A method, device and system for correcting inertial navigation data

Abstract

The present invention discloses a correction method, device and system for inertial navigation data, the method comprising: determining the inertial navigation measurement direction and inertial navigation measurement speed of a vehicle carrying an inertial measurement unit based on measurement data output by an inertial measurement unit; when a direction calibration condition is met, the inertial navigation measurement direction is corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation; when a speed calibration condition is met, the inertial navigation measurement speed is corrected based on the GNSS positioning data of the vehicle, and the corrected speed is used for inertial navigation position calculation; when a position calibration condition is met, the inertial navigation position is corrected based on the GNSS positioning data, road network data or visual positioning data, and the corrected inertial navigation position is used for inertial navigation position calculation. The accuracy of each motion parameter obtained by the method meets the inertial navigation requirements, and improves the accuracy of navigation.

Description

Technical Field

[0001] The present invention relates to the field of navigation technology, and in particular to a correction method, device and system for inertial navigation data. Background Art

[0002] Inertial Navigation System (INS) is an autonomous navigation system that does not rely on external information and is not easily disturbed. The basic working principle of inertial navigation is based on Newton's laws of mechanics. The acceleration and angular velocity of a vehicle (such as a vehicle) are measured by an inertial measurement unit (IMU), and the measured data is integrated over time to determine the motion parameters such as the speed, direction and position of the vehicle. However, when the accuracy of motion parameters is required to be high, the IMU needs to integrate multiple sensors including accelerometers, gyroscopes, and magnetometers.

[0003] The inventor of the present application has found that the IMU carried by general hardware equipment will integrate accelerometers and gyroscopes, but not necessarily magnetometers. The motion parameters of the vehicle determined based on the data of the vehicle measured by the IMU that only integrates accelerometers and gyroscopes have errors. If the error is too large, it cannot meet the navigation requirements. Therefore, it is urgent to provide a new inertial navigation method, which can obtain real-time, stable, and reliable measurement data based on the measurement data of the accelerometer and gyroscope integrated in the IMU to meet the navigation requirements. Summary of the invention

[0004] In view of the above problems, the present invention is proposed to provide a method, device and system for correcting inertial navigation data that overcome the above problems or at least partially solve the above problems.

[0005] In a first aspect, an embodiment of the present invention provides a method for correcting inertial navigation data, comprising:

[0006] Determining an inertial navigation measurement direction and an inertial navigation measurement speed of a vehicle carrying the inertial navigation measurement unit based on measurement data output by the inertial measurement unit, wherein the measurement data includes gyroscope data and accelerometer data;

[0007] When the direction calibration condition is met, the inertial navigation measurement direction is corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation;

[0008] When the velocity calibration condition is met, the inertial navigation measurement velocity is corrected based on the GNSS positioning data of the vehicle, and the corrected velocity is used for inertial navigation position calculation;

[0009] When the position calibration conditions are met, the inertial navigation position is corrected based on GNSS positioning data, road network data or visual positioning data, and the corrected inertial navigation position is used for inertial navigation position estimation.

[0010] In a second aspect, an embodiment of the present invention provides a correction device for inertial navigation data, comprising:

[0011] An inertial navigation module, configured to determine an inertial navigation measurement direction and an inertial navigation measurement speed of a vehicle carrying the inertial measurement unit based on measurement data output by the inertial measurement unit, wherein the measurement data includes gyroscope data and accelerometer data;

[0012] A direction correction module, used to correct the inertial navigation measurement direction based on the GNSS positioning data, road network data or visual positioning data of the vehicle when the direction calibration condition is met, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation;

[0013] A speed correction module, used to correct the inertial navigation measurement speed based on the GNSS positioning data of the vehicle when the speed calibration condition is met, and the corrected speed is used for inertial navigation position calculation;

[0014] The position correction module is used to correct the inertial navigation position based on GNSS positioning data, road network data or visual positioning data when the position calibration conditions are met. The corrected inertial navigation position is used for inertial navigation position estimation.

[0015] In a third aspect, an embodiment of the present invention provides a navigation system, comprising: a GNSS positioning server, a road network data server, a visual positioning server, a navigation server, and a correction device for the above-mentioned inertial navigation data;

[0016] The GNSS positioning server is used to provide GNSS positioning data;

[0017] The road network data server is used to provide road network data;

[0018] The visual positioning server is used to provide visual positioning data;

[0019] The navigation server is used to provide navigation guidance data.

[0020] In a fourth aspect, an embodiment of the present invention provides an inertial navigation service, which executes the above-mentioned inertial navigation data correction method when the service is running.

[0021] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0022] The embodiment of the present invention provides a method for correcting inertial navigation data. When it is determined that the calibration conditions are met, the inertial navigation measurement direction and inertial navigation measurement speed obtained by inertial navigation are corrected respectively, and the corrected speed and direction continue to be used for inertial navigation position calculation. In the case where the measurement data of the magnetometer is not needed, the inertial navigation measurement direction, inertial navigation measurement speed and inertial navigation position obtained based on the measurement data of the accelerometer and gyroscope integrated in the IMU are corrected, and the errors of the inertial navigation measurement direction, inertial navigation measurement speed and inertial navigation position obtained by inertial navigation are eliminated or reduced, and real-time, stable, and accurate and reliable direction, speed and position are obtained. The various motion parameters obtained by this method meet the navigation requirements, and can be applied to hardware devices equipped with an IMU that only integrates accelerometers and gyroscopes, reducing the cost of realizing navigation and improving the accuracy of navigation.

[0023] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0024] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 A flowchart of a method for correcting inertial navigation data provided by an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the structure of an inertial navigation data correction device provided by an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the structure of a navigation system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0030] The specific implementation of the inertial navigation data correction method, device and system provided by the embodiments of the present invention are described in detail below.

[0031] The present invention provides a method for correcting inertial navigation data, the process of which is as follows: Figure 1 As shown, the following steps are included:

[0032] S11: determining an inertial navigation measurement direction and an inertial navigation measurement speed of a vehicle carrying the inertial measurement unit based on measurement data output by the inertial measurement unit, wherein the measurement data includes gyroscope data and accelerometer data;

[0033] Among them, the measurement data output by the inertial measurement unit can be the data measured by the inertial measurement unit IMU including an accelerometer and a gyroscope in the prior art when performing inertial navigation. The gyroscope of the IMU can adopt the three-axis gyroscope or three single-axis gyroscopes in the prior art, and the above-mentioned gyroscope data measured by the gyroscope of the IMU includes the real-time angular velocity data of the X-axis, Y-axis and Z-axis directions in the spatial rectangular coordinate system; the accelerometer of the IMU can adopt the three-axis accelerometer or three single-axis accelerometers in the prior art, and the above-mentioned acceleration data measured by the accelerometer of the IMU includes the angle data of the X-axis, Y-axis and Z-axis directions in the spatial rectangular coordinate system. The above-mentioned method for determining the inertial navigation measurement direction and inertial navigation measurement speed of the carrier equipped with the inertial measurement unit based on the acquired gyroscope data and accelerometer data can adopt the preset inertial navigation algorithm in the prior art, which is not specifically limited here.

[0034] S12: When it is determined that the direction calibration condition is met, the inertial navigation measurement direction is corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation;

[0035] In the above step S12, since the direction of the vehicle may change at any time during the movement, if the inertial navigation measurement direction of the vehicle is corrected during the change of the direction of the vehicle, the corrected direction cannot eliminate the error of the inertial navigation measurement direction, and may also cause the error of the inertial navigation measurement direction to become larger. Therefore, before correcting the inertial navigation measurement direction of the vehicle, it is necessary to first determine whether the vehicle meets the direction calibration conditions at the current moment. If the direction calibration conditions are met, the inertial navigation measurement direction of the vehicle can be corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle. The corrected direction can eliminate the error of the inertial navigation measurement direction of the vehicle determined based on the measurement data output by the IMU, and improve the accuracy of the corrected direction. The direction corrected in the above manner is the corrected inertial navigation direction of the vehicle, and the corrected inertial navigation direction of the vehicle can continue to be used for inertial navigation direction and inertial navigation position calculation. The road network data can be ordinary map data or high-precision map data.

[0036] The visual positioning data of the above-mentioned vehicle may be data obtained by visual positioning. The specific implementation of visual positioning and the implementation process of obtaining the visual positioning data may refer to the description of the relevant methods in the prior art. The embodiments of the present invention are not specifically limited here. The road network data of the above-mentioned vehicle may be data obtained from a road network data server. The GNSS positioning data of the above-mentioned vehicle may be positioning data obtained by positioning through the Global Navigation Satellite System (GNSS). Among them, the GNSS global satellite positioning system may be the GPS global positioning system, the BDS Beidou satellite navigation system, the GLONASS global satellite positioning system or the Galileo satellite navigation system.

[0037] S13: When the speed calibration condition is met, the inertial navigation measurement speed is corrected based on the GNSS positioning data of the vehicle, and the corrected speed is used for inertial navigation position calculation;

[0038] In the above step S13, since the sampling time interval of the GNSS global satellite positioning system is much longer than the sampling period T of the IMU s Therefore, the GNSS positioning speed of the vehicle obtained from the GNSS positioning data has a certain delay compared to the inertial navigation measurement speed of the vehicle determined based on the measurement data output by the IMU. If the change trend of the GNSS positioning speed of the vehicle and the inertial navigation measurement speed of the vehicle within the preset time is very different, it indicates that the vehicle is not traveling stably. The GNSS positioning speed of the vehicle obtained from the GNSS positioning data cannot accurately reflect the real speed of the vehicle at the current moment. Therefore, before correcting the inertial navigation measurement speed based on the GNSS positioning data of the vehicle, it is necessary to first determine whether the vehicle meets the speed calibration condition at the current moment. If the speed calibration condition is met, the inertial navigation measurement speed can be corrected based on the GNSS positioning data of the vehicle. The corrected speed can eliminate the error of the inertial navigation measurement speed of the vehicle determined based on the measurement data output by the IMU, and improve the accuracy of the corrected speed. The speed corrected in the above manner is the corrected inertial navigation speed of the vehicle, and the corrected inertial navigation speed of the vehicle can continue to be used for inertial navigation position estimation.

[0039] S14: When the position calibration conditions are met, the inertial navigation position is corrected based on the GNSS positioning data, the road network data or the visual positioning data, and the corrected inertial navigation position is used for inertial navigation position estimation.

[0040] In the above step S14, in order to eliminate the error of the inertial navigation position and improve the accuracy of navigation, the inertial navigation position can be corrected based on the position of the vehicle obtained by GNSS positioning data, road network data or visual positioning data when the position calibration conditions are met. Before correcting the inertial navigation position, the inertial navigation position can be calculated based on the direction corrected in the above step S12 and the speed corrected in the above step S13 to obtain the inertial navigation position before correction. The specific method for realizing the inertial navigation position calculation can refer to the inertial navigation algorithm in the prior art.

[0041] In one embodiment, the process of determining the inertial navigation measurement direction and the inertial navigation measurement speed of the vehicle carrying the inertial measurement unit based on the measurement data output by the inertial measurement unit described in the above step S11 specifically includes the following steps:

[0042] According to a preset inertial navigation algorithm, based on the gyroscope data output by the IMU, real-time angular velocity data is obtained, based on the accelerometer data output by the IMU, real-time angle data is obtained by processing, and based on the real-time angle data and the real-time angular velocity data, the inertial navigation measurement direction of the carrier equipped with the IMU is determined;

[0043] According to the preset inertial navigation algorithm, based on the accelerometer data output by the IMU, the inertial navigation measurement speed of the vehicle equipped with the IMU is determined.

[0044] In the embodiment of the present invention, before determining the inertial navigation measurement direction and inertial navigation measurement speed of the vehicle equipped with the IMU based on the measurement data output by the acquired IMU, it is also necessary to determine the initial inertial navigation direction, initial inertial navigation speed and initial inertial navigation position of the vehicle based on the GNSS positioning data and road network data acquired within a preset time length. Since the IMU needs to perform inertial navigation processing to obtain measurement data accurately after the vehicle enters a stable operating state, it is necessary to use the direction, speed and position of the vehicle determined based on the GNSS positioning data and road network data after the vehicle starts to move for a preset time length as the initial inertial navigation direction, initial inertial navigation speed and initial inertial navigation position of the vehicle. The specific process of determining the initial inertial navigation direction, initial inertial navigation speed and initial inertial navigation position of the vehicle can refer to the description in the prior art, and is not specifically limited in the embodiment of the present invention.

[0045] After determining the initial inertial navigation direction, initial inertial navigation orientation and initial inertial navigation position of the vehicle, based on the gyroscope data and accelerometer data output by the IMU and according to the preset inertial navigation algorithm, the inertial navigation measurement direction and inertial navigation measurement speed of the vehicle during operation can be continuously obtained.

[0046] Among them, taking the initial inertial navigation direction as the reference orientation, the angular velocity data in the gyroscope data is integrated, and the posture inclination angle of the carrier can be obtained in real time. The accelerometer data obtained by the accelerometer measurement reflects the acceleration of the carrier relative to the direction of movement. Since the accelerometer is fixed to the carrier and rotates with the carrier, its own direction is unknown. According to the accelerometer data, it can be known how the carrier accelerates relative to itself, that is, forward, backward, upward, downward, left or right acceleration, but the direction of the carrier relative to the ground is unknown. Therefore, it is necessary to track the real-time angular velocity data in the gyroscope data and the real-time angle data obtained based on the accelerometer data to finally determine the posture inclination angle of the carrier. The attitude angle includes the yaw angle of the carrier, the pitch angle of the carrier and the roll angle of the carrier. The yaw angle of the carrier is the inertial navigation measurement direction of the carrier. Taking the initial inertial navigation velocity as the initial velocity and applying the kinematic equation provided by the inertial navigation algorithm, the inertial navigation acceleration is integrated to obtain the inertial navigation measurement velocity of the vehicle. Then, taking the initial inertial navigation position as the initial position, the inertial navigation position of the vehicle is obtained by integrating again.

[0047] The following is a specific example to illustrate the specific process of determining the inertial navigation measurement direction of the carrier:

[0048] In the preset sampling period T s , obtain gyroscope data through the IMU's gyroscope, and obtain accelerometer data through the IMU's accelerometer.

[0049] The following formula (1) is used to process the gyroscope data to obtain the real-time angular velocity data u gyro (t):

[0050]

[0051] Among them, x1(t) represents the gyroscope data, x2(t) represents the deviation of the gyroscope data, It represents the optimal estimated value of the vehicle's attitude angle, that is, the output attitude angle after fusion of gyroscope data; represents the deviation of the optimal estimate, u gyro (t) represents the real-time angular velocity data detected by the gyroscope, and w(t) is the process noise.

[0052] In the embodiment of the present invention, based on the dynamic characteristics of the gyroscope, when solving the attitude angle of the vehicle, the state equation in the Kalman filter is constructed by integrating the gyroscope data, that is, the angular velocity measured by the gyroscope, to obtain the above formula (1).

[0053] The accelerometer data is processed using the following formula (2) to obtain real-time angle data z(t):

[0054]

[0055] Wherein, x′1(t) represents the accelerometer data, x′2(t) represents the deviation of the accelerometer data, z(t) represents the real-time angle data calculated by the accelerometer, and v(t) represents the corresponding measurement noise.

[0056] Specifically, the acceleration data includes the acceleration components on the X-axis, Y-axis and Z-axis in the rectangular coordinate system of the space during motion. By calculating the angle between each axis and the accelerometer component on the corresponding axis, the attitude angle of the vehicle in the direction of the axis can be obtained. Compared with the gyroscope, which needs to rely on the integration of time to calculate the angle, the accelerometer can obtain the attitude angle of the vehicle at any time without being affected by the state at the previous time. Based on this, the measurement equation of the Kalman filter is constructed to obtain the above formula (2).

[0057] The following formula (3) is used to calculate the real-time angle data z(t) and the real-time angular velocity data u gyro (t) Perform Kalman filter calculation to obtain the inertial navigation measurement direction of the vehicle:

[0058]

[0059] Where t = 0, 1, 2, ... is the discrete time, Ts is the preset sampling period, that is, the time interval for obtaining gyroscope data and accelerometer data, z(t) is the real-time angle data calculated by the accelerometer, and u gyro (t) is the real-time angular velocity data calculated by the gyroscope, x1(t) represents the gyroscope data, x2(t) represents the deviation of the gyroscope data, x′1(t) represents the accelerometer data, x′2(t) represents the deviation of the accelerometer data, x1(t+T s ) is the attitude angle after the Kalman filter fuses the gyroscope data and the accelerometer data, x2(t+T s ) is the deviation of the best estimate.

[0060] According to the above formula (3), the attitude angle after the fusion of the gyroscope data and the accelerometer data is obtained, and the attitude angle includes the yaw angle of the vehicle, the pitch angle of the vehicle and the roll angle of the vehicle. The yaw angle of the vehicle is the inertial navigation measurement direction of the vehicle.

[0061] In the embodiment of the present invention, in order to realize the Kalman filter, the combined equations are discretized, the process noise w(t) and the measurement noise v(t) are extracted and converted into the noise covariance matrix according to the Kalman filter iterative update format, and the system equation of the Kalman filter is constructed to obtain the above formula (3).

[0062] In one embodiment, in the embodiment of the present invention, when executing the above step S12, whether the direction calibration condition is met can be determined in the following manner:

[0063] Determining whether the vehicle is traveling stably based on gyroscope data output by the inertial measurement unit;

[0064] Determining whether the vehicle is traveling along a straight road based on the GNSS positioning data of the vehicle and the road network data;

[0065] Determining whether the driving speed of the vehicle is higher than a preset speed threshold based on the GNSS positioning data of the vehicle;

[0066] When the vehicle is traveling stably along a straight road and the driving speed is higher than a preset speed threshold, it is determined that the direction calibration condition is met.

[0067] Wherein, determining whether the vehicle is traveling stably based on the gyroscope data output by the inertial measurement unit can be achieved in the following manner:

[0068] The measurement data output by the inertial measurement unit within a preset time length is obtained, and the change of the gyroscope data in the measurement data is determined. If the gyroscope data values ​​continuously sampled within the preset time length are basically consistent or the jitter of the data does not exceed the preset threshold range, it is determined that the vehicle is running stably.

[0069] Wherein, determining whether the vehicle is traveling along a straight road based on the GNSS positioning data of the vehicle and the road network data can be achieved in the following manner:

[0070] The positioning position of the vehicle obtained from the GNSS positioning data is matched to the road network data to obtain the road network matching position of the vehicle. Based on the road network shape point ahead at the road network matching position of the vehicle in the road network data, it is determined whether the road where the vehicle is located is a straight road. If so, it is determined that the vehicle is traveling along a straight road.

[0071] Wherein, based on the GNSS positioning data of the vehicle, determining whether the driving speed of the vehicle is higher than a preset speed threshold can be achieved in the following manner:

[0072] The GNSS positioning speed of the vehicle obtained from the GNSS positioning data is regarded as the true value of the vehicle's driving speed, and the GNSS positioning speed is compared with a preset speed threshold. If the GNSS positioning speed is higher than the preset speed threshold, it is determined that the vehicle's driving speed is higher than the preset speed threshold.

[0073] In a specific embodiment, when the vehicle is in a navigation state, the method for correcting the inertial navigation data may further include:

[0074] Based on the GNSS positioning data, navigation guidance data and road network data of the vehicle, determine whether there is an intersection in front of the vehicle. If it is an intersection and the navigation action of the vehicle at the intersection is a turn, the direction calibration condition is not met. If it is an intersection and the navigation action of the vehicle at the intersection is straight, the direction calibration condition is met.

[0075] In an embodiment of the present invention, when a vehicle is in a navigation state, since AR navigation is usually started when the road ahead of the vehicle is an intersection, when AR navigation is started at the intersection, if the direction of the vehicle changes, it is necessary to suppress the correction of the inertial navigation measurement direction of the vehicle, that is, the inertial navigation direction of the vehicle can no longer be corrected when the vehicle turns at the intersection. Therefore, in an embodiment of the present invention, the positioning position of the vehicle obtained from the GNSS positioning data can be first matched to the road network data to obtain the road network matching position of the vehicle, and determine whether the road ahead of the vehicle is an intersection based on the road network shape point at the road network matching position of the vehicle in the road network data. If it is an intersection, the navigation action type in the navigation guidance data is further obtained. If the navigation action of the vehicle at the intersection is a turn, it is determined that the direction calibration condition is not met. If the navigation action of the vehicle at the intersection is a straight line, it is considered that there is no need to suppress the inertial navigation direction correction of the vehicle, that is, the direction calibration condition is met.

[0076] In a specific embodiment, in order to more accurately determine whether the direction calibration condition is met, when it is determined that there is an intersection in front of the vehicle, the navigation guidance data closest to the location of the vehicle in the navigation data can be obtained, and it is determined whether the navigation action type in the navigation guidance data is a turning action, and whether the navigation action distance of the navigation action in the navigation guidance data is greater than a preset distance. If the navigation action is not a turning action, or the navigation action is a turning action but the navigation action distance of the navigation action is greater than the preset distance, it is determined that the direction calibration condition is met. The navigation guidance data can be data obtained from a navigation server. During the navigation process of the vehicle, the navigation server can continuously send the navigation guidance data in the navigation guidance data to the navigation service receiving end on the vehicle.

[0077] The above-mentioned navigation action distance can be the navigation action starting point position, that is, the distance between the position of the vehicle obtained from the GNSS positioning data and the position where the vehicle performs the navigation action. For example, when the distance between the position of the vehicle and the position where the vehicle performs the navigation action is 200m, the navigation server initiates navigation guidance and performs a navigation action reminder, then the navigation action distance is 200m. The intersection described in the embodiment of the present invention can be the type of intersection of the road in the road network in the prior art, for example, a flat intersection, a roundabout, a grade-separated intersection, a turning intersection or a U-turn intersection, etc., wherein the flat intersection can include an X-shaped intersection, a T-shaped intersection, a Y-shaped intersection and a multi-intersection intersection, etc.

[0078] In an embodiment of the present invention, in order to more accurately determine whether the direction calibration condition is met, before executing the step of determining whether there is an intersection ahead of the vehicle based on the GNSS positioning data, navigation guidance data and road network data of the vehicle, if it is an intersection and the navigation action of the vehicle at the intersection is a turn, the direction calibration condition is not met; if it is an intersection and the navigation action of the vehicle at the intersection is a straight line, before the step of meeting the direction calibration condition, the following may be further included:

[0079] Match the positioning position of the vehicle obtained from the GNSS positioning data to the road network data to obtain the road network matching position of the vehicle, and when it is determined based on the road network shape point at the road network matching position of the vehicle in the road network data that there is a turning road at a preset distance ahead of the road where the vehicle is located and the path is unique, supplement the navigation action in the navigation data;

[0080] The positioning position of the vehicle obtained from the GNSS positioning data is matched to the road network data to obtain the road network matching position of the vehicle. When it is determined based on the road network shape points at the road network matching position of the vehicle in the road network data that the preset distance ahead of the road where the vehicle is located is a straight road and the path is not unique, the navigation action in the navigation data is deleted.

[0081] In an embodiment of the present invention, the position of the vehicle obtained from the GNSS positioning data is matched to the road network data, and the path condition of the road on which the vehicle is located can be determined based on the road network shape points in the road network data, that is, it is determined whether the front path of the road on which the vehicle is currently located is a straight road, the front path is an intersection, there is a turning road at a preset distance ahead and the path is unique, or the front distance is a straight road and the front path is not unique. When the path ahead is a straight road, the motion trajectory of the vehicle is a straight line, so the navigation action in the navigation data at this time is straight ahead, or when the navigation data does not include navigation guidance data, we can also default to the navigation action being straight ahead; if the path ahead is an intersection, the navigation data includes a turn as the navigation action, and the navigation action includes turning left at the intersection ahead, turning right at the intersection ahead, driving on the left ahead, and driving on the right ahead, so as to guide the vehicle to turn, go straight, drive on the left, or drive on the right; if there is a turning road at a preset distance ahead and the path is unique, there is no need to perform navigation guidance on the vehicle, so the navigation guidance data often lacks the navigation action when there is a turning road at a preset distance ahead and the path is unique. At this time, in order to ensure the accuracy of the IMU data when the vehicle turns and avoid correcting the inertial navigation measurement direction during the vehicle turning process, the navigation guidance needs to be corrected. The navigation action type missing in the navigation data is supplemented by a navigation action of a turn; if the preset distance ahead is a straight road and the path is not unique, for example, a highway exit is often set in the outermost lane of the straight road. In order to prevent the user from driving on the road where the highway exit is located, the navigation data generally includes navigation guidance data corresponding to a prompt that the highway exit cannot be reached, such as a navigation action of driving on the left or driving on the right, to remind the user to avoid the road where the highway exit is located. Since the preset distance ahead is a straight road at this time, the direction calibration condition can be met. Therefore, when the preset distance ahead is a straight road and the path is not unique, the navigation guidance data corresponding to the navigation action of driving on the left or driving on the right in the navigation data needs to be deleted to avoid suppressing the correction of the inertial navigation measurement of the vehicle due to the existence of the navigation action.

[0082] In a specific embodiment, when it is determined that the direction calibration condition is met, the inertial navigation measurement direction is corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle, specifically including:

[0083] the direction of the vehicle obtained from the GNSS positioning data of the vehicle, or,

[0084] Based on the GNSS positioning data of the vehicle and the path direction of the road where the vehicle is located obtained from the road network data, or,

[0085] Obtaining the direction of the vehicle from the visual positioning data of the vehicle;

[0086] The inertial navigation measurement direction is corrected based on at least one of the directions, and a modified direction is determined.

[0087] In an embodiment of the present invention, before the inertial navigation measurement direction of the vehicle is corrected, it can be determined whether the GNSS signal meets the preset conditions according to the GNSS positioning data. If so, it is determined that the inertial navigation measurement direction can be corrected based on the direction of the vehicle obtained from the GNSS positioning data. Since in the prior art, during the positioning process using the GNSS global satellite positioning system, it is necessary to receive the GNSS positioning data sent by the GNSS navigation server through the GNSS receiver. If the signal is interfered or blocked in the road environment, the strength of the GNSS signal obtained by the GNSS receiver may be weakened. At this time, the direction of the vehicle obtained from the GNSS positioning data cannot reflect the true driving direction of the vehicle. At this time, the direction of the vehicle obtained from the GNSS positioning data cannot be used to calibrate the inertial navigation measurement direction of the vehicle. Therefore, when correcting the inertial navigation measurement direction of the vehicle, it is necessary to first determine whether the GNSS signal in the GNSS positioning data meets the preset conditions, that is, whether the strength of the GNSS signal meets the requirements for correcting the inertial navigation measurement direction of the vehicle. Among them, the judgment of the strength of the GNSS signal can refer to the method in the prior art, and in the embodiment of the present invention, it is not specifically limited here.

[0088] In an embodiment of the present invention, the positioning position of the vehicle obtained from the GNSS positioning data is matched to the road network data to obtain the road network matching position of the vehicle, and the road where the vehicle is located is determined based on the road network shape points at the road network matching position of the vehicle in the road network data, and the path direction of the road can be obtained at the same time.

[0089] The visual positioning data in the embodiment of the present invention can be obtained by the following method:

[0090] Acquire a road image collected by a visual sensor carried by a vehicle and GNSS positioning data of the vehicle;

[0091] Based on the road image and the GNSS positioning data of the vehicle, a visual positioning service is requested to return visual positioning data determined based on the road image and the GNSS positioning data of the vehicle, wherein the visual positioning data includes a positioning position of the vehicle and a direction of the vehicle.

[0092] In an embodiment of the present invention, a visual sensor and an IMU for collecting road images can be mounted on a vehicle together, and the visual sensor and the IMU always maintain a fixed positional relationship and attitude relationship. During the operation of the vehicle, the visual sensor captures a road image of the road environment in front of the vehicle. After the road image of the vehicle and the GNSS positioning data of the vehicle are obtained, the collected road image and GNSS positioning data can be sent to a visual positioning server through the data transmission device of the vehicle, and the visual positioning service is requested to return the visual positioning data determined based on the road image and the GNSS positioning data of the vehicle.

[0093] When the visual positioning server receives the collected road image and GNSS positioning data, the visual positioning server obtains the positioning position of the vehicle in the GNSS positioning data, and compares the positioning position of the vehicle with the collection position in each pre-stored panoramic image, so as to obtain the panoramic image closest to the positioning position of the vehicle, that is, the panoramic image at the positioning position of the vehicle in the GNSS positioning data. Then, based on the position and direction of each reference object in the collected road image, and the position and direction of the reference object in the panoramic image that is the same as that in the road image, a preset visual positioning algorithm is used to obtain the distance and direction of the vehicle relative to the collection position of the panoramic image, and obtain visual positioning data, including the positioning position and direction of the vehicle. Finally, the visual positioning server returns the visual positioning data determined based on the collected road image and the GNSS positioning data of the vehicle according to the above request for obtaining visual positioning data.

[0094] In an embodiment of the present invention, factors such as the road environment and weather of the vehicle may affect the clarity of the road image collected by the visual sensor. For example, if the road environment in which the vehicle is located is dark or the weather is foggy or rainy, the clarity of the road image collected by the visual sensor is not high, and there are fewer features of the reference objects in the road image, resulting in inaccurate visual positioning data determined by the visual positioning server or the inability to obtain the visual positioning data. Therefore, before correcting the inertial navigation measurement direction of the vehicle, it is possible to first determine whether the visual positioning data is available based on the collected road image. If so, it is determined that the inertial navigation measurement direction can be corrected based on the direction of the vehicle obtained from the visual positioning data.

[0095] In the embodiment of the present invention, the above-mentioned preset visual positioning algorithm and the specific scheme for implementing visual positioning can refer to the description of the visual positioning technology in the prior art, and in the embodiment of the present invention, no specific limitation is made to this. Among them, each panoramic image pre-stored in the visual positioning server can be a 360° panoramic image of a preset position in the road collected by a collection device, such as a collection vehicle, and reported to the visual positioning server. When collecting panoramic images, the collection device will simultaneously obtain the GNSS positioning data of the collection device at the current collection position.

[0096] In an embodiment of the present invention, when correcting the inertial navigation measurement direction of a vehicle, the direction determined by one of the data with the highest confidence level among the GNSS positioning data, the road network data and the visual positioning data can be selected to correct the inertial navigation measurement direction of the vehicle; or, any one of the direction of the vehicle obtained from the GNSS positioning data, the path direction of the road where the vehicle is located determined based on the GNSS positioning data of the vehicle and the road network data, and the direction of the vehicle obtained from the visual positioning data can be randomly selected to correct the inertial navigation measurement direction of the vehicle; or, at least one of the direction of the vehicle obtained from the GNSS positioning data, the path direction of the road where the vehicle is located determined based on the GNSS positioning data of the vehicle and the road network data, and the direction of the vehicle obtained from the visual positioning data can be comprehensively considered to correct the inertial navigation measurement direction of the vehicle.

[0097] In a specific embodiment, when correcting the inertial navigation measurement direction, any one of the direction of the vehicle obtained from the GNSS positioning data of the vehicle, the path direction of the road on which the vehicle is located determined based on the GNSS positioning data of the vehicle and the road network data, and the direction of the vehicle obtained from the visual positioning data of the vehicle can be taken as the true value, and the inertial navigation measurement direction of the vehicle is corrected to the direction of the vehicle as the true value.

[0098] In one embodiment, in the embodiment of the present invention, when executing the above step S13, whether the speed calibration condition is met can be determined in the following manner:

[0099] When a GNSS positioning speed curve of the vehicle determined based on the GNSS positioning data of the vehicle and an inertial navigation speed curve of the vehicle determined based on the measurement data output by the inertial measurement unit are similar, it is determined that the speed calibration condition is met.

[0100] In an embodiment of the present invention, if the GNSS positioning speed of the vehicle in the GNSS positioning data is to be used to calibrate the inertial navigation measurement speed of the vehicle, it is necessary to determine whether the changing trend of the GNSS positioning speed of the vehicle in the GNSS positioning data within a preset time period is consistent with the changing trend of the inertial navigation measurement speed determined by the measurement data output by the inertial measurement unit. The specific implementation process of determining the changing trend of the GNSS positioning speed and the inertial navigation measurement speed may be: respectively obtaining the GNSS positioning speed of the carrier in the GNSS positioning data of the carrier within a preset time period to obtain the GNSS positioning speed curve; and obtaining the inertial navigation measurement speed of the carrier determined based on the measurement data output by the inertial measurement unit within the preset time period to obtain the inertial navigation speed curve, representing the changing trend of the GNSS positioning speed of the carrier within the preset time period by the GNSS positioning speed curve, and representing the changing trend of the inertial navigation measurement speed of the carrier by the inertial navigation speed curve, comparing the similarity between the GNSS positioning speed curve and the inertial navigation speed curve to determine whether the two are similar; if the similarity between the two meets the preset condition, it is considered that the changing trends of the GNSS positioning speed and the inertial navigation measurement speed are consistent, and at this time, the GNSS positioning speed of the carrier in the GNSS positioning data can be used to correct the inertial navigation measurement speed of the carrier.

[0101] When performing inertial navigation measurement speed correction, the GNSS positioning speed of the vehicle obtained from the GNSS positioning data can be used as the true value, and the inertial navigation measurement speed of the vehicle can be corrected to the GNSS positioning speed of the vehicle. The specific implementation method of the inertial navigation measurement speed correction of the vehicle can refer to the specific implementation scheme of speed correction in the prior art, and is not specifically limited in the embodiments of the present invention.

[0102] In a specific embodiment, the similarity between the GNSS positioning velocity curve and the inertial navigation velocity curve can be determined by a specific implementation method in the prior art. For example, by comparing the waveforms of the GNSS positioning velocity curve and the inertial navigation velocity curve, the waveform similarity of the two can be determined. The specific method for determining the waveform similarity can be a method of calculating the cosine similarity or a method of calculating the Euclidean distance between the two waveforms. Any method that can determine the similarity between the two waveforms can be used. In the embodiments of the present invention, no specific limitation is made to this.

[0103] In a specific embodiment, when the vehicle is in a navigation state, the method for correcting the inertial navigation data may further include: when the vehicle is driving stably along a regular road and the driving speed is higher than a preset speed threshold, determining that the speed calibration condition is met.

[0104] The implementation process of determining whether the vehicle is traveling stably may refer to the detailed description of determining whether the vehicle is traveling stably based on the gyroscope data output by the inertial measurement unit in the above embodiment, which will not be repeated here.

[0105] Among them, whether the vehicle is traveling along a regular road can be determined by the following methods:

[0106] The positioning position of the vehicle obtained from the GNSS positioning data is matched to the road network data to obtain the road network matching position of the vehicle, and whether the road where the vehicle is located is a regular road is determined according to the road network shape point at the road network matching position of the vehicle in the road network data, and if so, it is determined that the vehicle is traveling along the regular road. The regular road described in the embodiment of the present invention can be a straight road or a roundabout road.

[0107] Among them, the implementation process of determining whether the driving speed of the vehicle is higher than the preset speed threshold can refer to the detailed description of determining whether the driving speed of the vehicle is higher than the preset speed threshold based on the GNSS positioning data of the vehicle in the above embodiment, which will not be repeated here.

[0108] In an embodiment of the present invention, when the inertial navigation measurement speed is corrected based on the GNSS positioning data of the vehicle, the GNSS positioning speed obtained from the GNSS positioning data can be used to correct the inertial navigation measurement speed of the vehicle when the vehicle is traveling stably along a regular road and the driving speed is higher than a preset speed threshold. This is because the GNSS positioning speed obtained when the vehicle is traveling stably along a regular road and the driving speed is higher than a preset speed threshold can more accurately reflect the actual driving speed of the vehicle. In this case, the GNSS positioning speed of the vehicle is used to correct the inertial navigation measurement speed of the vehicle. The corrected inertial navigation speed can eliminate or reduce the error generated during the inertial navigation measurement, thereby improving the accuracy of the corrected inertial navigation speed.

[0109] In one embodiment, in the embodiment of the present invention, when executing the above step S14, whether the position calibration condition is met can be determined in the following manner:

[0110] Performing position calculation based on the corrected direction and the corrected speed to determine the inertial navigation position of the vehicle;

[0111] Determining a road network matching position of the vehicle based on the GNSS positioning data of the vehicle and the road network data;

[0112] When the distance between the inertial navigation position and the road network matching position is greater than a preset distance threshold, it is determined that the position calibration condition is met.

[0113] In an embodiment of the present invention, position estimation is performed based on the corrected direction and the corrected speed to obtain the inertial navigation position of the vehicle. This can be achieved according to a preset inertial navigation algorithm. The specific implementation process can also refer to the detailed description of the inertial navigation algorithm above, which will not be repeated here.

[0114] In the embodiment of the present invention, the specific implementation process of determining the road network matching position of the vehicle based on the GNSS positioning data of the vehicle and the road network data can refer to the methods in the prior art and will not be repeated here.

[0115] In a specific embodiment, when it is determined that the position calibration condition is met, the inertial navigation position is corrected based on the GNSS positioning data, the road network data or the visual positioning data, including:

[0116] The inertial navigation position is corrected based on at least one of the positioning position of the vehicle obtained from the GNSS positioning data, the position data matched by the GNSS positioning data in the road network data, and the positioning position of the vehicle obtained from the visual positioning data to determine the corrected inertial navigation position.

[0117] In an embodiment of the present invention, before correcting the inertial navigation position of the vehicle, it is possible to first determine whether the GNSS signal meets a preset condition based on the GNSS positioning data. If so, it is determined that the inertial navigation position can be corrected based on the position of the vehicle obtained from the GNSS positioning data. Since in the prior art, during the positioning process using the GNSS global satellite positioning system, it is necessary to receive the GNSS positioning data sent by the GNSS navigation server through a GNSS receiver, if affected by signal interference or shielding in a road environment, the strength of the GNSS signal obtained by the GNSS receiver may be weakened. At this time, the position of the vehicle obtained from the GNSS positioning data cannot reflect the true position of the vehicle. At this time, the position of the vehicle obtained from the GNSS positioning data cannot be used to calibrate the inertial navigation position of the vehicle. Therefore, when correcting the inertial navigation position of the vehicle, it is necessary to first determine whether the GNSS signal in the GNSS positioning data meets the preset condition, that is, whether the strength of the GNSS signal meets the requirement for correcting the inertial navigation position of the vehicle.

[0118] In an embodiment of the present invention, when the inertial navigation position is corrected based on the position of the carrier obtained from the GNSS positioning data, the inertial navigation position of the carrier can be corrected by interpolation according to the difference in the horizontal and vertical distances between the position of the carrier obtained from the GNSS positioning data and the inertial navigation position of the carrier. A reasonable interpolation step is set based on the distance between the position of the carrier obtained from the GNSS positioning data and the inertial navigation position of the carrier. When the distance between the two positions is farther, the interpolation step is larger, and when the distance between the two positions is closer, the interpolation step is smaller. The inertial navigation position of the carrier is offset to the position of the carrier obtained from the GNSS positioning data to obtain the corrected inertial navigation position of the carrier. After multiple corrections, the inertial navigation position of the carrier can be smoothly offset to the position of the carrier obtained from the GNSS positioning data. Among them, the interpolation step refers to the distance by which the inertial navigation position of the carrier is offset each time the interpolation occurs.

[0119] In an embodiment of the present invention, since the road network shape points in the road network data may not fit well with the roads in the actual road network environment, that is, the connecting lines of the road network shape points in the road network data are inconsistent with the roads in the actual road network environment, therefore, when using the position data matched by the GNSS positioning data in the road network data to correct the inertial navigation position of the vehicle, the road network matching position can be used as a reference position, and the inertial navigation position of the vehicle can be corrected to a range less than a preset distance threshold from the road network matching position, and it is not necessary to correct it to the road network matching position.

[0120] In a specific embodiment, when the inertial navigation position is corrected based on the position data matched by the GNSS positioning data in the road network data, the position of the vehicle obtained from the GPS data can be matched to the road network data to obtain the road network matching position of the vehicle, and whether the road where the vehicle is located is a regular road network is determined based on the road network shape point in front of the road network matching position of the vehicle in the road network data, for example, whether the road where the vehicle is located is a straight road or a roundabout road. If it is determined that the road where the vehicle is located is a regular road network, the waveform of the connecting line of the road network shape points is further compared with the waveform of the trajectory formed according to the inertial navigation position of the vehicle to determine the similarity of the two waveforms. If the similarity of the two waveforms is greater than a preset value, it indicates that the driving trajectory of the vehicle is also regular, and the angle or curvature of the waveform of the trajectory formed by the inertial navigation position of the vehicle can be corrected based on the angle or curvature of the waveform of the connecting line of the road network shape points, so as to achieve the correction of the inertial navigation position of the vehicle to a range less than a preset distance threshold from the road network matching position.

[0121] In the embodiment of the present invention, factors such as the road environment and weather of the vehicle may affect the clarity of the road image collected by the visual sensor. For example, if the road environment of the vehicle is dark or the weather is foggy or rainy, the clarity of the road image collected by the visual sensor is not high, and the features of the reference objects in the road image are relatively few, resulting in inaccurate visual positioning data determined by the visual positioning server or the inability to obtain the visual positioning data. Therefore, before correcting the inertial navigation measurement direction of the vehicle, it is possible to first determine whether the visual positioning data is available based on the collected road image. If so, it is determined that the inertial navigation position can be corrected based on the positioning position of the vehicle obtained from the visual positioning data. When the positioning position of the vehicle obtained from the visual positioning data is used to correct the inertial navigation position of the vehicle, the positioning position of the vehicle can be taken as the true value, and the inertial navigation position of the vehicle can be corrected to the positioning position of the vehicle.

[0122] In an embodiment of the present invention, when correcting the inertial navigation position of a vehicle, any one of the vehicle positioning position obtained from the GNSS positioning data, the vehicle road network matching position obtained from the position data matched by the GNSS positioning data in the road network data, and the vehicle positioning position obtained from the visual positioning data can be randomly selected to correct the inertial navigation position of the vehicle. The inertial navigation position of the vehicle can also be corrected by comprehensively considering the vehicle positioning position in the GNSS positioning data, the position data matched by the GNSS positioning data in the road network data, and the vehicle positioning position obtained from the visual positioning data.

[0123] In the embodiment of the present invention, due to the different strengths of GNSS signals, the credibility of the position of the vehicle obtained from the GNSS positioning data varies; due to the different clarity of the road images collected by the visual sensor, the accuracy of the obtained visual positioning data will also vary; and because the road network data is pre-made based on the actual road environment, the road network shape points in the road network data are highly stable, and the road network matching position of the vehicle obtained by matching the GNSS positioning data to the road network data is highly stable. Therefore, when correcting the inertial navigation position of the vehicle, the position determined by the data with the highest confidence among the GNSS positioning data, the road network data and the visual positioning data can be selected to correct the inertial navigation measurement direction of the vehicle. The specific implementation method of correcting the inertial navigation position can also refer to the specific implementation scheme for direction correction in the prior art, and is not specifically limited in the embodiment of the present invention.

[0124] Based on the same inventive concept, an embodiment of the present invention also provides an inertial navigation data correction device and system. Since the principles of the problems solved by these devices and systems are similar to those of the aforementioned inertial navigation data correction method, the implementation of the device and system can refer to the implementation of the aforementioned inertial navigation data correction method, and the repeated parts will not be repeated.

[0125] The embodiment of the present invention also provides a correction device for inertial navigation data, referring to Figure 2 As shown, the device comprises:

[0126] An inertial navigation module 101, configured to determine an inertial navigation measurement direction and an inertial navigation measurement speed of a vehicle carrying the inertial measurement unit based on measurement data output by the inertial measurement unit, wherein the measurement data includes gyroscope data and accelerometer data;

[0127] A direction correction module 102 is used to correct the inertial navigation measurement direction based on the GNSS positioning data, road network data or visual positioning data of the vehicle when the direction calibration condition is met, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation;

[0128] The speed correction module 103 is used to correct the inertial navigation measurement speed based on the GNSS positioning data of the vehicle when the speed calibration condition is met, and the corrected speed is used for inertial navigation position calculation;

[0129] The position correction module 104 is used to correct the inertial navigation position based on GNSS positioning data, road network data or visual positioning data when the position calibration conditions are met, and the corrected inertial navigation position is used for inertial navigation position estimation.

[0130] In one embodiment, the direction correction module 102 is further used to determine whether the vehicle is traveling stably based on the gyroscope data output by the inertial measurement unit;

[0131] Determining whether the vehicle is traveling along a straight road based on the GNSS positioning data of the vehicle and the road network data;

[0132] Determining whether the driving speed of the vehicle is higher than a preset speed threshold based on the GNSS positioning data of the vehicle;

[0133] When the vehicle is traveling stably along a straight road and the driving speed is higher than a preset speed threshold, it is determined that the direction calibration condition is met.

[0134] In one embodiment, when the vehicle is in a navigation state, the direction correction module 102 is further used to determine whether there is an intersection in front of the vehicle based on the GNSS positioning data, navigation guidance data and road network data of the vehicle. If it is an intersection and the navigation action of the vehicle at the intersection is a turn, the direction calibration condition is not met; if it is an intersection and the navigation action of the vehicle at the intersection is a straight line, the direction calibration condition is met.

[0135] In one embodiment, the direction correction module 102 is specifically used to obtain the direction of the vehicle from the GNSS positioning data of the vehicle, or,

[0136] The path direction of the road where the vehicle is located is determined based on the GNSS positioning data of the vehicle and the road network data, or,

[0137] Obtaining the direction of the vehicle from the visual positioning data of the vehicle;

[0138] The inertial navigation measurement direction is corrected based on at least one of the directions, and a modified direction is determined.

[0139] In one embodiment, the speed correction module 103 is further used to determine that the speed calibration condition is met when the GNSS positioning speed curve of the carrier determined based on the GNSS positioning data of the carrier is similar to the inertial navigation speed curve of the carrier determined based on the measurement data output by the inertial measurement unit.

[0140] In one embodiment, the speed correction module 103 is specifically used to obtain the GNSS positioning speed of the vehicle in the GNSS positioning data of the vehicle within a preset time period to obtain the GNSS positioning speed curve;

[0141] Acquire the inertial navigation measurement speed of the vehicle determined based on the measurement data output by the inertial measurement unit within the preset time period to obtain the inertial navigation speed curve;

[0142] The similarity between the GNSS positioning velocity curve and the inertial navigation velocity curve is compared to determine whether the two are similar.

[0143] In one embodiment, the position correction module 104 is further used to perform position estimation based on the corrected direction and the corrected speed to determine the inertial navigation position of the vehicle;

[0144] Determining a road network matching position of the vehicle based on the GNSS positioning data of the vehicle and the road network data;

[0145] When the distance between the inertial navigation position and the road network matching position is greater than a preset distance threshold, it is determined that the position calibration condition is met.

[0146] In one embodiment, the above-mentioned position correction module 104 is also used to correct the inertial navigation position based on at least one of the positioning position of the vehicle obtained from the GNSS positioning data, the position data matched by the GNSS positioning data in the road network data, and the positioning position of the vehicle obtained from the visual positioning data, so as to determine the corrected inertial navigation position.

[0147] In one embodiment, the inertial navigation device further includes a visual positioning request module, which is used to obtain a road image collected by a visual sensor carried by a vehicle and GNSS positioning data of the vehicle;

[0148] Based on the road image and the GNSS positioning data of the vehicle, a visual positioning service is requested to return visual positioning data determined based on the road image and the GNSS positioning data of the vehicle, wherein the visual positioning data includes a positioning position of the vehicle and a direction of the vehicle.

[0149] The embodiment of the present invention also provides a navigation system, referring to Figure 3 As shown, the system includes: a GNSS positioning server 2, a road network data server 3, a visual positioning server 4, a navigation server 5 and the above-mentioned inertial navigation data correction device 1;

[0150] The GNSS positioning server 2 is used to provide GNSS positioning data;

[0151] The road network data server 3 is used to provide road network data;

[0152] The visual positioning server 4 is used to provide visual positioning data;

[0153] The navigation server 5 is used to provide navigation data.

[0154] An embodiment of the present invention further provides an inertial navigation service, which executes the above-mentioned inertial navigation data correction method when the service is running.

[0155] The above-mentioned inertial navigation data correction method provided by the embodiment of the present invention, when it is determined that the calibration conditions are met, the inertial navigation measurement direction and inertial navigation measurement speed obtained by inertial navigation are respectively corrected, and the corrected speed and direction continue to be used for inertial navigation position calculation. In the case where the measurement data of the magnetometer is not needed, the inertial navigation measurement direction, inertial navigation measurement speed and inertial navigation position obtained based on the measurement data of the accelerometer and gyroscope integrated in the IMU are corrected, and the errors of the inertial navigation measurement direction, inertial navigation measurement speed and inertial navigation position obtained by inertial navigation are eliminated or reduced, and real-time, stable, and accurate and reliable direction, speed and position are obtained. The various motion parameters obtained by this method meet the navigation requirements, and can be applied to hardware devices equipped with IMUs that only integrate accelerometers and gyroscopes, reducing the cost of realizing navigation and improving the accuracy of navigation.

[0156] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0157] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0158] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0159] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0160] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for correcting inertial navigation data, comprising: Determining an inertial navigation measurement direction and an inertial navigation measurement speed of a vehicle carrying the inertial navigation measurement unit based on measurement data output by the inertial measurement unit, wherein the measurement data includes gyroscope data and accelerometer data; When the direction calibration condition is met, the inertial navigation measurement direction is corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation; When the velocity calibration condition is met, the inertial navigation measurement velocity is corrected based on the GNSS positioning data of the vehicle, and the corrected velocity is used for inertial navigation position calculation; When the position calibration conditions are met, the inertial navigation position is corrected based on GNSS positioning data, road network data or visual positioning data, and the corrected inertial navigation position is used for inertial navigation position estimation; The following method is used to determine whether the direction calibration condition is met: Determining whether the vehicle is traveling stably based on gyroscope data output by the inertial measurement unit; Determining whether the vehicle is traveling along a straight road based on the GNSS positioning data and the road network data of the vehicle; Determining whether the driving speed of the vehicle is higher than a preset speed threshold based on the GNSS positioning data of the vehicle; When the vehicle is traveling stably along a straight road and the driving speed is higher than a preset speed threshold, it is determined that the direction calibration condition is met.

2. The method of claim 1, wherein: The vehicle is in a navigation state, and the method further comprises: Based on the GNSS positioning data, navigation guidance data and road network data of the vehicle, determine whether there is an intersection in front of the vehicle. If it is an intersection and the navigation action of the vehicle at the intersection is a turn, the direction calibration condition is not met. If it is an intersection and the navigation action of the vehicle at the intersection is straight, the direction calibration condition is met.

3. The method according to claim 2, wherein the inertial navigation measurement direction is corrected based on the GNSS positioning data, road network data or visual positioning data of the vehicle, comprising: the direction of the vehicle obtained from the GNSS positioning data of the vehicle, or, The path direction of the road where the vehicle is located is determined based on the GNSS positioning data of the vehicle and the road network data, or, Obtaining the direction of the vehicle from the visual positioning data of the vehicle; The inertial navigation measurement direction is corrected based on at least one of the directions, and a modified direction is determined.

4. The method of claim 1, wherein: When a GNSS positioning speed curve of the vehicle determined based on the GNSS positioning data of the vehicle and an inertial navigation speed curve of the vehicle determined based on the measurement data output by the inertial measurement unit are similar, it is determined that the speed calibration condition is met.

5. The method of claim 4, further comprising: Determining whether the GNSS positioning speed curve of the vehicle determined based on the GNSS positioning data of the vehicle and the inertial navigation speed curve of the vehicle determined based on the measurement data output by the inertial measurement unit are similar is done in the following manner: Obtaining the GNSS positioning speed of the vehicle from the GNSS positioning data of the vehicle within a preset time period, and obtaining the GNSS positioning speed curve; Acquire the inertial navigation measurement speed of the vehicle determined based on the measurement data output by the inertial measurement unit within the preset time period to obtain the inertial navigation speed curve; The similarity between the GNSS positioning velocity curve and the inertial navigation velocity curve is compared to determine whether the two are similar.

6. The method of claim 1, wherein: Performing position calculation based on the corrected direction and the corrected speed to determine the inertial navigation position of the vehicle; Determining a road network matching position of the vehicle based on the GNSS positioning data of the vehicle and the road network data; When the distance between the inertial navigation position and the road network matching position is greater than a preset distance threshold, it is determined that the position calibration condition is met.

7. The method according to claim 6, wherein the correction of the inertial navigation position based on GNSS positioning data, road network data or visual positioning data comprises: The inertial navigation position is corrected based on at least one of the positioning position of the vehicle obtained from the GNSS positioning data, the position data matched by the GNSS positioning data in the road network data, and the positioning position of the vehicle obtained from the visual positioning data to determine the corrected inertial navigation position.

8. The method according to any one of claims 1 to 7, wherein: Acquire a road image collected by a visual sensor carried by a vehicle and GNSS positioning data of the vehicle; Based on the road image and the GNSS positioning data of the vehicle, a visual positioning service is requested to return visual positioning data determined based on the road image and the GNSS positioning data of the vehicle, wherein the visual positioning data includes a positioning position of the vehicle and a direction of the vehicle.

9. A correction device for inertial navigation data, comprising: An inertial navigation module, configured to determine an inertial navigation measurement direction and an inertial navigation measurement speed of a vehicle carrying the inertial measurement unit based on measurement data output by the inertial measurement unit, wherein the measurement data includes gyroscope data and accelerometer data; A direction correction module, used to correct the inertial navigation measurement direction based on the GNSS positioning data, road network data or visual positioning data of the vehicle when the direction calibration condition is met, and the corrected direction is used for inertial navigation direction and inertial navigation position calculation; A speed correction module, used to correct the inertial navigation measurement speed based on the GNSS positioning data of the vehicle when the speed calibration condition is met, and the corrected speed is used for inertial navigation position calculation; The position correction module is used to correct the inertial navigation position based on GNSS positioning data, road network data or visual positioning data when the position calibration conditions are met. The corrected inertial navigation position is used for inertial navigation position estimation; The direction correction module is further used to determine whether the vehicle is traveling stably based on the gyroscope data output by the inertial measurement unit; Determining whether the vehicle is traveling along a straight road based on the GNSS positioning data and the road network data of the vehicle; Determining whether the driving speed of the vehicle is higher than a preset speed threshold based on the GNSS positioning data of the vehicle; When the vehicle is traveling stably along a straight road and the driving speed is higher than a preset speed threshold, it is determined that the direction calibration condition is met.

10. A navigation system comprising: GNSS positioning server, road network data server, visual positioning server, navigation server and the inertial navigation data correction device as claimed in claim 9; The GNSS positioning server is used to provide GNSS positioning data; The road network data server is used to provide road network data; The visual positioning server is used to provide visual positioning data; The navigation server is used to provide navigation guidance data.

Images