TWI564546B - On - board Vehicle Navigation System Calibration Method - Google Patents

Description

Landborne navigation system correction method

The present invention relates to instrument calibration techniques, and more particularly to a method for correcting a landborne navigation system for correcting the installation error angle of a navigation system device for a land vehicle.

In general, the main function of the land navigation system is to provide information such as the position, speed and attitude of the land vehicle itself. The range of location and speed information applications includes some vehicle dispatch systems (such as Taiwan's big teams, etc.) to understand the current location of the vehicle and to quickly and effectively deliver the car service. For example, the vehicle navigation software can use the current location information and purpose. The route is optimized for planning; the location and speed information can also be used to provide relevant warning services such as speeding photography at nearby locations. As for the current attitude of the vehicle, it can be used as an important reference for other auxiliary equipment. For example, the antenna system must adjust the antenna orientation (Azimuth Angle) and the elevation angle (Elevation Angle) according to the current vehicle attitude to obtain the best signal reception ratio. (Signal Noise Ratio), one of the key parameters of the vehicle's own attitude information, whether it can be successfully demodulated, such as satellite phones and satellite TV; in military vehicles, the correct vehicle attitude can assist itself The artillery (missile) system accurately hits enemy targets and improves the hit rate.

The general navigation system mainly uses the gyroscope and accelerometer to sense the angular velocity and acceleration of the vehicle body. After error compensation, the physical quantity is integrated into the digital signal processor (DSP) according to Newton's law of motion. In order to obtain navigation information such as the position, speed and posture of the vehicle itself. Due to factors such as the initial attitude error and the error of the sensing component drift, the navigation data obtained by the calculation is incorrect and its error gradually diverges with time. The position and velocity information provided by the error is too large, which causes the related application to lose its meaning. In order to improve the navigation accuracy, another way is to integrate the navigation data that can be collected on the vehicle, and to use the characteristics of the individual measurement data to not diverge with time, to correct and reduce various error sources in the inertial navigation system, so that The navigation accuracy has been improved, and this system is called an auxiliary navigation system.

At present, the most commonly used external navigation system for navigation systems is the global positioning system. The global positioning system is mainly divided into three parts: Control Segment, Space Segment and User Segment. The main output data of GPS is longitude, latitude, altitude and three-axis speed (ICD-GPS-200C). The error does not accumulate and accumulate with time. The integrated INS/GPS integrated navigation system has low cost and high precision. characteristic.

Although the INS/GPS integrated navigation system has many good features of low cost and high precision, satellite signals are easily shielded by external environments (such as buildings, tunnels, etc. in high-rise buildings) or signal interference (wireless base stations). The entire system cannot meet the requirements of self-sufficiency. To increase the anti-interference ability and When it is self-contained, the odometer becomes an important auxiliary equipment. Land vehicles generally install a so-called odometer (Odometer: ODO). The odometer can provide the mileage of the vehicle, in some special In the scenario, INS/GPS with INS/ODO can greatly improve the accuracy and meet the dual requirements of autonomy. Since the odometer is standard equipment for general vehicles, it can save a lot of money without additional reinstallation.

INS/GPS or INS/ODO assisted navigation system mainly adopts Kalman Filter as the data fusion architecture, and the filtering theory is optimized based on the accuracy of external measurement data at that time. At this time, the position, speed and attitude of the integrated navigation system at this time can meet the accuracy requirements of related applications.

At this stage, when the navigation system is installed to the land vehicle through the mounting base, the mechanical coordinate technology makes the body coordinates of the navigation system and the body coordinates on the vehicle cannot be completely consistent, but the tightness (between the two coordinate systems) Consistency) is a very important factor in the accuracy of INS/ODO-assisted navigation. Nowadays, the use of micro-electromechanical sensing elements in navigation systems has gradually become a trend. However, due to the accuracy of components, it is quite difficult to estimate the angle of installation error. The attitude of the navigation system can truly represent the vehicle at that time. Attitude, the most direct way is to accurately measure the installation angle error between the vehicle and the navigation system through the optical calibration method, and input this data into the navigation system. The navigation system then deducts this error when outputting the attitude. The attitude of the output can be regarded as the attitude of the vehicle itself. This method requires additional preparation of light. School equipment is expensive and time consuming. Another way is to refer to the vehicle dynamics combined with the odometer output for data fusion of the navigation system. Although the analysis of the angle error correlation is proposed, most of the current literature is limited to theoretical derivation, and how to correct the installation angle error of the navigation system is still No obvious and precise practice has been proposed. Another disadvantage of the existing rules is that the application scenarios of the body dynamics are limited to straight roads and cannot be adapted to the turning environment. Another consideration for the prior art is the production cost, such as the simple navigation system constructed by considering only the odometer plus gyroscope (US4347573) or GPS plus odometer (US5525998), GPS plus accelerometer (US5862511), etc. Most of them cannot display the full three-axis attitude of roll, pitch and azimuth, or the attitude output cannot provide sufficient accuracy.

In view of the shortcomings of the conventional technology, the present invention provides a landborne navigation system correction method for correcting the installation angle error caused by the installation process of the navigation system equipped with the landlord to ensure the accuracy of the navigation system.

The invention provides a method for correcting a landborne navigation system, which is used for calculating a pitch misalignment angle and a horizontal azimuth mismatch angle generated by a navigation system mounted on a vehicle, for compensating between the navigation system and the carrier coordinate The angular error is installed to correct the attitude accuracy of the navigation system output. The navigation system has a global satellite positioning device, a gyroscope, an accelerometer and a Kalman filter. The method for correcting method of the landborne navigation system of the present invention includes: The vehicle of the navigation system is placed on a ramp, the front end of the vehicle faces the slope, and the pitch angle of the navigation system is read to obtain a first pitch angle; the carrier is turned 180 degrees to make the vehicle The back end faces the slope height, reads the pitch angle of the navigation system, and obtains a second pitch angle; adds the first pitch angle to the second pitch angle value and divides by 2 to obtain a pitch misplacement angle Reading the horizontal azimuth of the body output of the navigation system; reading the horizontal direction angle of the satellite positioning output by the navigation system; subtracting the horizontal azimuth angle of the body from the horizontal direction angle of the satellite positioning to obtain a horizontal orientation misassembly Angle information, as external measurement data of the Kalman filter.

The invention relates to a landborne navigation system correction method, wherein the value of the first pitch angle is the sum of the slope angle and the pitch misload angle; the value of the second pitch angle is the negative of the slope angle The sum of the pitch misalignment angles; the satellite positioning horizontal velocity direction angle is the azimuth of the vehicle traveling speed (relative to true north); the body horizontal azimuth is the azimuth of the navigation system itself (body) output.

The present invention provides a landborne navigation system correction method, wherein the vehicle has an odometer, and the invention can utilize the mileage output by the odometer as an auxiliary navigation correction parameter when the GPS signal of the navigation system is interfered. . The landborne navigation system correction method of the present invention further includes the following steps: calculating the three-axis velocity value of the carrier based on the number of miles traveled by the carrier per unit time. The three axial speed refers to the actual speed at which the carrier moves on the ground.

The above summary, the following detailed description and the accompanying drawings are intended to further illustrate the manner, the Other objects and advantages of the present invention will be described in the following description and drawings.

S1~S6‧‧‧ method for correcting landborne navigation system of the invention

FIG. 1 is a schematic diagram of a satellite navigation system architecture of the prior art.

2 is a diagram showing the relationship between the coordinate system of the vehicle (vehicle) of the present invention and the coordinates of the navigation system body.

3 is a diagram showing the steps of a method for correcting a landborne navigation system of the present invention.

4 is a diagram showing the relationship between the body coordinates of the navigation system and the coordinates of the vehicle at the ideal level of the road surface of the present invention.

FIG. 5 is a schematic diagram of the tilting misalignment angle measurement operation of the present invention.

Figure 6 is a schematic view of the horizontal orientation misalignment angle between the navigation system and the carrier coordinates of the present invention.

FIG. 7 is a graph showing the convergence result of the ε _D standard deviation according to an embodiment of the present invention.

Figure 8 is a diagram showing the relationship between the rear wheel speeds before the vehicle.

The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily appreciate other advantages and functions of the present invention from the disclosure herein.

Due to GPS receiver (Global Positioning System The rapid development of Receiver:GPSR) and the continuous improvement of semiconductor manufacturing process, the current stage of land navigation system uses the so-called INS/GPS as the most common integrated architecture. The schematic diagram of the prior art satellite navigation system is shown in Figure 1. The rule adopted is Kalman Filter. The most common filtering period is 1 time per second (frequency is 1 Hz). The integration period of the internal navigation system through the gyroscope and the accelerometer according to Newton's law of motion is usually Set to 10 milliseconds (10ms), the GPSR output data cycle is once per second, and the navigation data content is UTC Time, Longitude, Latitude, Height and Triaxial Speed (expressed in the WGS-84 North Pointing NED coordinate system). Since the navigation data provided by GPS covers the position and speed of the three axes, and the information provided is accurate, under ideal conditions, the integrated navigation system can achieve satisfactory results. However, in the actual environment, the GPS satellite signal is easily obscured by terrain, obstacles or buildings, so that the vehicle cannot solve the navigation data when the number of satellites received is less than four. In addition, the satellite signal itself is used. Spread Spectrum Theory, but still very susceptible to interference, due to the above shortcomings, INS/GPS integrated navigation can not meet the requirements of strong construction and autonomy; for the above reasons, the general land navigation system will join the odometer ( Odometer) is used to assist navigation to suppress the inherent loss of accuracy of pure inertial navigation over time. Plus the odometer is almost standard equipment for general land vehicles. No additional equipment and wiring are required. The above makes INS/ODO The navigation system becomes another possible option. The principle of Kalman filtering is mainly to output the data of the navigation system (A1) and the output of GPS (A2) or odometer (A3). After comparing the materials, Estimation of each state error is performed according to the state equation of the navigation system itself. The estimation rule adopts the Kalman best estimation theory (A5), and finally the error term is corrected (A6) and sent to the precision. Navigation data (A7).

A landborne vehicle as defined by the present invention refers to a land vehicle, including a wheeled vehicle and a tracked vehicle. The navigation system defined by the invention has a global satellite positioning device (GPS), a gyroscope, an accelerometer and a Kalman filter, and the navigation system can output signals of satellite positioning signals, pitch angles, horizontal azimuth angles and acceleration signals. . Theoretically, when the navigation system is mounted on the vehicle (vehicle) and the coordinate system of the two is completely matched, the attitude and position signal output by the navigation system is equivalent to the posture and position of the vehicle, but in reality, it is difficult to navigate between the navigation system and the vehicle. Avoiding the installation error angle (missing angle), the coordinate system of the two is difficult to fully match, resulting in a gap between the attitude of the navigation system output, the position signal and the actual posture and position of the vehicle. The relationship between the vehicle coordinate system (Vehicle Coordinate System: V) and the coordinate system body (Body Coordinate: B) is shown in Figure 2, where X _B , Y _B and Z _{B are} formed. Cartesian body coordinates (B) Cartesian right-handed right-angle coordinate system; X _V , Y _V and Z _V form the Cartesian (V) coordinates of the Cartesian right-handed right-angle coordinate system; ε _E is the pitch mis-installation angle That means the installation error angle of the navigation system and the vehicle in the pitch direction; ε _D is the horizontal azimuth mismatch angle, which means the installation error angle of the navigation system and the vehicle in the horizontal orientation. When ε _D and ε _E are both small angles (sin θ ≒ θ and cos θ ≒1, in practice, usually less than 3 deg), the coordinates between the body (carrier) coordinate V and the navigation system coordinate B Conversion can use the following coordinate transformation matrix relationship Indicates: The invention provides a method for correcting a landborne navigation system, which can calculate the horizontal azimuth mismatch angle ε _D and the pitch mismatch angle ε _E simply and effectively, and obtain the installation angle between the navigation system and the vehicle body (carrier) coordinates. The error is compensated by the above matrix relationship to improve the attitude accuracy of the navigation system output.

The invention relates to a method for correcting a landborne navigation system, which is used for calculating a pitch misalignment angle and a horizontal azimuth mismatch angle generated by a navigation system mounted on a vehicle, for compensating between the navigation system and the carrier coordinate Install the angle error to correct the attitude accuracy of the navigation system output. The step of the method for correcting the landborne navigation system of the present invention is as shown in FIG. 3. The step includes: placing the vehicle equipped with the navigation system on a ramp, the front end of the vehicle is facing the slope, and reading Taking the pitch angle of the navigation system to obtain a first pitch angle S1; turning the carrier to 180 degrees, causing the rear end of the vehicle to face the slope height, reading the pitch angle of the navigation system, and obtaining a second a pitch angle S2; adding the first pitch angle to the second pitch angle value and dividing by 2 to obtain a pitch mismatch angle S3; reading the body horizontal azimuth angle S4 output by the navigation system; reading the navigation system output The satellite locates the horizontal velocity direction angle S5; the horizontal azimuth angle of the body is subtracted from the satellite positioning horizontal velocity direction angle to obtain a horizontal azimuth misfit angle S6.

The invention provides a correction device for a landborne navigation system First, the first step is to calculate the pitch mis-installation angle generated by the navigation system installed on the land-mounted vehicle. The step of calculating the pitch mis-installation angle is: placing the vehicle equipped with the navigation system on a ramp, the front end of the vehicle is oriented toward the The slope is high, the pitch angle of the navigation system is read, and a first pitch angle value is obtained; the vehicle is turned 180 degrees, the rear end of the vehicle is oriented toward the slope, and the pitch of the navigation system is read. Angle, a second pitch angle value is obtained; the first pitch angle is added to the second pitch angle value and divided by 2 to obtain a pitch misload angle value.

The relationship between the coordinates of the body of the navigation system and the coordinates of the vehicle at the ideal level of the road surface of the present invention is shown in Fig. 4. On the ideal level (Local-Level), the pitch angle (θ) of the navigation system A1 itself is output. That is, the pitch mismatch angle ε _E between the navigation system and the vehicle, that is, ε _E = θ. However, considering the application scenario in real life, the location of the vehicle carrier may not be the absolute level of the local area, so The present invention provides a method for quickly calculating a pitch misalignment angle. The schematic diagram of the tilting misalignment angle measuring operation of the present invention is as shown in FIG. 5, and the carrier equipped with the navigation system is placed on a slope of a fixed angle so that the front end (head) F of the vehicle faces the slope. Reading the pitch angle of the navigation system to obtain a first pitch angle θ _IMU1 , and then positioning the front end (the front end) of the vehicle toward the lower slope, reading the pitch angle of the navigation system to obtain a second pitch angle θ _IMU2 , the first pitch angle and the second pitch angle are defined as follows: θ _{IMU 1} = + α + ε _E θ _{IMU 2} = - α + ε _E where α is the inclination angle of the ramp, and the above relationship can be used The pitch misplacement angle ε _{E of} the navigation system mounted on the carrier: In the practical application of the present invention, the front end (the front end) of the vehicle should be stopped as far as possible in the original area before and after the steering to ensure that the inclination angle ( α ) of the slope is consistent, and the inclination angle of the selected location should not be too large, the main reason is excessive At the oblique angle, the body gravity effect may cause the tire to be deformed, resulting in a deviation in the calculation of the pitch misalignment angle of the present invention. Since the existing navigation system can output and display the pitch angle value instantaneously, the time required by the method provided by the present invention is only the time taken for the vehicle carrier to turn 180 degrees, which is much simpler and faster than the general optical calibration method, and the cost is low. It can be operated without the need to construct precision instruments and equipment.

The method for correcting the landborne navigation system of the present invention calculates the pitch mis-installation angle between the navigation system and the vehicle, and then calculates the horizontal azimuth mismatch angle between the navigation system and the vehicle. In general, the INS/GPS integrated navigation system is a data fusion that is optimized by the so-called Velocity Matching method. The navigation output error of the navigation system itself is different from the internal sensing component. Make estimates and eliminate them. However, for the horizontal azimuth misfit angle ε _D , it is not in the state error of the navigation system, so it cannot be estimated by the existing general INS/GPS optimization theory, but the azimuth output of the integrated navigation is This error also exists, resulting in the navigation system not being able to provide the exact azimuth of the vehicle (body), which also limits the positioning accuracy of the vehicle equipment, such as the antenna pointing system of the satellite communication vehicle and the solar energy of the mobile solar power vehicle. Plate-to-light systems, or artillery correction for military applications, missile guidance, positioning applications for radar photodetection devices, and more. In the prior art, if the ε _D horizontal azimuth misfit angle is to be found, additional vehicle dynamic information must be introduced to achieve this. For example, by means of an odometer combined with the dynamic characteristics of a land vehicle traveling on a straight road, the most common practice is: The above formula shows that when the land vehicle advances on a straight road, the lateral (Lateral) and vertical (Vertical) speed values on the road surface are 0 (expressed in the body coordinate V), but the estimation of the angle using the speed information is an indirect push. In the estimation method, and the related navigation state errors are coupled to each other in the estimation process, the convergence time is too long and the accuracy convergence is not good.

In order to solve the shortcomings of the prior art, the present invention proposes a method for comparing the horizontal direction direction angle of the satellite positioning and the horizontal azimuth angle of the navigation system, which is known by the GPS technology, to learn the horizontal azimuth mismatch angle of the navigation system. The measurement data used in the present invention is directly related to ε _D , which can avoid the convergence time and accuracy bottleneck encountered in the prior art. According to the general GPSR navigation output data (NMEA 0183 V3.0), there is a so-called vehicle horizontal speed direction, such as $GPRMC (Recommended Minimum Course: RMC) and $GPVTG (Course and Speed Over The Ground: in the NEMA Agreement). VTG) and so on contain the so-called Course Over Ground (COG); the physical meaning represented by COG is the azimuth of the speed of the vehicle (relative to true north), without considering the restriction of the car to slip ( δ ≒ 0) In fact, the direction provided by the COG is equivalent to the X _V direction on the body coordinates, that is, the straight traveling direction of the vehicle (vehicle). Therefore, the horizontal direction angle of the satellite positioning defined by the present invention is COG. The schematic diagram of the horizontal orientation mismatch angle between the navigation system and the carrier coordinate of the present invention is shown in FIG. 6. The horizontal azimuth angle of the body defined by the present invention is the azimuth of the navigation system body output by the INS/GPS, and the orientation of the navigation system itself. The angular attitude output is equivalent to the X _B direction, and the horizontal azimuth angle of the body is subtracted from the horizontal direction angle of the satellite positioning, and the horizontal orientation mismatch angle ε _{D of} the navigation system is known. If the GPS cannot output the NMEA 0183 protocol, the COG can be obtained by using the north axial velocity (V ^N ) and the east axial velocity (V ^E ) of the output according to the following formula: The present invention further proposes a calculation formula for calculating the horizontal azimuth misfit angle ε _D : z = _{INS INS -} COG = ε _{D -} Φ _D + ω _COG (3) where Ψ _INS is the body's horizontal azimuth of the navigation system; _D is the horizontal azimuth output error of the navigation system; COG is the horizontal direction angle of the satellite positioning (relative to true north); ω _COG is the angular error of the speed direction of the COG. Observe the right side of the equation, which only contains ε _D and ψ _D. The ψ _D azimuth error can be eliminated or reduced by the car to accelerate or turn; for ω _COG is the noise error of COG itself, the accuracy of COG The degree is related to the speed accuracy of the GPSR output. The general commercial GPSR has a speed accuracy of about 0.1m/s (1 σ). With a land vehicle speed of 60km/hr, the COG output accuracy can easily reach 0.1 degrees or more. Assuming that the COG error mode belongs to Gaussian Noise Distribution, considering other error factors (such as timing alignment error, etc.), the present invention proposes an error value mode: ω _COG ~ N (0, 0.3) (4) The embodiment of the invention introduces the formula (3) as the external measurement data into the Kalman filter, and the formula (4) is its error mode, assuming that the initial GPS horizontal velocity azimuth error has converge to 0.1 degree through the Kalman filter, FIG. 7 For the ε _D standard variance convergence result graph of the embodiment of the present invention, the R curve is the horizontal azimuth output error of the navigation system, and the B curve is the horizontal azimuth mismatch angle ε _D , and FIG. 7 illustrates the method proposed by the present invention, ε _D precision can Converges to a value of the level and ψ _D, ψ _D more accurately, the accuracy of ε _D more helpful.

The landborne navigation system correction method of the present invention can further install an odometer in the vehicle, and the information output by the odometer is used as an auxiliary of the navigation system. The INS/GPS integrated navigation system is the most common architecture for land navigation systems. Although satellite signals are used to improve navigation accuracy, it also sacrifices autonomy, vulnerability to interference, and building obscuration. The (ODO) assisted navigation can achieve complementary effects. When the GPSR suffers deliberate/unintentional interference, the navigation system can use the INS/ODO mode to assist navigation to improve accuracy. The output of the odometer installed on the vehicle is the mileage traveled by the vehicle. The vehicle does not consider the sliding friction condition of the wheel, and the vehicle is in the lateral direction of the straight road, and the vehicle is laterally and perpendicular to the road. The speed of the road surface is 0. From the perspective of the car body coordinates, the vehicle has the following relationship: The above formula (5) is the non-Holonomic Constraint mentioned in the existing literature, and can be applied to general vehicles with linear motion. If the odometer output on the vehicle is taken into consideration, the unit is assumed. When the mileage traveled in time (ΔT) is ΔS, the velocity value in the X _V axis can be expressed as In the prior art, using the formula (5) and the formula (6), the odometer assisted navigation system can be utilized to construct a complete and low-cost three-axis velocity measurement information. However, the above calculation method is only applicable to a straight road that cannot adapt to a turning road condition. Therefore, the present invention proposes a method for correcting an error caused by a turning odometer when assisting navigation, and taking a four-wheeled vehicle (vehicle) having a front wheel steering system as an example. The front wheel speed relationship diagram of the vehicle is shown in Figure 8. The point B is the odometer installed at the center of the front axle, the point A is at the center of the rear axle, and the vehicle (vehicle) is now at an angular rate of ω . Turning action; under normal driving conditions, the side-slip angle ( δ ) is close to 0. Assuming the odometer is installed at point B, it can be concluded that: Where ω is the angular rate measured by the turning of the vehicle (Yaw-Rate); R is the turning radius of the vehicle; V _B is the speed of the vehicle when the odometer is installed at point B; d is between the front and rear axles of the vehicle the distance. Using equation (7), we can get the velocity vector of point B (indicated on the body coordinate V): According to the above derivation, the non-Hankak restriction condition can be further extended to the application environment of the turn, and the three axial speed values of the vehicle (vehicle) are: Where ΔT is the unit time and ΔS is the output value (mileage) of the odometer per unit time (ΔT). According to the data output from the B-point odometer, we can further estimate the velocity vector at the point A of the rear axle center: In other words, although the odometer is installed at point B of the front axle center, according to equation (10), we can still estimate the point A of the rear axle center. The three axial speed values of the carrier are: The calibration method of the landborne navigation system of the present invention is to improve the turning error problem when the existing odometer is used in the navigation system, further extend the non-Hankak restriction condition, and take into consideration the vehicle dynamics during turn and the installation position of the odometer It can provide more accurate mileage conversion speed data of the navigation system. The external measurement data required for INS/ODO integrated navigation can also be applied during cornering, which greatly improves the navigation accuracy of INS/ODO integration.

The above-described embodiments are merely illustrative of the features and functions of the present invention, and are not intended to limit the scope of the technical scope of the present invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the scope of the claims described below.

S1~S6‧‧‧ method for correcting landborne navigation system of the invention

Claims (10)

A method for correcting a landborne navigation system includes the steps of: placing a vehicle equipped with a navigation system on a ramp, the front end of the vehicle facing the slope, reading a pitch angle of the navigation system, and obtaining a a first pitch angle; the vehicle is turned 180 degrees, the rear end of the vehicle is oriented toward the slope, and the pitch angle of the navigation system is read to obtain a second pitch angle; the first pitch angle is The two pitch angle values are added and divided by 2 to obtain a pitch misfit angle. The method for correcting a land-based navigation system according to claim 1, wherein the navigation system has a global satellite positioning device, a gyroscope, an accelerometer, and a Kalman filter. The method for correcting a land-based navigation system according to claim 1, wherein the value of the first pitch angle is a sum of the slope angle and the pitch mis-assembly angle. The method for correcting a land-based navigation system according to claim 1, wherein the value of the second pitch angle is a sum of a negative angle of the slope angle and the pitch mis-assembly angle. The method for correcting a land-based navigation system according to claim 2, further comprising: reading a horizontal azimuth of the body of the navigation system; and reading a horizontal direction angle of the satellite positioning output by the navigation system; The horizontal azimuth of the body is subtracted from the horizontal direction angle of the satellite positioning to obtain a horizontal azimuth angle information, which is used as external measurement data of the Kalman filter. The method for correcting a land-based navigation system according to claim 1, wherein the vehicle has an odometer. The method for correcting a landborne navigation system according to claim 6, wherein the carrier is a four-wheeled vehicle with a front wheel steering system. The method for correcting a land-based navigation system according to claim 7, wherein the method further comprises: calculating a value of the three-axis speed of the vehicle according to the number of miles moved by the vehicle in a unit time. The three axial speed refers to the actual speed at which the carrier moves on the ground. The method for correcting a land-based navigation system according to claim 8 is as follows: when the odometer is installed at the center of the axle before the vehicle, the three-axis speed value is calculated as: For the three axial velocity values of the vehicle, ω is the angular velocity measured by the vehicle turning, d is the distance between the front axle and the rear axle of the vehicle, ΔT is the unit time, and ΔS is the odometer per unit time. The number of miles exported. The method for correcting a landborne navigation system according to claim 8 is as follows: when the odometer is installed at the center of the axle before the carrier, the calculation of the three axial velocity values at the center of the rear axle is: For the value of the three axial speeds at the center of the rear axle of the vehicle, ω is the angular velocity measured by the turning of the vehicle, d is the distance between the front axle and the rear axle of the vehicle, ΔT is the unit time, and ΔS is the unit. The number of miles output by the odometer during the time.