GNSS dual-antenna calibration method and system

Abstract

The present invention discloses a GNSS dual-antenna calibration method and system, wherein a GNSS dual-antenna calibration method includes: determining a coarsely calibrated installation deflection between the dual antenna and the longitudinal axis of the vehicle body through the difference between the track angle and the dual-antenna heading angle in the GNSS positioning data; compensating the dual-antenna heading angle using the coarsely calibrated installation deflection to obtain a compensated dual-antenna heading angle; and obtaining a precisely calibrated dual-antenna orientation through the heading angle of the vehicle body and the compensated dual-antenna heading angle. In an embodiment of the present application, a coarsely calibrated installation deflection is first obtained using the track angle and the dual-antenna heading angle, and the compensated dual-antenna heading angle is obtained using the coarsely calibrated installation deflection. The compensated dual-antenna heading angle is then used in subsequent calculations, and a more accurate precisely calibrated dual-antenna orientation can be obtained through the vehicle body heading angle and the compensated dual-antenna heading angle.

Description

Technical Field

[0001] The present invention belongs to the technical field of GNSS dual-antenna orientation calibration, and in particular relates to a GNSS dual-antenna calibration method and system. Background Art

[0002] Dual-antenna heading is currently crucial in vehicle-mounted integrated navigation systems, particularly for autonomous driving systems, which place high demands on positioning and orientation. When using GNSS dual-antenna heading, the baseline length is closely linked to heading accuracy. For example, a one-meter baseline typically has an accuracy of 0.2°, while a two-meter baseline has an accuracy of 0.1°.

[0003] Existing technical solutions have high requirements for the installation of dual antennas, such as strict requirements for left-right installation (with an angle of ±90° to the center axis of the vehicle body) or front-to-back installation (with an angle of 0° or 180° to the center axis of the vehicle body), which has certain limitations. However, in autonomous vehicles, due to vehicle model restrictions, limited distance between the vehicle body and width, and space occupied by the installation of other sensors, the GNSS dual antennas cannot be strictly placed front-to-back or left-to-right. Sometimes they need to be placed diagonally to maximize the baseline length between the dual antennas to improve the directional accuracy. In this case, calibrating the angle between the dual antennas and the vehicle body becomes difficult. Summary of the Invention

[0004] The embodiments of the present invention provide a GNSS dual-antenna calibration method and apparatus, which are used to solve at least one of the above-mentioned technical problems.

[0005] In a first aspect, an embodiment of the present invention provides a GNSS dual-antenna calibration method for a vehicle body, comprising: determining a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body through the difference between the track angle and the dual-antenna heading angle in the GNSS positioning data; compensating the dual-antenna heading angle using the coarsely calibrated installation deflection angle to obtain a compensated dual-antenna heading angle; and obtaining a finely calibrated dual-antenna orientation through the vehicle body heading angle and the compensated dual-antenna heading angle.

[0006] In a second aspect, an embodiment of the present invention provides a GNSS dual-antenna calibration system for a vehicle body, comprising: a coarse calibration program unit, configured to determine a coarsely calibrated installation deflection angle between the dual antenna and the longitudinal axis of the vehicle body through the difference between the track angle and the dual-antenna heading angle in the GNSS positioning data; a compensation program unit, configured to compensate the dual-antenna heading angle using the coarsely calibrated installation deflection angle to obtain a compensated dual-antenna heading angle; and a fine calibration program unit, configured to obtain a finely calibrated orientation of the dual antenna through the heading angle of the vehicle body and the compensated dual-antenna heading angle.

[0007] In a third aspect, an electronic device is provided, comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the GNSS dual-antenna calibration method of any embodiment of the present invention.

[0008] In a fourth aspect, an embodiment of the present invention further provides a computer program product, which includes a computer program stored on a non-volatile computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the steps of the GNSS dual-antenna calibration method of any embodiment of the present invention.

[0009] The method and system of the present application first use the track angle and the dual-antenna heading angle to obtain a coarsely calibrated installation deflection angle, use the coarsely calibrated installation deflection angle to obtain the compensated dual-antenna heading angle, and then use the compensated dual-antenna heading angle in subsequent calculations. Afterwards, a more accurately calibrated dual-antenna orientation can be obtained through the vehicle's heading angle and the compensated dual-antenna heading angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0011] Figure 1 A flowchart of a GNSS dual-antenna calibration method provided by one embodiment of the present invention;

[0012] Figure 2 A flowchart of another GNSS dual-antenna calibration method provided by one embodiment of the present invention;

[0013] Figure 3 A flowchart of another GNSS dual-antenna calibration method provided by one embodiment of the present invention;

[0014] Figure 4 A schematic diagram of the application and execution process of the RTS (Rauch-Tung-Striebel) algorithm in GNSS / INS integrated navigation in a specific example provided in one embodiment of the present invention;

[0015] Figure 5 A block diagram of a GNSS dual-antenna calibration system provided by one embodiment of the present invention;

[0016] Figure 6 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0018] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0019] The present invention may be described in the general context of computer-executable instructions, such as program modules, executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media, including storage devices.

[0020] In the present invention, "module", "device", "system" and the like refer to related entities applied to a computer, such as hardware, a combination of hardware and software, software or software in execution, etc. Specifically, for example, an element can be, but is not limited to, a process running on a processor, a processor, an object, an executable element, an execution thread, a program and / or a computer. In addition, an application or script program running on a server, or a server can all be an element. One or more elements can be in an execution process and / or thread, and an element can be localized on a computer and / or distributed between two or more computers, and can be run by various computer-readable media. An element can also communicate through local and / or remote processes based on a signal having one or more data packets, for example, a signal from a data packet interacting with another element in a local system, a distributed system, and / or a signal from a network on the Internet that interacts with other systems via signals.

[0021] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include" and "comprise" include not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or device. In the absence of further limitations, the elements defined by the phrase "include..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0022] Please refer to Figure 1 , which shows a flowchart of an embodiment of the GNSS dual-antenna calibration method of the present application. The GNSS dual-antenna calibration method of this embodiment can be applied to vehicles with navigation and positioning systems, including but not limited to vehicles with six autonomous driving technology levels L0-L5 as formulated by the Society of Automotive Engineers International (SAE International) or the Chinese national standard "Automotive Driving Automation Classification".

[0023] In this application, the vehicle may have a passenger-carrying function (such as a family car, a bus, etc.), a cargo-carrying function (such as an ordinary truck, a van, a trailer, a closed truck, a tank truck, a flatbed truck, a container truck, a dump truck, a truck with a special structure, etc.), a tool function (such as a logistics distribution vehicle, an automatic guided vehicle AGV, a patrol car, a crane, a crane, an excavator, a bulldozer, a forklift, a road roller, a loader, an off-road engineering vehicle, an armored engineering vehicle, a sewage treatment vehicle, a sanitation vehicle, a vacuum cleaner, a floor washer, a sprinkler truck, a sweeping robot, a lawn mower, a golf cart), an entertainment function (such as an entertainment vehicle, an amusement park automatic driving device, a balance car) or a special rescue function (such as a fire truck, an ambulance, a power repair vehicle, an engineering rescue vehicle, etc.).

[0024] like Figure 1 As shown, in step 101, the roughly calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body (hereinafter referred to as the vehicle body) is determined by the difference between the track angle and the dual antenna heading angle in the GNSS positioning data;

[0025] In step 102, the dual-antenna heading angle is compensated using the roughly calibrated installation deflection angle to obtain a compensated dual-antenna heading angle;

[0026] In step 103, the orientation of the precisely calibrated dual antennas is obtained by using the heading angle of the vehicle body and the compensated dual antenna heading angles.

[0027] In this embodiment, for step 101, the GNSS dual-antenna calibration system can determine the roughly calibrated installation deflection angle between the GNSS dual antenna and the longitudinal axis of the vehicle body based on the difference between the collected track angle and the dual-antenna heading angle in the GNSS positioning data. Among them, the track angle can be directly output in some satellite navigation positioning boards or chips, such as the UB482 board of Hexinxingtong, and this application is not limited here. The heading angle can be obtained from the GNSS positioning data, and the method and process of obtaining it are not repeated here. By obtaining the difference between the track angle and the heading angle in a set time period, the installation deflection angle can be roughly positioned to obtain a rough positioning value of the installation deflection angle. Among them, the set time period can refer to a time period after the vehicle starts moving (the speed can be selected as high as possible, for example, greater than 10m / s). The GNSS board will always output the dual-antenna heading angle and track angle, for example 10 times per second, and collect data for a period of time, that is, the set time period can refer to a time period when the vehicle is traveling at a speed greater than 10m / s.

[0028] Then, for step 102, the dual-antenna heading angle in the subsequent GNSS positioning data is compensated using the coarse positioning value of the installation deflection angle to obtain the compensated dual-antenna heading angle value.

[0029] Finally, in step 103, the precisely calibrated dual-antenna orientation can be obtained using the vehicle's heading angle and the compensated heading angle. The compensated dual-antenna heading angle is also used in the process of obtaining the vehicle's heading angle. By obtaining the difference between the vehicle's heading angle and the compensated heading angle within a set time period, a precisely calibrated value for the dual-antenna orientation can be obtained. The set time period here can refer to the time period during which the vehicle runs on a straight road (or a road section without large curves) after maneuvering. For example, the vehicle can first run on an open straight road at the fastest possible speed (e.g., greater than 10 m / s), then come to rest, and then run a section of the route in a maneuvering manner. Maneuvering includes turning or accelerating or decelerating with large speed changes, followed by running on a straight road. In this embodiment, the set time period can be the time period after turning or accelerating or decelerating before running on a straight road.

[0030] The method of this embodiment first uses the track angle and the dual-antenna heading angle to obtain a coarsely calibrated installation deflection angle, uses the coarsely calibrated installation deflection angle to obtain the compensated dual-antenna heading angle, and then uses the compensated dual-antenna heading angle in subsequent calculations. Thereafter, a more accurate and precisely calibrated dual-antenna orientation can be obtained by combining the vehicle's heading angle with the compensated dual-antenna heading angle.

[0031] In some optional embodiments, after obtaining the finely calibrated dual-antenna orientation, the method further includes determining a calibration angle between the dual GNSS antenna heading angle and the longitudinal axis of the vehicle body based on the coarsely calibrated installation deflection and the finely calibrated dual-antenna orientation. Through coarse and fine calibration, a more precise calibration angle can be obtained. This more precise calibration angle calculation method allows the dual GNSS antennas to be placed at an angle or in any desired position.

[0032] In other optional embodiments, before obtaining the precisely calibrated dual-antenna orientation using the vehicle's heading angle and the compensated dual-antenna heading angle, the method further includes: estimating the vehicle's state using a GNSS / INS navigation system to obtain the vehicle's heading angle. After obtaining the vehicle's state estimate using the GNSS / INS navigation system, compensation can be performed within the inertial navigation system to obtain the vehicle's attitude, and thus the vehicle's heading angle.

[0033] In some optional embodiments, estimating the vehicle state using a combined GNSS / INS navigation system includes estimating the vehicle state using an RTS smoothing algorithm. A Rauch-Tung-Striebel (RTS) smoothing algorithm may be used in the GNSS / INS combined navigation algorithm instead of a conventional extended Kalman filter (EKF) algorithm because, compared to the EKF algorithm, the RTS smoothing algorithm can achieve more accurate state estimation, particularly higher attitude accuracy. The attitude accuracy achieved using this method is comparable to, to a certain extent, that of higher-precision inertial navigation devices.

[0034] Further references Figure 2 , which shows a flowchart of another GNSS dual-antenna calibration method provided by an embodiment of the present invention. Figure 1 A flowchart of the steps further defined in step 101 of "determining a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body by the difference between the track angle and the dual antenna heading angle in the GNSS positioning data".

[0035] like Figure 2 As shown, in step 201, multiple differences between the matched track angles at multiple moments in a time period when the vehicle speed is greater than a threshold and the dual-antenna heading angles in the GNSS positioning data are averaged;

[0036] In step 202 , the averaged difference is used as a roughly calibrated installation angle between the dual antennas and the longitudinal axis of the vehicle body.

[0037] In this embodiment, data is collected over a period of time, and then the differences between multiple matched track angles and the dual-antenna heading angles in the GNSS positioning data during this period are calculated. That is, the track angles and the dual-antenna heading angles in the GNSS positioning data are both selected at the same time, and then multiple differences are calculated. The multiple moments refer to multiple moments in a time period when the vehicle speed is greater than a threshold, making it easier to obtain a track angle with higher accuracy. For example, the multiple moments can refer to the time after the vehicle body starts moving (it is best to select a time when the speed is higher, such as greater than 10m / s). The GNSS board will constantly output the dual-antenna heading angle and track angle, such as 10 times per second, and data can be collected for a period of time. That is, the period in this case can refer to a time period when the vehicle body speed is greater than 10m / s. Afterwards, the multiple differences obtained are averaged, for example, by calculating the average value, to obtain a coarsely calibrated installation deflection angle. Since the coarsely calibrated installation deflection angle is obtained by averaging the data of a set time period, it can reflect the average situation of the time period and has a certain degree of accuracy.

[0038] Further references Figure 3 , which shows a flowchart of another GNSS dual-antenna calibration method provided by an embodiment of the present invention. Figure 1 A flowchart of the steps further defined in step 103 of "obtaining the orientation of the precisely calibrated dual antennas through the heading angle of the vehicle body and the compensated dual antenna heading angles".

[0039] like Figure 3 As shown, in step 301, a plurality of differences between the matched compensated dual-antenna heading angles and the heading angle of the vehicle body at a plurality of moments in a time period after the vehicle acceleration is greater than a threshold are averaged;

[0040] In step 302, the averaged difference is used as the orientation of the precisely calibrated dual antennas.

[0041] In this embodiment, by collecting data for a period of time, and then calculating the difference between the multiple matched compensated dual antenna heading angles and the heading angle of the vehicle body during this period, that is, calculating the difference at the same time, a plurality of difference values ​​can be obtained. Among them, the plurality of moments refer to a plurality of moments in a time period after the vehicle acceleration is greater than a threshold value. The time period can be a time period after the vehicle accelerates or decelerates or turns, so that the combined navigation filter can fully converge. For example, the plurality of moments here can refer to the time period when the vehicle runs straight after maneuvering. For example, the vehicle can first run a section of open straight road at the fastest possible speed (such as greater than 10m / s), then stop, and then run a route in a maneuverable manner, such as turning or accelerating or decelerating, and then running straight again. The plurality of moments in this embodiment can be taken from the time period when the vehicle runs straight after turning or accelerating or decelerating. Then, the plurality of difference values ​​are averaged, for example, taking the average value of the plurality of difference values. Of course, each difference value can also be filtered first to filter out the value with larger deviation, and then averaged. This application is not limited to this. Since the finely calibrated dual-antenna orientation is calculated using data from a period of time, and the installation deflection angle obtained from the previous coarse calibration is used in this process, the obtained dual-antenna orientation can be relatively accurate.

[0042] In some optional embodiments, the track angle and the dual-antenna heading angle in the GNSS positioning data are obtained from data collected when driving on a road section with a speed greater than a threshold. For example, an open, unobstructed road section can be selected to ensure that the GNSS can locate and orient itself, and a road section with a higher speed (such as a straight road section or a road section without large bends) can be selected to ensure the accuracy of the track angle. Furthermore, the speed threshold can be 10m / s. Selecting a road section with a speed greater than 10m / s makes it easier to obtain a track angle with higher accuracy.

[0043] In some optional embodiments, the initial value of the vehicle's heading angle is selected from a stationary state, and subsequent values ​​of the vehicle's heading angle are selected from data collected during driving on a road section following a turning maneuver. During fine calibration, the initial value of the INS must be selected while the vehicle is stationary, and the fine calibration process must be performed on a road section following a turning maneuver (e.g., a straight road section or a road section without sharp curves) to ensure sufficient convergence of the integrated navigation filter.

[0044] It should be noted that the above method steps are not used to limit the execution order of each step. In fact, some steps may be executed simultaneously or in the opposite order to the step limit. This application has no limitation on this.

[0045] The following describes some problems encountered by the inventor in the process of implementing the present invention and a specific embodiment of the solution finally determined, so that those skilled in the art can better understand the solution of the present application.

[0046] The calibration steps of the GNSS dual-antenna orientation and vehicle body installation deflection provided by the present invention are as follows: Step 1: Collect data according to the following requirements:

[0047] After the equipment is installed, first let the car run a section of open straight road at the fastest possible speed (greater than 10m / s), then stop, and then run a section of the route in a maneuverable manner, such as turning or accelerating or decelerating, and then run a straight road again. The GPS positioning must be ensured throughout the whole process.

[0048] Step 2: Calibrate by collecting data:

[0049] 1. Coarse calibration. Find the portion of the collected data where the speed is greater than 10 m / s and the track angle is open and straight. Obtain the dual-antenna directional heading angle Yaw1 and the track angle Yaw2 from the GNSS positioning data. The track angle Yaw2 can be directly output by some satellite navigation and positioning boards or chips (such as the UB482 board from Unicore Starlink). If this is not directly output, calculate the track angle Yaw2 using the easting velocity Ve and the northing velocity Vn to obtain Yaw2 = atan2(Ve, Vn). After obtaining the simultaneous dual-antenna heading angle Yaw1 and track angle Yaw2, the difference between the two is calculated as deltaYaw(k) = Yaw2(k) - Yaw1(k). Then, the deltaYaw(k) values ​​within the specified time period (e.g., when the speed is greater than 10 m / s and the vehicle is running on an open straight road) are averaged to obtain deltaYaw1. This deltaYaw1 angle is the rough calibration value of the installation deflection angle between the dual antennas and the longitudinal axis of the vehicle. When using the dual-antenna heading angle later, Yaw1 must be compensated first, that is:

[0050] Yaw1(k)=Yaw1(k)+deltaYaw1 (1)

[0051] 2. Precision calibration. In autonomous vehicles, in addition to GNSS, the positioning system also includes sensors such as MEMS IMUs and odometers (odom). Precision calibration requires the use of a combined GNSS / INS navigation algorithm. The following four steps describe this process.

[0052] (I) The RTS smoothing algorithm is used to replace the conventional extended Kalman filter (EKF) algorithm in the GNSS / INS integrated navigation algorithm. The reason is that compared with the EKF algorithm, the RTS smoothing algorithm can obtain more accurate state estimation accuracy, especially higher attitude accuracy. The attitude accuracy obtained by this method can be comparable to that of higher-precision inertial navigation equipment to a certain extent. The application and execution process of this algorithm in GNSS / INS integrated navigation is as follows: Figure 4As shown in the figure, the speed and position information of a period of time predicted by inertial navigation (Predict) is combined with the speed and position information of a period of time obtained by GNSS. On the basis of EKF algorithm, the RTS smoothing algorithm is further used to obtain the RTS smoothing result. The RTS smoothing result can be further compensated in the inertial navigation to obtain the attitude of the carrier. Velocity v and position information r.

[0053] Specifically, the execution process of the RTS smoothing algorithm is as follows:

[0054] K=P f,k F k P -1 f,k+1 / k

[0055]

[0056] P s,k =P f,k +K(P s,k+1 -P f,k+1 / k )K T (2)

[0057] Among them, K represents the filter gain matrix, F k Represents the state transfer matrix of the filter, P f,k Represents the posterior covariance of the EKF filtering algorithm correction value, P f,k+1 / k Indicates the one-step prediction covariance of the EKF filtering algorithm, Represents the correction value of the EKF filtering algorithm, represents the one-step prediction value of the EKF filtering algorithm, Indicates the RTS smoothing result, P s，k Represents the smoothing variance. Note: The RTS algorithm here requires storing variables for a period of time and is generally used for offline processing. If the processor memory capacity is large and the real-time requirements are not high, it can also be used for real-time processing. Further using the RTS smoothing algorithm based on the EKF can improve the accuracy of state estimation. In this algorithm, it is assumed that the IMU coordinate system completely coincides with the carrier coordinate system, that is, calibration has been done in advance. The state vector (15 dimensions) and the observation vector (6 dimensions) are as follows:

[0058]

[0059] Y=[δv,δp] T (3)

[0060] Among them, X represents the state vector of the filter, Y represents the observation vector, φ is the attitude misalignment angle, δv is the velocity error, δp is the position error, and ε is the gyro bias. The above state quantities can be estimated by using the RTS smoothing algorithm. Then, compensation is performed in the inertial navigation to obtain the attitude of the carrier. Speed ​​v and position information r, see above Figure 4 .

[0061] Note: In the INS module of this RTS smoothing algorithm, the initial heading angle is assigned by the compensated dual-antenna heading angle Yaw1 (obtained by formula (1)), and only the GNSS position and velocity are used as observations during the fusion process.

[0062] (II) Through the above RTS smoothing algorithm, the heading angle Yaw_RTS of the carrier can be obtained (by Calculate the Yaw_RTS(k) when running straight after the maneuver. The Yaw_RTS(k) at this moment is obtained after the filter converges and has a relatively high accuracy compared to the values ​​at other times. Then find the GNSS dual antenna heading angle Yaw1(k) after compensation at the same moment and subtract it to get:

[0063] deltaYaw_RTS(k)=Yaw_RTS(k)-Yaw1(k) (4)

[0064] Then take a period of time deltaYaw_RTS(k) and calculate its average value deltaYaw2, which is the precise calibration value of the dual-antenna direction.

[0065] (III) The coarse calibration value deltaYaw1 and the fine calibration value deltaYaw2 are obtained through steps 1 and 2 above, respectively. The calibration angle between the GNSS dual antenna heading angle and the vehicle longitudinal axis can be expressed as:

[0066] deltaYaw=deltaYaw1+deltaYaw2 (5)

[0067] After calibration, when using the GNSS dual-antenna heading angle for fusion, deltaYaw compensation must be performed first.

[0068] (IV) During the calibration process, some engineering details may affect the calibration results, such as: (i) the time synchronization between the GNSS / INS integrated navigation system heading angle Yaw_RTS obtained through RTS smoothing and the dual-antenna heading Yaw1(k) after rough calibration; (ii) the directional accuracy of the dual-antenna heading angle itself; and (iii) how to judge the convergence of the integrated navigation heading. These factors may all affect the calibration results. Therefore, it is necessary to repeatedly collect several sets of similar data and then average the deltaYaw obtained from each calibration to ensure the accuracy of the calibration.

[0069] It is important to note that in Step 1, the road should be as open and unobstructed as possible to ensure GNSS positioning and orientation. Turns and acceleration and deceleration maneuvers should also be performed to ensure convergence of the integrated navigation filter. During data processing in Step 2, coarse calibration should be performed on a direct road section at high speeds to ensure track angle accuracy. During fine calibration, the initial INS value should be selected while the vehicle is stationary, and the fine calibration process should be performed on a straight road section after a turn to ensure full filter convergence and track angle accuracy.

[0070] The solution of the embodiment of the present application can bring the following three beneficial effects and can be conveniently applied to a vehicle-mounted positioning and orientation system in engineering, as follows:

[0071] 1. By using track angle for coarse calibration, the heading angles of the GNSS dual antennas can be aligned with the vehicle's longitudinal axis as closely as possible, ensuring the accuracy of subsequent fine calibration. Furthermore, during the calibration process, the dual antennas can be positioned arbitrarily, as long as the baseline length is as long as possible, providing high flexibility.

[0072] 2. The entire calibration process uses only two sensors, GNSS and IMU, without any other additional sensors, making the operation simple and easy to perform.

[0073] 3. The RTS smoothing algorithm can obtain higher-precision attitude information than the conventional EKF algorithm, which is equivalent to a higher-precision inertial navigation, thereby obtaining higher-precision GNSS dual antenna and vehicle-mounted deflection angles.

[0074] Please refer to Figure 5 , which shows a block diagram of a GNSS dual-antenna calibration system provided by an embodiment of the present invention, and the GNSS dual-antenna calibration system can be applied to vehicles.

[0075] like Figure 5 As shown, the GNSS dual-antenna calibration device 500 includes a coarse calibration program unit 510 , a compensation program unit 520 and a fine calibration program unit 530 .

[0076] Among them, the coarse calibration program unit 510 is configured to determine the coarse calibrated installation deflection angle between the dual antenna and the longitudinal axis of the vehicle body through the difference between the track angle and the dual antenna heading angle in the GNSS positioning data; the compensation program unit 520 is configured to use the coarse calibrated installation deflection angle to compensate the dual antenna heading angle to obtain the compensated dual antenna heading angle; and the fine calibration program unit 530 is configured to obtain the fine calibrated orientation of the dual antenna through the heading angle of the vehicle body and the compensated dual antenna heading angle.

[0077] It should be understood that Figure 5 The units and references in Figure 1Therefore, the operations and features described above for the method and the corresponding technical effects also apply to Figure 5 The units in it will not be described in detail here.

[0078] It is worth noting that the units described in the embodiments of the present disclosure are not intended to limit the solutions of the present disclosure. For example, the coarse calibration program unit can be described as a unit that determines a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body based on the difference between the track angle and the dual-antenna heading angle in the GNSS positioning data. Furthermore, related units can also be implemented using a hardware processor, such as the coarse calibration program unit, which will not be further described here.

[0079] In other embodiments, embodiments of the present invention further provide a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions can execute the GNSS dual-antenna calibration method in any of the above method embodiments;

[0080] As an embodiment, the non-volatile computer storage medium of the present invention stores computer-executable instructions, and the computer-executable instructions are configured as follows:

[0081] Determine a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body by using the difference between the track angle and the dual antenna heading angle in the GNSS positioning data;

[0082] Compensating the dual-antenna heading angle using the roughly calibrated installation deflection angle to obtain a compensated dual-antenna heading angle;

[0083] The precisely calibrated dual antenna orientations are obtained through the vehicle's heading angle and the compensated dual antenna heading angles.

[0084] In some embodiments, an embodiment of the present invention also provides an electronic device, comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the GNSS dual-antenna calibration method.

[0085] In some embodiments, the present invention further provides a mobile device comprising a main body and an electronic device according to any of the preceding embodiments mounted on the main body. The mobile device may be an unmanned vehicle, such as an unmanned sweeper, unmanned floor scrubber, unmanned logistics vehicle, unmanned passenger vehicle, unmanned sanitation vehicle, unmanned minibus / bus, truck, mining vehicle, etc., or a robot.

[0086] In some embodiments, an embodiment of the present invention provides a computer-readable storage medium, including a program or instruction. When the program or instruction is executed on a computer, the GNSS dual-antenna calibration method described in any one of the embodiments of the present invention is implemented.

[0087] In some embodiments, an embodiment of the present invention further provides a computer program product, which, when executed on a computer, enables the computer to execute the GNSS dual-antenna calibration method described in any one of the embodiments of the present invention.

[0088] Figure 6 FIG is a schematic diagram of the hardware structure of an electronic device for executing a GNSS dual-antenna calibration method according to an embodiment of the present invention. Figure 6 As shown, the device includes:

[0089] One or more processors 610 and memory 620, Figure 6 A processor 610 is taken as an example.

[0090] The apparatus for the GNSS dual-antenna calibration method may further include: an input device 630 and an output device 640 .

[0091] The processor 610, the memory 620, the input device 630 and the output device 640 may be connected via a bus or other means. Figure 6 The bus connection is taken as an example.

[0092] Memory 620, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the GNSS dual-antenna calibration method in the embodiments of this application. Processor 610 executes the non-volatile software programs, instructions, and modules stored in memory 620 to execute various server functional applications and data processing, thereby implementing the GNSS dual-antenna calibration method in the aforementioned method embodiment.

[0093] The memory 620 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the GNSS dual-antenna calibration device, etc. In addition, the memory 620 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 620 may optionally include a memory remotely located relative to the processor 610, and these remote memories may be connected to the GNSS dual-antenna calibration device via a network. Examples of the aforementioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0094] The input device 630 can receive input digital or character information and generate signals related to user settings and function control of the GNSS dual-antenna calibration device. The output device 640 can include a display device such as a display screen.

[0095] The one or more modules are stored in the memory 620 and, when executed by the one or more processors 610 , perform the GNSS dual-antenna calibration method in any of the above method embodiments.

[0096] The above-mentioned product can execute the method provided in the embodiment of this application, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the method provided in the embodiment of this application.

[0097] The electronic devices of the embodiments of the present application exist in various forms, including but not limited to:

[0098] (1) Mobile communication devices: These devices are characterized by their mobile communication capabilities and are primarily designed to provide voice and data communications. These terminals include smartphones (e.g., iPhones), multimedia phones, feature phones, and low-end phones.

[0099] (2) Ultra-mobile personal computer devices: These devices fall under the category of personal computers, have computing and processing capabilities, and generally also have mobile Internet access. These terminals include PDAs, MIDs, and UMPCs, such as the iPad.

[0100] (3) Portable entertainment devices: These devices can display and play multimedia content. These devices include audio and video players (such as iPods), handheld game consoles, e-books, smart toys, and portable car navigation devices.

[0101] (4) Other onboard electronic devices with data interaction functions, such as onboard computer devices installed in vehicles.

[0102] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0103] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, or of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiment.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A GNSS dual-antenna calibration method for a vehicle, comprising: Determining a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body by using the difference between the track angle and the dual antenna heading angle in the GNSS positioning data, wherein the track angle and the dual antenna heading angle are obtained by real-time output of the GNSS board of the running vehicle; Compensating the dual-antenna heading angle using the roughly calibrated installation deflection angle to obtain a compensated dual-antenna heading angle; estimating the state of the vehicle body by a GNSS / INS navigation combination system to obtain a heading angle of the vehicle body, wherein estimating the state of the vehicle body by a GNSS / INS navigation combination system includes estimating the state of the vehicle body by an RTS smoothing algorithm; Obtaining the precisely calibrated dual-antenna orientations using the vehicle's heading angle and the compensated dual-antenna heading angles; A calibrated angle between the heading angle of the GNSS dual antenna and the longitudinal axis of the vehicle body is determined based on the coarsely calibrated installation deflection angle and the finely calibrated dual antenna orientation.

2. The method according to claim 1, wherein Determining a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body by using a difference between the track angle and the dual antenna heading angle in the GNSS positioning data includes: averaging a plurality of differences between the matched track angles at a plurality of moments in a time period in which the vehicle speed is greater than a threshold and the dual-antenna heading angles in the GNSS positioning data; The averaged difference is used as a roughly calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body.

3. The method according to claim 1, wherein Obtaining the precisely calibrated dual-antenna orientations using the vehicle's heading angle and the compensated dual-antenna heading angles includes: averaging a plurality of differences between the matched compensated dual-antenna heading angles and the heading angle of the vehicle body at a plurality of moments in a time period after the vehicle acceleration exceeds a threshold; The difference after averaging is used as the orientation of the precisely calibrated dual antennas.

4. The method according to claim 1, wherein The track angle and the dual-antenna heading angle in the GNSS positioning data are obtained from data when the vehicle is traveling on a road section where the vehicle speed is greater than a threshold.

5. The method according to claim 1, wherein The initial value of the heading angle of the vehicle body is selected from the data when the vehicle body is in a stationary state, and the subsequent value of the heading angle of the vehicle body is selected from the data when the vehicle body is traveling on the road section after the turning maneuver.

6. A GNSS dual-antenna calibration system for a vehicle, comprising: a coarse calibration program unit configured to determine a coarsely calibrated installation deflection angle between the dual antennas and the longitudinal axis of the vehicle body based on a difference between a track angle and a dual antenna heading angle in GNSS positioning data, wherein the track angle and the dual antenna heading angle are obtained through real-time output of a GNSS board of a running vehicle; a compensation program unit configured to compensate the dual-antenna heading angle using the roughly calibrated installation deflection angle to obtain a compensated dual-antenna heading angle; an estimation program unit configured to estimate the state of the vehicle body through a GNSS / INS navigation combination system to obtain a heading angle of the vehicle body, wherein the estimating the state of the vehicle body through the GNSS / INS navigation combination system includes estimating the state of the vehicle body using an RTS smoothing algorithm; A precision calibration program unit is configured to obtain a precision-calibrated dual-antenna orientation through the vehicle's heading angle and the compensated dual-antenna heading angle; A determination program unit is configured to determine a calibrated angle between the heading angle of the GNSS dual antenna and the longitudinal axis of the vehicle body based on the coarsely calibrated installation deflection angle and the finely calibrated orientation of the dual antenna.

7. A storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

9. A computer system comprising a memory, a processor, and a computer program stored in the memory, wherein: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 5.

10. A vehicle, characterized in that: Comprising the computer system of claim 9.

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