Satellite-Inertial Navigation Method and System Based on Odometry Correction Factor

Abstract

This invention relates to the field of satellite-inertial navigation integration technology, and provides a satellite-inertial navigation integration method and system based on an odometer correction factor. The method includes: obtaining first navigation information output at a first frequency through combined filtering of satellite navigation information and inertial navigation information; obtaining second navigation information output at a second frequency by running a Kalman filter based on an odometer correction factor during the output intervals of adjacent first navigation information; and outputting satellite-inertial navigation integration information based on the first and second navigation information. This invention reduces the accumulated error of the inertial mode through an odometer correction factor, obtaining more accurate inertial navigation information, i.e., the second navigation information. Based on this, combined filtering of satellite navigation information yields the first navigation information. The satellite-inertial navigation integration information, combining the first and second navigation information, achieves more accurate navigation.

Description

Technical Field

[0001] This invention relates to the field of satellite-inertial navigation technology, and in particular to a satellite-inertial navigation method and system based on an odometer correction factor. Background Technology

[0002] The design principle block diagram of a typical satellite-inertial combined device in the prior art is as follows: Figure 2 As shown, the current principle of satellite-inertial navigation integration is to combine the navigation information output by the inertial navigation system with the navigation information output by the satellite navigation board using Kalman filtering.

[0003] Due to the low frequency of satellite signals, navigation equipment will inevitably use inertial navigation during some gaps. In pure inertial mode, the error of the IMU (Inertial Measurement Unit) components will accumulate with integration, causing the equipment accuracy to decrease.

[0004] Under normal circumstances, the accumulated error of inertial mode can be corrected to some extent by satellite signals with relatively large intervals. However, considering the limited positioning accuracy of satellite signals, which also have certain errors, although the accuracy and reliability of satellite-inertial integrated navigation can meet the needs of some scenarios in the long run, there is still a problem of insufficient short-term accuracy (this problem is particularly prominent when the satellite signal strength is poor).

[0005] Therefore, how to provide a more accurate satellite-inertial integrated navigation method and system has become a technical problem that urgently needs to be solved in the industry. Summary of the Invention

[0006] This invention provides a satellite-inertial navigation integrated method and system based on odometer correction factor to address the shortcomings of insufficient short-term accuracy in existing technologies and achieve more accurate satellite-inertial navigation integrated.

[0007] This invention provides a satellite-inertial integrated navigation method based on an odometer correction factor, comprising:

[0008] First navigation information is obtained by combining and filtering satellite navigation information and inertial navigation information, and output at a first frequency; the first frequency is a parameter set according to the frequency of the satellite navigation information.

[0009] During the output intervals of adjacent first navigation information, a Kalman filter is run based on an odometer correction factor to obtain second navigation information output at a second frequency; the second frequency is greater than the first frequency.

[0010] Based on the first navigation information and the second navigation information, output satellite-inertial integrated navigation information;

[0011] The odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation speed error, inertial navigation position error, odometer speed error, and odometer coordinate system error.

[0012] According to the present invention, a satellite-inertial navigation method based on an odometer correction factor is provided, wherein the step of running a Kalman filter based on the odometer correction factor to obtain second navigation information output at a second frequency includes:

[0013] The output data of the attitude sensor is averaged and down-processed to obtain attitude down-frequency data.

[0014] Based on the attitude down-frequency data and the odometer correction factor, the position information and / or velocity information are calculated as the first data.

[0015] The position information and / or velocity information are calculated based on the attitude down-frequency data and used as the second data.

[0016] Using the difference between the first data and the second data as a quantity measurement, a Kalman filter is run to obtain the second navigation information output at the second frequency;

[0017] The state vector of the Kalman filter includes any one or a combination of longitude, latitude, altitude, northward velocity, eastward velocity, celestial velocity, pitch angle, roll angle, heading angle, gyroscope three-axis zero bias, accelerometer three-axis zero bias, and odometer scale.

[0018] According to the present invention, a satellite-inertial navigation method based on an odometry correction factor is provided, wherein the step of calculating position information and / or velocity information as first data based on the attitude downsampling data and the odometry correction factor includes:

[0019] Based on the attitude down-frequency data, the odometer correction factor, and the output data of the lidar, the position information and / or velocity information are calculated as the first data.

[0020] The attitude down-frequency data has the same frequency as the output data frequency of the lidar; the frequency of the first data has the same frequency as the output data frequency of the lidar.

[0021] According to the present invention, a satellite-inertial navigation integrated method based on an odometer correction factor is provided, wherein the step of outputting satellite-inertial navigation integrated information based on the first navigation information and the second navigation information includes:

[0022] Using the second navigation information as the corrected inertial navigation information, and combining it with the satellite navigation data for filtering and correction of the first navigation information, a third navigation information is obtained; the frequency of the third navigation information is the first frequency.

[0023] The satellite-inertial navigation information is obtained by interpolating the third navigation information with the second navigation information and then output.

[0024] According to the present invention, a satellite-inertial navigation method based on an odometer correction factor is provided, wherein the step of obtaining and outputting satellite-inertial navigation information by interpolating the third navigation information with the second navigation information further includes:

[0025] The output data from the vision sensor is processed to obtain the fourth navigation information;

[0026] After interpolating the third navigation information with the second navigation information, the fourth navigation information is fused to obtain satellite-inertial navigation combined information and output.

[0027] The satellite-inertial navigation method based on an odometer correction factor provided by the present invention further includes:

[0028] The odometer scale is corrected based on the second navigation information.

[0029] The present invention also provides a satellite-inertial integrated navigation system based on an odometer correction factor, comprising:

[0030] The first navigation module is used to obtain first navigation information at a first frequency by combining and filtering satellite navigation information and inertial navigation information; the first frequency is a parameter set according to the frequency of the satellite navigation information.

[0031] The second navigation module is used to run a Kalman filter based on an odometer correction factor to obtain second navigation information output at a second frequency during the output intervals of adjacent first navigation information; the second frequency is greater than the first frequency.

[0032] The output module is used to output satellite-inertial navigation combined information based on the first navigation information and the second navigation information;

[0033] The odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation speed error, inertial navigation position error, odometer speed error, and odometer coordinate system error.

[0034] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the satellite-inertial navigation method based on the odometer correction factor as described above.

[0035] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the satellite-inertial navigation method based on the odometer correction factor as described above.

[0036] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the satellite-inertial navigation method based on the odometer correction factor described above.

[0037] The satellite-inertial navigation method and system based on odometer correction factor provided by this invention reduces the accumulated error of the inertial mode by using the odometer correction factor to obtain more accurate inertial navigation information, namely the second navigation information. On this basis, satellite navigation information is combined with filtering to obtain the first navigation information. The satellite-inertial navigation information that combines the first navigation information and the second navigation information can achieve more accurate navigation. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a flowchart illustrating the satellite-inertial navigation integration method based on odometer correction factor provided by the present invention.

[0040] Figure 2 This is a schematic diagram of the process of satellite-inertial integrated navigation in the existing technology;

[0041] Figure 3 This is a schematic diagram of the process of the inertial navigation / satellite navigation / odometer integrated navigation provided in an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of signal transmission for the inertial navigation / satellite navigation / odometer integrated navigation system provided in an embodiment of the present invention;

[0043] Figure 5 A schematic diagram of the lever arm effect of the odometer provided by the present invention;

[0044] Figure 6 This is a schematic diagram of the implementation device structure of the inertial navigation / satellite navigation / odometer integrated navigation provided in an embodiment of the present invention;

[0045] Figure 7 This is a schematic diagram of the signal processing timing of the inertial navigation / satellite navigation / odometer integrated navigation system provided in an embodiment of the present invention;

[0046] Figure 8 This is a schematic diagram of the structure of the electronic device provided by the present invention;

[0047] Figure 9 This is a schematic diagram of the satellite-inertial navigation device based on odometer correction factor provided by the present invention.

[0048] Figure label:

[0049] 801: First navigation module;

[0050] 802: Second navigation module;

[0051] 803: Output module;

[0052] 810: Processor;

[0053] 820: Communication interface;

[0054] 830: Memory;

[0055] 840: Communication bus. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0057] The following is combined Figures 1-6 The present invention describes a satellite-inertial navigation method based on an odometer correction factor.

[0058] like Figure 1 As shown, this embodiment of the invention provides a satellite-inertial navigation method based on an odometer correction factor, comprising:

[0059] Step 102: Filter the satellite navigation information and inertial navigation information to obtain first navigation information output at a first frequency; the first frequency is a parameter set according to the frequency of the satellite navigation information.

[0060] Step 104: During the output gaps of adjacent first navigation information, a Kalman filter is run based on the mileage correction factor to obtain second navigation information output at a second frequency; the second frequency is greater than the first frequency.

[0061] Step 106: Output satellite-inertial navigation integrated information based on the first navigation information and the second navigation information;

[0062] The odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation speed error, inertial navigation position error, odometer speed error, and odometer coordinate system error.

[0063] In this embodiment, the sequence numbers of steps 102 and 104 should not be interpreted as limiting the execution order of these two steps. In fact, steps 102 and 104 can be understood as being executed simultaneously, but the output of step 102, i.e., the output frequency of the first navigation information, is relatively low; while the output of step 104, i.e., the output frequency of the second navigation information, is relatively high.

[0064] It is worth noting that the second navigation information is obtained by running a Kalman filter based on the mileage correction factor. The mileage correction factor is related to mileage information and inertial navigation information, and its calculation process does not involve non-inertial navigation quantities. Therefore, the second navigation information can be understood as mileage-corrected inertial navigation information.

[0065] Understandable, such as Figure 3 As shown, this embodiment essentially provides a navigation method that combines inertial navigation, satellite navigation, and odometry.

[0066] Based on this, considering the outputs of steps 102 and 104 from a timing perspective, we have the following within a single cycle of the first navigation information:

[0067] 1. The first data output of the first navigation information, which is navigation information filtered by a combination of satellite navigation and inertial navigation;

[0068] 2. The first to nth data points of the second navigation information are output sequentially. This output is inertial navigation information based on mileage information, speed information, and acceleration information.

[0069] 3. The second data output of the first navigation information is navigation information that is filtered by a combination of satellite navigation and inertial navigation (inertial navigation can be the first to nth data output of the second navigation information).

[0070] In other words, in a preferred embodiment:

[0071] The second navigation information is the odometer-corrected inertial navigation information; the first navigation information is obtained by combining and filtering satellite navigation information and the corrected inertial navigation information (i.e., the second navigation information).

[0072] The beneficial effects of this embodiment are as follows:

[0073] By reducing the cumulative error of the inertial mode through the odometer correction factor, more accurate inertial navigation information, namely the second navigation information, is obtained. Based on this, the first navigation information is obtained by combining and filtering satellite navigation information. The combined satellite-inertial navigation information, which combines the first navigation information and the second navigation information, can achieve more accurate navigation.

[0074] According to the above embodiments, in this embodiment:

[0075] The step of running a Kalman filter based on the odometer correction factor to obtain the second navigation information output at the second frequency includes:

[0076] The output data of the attitude sensor is averaged and down-processed to obtain attitude down-frequency data.

[0077] Based on the attitude down-frequency data and the odometer correction factor, the position information and / or velocity information are calculated as the first data.

[0078] The position information and / or velocity information are calculated based on the attitude down-frequency data and used as the second data.

[0079] Using the difference between the first data and the second data as a quantity measurement, a Kalman filter is run to obtain the second navigation information output at the second frequency;

[0080] The state vector of the Kalman filter includes any one or a combination of longitude, latitude, altitude, northward velocity, eastward velocity, celestial velocity, pitch angle, roll angle, heading angle, gyroscope three-axis zero bias, accelerometer three-axis zero bias, and odometer scale.

[0081] In a preferred embodiment, the step of calculating the position information and / or velocity information as the first data based on the attitude downsampling data and the odometer correction factor includes:

[0082] Based on the attitude down-frequency data, the odometer correction factor, and the output data of the lidar, the position information and / or velocity information are calculated as the first data.

[0083] The attitude down-frequency data has the same frequency as the output data frequency of the lidar; the frequency of the first data has the same frequency as the output data frequency of the lidar.

[0084] The following will combine Figure 4 The calculation and filtering processes of the mileage correction factor are illustrated with examples.

[0085] It should be noted that this invention relates to multiple coordinate systems, including the i-system, e-system, n-system, and b-system, with the specific meanings as follows:

[0086] The i-frame is an inertial coordinate system with the Earth's center of mass at its origin. The Z-axis is the Earth's rotation axis, pointing towards the North Pole. The X-axis lies in the equatorial plane and points towards the vernal equinox. The Y-axis, Z-axis, and X-axis form a right-handed orthogonal coordinate system.

[0087] The e-frame is the Earth coordinate system, with the origin at the Earth's center of mass, the Z-axis being the Earth's rotation axis pointing towards the North Pole, the X-axis pointing towards the Prime Meridian in the equatorial plane, and the Y-axis forming a right-handed orthogonal coordinate system with the Z-axis and X-axis.

[0088] The n-system is the navigation coordinate system, namely the East-North-Sky coordinate system. The origin of the coordinate system is the center of gravity of the vehicle. The X-axis points east in the local horizontal plane, the Y-axis points north in the local horizontal plane, and the Y-axis points to the sky along the local plumb line.

[0089] The b-system is the carrier coordinate system, with the origin at the carrier's center of gravity. The X-axis points to the right along the carrier's horizontal axis, the Y-axis points forward along the carrier's vertical axis, and the Z-axis points upward along the carrier's vertical axis, forming a right-front-up coordinate system.

[0090] Figure 4 In this process, the combined filtering solution includes inertial navigation / satellite navigation combined filtering and inertial navigation / odometer combined filtering.

[0091] 1. Error equations of strapdown inertial navigation systems

[0092] 1) Attitude error equation

[0093] Let attitude error angle δθ is the error angle between the ideal navigation frame n and the calculated navigation frame n′ of the strapdown inertial navigation system, where δθ is the pitch error angle, δγ is the roll error angle, and δψ is the heading error angle. For small angles and neglecting the installation, calibration coefficient errors, and gravity model errors of gyroscopes and accelerometers, the linear error model of strapdown inertial navigation is as follows:

[0094]

[0095] in, Let be the angular velocity of rotation of the local geographic coordinate system relative to the inertial frame. ε b This refers to the constant drift calibration error of the gyroscope. Let be the rotation matrix from the b-system to the n-system. It measures the projection of the angular error in the n-system.

[0096]

[0097] in, ω represents the projection of the Earth's rotational angular velocity in the n-frame; δ() represents the error in the quantity within the parentheses, such as δL representing the error in L; ie ω is the Earth's rotational angular velocity; L is the latitude of the current location.

[0098]

[0099] in, The projection of the northward horizontal velocity component of the carrier's motion velocity onto the n-frame; R is the projection of the eastward horizontal velocity component of the carrier's motion velocity in the n-frame; M R is the radius of curvature of the meridian (along the north-south direction) where the carrier is located;N denoted by , where is the radius of curvature of the yoke (east-west direction) where the carrier is located; h is the height of the carrier's location. Let be the projection of the angle of the n-frame relative to the e-frame onto the n-frame.

[0100] Define the speed error as These represent the eastward error, northward error, and celestial error, respectively. Let δp be the projection of the celestial velocity component of the carrier's motion velocity onto the n-frame, and define the position error as δp = [δL δλ δh] T Let represent latitude error, longitude error, and altitude error, respectively. The above formula can be rewritten as:

[0101]

[0102]

[0103] remember:

[0104]

[0105]

[0106] The attitude error equation of the strapdown inertial navigation system can be simplified as follows:

[0107]

[0108] 2) Velocity error equation

[0109] Based on the velocity differential equation of the strapdown inertial navigation system, neglecting minor errors, the velocity error equation can be simplified as follows:

[0110]

[0111] in, This is the representation of the proportional acceleration vector in the navigation coordinate system.

[0112] remember:

[0113]

[0114]

[0115] The velocity error equation can be simplified as follows:

[0116]

[0117] in, This is the calibration error for the constant bias of the accelerometer.

[0118] 3) Position error equation

[0119] Based on the position differential equation of the strapdown inertial navigation system, its error equation can be directly written as:

[0120]

[0121]

[0122]

[0123] remember:

[0124]

[0125]

[0126] The position error equation can be simplified as follows:

[0127]

[0128] 2. Odometer speed error equation

[0129] This system mounts the odometer on the non-steering wheels of the vehicle body, ensuring that the odometer's speed output always points directly forward. Assuming good road conditions, with wheels firmly in contact with the road surface and no slippage or other adverse conditions, the odometer's output value is the speed in the forward direction of the vehicle. Let the odometer's coordinate system be the m-system, a right-front-up coordinate system fixed to the vehicle body, with its origin at o. The three axes are the ox axis, oy axis, and oz axis, where the ox axis is along the vehicle's transverse axis to the right, the oy axis is along the vehicle's longitudinal axis forward, and the oz axis is perpendicular to the ground and upward. Then, the speed output by the odometer in the m-system is expressed as:

[0130]

[0131] Among them, v D The speed of the carrier is output by the odometer. This is the projection of the odometer output velocity onto the m-frame. When the odometer is combined with a strapdown inertial navigation system, assuming the vehicle's attitude matrix is ​​C, and ideally the b-frame coincides with the m-frame, the odometer's velocity in the navigation coordinate system is:

[0132]

[0133] in, Let be the rotation matrix from the b-system to the n-system. In practice, due to road conditions, environment, and other factors, the odometer's calibration coefficient cannot be accurately obtained. Therefore, the odometer's calibration coefficient error must be considered in practical use. Let the calibration coefficient error be δK. D When the actual speed of the carrier is At that time, the speed output by the odometer for:

[0134]

[0135] In practical use, the odometer is connected to the axle and generally cannot be installed in the same position as the strapdown inertial navigation system. Therefore, the coordinate axes of the inertial measurement unit cannot be parallel to the axes of the vehicle system. Assuming the coordinate system of the strapdown inertial navigation is the b-frame, the b-frame and the m-frame do not completely coincide, and there is a small installation deviation angle. Let the pitch installation deviation angle be α. θ The roll installation deviation angle is α. γ The heading installation deviation angle is α ψ Let α = [α θ α γ α ψ ] T Then the installation error matrix from system b to system m is:

[0136]

[0137] When there is a small installation deviation angle between the b-series and the m-series, the output speed of the odometer for:

[0138]

[0139] We also need to consider the attitude error inherent in the strapdown inertial navigation system. Let the attitude error angle of the strapdown inertial navigation system be... The speed measured by the odometer in the navigation coordinate system is represented as follows:

[0140]

[0141] Where I is the identity matrix, C ij (i, j = 1, 2, 3) is The unfolding of various aspects, This is when there is a small installation deviation angle between the B-series and the M-series. Meanwhile, the above formula shows that the roll error angles of the b-series and m-series do not affect the speed measurement of the odometer. For ease of representation, δK is used. D Replace α γ Therefore, the speed error is:

[0142]

[0143] Because the odometer's shaft and the axle are mechanically connected, the rotation of the odometer's shaft will lag behind the rotation of the axle. At the same time, there will be a delay in the odometer's sampling and signal conversion. In the combined system of odometer and strapdown inertial navigation, there will also be a situation where the sampling frequencies of the odometer and the inertial device are inconsistent. Therefore, it is necessary to consider the error caused by the time asynchrony between the odometer and the inertial navigation system.

[0144] Let δt be the time asynchrony error between the odometer and the inertial navigation system. Then the correspondence between the odometer speed and the inertial navigation speed is as follows:

[0145]

[0146] Among them, v n For inertial navigation velocity, a n The average linear acceleration of the carrier during the error time period can be approximated by linear extrapolation:

[0147]

[0148] Where T = t m -t m-1 For inertial navigation system (INS) calculation time interval, and These are the velocity values ​​of the inertial navigation system at the current moment and the previous moment, respectively.

[0149] After comprehensively considering the calibration error of the odometer, the attitude error of the strapdown inertial navigation system, and the installation error angle and time error between the two, the error of the odometer in the combined system can be obtained as follows:

[0150]

[0151] remember:

[0152]

[0153]

[0154] The above formula can be written as:

[0155]

[0156] 3. Kalman filter design

[0157] The error equation of the inertial navigation / odometry combined positioning and orientation system is as follows:

[0158]

[0159] Assume the state-space model of the integrated positioning and orientation system is as follows:

[0160]

[0161] In this system, the velocity in the n-frame calculated using inertial navigation is compared with the velocity in the n-frame obtained from the odometer after error compensation. The difference between these two velocities is used as the measurement of the Kalman filter. The system's observation equation is z = Hx. k +V, x k Let x be the estimated state variable at time k.k-1 Let be the estimated state variable at time k-1, z be the measurement vector, F be the one-step transition matrix, w be the system noise matrix, H be the measurement matrix, G be the weighted matrix of system noise, and V be the system measurement white noise.

[0162] Furthermore, the specific form of G is:

[0163]

[0164] Furthermore, the specific form of H is:

[0165]

[0166] Where I is the identity matrix.

[0167] Furthermore, the specific form of W is:

[0168]

[0169] in, The gyroscope's angular rate white noise generally satisfies The random walk coefficient for the gyroscope's angle; For the specific force white noise of the accelerometer, it generally satisfies Let be the velocity random walk coefficient.

[0170] Taking into account all errors of the inertial navigation system and the odometer, the 19-dimensional state vector of the combined system is defined as follows:

[0171]

[0172] In another alternative implementation, the combined navigation filter state vector is 17-dimensional, and the input quantities are the attitude (pitch angle, roll angle, and heading angle) of the carrier on which the device is located. Position error (longitude error, latitude error, altitude error) δp, velocity error (northward error, eastward error, celestial error) δv n gyroscope three-axis zero bias ε b Accelerometer triaxial zero bias and odometer scale factor The time asynchrony error δt between the odometer and the inertial navigation system.

[0173] Assuming that the gyroscope constant drift, accelerator zero bias, inertial measurement unit installation deviation angle, odometer calibration coefficient error, and time error are all random constants, the system's state equation can be obtained, where the state transition matrix is:

[0174]

[0175] 4. Odometer lever arm

[0176] Figure 5 A schematic diagram of the lever arm effect of the odometer provided by the present invention, as shown below. Figure 5 As shown, the Earth coordinate system e is O. e x e y e z e The carrier coordinate system b is O b x b y b z b The odometer is installed at point 0 in space, and the lever arm from the center of the carrier's sway to the odometer's installation position is...

[0177] according to Figure 5 Obviously, there are:

[0178]

[0179] Differentiating the above equation and projecting it onto the Earth system, according to Chronoswiss's theorem, we get:

[0180]

[0181] in, The velocity at point 0 is denoted as . Let the velocity at the center of the carrier's sway be denoted as . The odometer is fixed in position relative to the center of the carrier's oscillation, therefore... Therefore, the above equation can be simplified and expressed in the navigation system as:

[0182]

[0183] in, It is the projection of the angular velocity of the carrier system relative to the Earth system onto the carrier system.

[0184] Considering the lever arm effect, the actual speed of the vehicle body is projected onto the load system in frame b. and projection in the odometer system m system The following relationship must be satisfied:

[0185]

[0186] The odometer information, after being compensated by the lever arm as described above, is transmitted into the inertial navigation / odometer integrated navigation system to compensate for the speed error caused by the lever arm, thereby further improving the accuracy of the equipment.

[0187] The beneficial effects of this embodiment are as follows:

[0188] 1. A satellite navigation / inertial navigation / odometer combined system was designed. The inertial navigation system was combined with the satellite navigation system and the odometer for filtering simultaneously. During the periodic arrival of satellite navigation data, the velocity information output by the odometer was used to constrain and estimate the error of the inertial navigation output data in pure inertial mode. This solved the problem of easy divergence of system error in pure inertial mode and improved the overall accuracy of the system.

[0189] 2. Perform lever compensation on the speed information of the odometer to reduce the error caused by the lever in the odometer data, so as to improve the combined filtering effect of the inertial navigation and odometer and further improve the system accuracy.

[0190] According to any of the above embodiments, in this embodiment:

[0191] The step of outputting satellite-inertial integrated navigation information based on the first navigation information and the second navigation information includes:

[0192] Using the second navigation information as the corrected inertial navigation information, and combining it with the satellite navigation data for filtering and correction of the first navigation information, a third navigation information is obtained; the frequency of the third navigation information is the first frequency.

[0193] The satellite-inertial navigation information is obtained by interpolating the third navigation information with the second navigation information and then output.

[0194] In a preferred embodiment, the step of obtaining and outputting satellite-inertial navigation integrated information by interpolating the third navigation information with the second navigation information further includes:

[0195] The output data from the vision sensor is processed to obtain the fourth navigation information;

[0196] After interpolating the third navigation information with the second navigation information, the fourth navigation information is fused to obtain satellite-inertial navigation combined information and output.

[0197] Figure 6 This is a schematic diagram of the implementation device structure of the inertial navigation / satellite navigation / odometer integrated navigation provided in an embodiment of the present invention. Figure 7 The signal processing timing of the integrated navigation is shown.

[0198] When the device is running, the FPGA receives signals from the fiber optic gyroscope, backup IMU, satellite navigation board, lidar and 1pps, and forwards the processed information to the ARM chip, where the system performs calculations, RTK data generation, user debugging and upgrades and other tasks.

[0199] Among them, the fiber optic gyroscope and backup IMU data are high-frequency outputs and need to be collected simultaneously. Next, the lidar data is collected at 10 Hz, the satellite guidance board data is collected at 5 Hz, and the visual information is collected at 1 Hz. After the data is collected, the IMU data is averaged and down-processed, and 200 Hz IMU data is output to the ARM, which forwards the 10 Hz lidar data, 5 Hz satellite guidance data, and 1 Hz visual data.

[0200] After receiving the data, the ARM performs 200Hz inertial navigation solution for position information interpolation, 10Hz inertial navigation solution, 10Hz lidar filtering solution, and 5Hz satellite-inertial combination solution, as well as fusion of 1Hz and visual information.

[0201] In an optional implementation, the satellite-inertial integrated navigation method based on the odometry correction factor further includes:

[0202] The odometer scale is corrected based on the second navigation information.

[0203] In other words, based on the above embodiments, this implementation method adds the following:

[0204] 1. Odometer information quality assessment

[0205] The odometer scale factor obtained by the combined filtering is judged. If the value of this factor is greater than the set threshold, the odometer data is judged to be unreliable and the odometer data at that moment is discarded. Only the satellite navigation data and the IMU solution results are combined. This can effectively avoid the reduction in the combined solution accuracy due to the failure of odometer data, making the whole system more adaptable and robust.

[0206] 2. Odometer data feedback

[0207] After obtaining the odometer scale factor through combined filtering, the scale factor is fed back to the odometer data calculation part. The odometer data is then corrected using this scale factor, further improving the accuracy of the odometer data, thereby improving the accuracy of the entire combined calculation result.

[0208] The beneficial effects of this embodiment are as follows:

[0209] By fusing multi-source data from odometry, lidar, visual sensors, and attitude sensors (such as IMU) to calculate inertial navigation information, the accuracy and reliability of satellite-inertial integrated navigation are further improved.

[0210] The satellite-inertial navigation device based on odometer correction factor provided by the present invention will be described below. The satellite-inertial navigation device based on odometer correction factor described below and the satellite-inertial navigation method based on odometer correction factor described above can be referred to in correspondence with each other.

[0211] like Figure 9As shown, this embodiment of the invention also provides a satellite-inertial integrated navigation system based on an odometer correction factor, comprising:

[0212] The first navigation module 801 is used to obtain first navigation information output at a first frequency by combining and filtering satellite navigation information and inertial navigation information; the first frequency is a parameter set according to the frequency of the satellite navigation information.

[0213] The second navigation module 802 is used to run a Kalman filter based on an odometer correction factor to obtain second navigation information output at a second frequency during the output intervals of adjacent first navigation information; the second frequency is greater than the first frequency.

[0214] Output module 803 is used to output satellite-inertial navigation combined information based on the first navigation information and the second navigation information;

[0215] The odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation speed error, inertial navigation position error, odometer speed error, and odometer coordinate system error.

[0216] Furthermore, the second navigation module 802 includes:

[0217] The frequency reduction unit is used to average and reduce the frequency of the output data of the attitude sensor to obtain attitude frequency-reduced data.

[0218] The first data unit is used to calculate position information and / or velocity information as first data based on the attitude down-frequency data and the odometer correction factor.

[0219] The second data unit is used to calculate position information and / or velocity information based on the attitude down-frequency data as the second data.

[0220] A Kalman filter unit is used to measure the difference between the first data and the second data, and run a Kalman filter to obtain second navigation information output at a second frequency.

[0221] The state vector of the Kalman filter includes any one or a combination of longitude, latitude, altitude, northward velocity, eastward velocity, celestial velocity, pitch angle, roll angle, heading angle, gyroscope three-axis zero bias, accelerometer three-axis zero bias, and odometer scale.

[0222] The first data unit includes:

[0223] The lidar fusion subunit is used to calculate position information and / or velocity information as first data based on the attitude down-frequency data, odometer correction factor and lidar output data.

[0224] The attitude down-frequency data has the same frequency as the output data frequency of the lidar; the frequency of the first data has the same frequency as the output data frequency of the lidar.

[0225] The output module 803 includes:

[0226] The third navigation unit is used to take the second navigation information as the corrected inertial navigation information, and combine it with the satellite navigation data to filter and correct the first navigation information to obtain the third navigation information; the frequency of the third navigation information is the first frequency;

[0227] An interpolation unit is used to interpolate the third navigation information with the second navigation information to obtain satellite-inertial navigation combined information and output it.

[0228] The interpolation unit further includes:

[0229] The vision subunit is used to process the output data of the vision sensor to obtain the fourth navigation information;

[0230] The visual fusion subunit is used to interpolate the third navigation information with the second navigation information, fuse the fourth navigation information, obtain satellite-inertial combined navigation information, and output it.

[0231] The satellite-inertial integrated navigation system based on the odometry correction factor also includes:

[0232] The odometer correction module is used to correct the odometer scale based on the second navigation information.

[0233] The beneficial effects of this embodiment are as follows:

[0234] By reducing the cumulative error of the inertial mode through the odometer correction factor, more accurate inertial navigation information, namely the second navigation information, is obtained. Based on this, the first navigation information is obtained by combining and filtering satellite navigation information. The combined satellite-inertial navigation information, which combines the first navigation information and the second navigation information, can achieve more accurate navigation.

[0235] Figure 8 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 8As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 can call logical instructions in the memory 830 to execute a satellite-inertial navigation integrated method based on an odometer correction factor. The method includes: obtaining first navigation information output at a first frequency by combining and filtering satellite navigation information and inertial navigation information; the first frequency is a parameter set according to the frequency of the satellite navigation information; during the output interval of adjacent first navigation information, running a Kalman filter based on an odometer correction factor to obtain second navigation information output at a second frequency; the second frequency is greater than the first frequency; and outputting satellite-inertial navigation integrated information based on the first navigation information and the second navigation information; the odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation velocity error, inertial navigation position error, odometer velocity error, and odometer coordinate system error.

[0236] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0237] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the satellite-inertial navigation integrated method based on the odometer correction factor provided by the above methods. The method includes: obtaining first navigation information output at a first frequency by combining and filtering satellite navigation information and inertial navigation information; the first frequency is a parameter set according to the frequency of the satellite navigation information; in the output gap of adjacent first navigation information, running a Kalman filter based on the odometer correction factor to obtain second navigation information output at a second frequency; the second frequency is greater than the first frequency; outputting satellite-inertial navigation integrated information based on the first navigation information and the second navigation information; the odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation velocity error, inertial navigation position error, odometer velocity error, and odometer coordinate system error.

[0238] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the satellite-inertial navigation method based on the odometer correction factor provided by the methods described above. This method includes: obtaining first navigation information output at a first frequency by combining and filtering satellite navigation information and inertial navigation information; the first frequency being a parameter set according to the frequency of the satellite navigation information; running a Kalman filter based on the odometer correction factor to obtain second navigation information output at a second frequency during the output intervals of adjacent first navigation information; the second frequency being greater than the first frequency; and outputting satellite-inertial navigation information based on the first navigation information and the second navigation information; wherein the odometer correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation velocity error, inertial navigation position error, odometer velocity error, and odometer coordinate system error.

[0239] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. 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 can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0240] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0241] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for integrated navigation of a satellite and inertial system based on a distance correction factor, characterized in that, Comprising: combining filter based on satellite navigation information and inertial navigation information to obtain first navigation information output at a first frequency; the first frequency is a parameter set according to the frequency of the satellite navigation information; in the adjacent output gap of the first navigation information, the Kalman filter is run based on the mileage correction factor to obtain the second navigation information output at the second frequency; the second frequency is greater than the first frequency; output integrated navigation information based on the first navigation information and the second navigation information; the mileage correction factor is an error equation calculated based on inertial navigation attitude error, inertial navigation speed error, inertial navigation position error, odometer speed error and odometer coordinate system error; wherein, the step of outputting integrated navigation information based on the first navigation information and the second navigation information comprises: combining filter based on the second navigation information and the satellite navigation information to correct the first navigation information, and obtain the third navigation information; the frequency of the third navigation information is the first frequency; interpolate the third navigation information with the second navigation information to obtain integrated navigation information and output.

2. The method of claim 1, wherein the method is based on a distance correction factor. the step of running Kalman filter based on the mileage correction factor to obtain the second navigation information output at the second frequency comprises: average the output data of the attitude sensor to obtain attitude downsampled data; according to the attitude downsampled data and the mileage correction factor, the position information and / or the speed information are calculated as the first data; according to the attitude downsampled data, the position information and / or the speed information are calculated as the second data; the difference between the first data and the second data is used as the measurement, and the Kalman filter is run to obtain the second navigation information output at the second frequency; the state vector of the Kalman filter includes any one or more combinations of longitude, latitude, altitude, northward speed, eastward speed, upward speed, pitch angle, roll angle, heading angle, gyroscope three-axis zero offset, accelerometer three-axis zero offset and odometer scale.

3. The method of claim 2, wherein the method is based on a distance correction factor. the step of calculating the position information and / or the speed information as the first data according to the attitude downsampled data and the mileage correction factor comprises: according to the attitude downsampled data, the mileage correction factor and the output data of the laser radar, the position information and / or the speed information are calculated as the first data; the frequency of the attitude downsampled data is the same as the output data of the laser radar; the frequency of the first data is the same as the output data of the laser radar.

4. The method of claim 1, wherein the method is a GNSS integrated navigation method based on a distance correction factor. the step of interpolating the third navigation information with the second navigation information to obtain integrated navigation information and output further comprises: calculate the output data of the visual sensor to obtain the fourth navigation information; fuse the fourth navigation information after interpolating the third navigation information with the second navigation information to obtain integrated navigation information and output.

5. The method according to any one of claims 1 to 4, wherein, Further comprising: correct the odometer scale based on the second navigation information.

6. A GNSS-based integrated navigation system based on a distance correction factor, characterized in that, Comprising: a first navigation module for combining filter based on satellite navigation information and inertial navigation information to obtain first navigation information output at a first frequency; the first frequency is a parameter set according to the frequency of the satellite navigation information; A second navigation module is configured to run a Kalman filter based on a mileage correction factor between adjacent output gaps of the first navigation information to obtain second navigation information output at a second frequency; The second frequency is greater than the first frequency; An output module is configured to output integrated navigation information based on the first navigation information and the second navigation information; The mileage correction factor is obtained based on an error equation of an inertial navigation attitude error, an inertial navigation speed error, an inertial navigation position error, a mileage speed error, and a mileage coordinate system error; The output module is configured to: combine the first navigation information with the satellite navigation information to obtain third navigation information, with the second navigation information as corrected inertial navigation information and the third navigation information having the first frequency; interpolate the third navigation information based on the second navigation information to obtain integrated navigation information and output the integrated navigation information.

7. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the steps of the integrated navigation method based on the mileage correction factor according to any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the integrated navigation method based on the mileage correction factor according to any one of claims 1 to 5.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the integrated navigation method based on the mileage correction factor according to any one of claims 1 to 5.

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