Calibration method and compensation method for installation deflection angle of vehicle-mounted inertial navigation unit and medium

Abstract

The invention provides an installation deflection angle calibration method and compensation method of a vehicle-mounted inertial navigation unit and a medium. The method comprises the following steps: when a vehicle is still on a flat road surface after driving according to a target driving strategy: acquiring a first roll angle of an inertial navigation unit on the vehicle through an integrated navigation unit of the vehicle; acquiring a second roll angle of the inertial navigation unit based on an acceleration parameter and a zero offset parameter of an accelerometer of the vehicle; and estimating the roll installation deflection angle of the inertial navigation unit according to the first roll angle and the second roll angle. The method not only realizes calibration of the roll installation deflection angle of the inertial navigation unit, but also improves the accuracy of the roll installation deflection angle.

Description

Technical Field

[0001] One or more embodiments of the present application relate to the field of positioning technology, and in particular, to a method for calibrating the installation angle of a vehicle-mounted inertial navigation unit, a compensation method, and a medium. Background Art

[0002] When installing the inertial navigation unit on the vehicle, the orientation of the inertial navigation unit needs to be parallel to the center axis of the vehicle and remain horizontal. However, in the actual installation process, it is difficult to ensure that the orientation of the inertial navigation unit is completely parallel to or completely horizontal with the center axis of the carrier. It is often the case that the inertial navigation unit is slightly tilted or installed crookedly. At this time, the angular offset between the inertial navigation unit and the vehicle is called the installation deflection of the inertial navigation unit. Since the larger the installation deflection, the greater the negative impact on the positioning result of the inertial navigation unit or the fusion positioning result of the inertial navigation unit and other positioning units, the installation deflection of the inertial navigation unit needs to be calibrated and compensated.

[0003] At present, the commonly used method for calibrating the installation angle of the inertial navigation unit is: expand the pitch installation angle and heading installation angle of the inertial navigation unit into the Kalman filter, and fuse the positioning results of the inertial navigation unit with the positioning results of other positioning units through the Kalman filter. During the fusion process, the Kalman filter outputs the pitch installation angle and heading installation angle of the inertial navigation unit.

[0004] However, the above method can only calibrate the pitch installation deflection angle and the heading installation deflection angle, but cannot calibrate the roll installation deflection angle. Summary of the invention

[0005] The present application provides a method for calibrating the installation angle of a vehicle-mounted inertial navigation unit, a compensation method and a medium, which not only realize the calibration of the roll installation angle of the inertial navigation unit, but also use a combined navigation unit and an accelerometer to jointly determine the roll installation angle of the inertial navigation unit when the vehicle is stationary on a flat road, thereby reducing the error caused by the noise of a single positioning unit and improving the accuracy of the roll installation angle; and, when determining the roll angle of the inertial navigation unit based on the accelerometer, not only the accelerometer parameters but also the zero bias parameters are considered, so that the roll angle determined based on the accelerometer is more accurate, and the accuracy of the roll installation angle determined based on the roll angle is further improved.

[0006] According to a first aspect of one or more embodiments of the present application, a method for calibrating an installation deflection angle of a vehicle-mounted inertial navigation unit is provided, the method comprising:

[0007] After the vehicle is driven according to the target driving strategy and is stationary on a flat road, perform the following steps:

[0008] Acquiring a first roll angle of an inertial navigation unit on the vehicle by means of a combined navigation unit of the vehicle;

[0009] Acquiring a second roll angle of the inertial navigation unit based on an acceleration parameter and a zero bias parameter of an accelerometer of the vehicle;

[0010] The roll installation angle of the inertial navigation unit is estimated according to the first roll angle and the second roll angle.

[0011] Optionally, the target driving strategy includes at least one of accelerating driving, decelerating driving and turning driving;

[0012] and / or,

[0013] The zero bias parameter is determined based on the RTK positioning result of the navigation and positioning unit in the integrated navigation unit, and the zero bias parameter is determined based on the process of the vehicle driving according to the target driving strategy.

[0014] Optionally, acquiring the second roll angle of the inertial navigation unit based on an acceleration parameter and a zero bias parameter of an accelerometer of the vehicle includes:

[0015] Obtaining sub-acceleration parameters and sub-bias parameters of the accelerometer in M ​​target directions, and compensating the sub-acceleration parameters by the sub-bias parameters of each target direction to obtain compensated sub-acceleration parameters of each target direction; wherein M is an integer greater than or equal to 2;

[0016] A second roll angle of the inertial navigation unit is determined based on the compensation sub-acceleration parameter of each target direction in the M target directions.

[0017] Optionally, after estimating the roll installation angle of the inertial navigation unit according to the first roll angle and the second roll angle, the method further includes:

[0018] The output of the inertial navigation unit at each moment is compensated by the roll installation deflection angle.

[0019] Optionally, the method further includes:

[0020] Obtaining the heading installation deflection angle and the pitch installation deflection angle of the inertial navigation unit;

[0021] Converting the roll installation deflection angle, the heading installation deflection angle, and the pitch installation deflection angle into a direction cosine matrix;

[0022] The output of the inertial navigation unit at each moment is compensated by the direction cosine matrix.

[0023] Optionally, compensating the output of the inertial navigation unit at each moment by using the direction cosine matrix includes:

[0024] Based on the direction cosine matrix, compensating the acceleration parameters output by the accelerometer of the inertial navigation unit to obtain compensated acceleration parameters;

[0025] Based on the direction cosine matrix, compensating the angular velocity parameters output by the gyroscope of the inertial navigation unit to obtain compensated angular velocity parameters;

[0026] An inertial navigation solution is performed based on the compensated acceleration parameter and the compensated angular velocity parameter.

[0027] Optionally, the method further includes:

[0028] When the vehicle is driving according to the target driving strategy, the following steps are performed:

[0029] For the i-th driving moment Ti among the k driving moments, a first angle value of the target direction angle at the driving moment Ti is obtained by a combined navigation algorithm, a second angle value of the target direction angle at the driving moment Ti is obtained by an RTK algorithm, and a target direction installation deflection angle corresponding to the driving moment Ti is determined based on an angle difference between the first angle value and the second angle value, the target direction angle includes a pitch angle and / or a heading angle, and the target direction installation deflection angle includes a pitch installation deflection angle and / or a heading installation deflection angle, wherein i and k are integers, and i∈[1, k];

[0030] The target direction installation deflection angle of the inertial navigation unit is determined based on the target direction installation deflection angles respectively corresponding to the k driving moments.

[0031] Optionally, the acquiring, by using an RTK algorithm, a second angle value of the target direction angle at the driving time Ti includes:

[0032] Obtaining a first RTK positioning result corresponding to the driving time Ti by using the RTK algorithm, and obtaining a second RTK positioning result corresponding to the driving time Ti-1;

[0033] Converting the first RTK positioning result and the second RTK positioning result from the latitude, longitude and height form into coordinate form to obtain a converted first RTK positioning result and a converted second RTK positioning result;

[0034] Determine a velocity vector of the vehicle based on a coordinate difference between the converted first RTK positioning result and the converted second RTK positioning result and a time difference between the driving time and the last driving time;

[0035] Based on the speed vector of the vehicle, a speed scalar of the vehicle is determined, and based on the speed vector and the speed scalar of the vehicle, a second angle value of the target direction angle at the driving time Ti is determined.

[0036] According to a second aspect of one or more embodiments of the present application, a compensation method for a vehicle-mounted inertial navigation unit is provided, the method comprising:

[0037] Obtaining a roll installation deflection angle, a heading installation deflection angle, and a pitch installation deflection angle of an inertial navigation unit of the vehicle, wherein the roll installation deflection angle is determined based on the method described in the first aspect above;

[0038] Converting the roll installation deflection angle, the heading installation deflection angle, and the pitch installation deflection angle into a direction cosine matrix;

[0039] The output of the inertial navigation unit at each moment is compensated by the direction cosine matrix.

[0040] Optionally, compensating the output of the inertial navigation unit at each moment by using the direction cosine matrix includes:

[0041] Based on the direction cosine matrix, compensating the acceleration parameters output by the accelerometer of the inertial navigation unit to obtain compensated acceleration parameters;

[0042] Based on the direction cosine matrix, compensating the angular velocity parameters output by the gyroscope of the inertial navigation unit to obtain compensated angular velocity parameters;

[0043] An inertial navigation solution is performed based on the compensated acceleration parameter and the compensated angular velocity parameter.

[0044] According to a third aspect of one or more embodiments of the present application, a computer-readable storage medium is provided, on which computer instructions are stored. When the instructions are executed by a processor, the steps of the method described in the embodiments of the first or second aspects above are implemented.

[0045] According to a fourth aspect of one or more embodiments of the present application, a computer program product is provided, on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the steps of the method described in the embodiment of the first aspect or the second aspect are implemented.

[0046] It can be seen from the above technical solutions that in one or more embodiments of the present application, the calibration of the roll installation angle of the inertial navigation unit is realized; and, when the vehicle is stationary on a flat road, the roll installation angle of the inertial navigation unit is determined by a combined navigation unit and an accelerometer, thereby reducing the error caused by the noise of a single positioning unit and improving the accuracy of the roll installation angle; and, when determining the roll angle of the inertial navigation unit based on the accelerometer, not only the accelerometer parameters are considered, but also the zero bias parameters, so that the roll angle determined based on the accelerometer is more accurate, and the accuracy of the roll installation angle determined based on the roll angle is further improved.

[0047] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0049] Figure 1 It is a flow chart of a method for calibrating the installation angle of a vehicle-mounted inertial navigation unit provided by an exemplary embodiment.

[0050] Figure 2 It is a flow chart of a method for calibrating the installation angle of a vehicle-mounted inertial navigation unit provided by an exemplary embodiment.

[0051] Figure 3 A flowchart for determining a target direction installation angle of a vehicle-mounted inertial navigation unit is provided by an exemplary embodiment.

[0052] Figure 4 It is a flow chart of a compensation method of a vehicle-mounted inertial navigation unit provided by an exemplary embodiment.

[0053] Figure 5 It is a flowchart of another compensation method of a vehicle-mounted inertial navigation unit provided by an exemplary embodiment.

[0054] Figure 6 It is a schematic structural diagram of an electronic device shown in an exemplary embodiment.

[0055] Figure 7 It is a block diagram of an installation deflection calibration device for a vehicle-mounted inertial navigation unit, shown as an exemplary embodiment.

[0056] Figure 8 It is a block diagram of a compensation device of a vehicle-mounted inertial navigation unit shown in an exemplary embodiment. DETAILED DESCRIPTION

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0058] It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed in the order shown and described in this application. In some other embodiments, the steps included in the method may be more or less than those described in this application. In addition, a single step described in this application may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this application may also be combined into a single step for description in other embodiments.

[0059] Next, one or more embodiments of the present application are described in detail.

[0060] Figure 1 The following is a flow chart of a method for calibrating the installation angle of a vehicle-mounted inertial navigation unit provided by an exemplary embodiment. Figure 1 As shown, the method may include the following steps:

[0061] S101. After the vehicle is driven according to the target driving strategy and stops on a flat road, the following steps are performed: a first roll angle of an inertial navigation unit on the vehicle is acquired through an integrated navigation unit of the vehicle.

[0062] If the inertial navigation unit does not have installation deviation, when the vehicle is stationary on a flat road, the roll angle of the inertial navigation unit on the vehicle is 0°. However, if the inertial navigation unit has installation deviation, when the vehicle is stationary on a flat road, the roll angle of the inertial navigation unit on the vehicle is not 0°, and the roll angle of the inertial navigation unit at this time is the same as the roll installation deviation angle of the inertial navigation unit. Therefore, in the embodiment of the present application, when the vehicle is stationary on a flat road, the roll installation deviation angle of the inertial navigation unit is determined by obtaining the roll angle of the inertial navigation unit.

[0063] The combined navigation unit is a unit that uses a combined navigation algorithm to obtain a positioning result. The combined navigation unit includes an inertial navigation unit and at least one other positioning unit, and the at least one other positioning unit is an arbitrary positioning unit of a different type from the inertial navigation positioning unit. For example, the at least one other positioning unit includes at least one of a navigation positioning unit, an odometer (Odometer, ODOM), a visual positioning unit, a wheel speed meter, etc. The combined navigation unit is used to fuse the positioning result of the inertial navigation unit with the positioning result of the at least one other positioning unit using a combined navigation algorithm to obtain a fused positioning result. The fused positioning result includes at least one of the position, attitude and speed of the vehicle. Among them, the attitude of the vehicle includes a roll angle, a pitch angle and a heading angle. In the embodiment of the present application, obtaining the first roll angle of the inertial navigation unit on the vehicle through the combined navigation unit of the vehicle is: obtaining the roll angle in the fused positioning result determined by the combined navigation unit of the vehicle, and using the roll angle as the first roll angle of the inertial navigation unit.

[0064] Among them, the inertial navigation unit is a positioning unit based on IMU (Inertial Measurement Unit), and the inertial navigation unit can be IMU, INS (Inertial Navigation System), SINS (Strapdown Inertial Navigation System), etc. The embodiment of the present application does not limit the inertial navigation unit.

[0065] The navigation and positioning unit is a GNSS (Global Navigation Satellite System). Among them, GNSS can be RTK-GNSS (Real-Time Kinematic-Global Navigation Satellite System, based on real-time differential positioning global navigation satellite system), GPS (Global Positioning System, Global Positioning System), BDS (BeiDou Navigation Satellite System, Beidou Satellite Navigation System), Galileo (Galileo Satellite Navigation System, Galileo Satellite Navigation System), etc., and the embodiments of the present application do not limit GNSS.

[0066] Exemplarily, the integrated navigation unit is a unit that uses an IMU / GNSS integrated navigation algorithm to obtain a positioning result. The integrated navigation unit includes an inertial navigation unit and a navigation positioning unit, and the integrated navigation unit is used to fuse the positioning results of the inertial navigation unit and the navigation positioning unit using the IMU / GNSS integrated navigation algorithm to obtain a fused positioning result.

[0067] The combined navigation algorithm may be a filtering algorithm, an optimization algorithm, etc., and the embodiment of the present application does not limit the combined navigation algorithm. The filtering algorithm may be a KF (Kalman Filter), an ESKF (Error State Kalman Filter), a PF (Particle Filter), a complementary filter, etc.

[0068] Next, the process of obtaining the fusion positioning result of the inertial navigation unit and the navigation positioning unit based on ESKF is used as an example to illustrate the process of determining the fusion positioning result of the combined navigation unit:

[0069] A state model and an observation model are constructed in ESKF. Through the state model and the observation model, the data of each positioning unit in the integrated navigation unit are processed to estimate the state error. Based on the state error, the positioning result of the inertial navigation unit (IMU, INS or SINS) is corrected to obtain the fused positioning result of the integrated navigation unit.

[0070] The state model is: X is the state error, A is the state transfer matrix, G is the process noise driving matrix, W is the process noise, represents the derivative of X.

[0071] The observation model is: Z = HX + V; where Z represents the observation value, which refers to the actual data obtained based on the positioning unit. H represents the observation matrix, which is used to describe how to calculate the predicted observation value based on the system state, A represents the state transfer matrix, and V represents the observation noise, which is used to represent the deviation between the measured value and the true value and can be configured based on the characteristics of the positioning unit.

[0072] Among them, the state error X is a 15-dimensional matrix, expressed as It is a three-dimensional attitude misalignment angle, including roll misalignment angle, pitch misalignment angle and heading misalignment angle. Among them, the roll misalignment angle is used to indicate the error in the roll direction of the attitude determined by the inertial navigation unit, the pitch misalignment angle is used to indicate the error in the pitch direction of the attitude determined by the inertial navigation unit, and the heading misalignment angle is used to indicate the error in the heading direction of the attitude determined by the inertial navigation unit. Among them, the direction of rotation around the X-axis constituting the three-dimensional coordinate system can be called the pitch direction, the direction of rotation around the Y-axis constituting the three-dimensional coordinate system can be called the roll direction, and the direction of rotation around the Z-axis constituting the three-dimensional coordinate system can be called the heading.

[0073] δv is the three-dimensional velocity error, which is used to indicate the error of the velocity determined by the inertial navigation unit in the directions indicated by the X-axis, Y-axis and Z-axis that constitute the three-dimensional coordinate system. δp is the three-dimensional position error, which is used to indicate the error of the position determined by the inertial navigation unit in the directions indicated by the X-axis, Y-axis and Z-axis that constitute the three-dimensional coordinate system. ε is the zero bias parameter of the gyroscope, which is used to indicate the non-zero reading output by the gyroscope in the inertial navigation unit when it is not rotating. It is the zero bias parameter of the accelerometer, which is used to indicate the non-zero reading output by the accelerometer in the inertial navigation unit when there is no acceleration.

[0074] Among them, the three-dimensional coordinate system can be a northeast celestial coordinate system or an upper right front coordinate system, etc. When the three-dimensional coordinate system is a northeast celestial coordinate system, the direction pointed by the X-axis is also the horizontal direction, which can be called the east direction; the direction pointed by the Y-axis is also the vertical direction, which can be called the north direction; the direction pointed by the Z-axis is also the elevation direction, which can be called the sky direction. When the three-dimensional coordinate system is an upper right front coordinate system, the direction pointed by the X-axis is also the horizontal direction, which can be called the right direction; the direction pointed by the Y-axis is also the vertical direction, which can be called the front direction; the direction pointed by the Z-axis is also the elevation direction, which can be called the up direction. It should be noted that the three-dimensional coordinate system is a geographic coordinate system, and the directions pointed by the X-axis, Y-axis and Z-axis will not change with the movement of the vehicle.

[0075] like Figure 2 As shown in the figure, the navigation and positioning unit (GNSS) inputs the position and speed determined by GNSS into ESKF, and the inertial navigation unit (SINS) inputs the attitude, position and speed determined by SINS into ESKF; ESKF processes the input data based on the state model and observation model, and outputs the state error X to SINS. SINS corrects the attitude, position and speed determined by itself based on the state error X, and outputs the corrected attitude, position and speed. The corrected attitude, position and speed are the fusion positioning results.

[0076] It should be noted that by fully maneuvering the vehicle, the zero bias parameters generated by the combined navigation unit can gradually converge, and more accurate zero bias parameters can be obtained, thereby generating a more accurate fusion positioning result. Therefore, in the embodiment of the present application, the vehicle first drives according to the target driving strategy, so that the vehicle fully maneuvers, and then executes the steps of obtaining the first roll angle and the second roll angle, so that a more accurate first roll angle and the second roll angle can be obtained.

[0077] Another point to be explained is that the driving state of the vehicle will change suddenly when the vehicle accelerates, decelerates, turns, etc., and the sudden change in the driving state of the vehicle will cause the vehicle to fully maneuver. Therefore, the target driving strategy may include at least one of accelerating driving, decelerating driving, and turning driving. Among them, turning driving refers to a driving mode in which the driving direction of the vehicle is constantly changing. Exemplarily, the turning driving may be driving in an "8" shape.

[0078] S102: Acquire a second roll angle of the inertial navigation unit based on an acceleration parameter and a zero bias parameter of an accelerometer of the vehicle.

[0079] By fully maneuvering the vehicle, the zero bias parameters generated by the combined navigation unit can gradually converge, and the vehicle can be fully maneuvered by driving according to the target driving strategy; it can be seen that the zero bias parameters of the accelerometer gradually converge when the vehicle drives according to the target driving strategy.

[0080] Therefore, the above step S102 is executed after the vehicle is driven according to the target driving strategy. In this way, the zero bias parameter of the accelerometer in the above step S102 is the zero bias parameter that is determined and converged during the process of the vehicle driving according to the target driving strategy. The zero bias parameter is more accurate, and thus the second roll angle determined based on the acceleration parameter and zero bias parameter of the vehicle's accelerometer is also more accurate.

[0081] In an illustrated embodiment, not only the vehicle running according to the target driving strategy can accelerate the convergence of the zero bias parameter, but also the accurate positioning result of any positioning unit in the integrated navigation unit can accelerate the convergence of the zero bias parameter. In one embodiment, the integrated navigation unit includes a navigation positioning unit, and the RTK positioning result of the navigation positioning unit (the RTK positioning result is the positioning result determined by the navigation positioning unit based on the RTK algorithm) can achieve centimeter-level accuracy, so the RTK positioning result is very accurate. If the integrated navigation unit obtains the fused positioning result based on the RTK positioning result, the convergence of the zero bias parameter can be accelerated. Exemplarily, the zero bias parameter is determined based on the RTK positioning result of the navigation positioning unit in the integrated navigation unit, and the zero bias parameter is determined based on the process of the vehicle running according to the target driving strategy.

[0082] The accelerometer on the vehicle is a sensor that can measure the acceleration of the vehicle, and the acceleration parameter is used to represent the acceleration measured by the accelerometer. When the vehicle is stationary on a flat road, the acceleration parameter of the vehicle's accelerometer represents the gravity acceleration measured by the accelerometer. Ideally, the accelerometer can only measure acceleration in the direction perpendicular to the ground, and cannot measure acceleration in other directions. If the inertial navigation unit has an installation angle, the accelerometer will also be able to measure acceleration in other directions. By analyzing the acceleration parameters of the accelerometer, the attitude of the inertial navigation unit can be determined. The attitude includes the roll angle of the inertial navigation unit. Therefore, the roll angle of the inertial navigation unit can be determined by analyzing the acceleration parameters of the accelerometer.

[0083] The zero bias parameter of the accelerometer is used to represent the non-zero reading output by the accelerometer in the inertial navigation unit when there is no acceleration. The reason why the accelerometer has zero bias may be due to errors in the manufacturing process, temperature changes, aging or other environmental factors, which will affect the accuracy of the accelerometer. Therefore, the embodiment of the present application obtains the second roll angle of the inertial navigation unit based on the acceleration parameter and zero bias parameter of the accelerometer of the vehicle. In this way, the acceleration parameter of the accelerometer can be compensated based on the zero bias parameter of the accelerometer to eliminate the error caused by the zero bias of the accelerometer to obtain a more accurate second roll angle. Exemplarily, the second roll angle of the inertial navigation unit is obtained based on the acceleration parameter and zero bias parameter of the accelerometer of the vehicle, including: based on the zero bias parameter of the accelerometer of the vehicle, the acceleration parameter of the accelerometer is compensated to obtain the compensated acceleration parameter; based on the compensated acceleration parameter, the second roll angle of the inertial navigation unit is determined.

[0084] In one illustrated embodiment, the acceleration parameters of the accelerometer include sub-acceleration parameters of the accelerometer in M ​​target directions. The sub-acceleration parameters of the accelerometer in any target direction are used to represent the acceleration measured by the accelerometer in the target direction. The zero bias parameters of the accelerometer include sub-zero bias parameters of the accelerometer in M ​​target directions. The sub-zero bias parameters of the acceleration in any target direction are used to represent the acceleration measured by the accelerometer in the target direction when there is no acceleration. Wherein, M is an integer greater than or equal to 2.

[0085] When compensating the acceleration parameters of the accelerometer based on the zero bias parameters of the accelerometer, it is necessary to use the sub-zero bias parameters of the accelerometer in the M target directions to compensate the sub-acceleration parameters of the accelerometer in the M target directions. In one embodiment, based on the acceleration parameters and zero bias parameters of the accelerometer of the vehicle, the second roll angle of the inertial navigation unit is obtained, including: obtaining the sub-acceleration parameters and sub-zero bias parameters of the accelerometer in the M target directions, and compensating the sub-acceleration parameters by the sub-zero bias parameters of each target direction to obtain the compensated sub-acceleration parameters of each target direction; based on the compensated sub-acceleration parameters of each target direction in the M target directions, the second roll angle of the inertial navigation unit is determined.

[0086] Wherein, when the sub-acceleration parameters are compensated by the sub-zero bias parameters of each target direction, the sub-acceleration parameters of the same target direction are compensated by the sub-zero bias parameters of each target direction. Exemplarily, the sub-acceleration parameters of the first target direction are compensated by the sub-zero bias parameters of the first target direction, and the sub-acceleration parameters of the second target direction are compensated by the sub-zero bias parameters of the second target direction.

[0087] In one embodiment, the M target directions may be directions indicated by at least two coordinate axes constituting an N-dimensional coordinate system, wherein N is an integer greater than or equal to 2. Exemplarily, the M target directions are directions indicated by an X-axis and a Z-axis constituting a three-dimensional coordinate system. Exemplarily, the M target directions are directions indicated by a Y-axis and a Z-axis constituting a three-dimensional coordinate system.

[0088] Taking the N-dimensional coordinate system as a three-dimensional coordinate system as an example, the direction indicated by the Z axis constituting the three-dimensional coordinate system is consistent with the direction of gravity, the direction indicated by the X axis constituting the three-dimensional coordinate system is consistent with the direction from the left side of the vehicle to the right side of the vehicle, and the direction indicated by the Y axis constituting the three-dimensional coordinate system is consistent with the direction from the rear of the vehicle to the front of the vehicle. It should be noted that the three-dimensional coordinate system is a vehicle coordinate system, and the directions indicated by the X axis and Y axis constituting the three-dimensional coordinate system can change as the vehicle moves.

[0089] Exemplarily, the M target directions may be the direction indicated by the X-axis constituting the three-dimensional coordinate system and the direction indicated by the Z-axis constituting the three-dimensional coordinate system. Based on the acceleration parameter and the zero bias parameter of the accelerometer of the vehicle, the second roll angle of the inertial navigation unit is obtained, including: obtaining the sub-acceleration parameter and the sub-bias parameter of the accelerometer in the direction indicated by the X-axis, and the sub-acceleration parameter and the sub-bias parameter of the accelerometer in the direction indicated by the Z-axis; compensating the sub-acceleration parameter of the accelerometer in the direction indicated by the X-axis by the sub-bias parameter of the accelerometer in the direction indicated by the X-axis to obtain the compensated sub-acceleration parameter of the accelerometer in the direction indicated by the X-axis, and compensating the sub-acceleration parameter of the accelerometer in the direction indicated by the Z-axis by the sub-bias parameter of the accelerometer in the direction indicated by the Z-axis to obtain the compensated sub-acceleration parameter of the accelerometer in the direction indicated by the Z-axis; determining the second roll angle of the inertial navigation unit based on the compensated sub-acceleration parameters of the accelerometer in the directions indicated by the X-axis and the Z-axis respectively.

[0090] For example, the second roll angle of the inertial navigation unit is Roll_acce=arctan(-acce_x-ace_bias_x, acce_z-ace_bias_z), where arctan is an inverse tangent function, acce_x is a sub-acceleration parameter of the accelerometer in the direction indicated by the X-axis, acce_z is a sub-acceleration parameter of the accelerometer in the direction indicated by the Z-axis, bias_x is a sub-zero bias parameter of the accelerometer in the direction indicated by the X-axis, and bias_z is a sub-zero bias parameter of the accelerometer in the direction indicated by the Z-axis.

[0091] S103: Estimate the roll installation angle of the inertial navigation unit according to the first roll angle and the second roll angle.

[0092] The embodiments of the present application take into account that if the first roll angle or the second roll angle is directly used as the roll installation angle of the inertial navigation unit, the determined roll installation deflection angle may be inaccurate due to the noise in the single positioning unit. Therefore, the roll installation deflection angle of the inertial navigation unit is estimated by combining the first roll angle determined by the combined navigation unit and the second roll angle determined by the accelerometer to obtain a more accurate roll installation deflection angle.

[0093] In an illustrated embodiment, estimating the roll installation angle of the inertial navigation unit according to the first roll angle and the second roll angle includes: performing statistical processing on the first roll angle and the second roll angle to obtain the roll installation angle of the inertial navigation unit.

[0094] The statistical processing refers to processing data using statistical methods. In one embodiment, the statistical processing is an average processing. The first roll angle and the second roll angle are statistically processed to obtain the roll installation deflection angle of the inertial navigation unit, including: averaging the first roll angle and the second roll angle to obtain the roll installation deflection angle of the inertial navigation unit.

[0095] For example, the roll installation deflection angle delta_roll = (Roll_acce+Roll_fusion) / 2, wherein Roll_fusion is the first roll angle, and Roll_acce is the second roll angle.

[0096] In another embodiment, the statistical processing is a weighted average processing. The first roll angle and the second roll angle are statistically processed to obtain the roll installation deflection angle of the inertial navigation unit, including: obtaining a first weighting coefficient of the first roll angle and a second weighting coefficient of the second roll angle, the first weighting coefficient is proportional to the positioning accuracy of the combined navigation unit, and the second weighting coefficient is proportional to the positioning accuracy of the accelerometer; based on the first weighting coefficient and the second weighting coefficient, the first roll angle and the second roll angle are weighted averaged to obtain the roll installation deflection angle of the inertial navigation unit.

[0097] Among them, the first weighting coefficient and the second weighting coefficient can be empirical values ​​or pre-set by a technician. The embodiment of the present application does not limit the first weighting coefficient and the second weighting coefficient. It is only necessary to ensure that the sum of the first weighting coefficient and the second weighting coefficient is 1.

[0098] The installation angle calibration method of the vehicle-mounted inertial navigation unit provided in the embodiment of the present application realizes the calibration of the roll installation angle of the inertial navigation unit; and, when the vehicle is stationary on a flat road, the roll installation angle of the inertial navigation unit is jointly determined by a combined navigation unit and an accelerometer, thereby reducing the error caused by the noise of a single positioning unit and improving the accuracy of the roll installation angle; and, when determining the roll angle of the inertial navigation unit based on the accelerometer, not only the accelerometer parameters but also the zero bias parameters are considered, so that the roll angle determined based on the accelerometer is more accurate, and the accuracy of the roll installation angle determined based on the roll angle is further improved.

[0099] Above Figure 1 The embodiment shown in the figure exemplifies the calibration method of the roll installation angle of the vehicle-mounted inertial navigation unit. The calibration of the pitch installation angle and / or the heading installation angle of the vehicle-mounted inertial navigation unit can be carried out by any calibration method in the prior art, or by using Figure 3 The present application does not limit the calibration method shown in the embodiment shown.

[0100] Figure 3 The following is a flow chart of a method for calibrating the installation angle of a vehicle-mounted inertial navigation unit provided by an exemplary embodiment. Figure 3 As shown, the method may include the following steps:

[0101] S301, for the i-th driving moment T among the k driving moments i , the target direction angle is obtained by the combined navigation algorithm at the driving time T i A first angle value of a target direction angle includes a pitch angle and / or a heading angle, wherein i and k are integers and i∈[1, k].

[0102] Since the pitch angle and / or heading angle can be obtained more accurately when the vehicle is in motion, Figure 3 The illustrated embodiment can be executed while the vehicle is driving according to the target driving strategy. That is, the vehicle first drives according to the target driving strategy, and the pitch installation angle and / or heading installation angle of the vehicle-mounted inertial navigation unit is determined during the driving process; then, the vehicle is stationary on a flat road, and the roll installation angle of the vehicle-mounted inertial navigation unit is determined.

[0103] In an embodiment of the present application, in order to obtain a more accurate pitch installation deflection angle and / or heading installation deflection angle, the pitch installation deflection angle and / or heading installation deflection angle are obtained at multiple driving moments when the vehicle is driving according to the target driving strategy, and the pitch installation deflection angle and heading installation deflection angle corresponding to the multiple driving moments are combined to determine the pitch installation deflection angle and / or heading installation deflection angle of the inertial navigation unit. In one embodiment, in order to obtain a more accurate first angle value and / or second angle value, the target driving strategy also includes high-speed driving. Exemplarily, high-speed driving refers to a driving speed of not less than 20 meters per second.

[0104] Since the process of obtaining the pitch installation deflection angle and / or the heading installation deflection angle is the same at each driving moment, the embodiment of the present application only uses the process of obtaining the pitch installation deflection angle and / or the heading installation deflection angle at the driving moment T i The process of obtaining the pitch installation deflection angle and / or the heading installation deflection angle is exemplarily described.

[0105] Among them, the target direction angle is obtained by the combined navigation algorithm at the driving time T i The first angle value is at the driving time T i , the angle value of the target direction angle is obtained through the integrated navigation unit. The fusion positioning result determined by the integrated navigation unit includes the angle value of the target direction angle, and the angle value of the target direction angle in the fusion positioning result can be directly obtained as the first angle value of the target direction angle.

[0106] Exemplarily, the fused positioning result determined by the combined navigation unit includes an angle value of a pitch angle and / or an angle value of a heading angle, and the angle value of the pitch angle in the fused positioning result is determined as a first angle value of the pitch angle, and / or the angle value of the heading angle in the fused positioning result is determined as a first angle value of the heading angle.

[0107] The process of determining the fusion positioning result by the combined navigation unit may refer to the above step S101, and the embodiments of the present application will not be described in detail here.

[0108] S302, obtaining the target direction angle at driving time T through the RTK algorithm i The second angle value.

[0109] In one illustrated embodiment, Figure 2 As shown, the integrated navigation unit includes a navigation positioning unit, which can obtain an RTK positioning result through an RTK algorithm. The RTK positioning result can be called an RTK fixed solution. i The second angle value is based on the driving time T i The obtained RTK positioning result is determined. Since the navigation positioning unit is a part of the integrated navigation unit, it can be seen that the implementation method of step S301 and step S302 is: at the driving time Ti , the inertial navigation unit in the integrated navigation unit determines the inertial navigation positioning result, the navigation positioning unit in the integrated navigation unit determines the RTK positioning result, and then the inertial navigation positioning result is fused with the RTK positioning result through the integrated navigation algorithm to obtain the fused positioning result, and the target direction angle is determined at the driving time T based on the fused positioning result i The first angle value is determined based on the RTK positioning result to determine the target direction angle at the driving time T i That is to say, the first angle value and the second angle value of the target direction angle can be determined based on the integrated navigation unit of the vehicle.

[0110] In another embodiment shown, the integrated navigation unit does not include a navigation positioning unit, and the first angle value and the second angle value of the target direction angle need to be determined based on the integrated navigation unit and the navigation positioning unit of the vehicle. Exemplarily, the integrated navigation unit includes an inertial navigation positioning unit and a visual positioning unit, and the above steps S301 and S302 are implemented as follows: at the driving time T i , the inertial navigation unit in the integrated navigation unit determines the inertial navigation positioning result, the visual positioning unit in the integrated navigation unit determines the visual positioning result, and then the inertial navigation positioning result and the visual positioning result are fused through the integrated navigation algorithm to obtain the fused positioning result, and the target direction angle is determined at the driving time T based on the fused positioning result i The first angle value; determining the RTK positioning result based on the navigation positioning unit, and determining the target direction angle at the driving time T based on the RTK positioning result i The second angle value.

[0111] Next, the embodiment of the present application obtains the target direction angle at the driving time T by using the RTK algorithm. i The process of obtaining the second angle value is exemplarily described as follows:

[0112] The RTK positioning result obtained by the RTK algorithm includes the position of the vehicle, but does not include the vehicle's posture. Therefore, it is impossible to directly obtain the angle value of the target direction angle from the RTK positioning result. However, the angle value of the target direction angle can be determined based on the change of the RTK positioning result. In one embodiment, the target direction angle obtained by the RTK algorithm at the driving time T i The second angle value includes: obtaining the driving time T through the RTK algorithm i The corresponding first RTK positioning result, and the driving time T i-1The first RTK positioning result and the second RTK positioning result are converted from the latitude and longitude form to the coordinate form to obtain the converted first RTK positioning result and the converted second RTK positioning result; based on the coordinate difference between the converted first RTK positioning result and the converted second RTK positioning result and the time difference between the driving time and the last driving time, the speed vector of the vehicle is determined; based on the speed vector of the vehicle, the speed scalar of the vehicle is determined; based on the speed vector of the vehicle and the speed scalar, the target direction angle at the driving time T is determined. i The second angle value.

[0113] The RTK positioning result determined by the RTK algorithm is expressed in the form of longitude, latitude and altitude, that is, the RTK positioning result includes longitude, latitude and altitude. The altitude is the vertical distance of the vehicle's position relative to the horizontal plane of the physical world or the sea level. Since the change of the longitude and latitude of the vehicle cannot directly reflect the change of the vehicle's position, after obtaining the first RTK positioning result and the second RTK positioning result, the first RTK positioning result and the second RTK positioning result will be converted from the longitude and latitude form to the coordinate form.

[0114] The RTK positioning result can be converted from the latitude, longitude and height form to the coordinate form by any conversion method. For example, the RTK positioning result can be converted from the latitude, longitude and height form to the coordinate form by using the UTM (Universal Transverse Mercator) coordinate system.

[0115] When a vehicle travels with the same speed scalar but in different postures, the vehicle's speed vector will be different. Therefore, the vehicle's posture can be inferred based on the vehicle's speed vector and speed scalar, and then the angle value of the target direction angle in the embodiment of the present application can be obtained.

[0116] For example, the RTK positioning result is converted through UTM, the longitude in the RTK positioning result is converted to the easting coordinate in the UTM coordinate system, the latitude in the RTK positioning result is converted to the northing coordinate in the UTM coordinate system, and the altitude in the RTK positioning result is converted to the celestial coordinate in the UTM coordinate system to obtain the converted RTK positioning result P (Pe, Pn, Pu), where Pe is the easting coordinate in the converted RTK positioning result, Pn is the northing coordinate in the converted RTK positioning result, and Pu is the celestial coordinate in the converted RTK positioning result. i and driving time T i-1 The corresponding converted RTK positioning result is subtracted and divided by the driving time T i and driving time T i-1 The time difference dt between them is used to obtain the driving time T iThe corresponding velocity vector V(Ve,Vn,Vu), where Ve is the eastward velocity in the velocity vector, Vn is the northward velocity in the velocity vector, and Vu is the celestial velocity in the velocity vector.

[0117] Based on the vehicle's velocity vector V(Ve, Vn, Vu), the vehicle's velocity scalar Vnorm=sqrt(Ve*Ve+Vn*Vn+Vu*Vu) can be determined. i The corresponding velocity vector V(Ve, Vn, Vu) and velocity scalar Vnorm can be used to calculate the vehicle's pitch angle and heading angle, as follows:

[0118] Yaw_rtk=arctan(Ve,Vn)

[0119] Pitch_rtk=arcsin(Vu,Vnorm)

[0120] Among them, Yaw_rtk represents the angle value of the heading angle, arctan is the inverse tangent function, Pitch_rtk represents the angle value of the pitch angle, and arcsin is the inverse sine function.

[0121] S303: Determine the driving time T based on the angle difference between the first angle value and the second angle value i The corresponding target direction installation deflection angle includes a pitch installation deflection angle and / or a heading installation deflection angle.

[0122] In the embodiment of the present application, the first angle value is determined based on the combined navigation unit. According to the record in the above step S101, the combined navigation unit obtains the fusion positioning result by correcting the inertial navigation positioning result. Therefore, the first angle value is the angle value of the target direction angle of the vehicle in the inertial navigation coordinate system. The second angle value is the angle value of the target direction angle of the vehicle in the vehicle coordinate system. If there is no installation deviation of the inertial navigation unit, the inertial navigation coordinate system and the vehicle coordinate system are overlapped, and the first angle value and the second angle value are also the same; if there is an installation deviation of the inertial navigation unit, the inertial navigation coordinate system and the vehicle coordinate system do not overlap, and there is a difference between the first angle value and the second angle value. Based on the difference, the installation deviation of the inertial navigation unit can be inferred.

[0123] When the target direction angle is a pitch angle, the corresponding target direction installation deflection angle is a pitch installation deflection angle. When the target direction angle is a heading angle, the corresponding target direction installation deflection angle is a heading installation deflection angle. When the target direction angle includes a pitch angle and a heading angle, the corresponding target direction installation deflection angle includes a pitch installation deflection angle and a heading installation deflection angle.

[0124] In one embodiment, the angle difference can be directly determined as the target direction installation deflection angle, or the angle difference can be further processed to obtain the target direction installation deflection angle, which is not limited in the present embodiment. For example, the driving time T is determined based on the angle difference between the first angle value and the second angle value. i The corresponding target direction installation deflection angle includes: taking the angle difference between the first angle value and the second angle value as the driving time T i The corresponding target direction installation deflection angle.

[0125] For example, the target direction angle includes a pitch angle and a heading angle, the first angle value of the pitch angle is expressed as Pitch_fusion, and the second angle value of the pitch angle is expressed as Pitch_rtk. Accordingly, the pitch installation deflection angle is expressed as delta_pitch=Pitch_rtk-Pitch_fusion. The first angle value of the heading angle is expressed as Yaw_fusion, and the second angle value of the heading angle is expressed as Yaw_rtk. Accordingly, the heading installation deflection angle is expressed as delta_yaw=Yaw_rtk-Yaw_fusion.

[0126] S304: Determine the target direction installation deflection angle of the inertial navigation unit based on the target direction installation deflection angles corresponding to the k driving moments.

[0127] Wherein, k can be any integer greater than 1, and the embodiment of the present application does not limit the size of k. Exemplarily, k is 50, 100, 200, etc. In the embodiment of the present application, the target direction installation deflection angles corresponding to the k driving moments can be statistically processed to obtain the target direction installation deflection angle of the inertial navigation unit.

[0128] In one embodiment, the statistical processing may be an average processing. Determining the target direction installation deflection angle of the inertial navigation unit based on the target direction installation deflection angles corresponding to the k driving moments includes: averaging the target direction installation deflection angles corresponding to the k driving moments to obtain the target direction installation deflection angle of the inertial navigation unit.

[0129] In another embodiment, the statistical processing may be a recursive least squares processing. Based on the target direction installation deflection angles corresponding to the k driving moments, determining the target direction installation deflection angle of the inertial navigation unit comprises: performing a recursive least squares processing on the target direction installation deflection angles corresponding to the k driving moments to obtain the target direction installation deflection angle of the inertial navigation unit.

[0130] It should be noted that the embodiment of the present application is only an illustrative explanation of statistical processing and does not limit statistical processing. Other statistical processing methods can also be used to process the target direction installation deflection angles corresponding to k driving moments to obtain the target direction installation deflection angle of the inertial navigation unit.

[0131] In one embodiment, the target direction installation deflection includes a pitch installation deflection. Based on the target direction installation deflection corresponding to k driving moments, the target direction installation deflection of the inertial navigation unit is determined, including: determining the pitch installation deflection of the inertial navigation unit based on the pitch installation deflection corresponding to the k driving moments. In another embodiment, the target direction installation deflection includes a heading installation deflection. Based on the target direction installation deflection corresponding to k driving moments, the target direction installation deflection of the inertial navigation unit is determined, including: determining the heading installation deflection of the inertial navigation unit based on the heading installation deflection corresponding to the k driving moments. In another embodiment, the target direction installation deflection includes a pitch installation deflection and a heading installation deflection. Based on the target direction installation deflection corresponding to k driving moments, the target direction installation deflection of the inertial navigation unit is determined, including: determining the pitch installation deflection of the inertial navigation unit based on the pitch installation deflection corresponding to the k driving moments; determining the heading installation deflection of the inertial navigation unit based on the heading installation deflection corresponding to the k driving moments.

[0132] The installation deflection calibration method of the vehicle-mounted inertial navigation unit provided in the embodiment of the present application is a method of installation deflection calibration with simpler calculation. The method takes into account that if the inertial navigation unit does not have an installation deflection, then the inertial navigation coordinate system and the vehicle coordinate system are overlapped; if the inertial navigation unit has an installation deflection, then the inertial navigation coordinate system and the vehicle coordinate system do not overlap, and there is also a difference between the angle of the target direction angle in the inertial navigation coordinate system and the angle of the target direction angle in the vehicle coordinate system. Therefore, the embodiment of the present application determines the angle difference between the target direction angle in the inertial navigation coordinate system and the target direction angle in the vehicle coordinate system to infer the target direction installation deflection of the inertial navigation unit. This method does not require a lot of calculations and is simpler.

[0133] Figure 4 The following is a flow chart of a compensation method for a vehicle-mounted inertial navigation unit provided by an exemplary embodiment. Figure 4 As shown, the method may include the following steps:

[0134] S401, compensating the output of the inertial navigation unit at each moment through the roll installation deflection angle.

[0135] The inertial navigation unit includes an accelerometer and a gyroscope. The accelerometer is used to output acceleration parameters, and the gyroscope is used to output angular velocity parameters. The output of the inertial navigation unit at each moment is compensated by the roll installation deflection angle, that is, the acceleration parameters output by the accelerometer at each moment are compensated by the roll installation deflection angle, and the angular velocity output by the gyroscope at each moment is compensated.

[0136] Since the inertial navigation unit has an installation deflection angle, the inertial navigation coordinate system is not a horizontal coordinate system, but an inclined coordinate system. Therefore, the embodiment of the present application can construct a rotation matrix based on the installation deflection angle of the inertial navigation unit, through which the output of the inertial navigation unit can be converted from the inclined inertial navigation coordinate system to the horizontal inertial navigation coordinate system, eliminating the error caused by the installation deflection angle.

[0137] In one embodiment, the rotation matrix is ​​a direction cosine matrix, and the direction cosine matrix is ​​used to represent the conversion relationship between the tilted inertial navigation coordinate system and the horizontal inertial navigation coordinate system. Compensating the output of the inertial navigation unit at each moment by the roll installation deflection angle includes: converting the roll installation deflection angle into a direction cosine matrix, compensating the acceleration parameters output by the accelerometer at each moment by the direction cosine matrix, and compensating the angular velocity parameters output by the gyroscope at each moment by the direction cosine matrix.

[0138] Compensating the acceleration parameters outputted by the accelerometer at each moment by the direction cosine matrix may be performed by multiplying the direction cosine matrix with the acceleration parameters outputted by the accelerometer at each moment. Compensating the angular velocity parameters outputted by the gyroscope at each moment by the direction cosine matrix may be performed by multiplying the direction cosine matrix with the angular velocity parameters outputted by the gyroscope at each moment.

[0139] The compensation method of the vehicle-mounted inertial navigation unit provided in the embodiment of the present application can compensate the output of the inertial navigation unit at each moment through the roll installation angle of the inertial navigation unit, thereby eliminating the error introduced by the roll installation angle of the inertial navigation unit. In this way, the positioning result determined based on the inertial navigation unit is also more accurate.

[0140] Figure 5 The following is a flow chart of a compensation method for a vehicle-mounted inertial navigation unit provided by an exemplary embodiment. Figure 5 As shown, the method may include the following steps:

[0141] S501: Obtain a roll installation deflection angle, a heading installation deflection angle, and a pitch installation deflection angle of an inertial navigation unit of a vehicle.

[0142] The roll installation deflection angle in step S501 may be based on Figure 1 In the embodiment shown in the figure, the pitch installation deflection angle and the heading installation deflection angle in the above step S501 can be based on Figure 3 The embodiment shown can be determined by expanding the pitch installation deflection angle and the heading installation deflection angle of the inertial navigation unit to a Kalman filter, or can be measured using high-precision measuring equipment (total station), which is not limited in the embodiment of the present application.

[0143] S502: Convert the roll installation deflection angle, the heading installation deflection angle, and the pitch installation deflection angle into a direction cosine matrix.

[0144] Exemplarily, the installation deflection angle includes a pitch installation deflection angle α, a roll installation deflection angle β, and a heading installation deflection angle γ, and the direction cosine matrix is ​​expressed as:

[0145] S503, compensating the output of the inertial navigation unit at each moment through the direction cosine matrix.

[0146] In one embodiment, the inertial navigation unit includes an accelerometer and a gyroscope. The output of the inertial navigation unit at each moment is compensated by a direction cosine matrix, including: based on the direction cosine matrix, compensating the acceleration parameters output by the accelerometer of the inertial navigation unit to obtain the compensated acceleration parameters; based on the direction cosine matrix, compensating the angular velocity parameters output by the gyroscope of the inertial navigation unit to obtain the compensated angular velocity parameters; and performing inertial navigation solution based on the compensated acceleration parameters and the compensated angular velocity parameters.

[0147] Compensating the acceleration parameters outputted by the accelerometer at each moment by the direction cosine matrix may be performed by multiplying the direction cosine matrix with the acceleration parameters outputted by the accelerometer at each moment. Compensating the angular velocity parameters outputted by the gyroscope at each moment by the direction cosine matrix may be performed by multiplying the direction cosine matrix with the angular velocity parameters outputted by the gyroscope at each moment.

[0148] Exemplarily, the way to compensate the output of the accelerometer and the gyroscope at each moment by using the direction cosine matrix is ​​as follows:

[0149] Gyro_after=Cbv*Gyro_before

[0150] Acce_after=Cbv*Acce_before

[0151] Among them, Gyro_before represents the angular velocity parameter output by the gyroscope at each moment, Cbv is the direction cosine matrix, and Gyro_after represents the angular velocity parameter after compensation; Acce_before represents the acceleration parameter output by the accelerometer at each moment, and Acce_after represents the acceleration parameter after compensation.

[0152] Among them, performing inertial navigation solution based on the compensated acceleration parameters and the compensated angular velocity parameters refers to determining the inertial navigation positioning result based on the compensated acceleration parameters and the compensated angular velocity parameters.

[0153] The compensation method of the vehicle-mounted inertial navigation unit provided in the embodiment of the present application can compensate the output of the inertial navigation unit at each moment through the roll installation deflection angle, pitch installation deflection angle and heading installation deflection angle of the inertial navigation unit, thereby eliminating the errors introduced by the roll installation deflection angle, pitch installation deflection angle and heading installation deflection angle of the inertial navigation unit. In this way, the positioning result determined based on the inertial navigation unit is also more accurate.

[0154] It should be noted that the user authority information, user information (including but not limited to user login account, user login password, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this manual are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0155] Corresponding to the above method embodiments, the present application also provides embodiments of a device for calibrating the installation angle of a vehicle-mounted inertial navigation unit and a compensation device for the vehicle-mounted inertial navigation unit.

[0156] Figure 6 is a schematic diagram of the structure of an electronic device according to an exemplary embodiment of the present application. Figure 6 At the hardware level, the electronic device includes a processor 602, an internal bus 604, a network interface 606, a memory 608, and a non-volatile memory 610, and may also include hardware required for other services. The processor 602 reads the corresponding computer program from the non-volatile memory 610 into the memory 608 and then runs it. Of course, in addition to the software implementation, this application does not exclude other implementations, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0157] Figure 7 is a block diagram of a device for calibrating the installation angle of a vehicle-mounted inertial navigation unit according to an exemplary embodiment of the present application. Figure 7 The device includes a first acquisition module 701, a second acquisition module 702, and an estimation module 703, wherein:

[0158] A first acquisition module 701 is used to acquire a first roll angle of an inertial navigation unit on the vehicle through an integrated navigation unit of the vehicle when the vehicle stops on a flat road after the vehicle travels according to the target driving strategy;

[0159] A second acquisition module 702 is used to acquire a second roll angle of the inertial navigation unit based on an acceleration parameter and a zero bias parameter of an accelerometer of the vehicle when the vehicle stops on a flat road after the vehicle travels according to the target driving strategy;

[0160] The estimation module 703 is used to estimate the roll installation angle of the inertial navigation unit according to the first roll angle and the second roll angle.

[0161] Optionally, the target driving strategy includes at least one of accelerating driving, decelerating driving and turning driving;

[0162] and / or,

[0163] The zero bias parameter is determined based on the RTK positioning result of the navigation positioning unit in the integrated navigation unit, and the zero bias parameter is determined based on the process of the vehicle driving according to the target driving strategy.

[0164] Optionally, the second acquisition module 702 is used to obtain sub-acceleration parameters and sub-zero bias parameters of the accelerometer in M ​​target directions, and compensate the sub-acceleration parameters by the sub-zero bias parameters of each target direction to obtain the compensated sub-acceleration parameters of each target direction; M is an integer greater than or equal to 2; based on the compensated sub-acceleration parameters of each target direction in the M target directions, the second roll angle of the inertial navigation unit is determined.

[0165] Optionally, the device further comprises:

[0166] The compensation module is used to compensate the output of the inertial navigation unit at each moment through the roll installation deflection angle.

[0167] Optionally, the device further comprises:

[0168] The third acquisition module is used to obtain the heading installation deflection angle and the pitch installation deflection angle of the inertial navigation unit;

[0169] A conversion module, used for converting a roll installation deflection angle, a heading installation deflection angle and a pitch installation deflection angle into a direction cosine matrix;

[0170] The compensation module is used to compensate the output of the inertial navigation unit at each moment through the direction cosine matrix.

[0171] Optionally, the compensation module is used to compensate the acceleration parameters output by the accelerometer of the inertial navigation unit based on the direction cosine matrix to obtain the compensated acceleration parameters; compensate the angular velocity parameters output by the gyroscope of the inertial navigation unit based on the direction cosine matrix to obtain the compensated angular velocity parameters; and perform inertial navigation solution based on the compensated acceleration parameters and the compensated angular velocity parameters.

[0172] Optionally, the device further includes a determination module, and the determination module is specifically configured to:

[0173] When the vehicle is driving according to the target driving strategy, the following steps are performed:

[0174] For the i-th driving moment T among k driving momentsi , the target direction angle is obtained by the combined navigation algorithm at the driving time T i The first angle value is obtained by the RTK algorithm to obtain the target direction angle at driving time T i The driving time T is determined based on the angle difference between the first angle value and the second angle value. i The corresponding target direction installation deflection angle, the target direction angle includes the pitch angle and / or the heading angle, and the target direction installation deflection angle includes the pitch installation deflection angle and / or the heading installation deflection angle, wherein i and k are integers, and i∈[1, k];

[0175] The target direction installation deflection angle of the inertial navigation unit is determined based on the target direction installation deflection angles corresponding to the k driving moments.

[0176] Optionally, the determination module is specifically used for:

[0177] Obtain driving time T through RTK algorithm i The corresponding first RTK positioning result, and the driving time T i-1 The corresponding second RTK positioning result;

[0178] Convert the first RTK positioning result and the second RTK positioning result from the latitude, longitude and height form into coordinate form to obtain a converted first RTK positioning result and a converted second RTK positioning result;

[0179] Determine a velocity vector of the vehicle based on a coordinate difference between the converted first RTK positioning result and the converted second RTK positioning result and a time difference between the driving time and the last driving time;

[0180] Based on the vehicle's velocity vector, determine the vehicle's velocity scalar, and based on the vehicle's velocity vector and velocity scalar, determine the target direction angle at the driving time T i The second angle value.

[0181] Figure 8 is a block diagram of a compensation device for a vehicle-mounted inertial navigation unit according to an exemplary embodiment of the present application. Figure 8 The device includes an acquisition module 801, a conversion module 802, and a compensation module 803, wherein:

[0182] The acquisition module 801 is used to obtain the roll installation deflection angle, heading installation deflection angle and pitch installation deflection angle of the vehicle's inertial navigation unit. The roll installation deflection angle is Figure 1 The embodiment shown is determined;

[0183] A conversion module 802 is used to convert the roll installation deflection angle, the heading installation deflection angle and the pitch installation deflection angle into a direction cosine matrix;

[0184] The compensation module 803 is used to compensate the output of the inertial navigation unit at each moment through the direction cosine matrix.

[0185] Optionally, the compensation module 803 is specifically used for:

[0186] Based on the direction cosine matrix, the acceleration parameters output by the accelerometer of the inertial navigation unit are compensated to obtain the compensated acceleration parameters;

[0187] Based on the direction cosine matrix, the angular velocity parameters output by the gyroscope of the inertial navigation unit are compensated to obtain the compensated angular velocity parameters;

[0188] Inertial navigation solution is performed based on the compensated acceleration parameters and the compensated angular velocity parameters.

[0189] The implementation process of the functions and effects of each module in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, which will not be repeated here.

[0190] The devices or modules described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which may be in the form of a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email transceiver, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0191] In a typical configuration, a computer includes one or more processors, including a central processing unit (CPU) and a graphics processing unit (GPU), an input / output interface, a network interface, and a memory. The CPU is used for computing simulations, and the GPU is used for outputting high-quality 3D images.

[0192] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0193] Computer-readable media include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0194] Corresponding to the embodiments of the aforementioned method for calibrating the installation angle of the vehicle-mounted inertial navigation unit and the method for compensating the vehicle-mounted inertial navigation unit, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of any embodiment of the method for calibrating the installation angle of the vehicle-mounted inertial navigation unit are implemented, or, when the program is executed by a processor, the steps of any embodiment of the method for compensating the vehicle-mounted inertial navigation unit are implemented.

[0195] Corresponding to the embodiments of the aforementioned method for calibrating the installation angle of the vehicle-mounted inertial navigation unit and the method for compensating the vehicle-mounted inertial navigation unit, the present application also provides a computer program product on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the steps of any embodiment of the method for calibrating the installation angle of the vehicle-mounted inertial navigation unit are implemented, or, when the program is executed by a processor, the steps of any embodiment of the method for compensating the vehicle-mounted inertial navigation unit are implemented.

[0196] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for calibrating the installation angle of a vehicle-mounted inertial navigation unit, characterized in that: The method comprises: After the vehicle is driven according to the target driving strategy and is stationary on a flat road, perform the following steps: Acquiring a first roll angle of an inertial navigation unit on the vehicle by means of a combined navigation unit of the vehicle; Acquiring a second roll angle of the inertial navigation unit based on an acceleration parameter and a zero bias parameter of an accelerometer of the vehicle; The roll installation angle of the inertial navigation unit is estimated according to the first roll angle and the second roll angle.

2. The method according to claim 1, characterized in that The target driving strategy includes at least one of accelerating driving, decelerating driving and turning driving; and / or, The zero bias parameter is determined based on the RTK positioning result of the navigation and positioning unit in the integrated navigation unit, and the zero bias parameter is determined based on the process of the vehicle driving according to the target driving strategy.

3. The method according to claim 1, characterized in that The acquiring the second roll angle of the inertial navigation unit based on the acceleration parameter and the zero bias parameter of the accelerometer of the vehicle comprises: Obtaining sub-acceleration parameters and sub-bias parameters of the accelerometer in M ​​target directions, and compensating the sub-acceleration parameters by the sub-bias parameters of each target direction to obtain compensated sub-acceleration parameters of each target direction; wherein M is an integer greater than or equal to 2; A second roll angle of the inertial navigation unit is determined based on the compensation sub-acceleration parameter of each target direction in the M target directions.

4. The method according to claim 1, characterized in that: After estimating the roll installation angle of the inertial navigation unit according to the first roll angle and the second roll angle, the method further includes: The output of the inertial navigation unit at each moment is compensated by the roll installation deflection angle.

5. The method according to claim 1, characterized in that The method further comprises: Obtaining the heading installation deflection angle and the pitch installation deflection angle of the inertial navigation unit; Converting the roll installation deflection angle, the heading installation deflection angle, and the pitch installation deflection angle into a direction cosine matrix; The output of the inertial navigation unit at each moment is compensated by the direction cosine matrix.

6. The method according to claim 5, characterized in that Compensating the output of the inertial navigation unit at each moment by using the direction cosine matrix includes: Based on the direction cosine matrix, compensating the acceleration parameters output by the accelerometer of the inertial navigation unit to obtain compensated acceleration parameters; Based on the direction cosine matrix, compensating the angular velocity parameters output by the gyroscope of the inertial navigation unit to obtain compensated angular velocity parameters; An inertial navigation solution is performed based on the compensated acceleration parameter and the compensated angular velocity parameter.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: When the vehicle is driving according to the target driving strategy, the following steps are performed: For the i-th driving moment T among k driving moments i , the target direction angle is obtained by the combined navigation algorithm at the driving time T i The first angle value is obtained by the RTK algorithm, and the target direction angle is obtained at the driving time T i The driving time T is determined based on the angle difference between the first angle value and the second angle value. i The corresponding target direction installation deflection angle, the target direction angle includes a pitch angle and / or a heading angle, and the target direction installation deflection angle includes a pitch installation deflection angle and / or a heading installation deflection angle, wherein i and k are integers, and i∈[1, k]; The target direction installation deflection angle of the inertial navigation unit is determined based on the target direction installation deflection angles respectively corresponding to the k driving moments.

8. The method according to claim 7, characterized in that The target direction angle is obtained by using the RTK algorithm at the driving time T i The second angle value includes: The driving time T is obtained by using the RTK algorithm i The corresponding first RTK positioning result, and the driving time T i-1 The corresponding second RTK positioning result; Converting the first RTK positioning result and the second RTK positioning result from the latitude, longitude and height form into coordinate form to obtain a converted first RTK positioning result and a converted second RTK positioning result; Determine a velocity vector of the vehicle based on a coordinate difference between the converted first RTK positioning result and the converted second RTK positioning result and a time difference between the driving time and the last driving time; Based on the speed vector of the vehicle, the speed scalar of the vehicle is determined, and based on the speed vector and the speed scalar of the vehicle, the target direction angle is determined at the driving time T i The second angle value.

9. A compensation method for a vehicle-mounted inertial navigation unit, characterized in that: The method comprises: Obtaining a roll installation deflection angle, a heading installation deflection angle, and a pitch installation deflection angle of an inertial navigation unit of the vehicle, wherein the roll installation deflection angle is determined based on the method according to any one of claims 1 to 8; Converting the roll installation deflection angle, the heading installation deflection angle, and the pitch installation deflection angle into a direction cosine matrix; The output of the inertial navigation unit at each moment is compensated by the direction cosine matrix.

10. The method according to claim 9, characterized in that The compensating the output of the inertial navigation unit at each moment by using the direction cosine matrix includes: Based on the direction cosine matrix, compensating the acceleration parameters output by the accelerometer of the inertial navigation unit to obtain compensated acceleration parameters; Based on the direction cosine matrix, compensating the angular velocity parameters output by the gyroscope of the inertial navigation unit to obtain compensated angular velocity parameters; An inertial navigation solution is performed based on the compensated acceleration parameter and the compensated angular velocity parameter.

11. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instruction is executed by a processor, the steps of the method as described in any one of claims 1-8 or 9-10 are implemented.

12. A computer program product having a computer program / instructions stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1-8 or 9-10 are implemented.

Images