position, initial velocity, initial attitude, linear acceleration, and angular velocity; Based on the initial velocity information and the acceleration, the target ground speed information of the target UAV is obtained; Based on the initial position information and the ground speed information, the target position information of the target UAV is obtained; Based on the initial attitude information and the angular velocity, the target attitude information of the target UAV is obtained; The target ground speed information, the target position information, and the target attitude information are set as the inertial navigation information of the target UAV.

7. A drone navigation device, characterized in that, include: The acquisition module is used to acquire the target UAV's inertial navigation information, satellite navigation signals, and vacuum speed. A wind speed calculation module is used to determine wind speed information based on the inertial navigation information and the vacuum speed; A navigation correction module is used to correct the inertial navigation information based on the wind speed information to obtain first navigation information if the signal strength of the satellite navigation signal is lower than a preset strength threshold. If the signal strength of the satellite navigation signal is lower than a preset strength threshold, the inertial navigation information is corrected based on the wind speed information to obtain first navigation information, including: If the signal strength of the satellite navigation signal is lower than a preset strength threshold, then the data statistical characteristics of the vacuum velocity are obtained; If the statistical characteristics of the vacuum velocity data are less than a preset characteristic threshold, the inertial navigation information is corrected according to the wind speed information to obtain the first navigation information; If the statistical characteristics of the vacuum velocity data are greater than or equal to a preset characteristic threshold, the attitude information in the inertial navigation information is corrected according to the linear acceleration of the target UAV to obtain corrected attitude information, and the corrected attitude information is set as the first navigation information.

8. A drone navigation device, characterized in that, The drone navigation device includes a processor, a memory, and a drone navigation program stored in the memory and executable on the processor. The processor executes the drone navigation program to implement the steps of the drone navigation method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a drone navigation program, which is executed by a processor to implement the steps of the drone navigation method according to any one of claims 1 to 6.

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