阅读说明：本技术 自身位置修正方法及自身位置修正装置 (Self-position correction method and self-position correction device ) 是由 野尻隆宏 于 2019-05-15 设计创作，主要内容包括：自身位置修正方法及自身位置修正装置将与车辆的前后方向平行的轴的坐标作为纵坐标,并将基于从登记在地图数据上的物体目标的位置所具有的纵坐标的值减去由检测部检测的物体目标的位置所具有的纵坐标的值得到的纵向修正量而设定的修正量,与车速相加来计算修正后车速,依次累计根据修正后车速和车辆的横摆率计算出的车辆的移动量来推定车辆的位置,由此,修正地图数据上的车辆的位置。(The self-position correction method and the self-position correction device correct the position of the vehicle on the map data by using the coordinate of an axis parallel to the front-rear direction of the vehicle as a vertical coordinate, adding a correction amount, which is set based on a longitudinal correction amount obtained by subtracting a value of the vertical coordinate included in the position of the object target detected by the detection unit from a value of the vertical coordinate included in the position of the object target registered on the map data, to the vehicle speed to calculate a corrected vehicle speed, and sequentially adding the movement amounts of the vehicle calculated from the corrected vehicle speed and the yaw rate of the vehicle to estimate the position of the vehicle.)

1. A self-position correction method of correcting a position of a vehicle on map data estimated by sequentially accumulating movement amounts of the vehicle based on a measurement result from a detection unit that detects an object target around the vehicle,

the coordinates of an axis parallel to the front-rear direction of the vehicle are taken as the ordinate,

a value of the ordinate that the position of the object target registered on the map data has is taken as a first registered value,

setting a value of the ordinate that the position of the object target detected by the detection unit has as a first observation value,

setting a correction amount based on a longitudinal correction amount obtained by subtracting the first observed value from the first registered value,

adding the correction amount to the vehicle speed of the vehicle to calculate a corrected vehicle speed,

calculating the movement amount of the vehicle from the corrected vehicle speed and the yaw rate of the vehicle,

sequentially accumulating the movement amounts to estimate the position of the vehicle.

2. The self-position correction method according to claim 1,

the larger the longitudinal correction amount is, the larger a value obtained by dividing the correction amount by the vehicle speed is set.

3. The self-position correction method according to claim 1 or 2,

the correction amount is set by multiplying the longitudinal correction amount by a positive predetermined coefficient.

4. The self-position correction method according to any one of claims 1 to 3,

when the longitudinal correction amount is equal to or less than a predetermined threshold value, the longitudinal correction amount is added to a value of the ordinate of the vehicle.

5. The self-position correction method according to any one of claims 1 to 4,

the coordinate of an axis parallel to the width direction of the vehicle is taken as the abscissa,

a value of the abscissa which the position of the object target registered on the map data has is taken as a second registered value,

setting a value of the abscissa that the position of the object target detected by the detection section has as a second observation value,

adding a lateral correction amount obtained by subtracting the second observation value from the second registered value to a value of the abscissa of the vehicle.

6. A self-position correction device, which is provided with a detection unit for detecting an object around a vehicle and a controller, and which corrects the position of the vehicle on map data estimated by sequentially accumulating the movement amounts of the vehicle, is characterized in that,

the controller performs control such that,

The coordinates of an axis parallel to the front-rear direction of the vehicle are taken as the ordinate,

a value of the ordinate that the position of the object target registered on the map data has is taken as a first registered value,

setting a value of the ordinate that the position of the object target detected by the detection unit has as a first observation value,

setting a correction amount based on a longitudinal correction amount obtained by subtracting the first observed value from the first registered value,

adding the correction amount to the vehicle speed of the vehicle to calculate a corrected vehicle speed,

calculating the movement amount of the vehicle from the corrected vehicle speed and the yaw rate of the vehicle,

sequentially accumulating the movement amounts to estimate the position of the vehicle.

Technical Field

The present invention relates to a self-position correction method and a self-position correction device.

Background

A vehicle position correction device has been proposed that generates a position trajectory of a vehicle based on a vehicle position measured by a navigation satellite, and calculates a position correction amount of the vehicle position by comparing shapes of a travel lane on which the vehicle travels and the position trajectory (see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-58235

According to the technique described in patent document 1, a position correction amount is added to position information indicating a current position of a vehicle on map data to correct the position information. Therefore, when the position correction amount is large in correcting the position information of the vehicle (for example, an autonomous vehicle) controlled to travel on a predetermined trajectory, the steering angle of the vehicle may be changed abruptly by the correction of the position information, and the occupant may be given a sense of unease. Such a sudden change in the steering angle due to the position correction is likely to occur, for example, when the vehicle is traveling on a curve.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object thereof is to provide a self-position correction method and a self-position correction device that can correct position information of a vehicle while suppressing a sudden change in a steering angle due to position correction when correcting the position information of the vehicle.

In order to solve the above-described problem, a self-position correction method and a self-position correction device according to an aspect of the present invention correct a position of a vehicle on map data by using coordinates of an axis parallel to a front-rear direction of the vehicle as vertical coordinates, adding a correction amount, which is set based on a vertical correction amount obtained by subtracting a value of the vertical coordinate included in a position of an object target detected by a detection unit from a value of the vertical coordinate included in the position of the object target registered on the map data, to a vehicle speed to calculate a vehicle speed after correction, and sequentially accumulating movement amounts of the vehicle calculated from the vehicle speed after correction and a yaw rate of the vehicle to estimate a position of the vehicle.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, when correcting the positional information of a vehicle controlled to travel on a predetermined trajectory, it is possible to correct the positional information of the vehicle while suppressing a sudden change in the steering angle due to the positional correction.

Drawings

Fig. 1 is a block diagram showing a configuration of a self-position estimating apparatus including a self-position correcting apparatus according to an embodiment of the present invention.

Fig. 2 is a flowchart showing a procedure of the self-position correction process according to the embodiment of the present invention.

Fig. 3 is a diagram illustrating a longitudinal correction amount with respect to the position of the vehicle.

Fig. 4 is a diagram illustrating a lateral correction amount with respect to the position of the vehicle.

Fig. 5 is a schematic diagram illustrating a change in the steering angle of the vehicle in a curve.

Detailed Description

Next, embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[ Structure of self-position correcting device ]

Fig. 1 is a block diagram showing a configuration of a self-position estimating apparatus including a self-position correcting apparatus according to the present embodiment. As shown in fig. 1, the self-position estimating device includes: the map acquisition device 51, the GPS receiver 53, the radar 55, the camera 57, the vehicle speed sensor 71, the inertial measurement sensor 73, the controller 100, and the output unit 91.

Here, the GPS receiver 53, the radar 55, the camera 57, the vehicle speed sensor 71, and the inertial measurement sensor 73 are mounted on the vehicle, but the map acquisition device 51, the controller 100, and the output unit 91 may be mounted on the vehicle or may be provided outside the vehicle. The map acquisition device 51, the GPS receiver 53, the radar 55, the camera 57, the vehicle speed sensor 71, the inertial measurement sensor 73, and the output unit 91 are connected to the controller 100 via a wired or wireless communication path.

The map acquisition device 51 acquires map data indicating the structure of a road on which the vehicle is traveling. The map data acquired by the map acquisition device 51 includes information on road structures such as absolute positions of lanes, connection relationships of lanes, and relative positional relationships. The map data acquired by the map acquisition device 51 may include facility information such as a parking lot and a gas station. The map data may include position information of the traffic signal, a type of the traffic signal, and the like. The map acquisition device 51 may have a map database storing map data, or may acquire map data from an external map data server by cloud computing. The map acquisition device 51 may acquire map data using vehicle-to-vehicle communication or road-to-vehicle communication.

The GPS receiver 53 detects the position of the vehicle on the ground by receiving radio waves from GPS (global positioning system) satellites.

The radar 55 emits a radio wave to the surroundings of the vehicle, and detects a three-dimensional object around the vehicle such as a road sign or a building by measuring the reflected wave.

The camera 57 captures an image of the surroundings of the vehicle, and acquires an image of a white line, a stop line, or the like captured around the vehicle.

Hereinafter, the GPS receiver 53, the radar 55, and the camera 57 are collectively referred to as a detection unit. The examples given here are examples of the detection unit, and are not limited to these examples. For example, the detection unit may be a laser radar (LiDAR), not shown.

The vehicle speed sensor 71 detects the vehicle speed of the vehicle. The vehicle speed sensor 71 may detect a vehicle speed from the rotational speed of the wheels of the vehicle, or may detect a relative speed with respect to a road on which the vehicle travels by the doppler effect or the like.

The inertial measurement sensor 73 is configured by an acceleration sensor that detects acceleration applied to the vehicle, a rotational angular acceleration sensor or a gyro sensor that detects a rotational angular velocity of the vehicle, a magnetic field sensor that detects an orientation of the vehicle, and the like. In particular, the inertial measurement sensor 73 detects the yaw rate of the vehicle.

The output unit 91 outputs a processing result of the controller 100 described later. For example, the output unit 91 outputs the position of the vehicle after the self-position correction to an automatic driving device not shown.

The controller 100 (an example of a control unit or a processing unit) is a general-purpose microcomputer including a CPU (central processing unit), a memory, and an input/output unit. The controller 100 is provided with a computer program (self-position correction device program) for functioning as a self-position correction device. By executing the computer program, the controller 100 functions as a plurality of information processing circuits (110, 120, 130, 140, 150, 160).

Here, an example is shown in which a plurality of information processing circuits (110, 120, 130, 140, 150, 160) provided in the self-position correction device are realized by software. However, dedicated hardware for executing each information processing described below may be prepared to configure the information processing circuits (110, 120, 130, 140, 150, and 160). The plurality of information processing circuits (110, 120, 130, 140, 150, 160) may be formed by separate hardware. Further, the information processing circuits (110, 120, 130, 140, 150, 160) may also serve as Electronic Control Units (ECUs) used for other controls related to the vehicle.

The controller 100 includes an object recognition unit 110, a longitudinal correction amount calculation unit 120, a lateral correction amount calculation unit 130, a vehicle speed correction unit 140, an integration unit 150, and a lateral position correction unit 160 as a plurality of information processing circuits (110, 120, 130, 140, 150, 160).

The object target recognition portion 110 recognizes an object target as a reference for determining the position of the vehicle, and calculates a relative positional relationship between the recognized object target and the vehicle.

As an example of the object target recognition unit 110, a position recognition unit based on the GPS receiver 53 can be cited. In addition, examples of the object target recognition unit 110 include a landmark recognition unit that detects a solid object (stationary object) around a vehicle such as a road sign or a building by a radar 55 or a laser radar (LiDAR), a white line recognition unit that recognizes a white line around the vehicle based on an image captured by the camera 57, a stop line recognition unit that detects a stop line, and the like.

In the following, a stationary object such as a display on a road around a vehicle such as a white line or a stop line, a road sign, or a three-dimensional object around a vehicle such as a building is described as an object target.

Specifically, the object target recognition unit 110 takes the coordinate of an axis parallel to the front-rear direction of the vehicle as the ordinate, and calculates the value of the ordinate that the position of the object target detected by the detection unit has as the first observation value. The object target recognition unit 110 sets the coordinates of an axis parallel to the width direction of the vehicle as the abscissa, and calculates the value of the abscissa included in the position of the object target detected by the detection unit as the second observation value.

In addition, a coordinate system defined by the ordinate and the abscissa is referred to as a vehicle coordinate system. The vehicle coordinate system is different from a map coordinate system for representing position information registered in the map data, but if the position and orientation of the vehicle in the map coordinate system and the position of the vehicle in the vehicle coordinate system are determined, the map coordinate system and the vehicle coordinate system may be associated with each other by coordinate transformation (transformation based on parallel movement and rotational movement). That is, by using coordinate transformation, the position information represented by the map coordinate system can be transformed into the position information in the vehicle coordinate system.

The longitudinal correction amount calculation unit 120 extracts the position information registered in the map data from the map data acquired by the map acquisition device 51 for the object recognized by the object recognition unit 110, performs coordinate transformation on the extracted position information, and calculates a value of a longitudinal coordinate included in the position of the recognized object as a first registration value. Then, the longitudinal correction amount calculation portion 120 calculates the longitudinal correction amount by subtracting the first observed value from the first registered value.

The calculation of the longitudinal correction amount will be described with reference to fig. 3. Fig. 3 is a diagram illustrating a longitudinal correction amount with respect to the position of the vehicle. In fig. 3, it is estimated that the vehicle is located at a point P1.

Here, on the map data, the object target registered as being located at the position TG1 is recognized as being located at the position TG2 by the object target recognition section 110. Comparing the position TG1 with the position TG2, the position TG2 is located at a position closer to the point P1 Δ x on the ordinate than the position TG1 in the vehicle coordinate system of the vehicle located at the position P1.

This means that the estimation that the vehicle is located at the point P1 includes an error, and that the vehicle is actually located at a point Q1, and that the point Q1 is a point that is advanced by Δ x ahead of the vehicle (or in the direction of travel of the vehicle, in the x-axis direction in the drawing) from the point P1 on the ordinate. Therefore, Δ x is used as a longitudinal correction amount for correcting the position P1 of the vehicle to the position Q1.

Note that the time at which the longitudinal correction amount can be calculated by the longitudinal correction amount calculation unit 120 is indicated. Typically, the longitudinal correction amount is calculated at a time when an object target located in front of or behind the vehicle can be identified. However, there is a case where an object target located in front of or behind the vehicle is hidden by another vehicle traveling around the vehicle and cannot be recognized. In this case, the longitudinal correction amount cannot be calculated.

The lateral correction amount calculation unit 130 extracts the position information registered in the map data from the map data acquired by the map acquisition device 51 for the object recognized by the object recognition unit 110, performs coordinate transformation on the extracted position information, and calculates a value of the lateral coordinate of the position of the recognized object as a second registration value. Then, the lateral correction amount calculation section 130 calculates a lateral correction amount by subtracting the second observed value from the second registered value.

The calculation of the lateral correction amount will be described with reference to fig. 4. Fig. 4 is a diagram illustrating a lateral correction amount with respect to the position of the vehicle. In fig. 4, it is estimated that the vehicle is located at a point P1 at the center TR in the width direction of the road.

Here, as a result of the object target recognition portion 110 recognizing the white line of the road, it is recognized that there is a white line at a position deviated by Δ y to the right side along the width direction of the vehicle from the position registered in the map data.

This means that the estimation that the vehicle is located at the point P1 includes an error, and in fact, the vehicle is located at the point Q1, and the point Q1 is advanced by Δ y on the abscissa toward the left side in the width direction of the vehicle (y-axis direction in the drawing) from the point P1. Therefore, Δ y is used as a lateral correction amount for correcting the position P1 of the vehicle to the position Q1.

Note that the time at which the lateral correction amount can be calculated by the lateral correction amount calculation unit 130 is indicated. Typically, the lateral correction amount is calculated at a time when an object target located on the side of the vehicle can be identified. Compared to an object target located in front of or behind the vehicle, an object target located on the side of the vehicle is less likely to be hidden from recognition by another vehicle traveling around the vehicle. Therefore, there is a tendency that the time during which the lateral correction amount can be calculated is more than the time during which the longitudinal correction amount can be calculated.

In addition, when there are a plurality of object targets recognized by the object target recognition unit 110, the longitudinal correction amount calculation unit 120 may calculate the longitudinal correction amount of each recognized object target, and calculate the average value of the plurality of longitudinal correction amounts as a representative longitudinal correction amount. Similarly, the lateral correction amount calculation unit 130 may calculate a lateral correction amount for each of the recognized object targets, and calculate an average value of the lateral correction amounts as a representative lateral correction amount.

The vehicle speed correction unit 140 sets a correction amount for the vehicle speed detected by the vehicle speed sensor 71 based on the longitudinal correction amount.

For example, the vehicle speed correction unit 140 may set the correction amount Δ v such that the value (Δ v/v) obtained by dividing the correction amount Δ v with respect to the vehicle speed by the vehicle speed v is set to be larger as the longitudinal correction amount Δ x is larger.

The vehicle speed correction unit 140 may set the correction amount Δ v such that Δ v/v increases stepwise as the longitudinal correction amount Δ x increases (for example, when the longitudinal correction amount Δ x is smaller than a predetermined value, Δ v/v is set to 1%, and when the longitudinal correction amount Δ x is equal to or larger than a predetermined value, Δ v/v is set to 10%).

The vehicle speed correction unit 140 may set Δ v such that Δ v/v continuously increases as the longitudinal correction amount Δ x increases.

The correction amount Δ v may be set by multiplying the vertical correction amount Δ x by a positive predetermined coefficient α (that is, Δ v ═ α · Δ x).

The vehicle speed correction unit 140 adds the correction amount set as described above to the vehicle speed detected by the vehicle speed sensor 71, and calculates the vehicle speed after correction.

The integrating unit 150 estimates the position of the vehicle on the map data by using a Dead Reckoning (Dead Reckoning) method. That is, the position of the vehicle on the map data is estimated by calculating the movement amount (vector component) of the vehicle during a predetermined time interval based on the vehicle speed and the yaw rate of the vehicle, and sequentially accumulating the calculated movement amounts. That is, the position of the vehicle on the map data at the current time is estimated by integrating the movement amount per unit time of the vehicle from the past time toward the current time, starting from the position of the vehicle at the past time.

In general dead reckoning, the amount of movement of the vehicle is calculated from the vehicle speed detected by the vehicle speed sensor 71 and the yaw rate of the vehicle detected by the inertia measurement sensor 73. On the other hand, in the integrating unit 150 of the present embodiment, instead of using the vehicle speed detected by the vehicle speed sensor 71, the vehicle movement amount of the vehicle is calculated using the vehicle speed after correction calculated by the vehicle speed correcting unit 140.

Here, when the time interval is Δ t, since the movement amount of the vehicle is calculated using the vehicle speed after correction, the correction amount of Δ v · Δ t is added to the movement amount 1 time during dead reckoning. When the correction amounts Δ v · Δ t added to each of the plurality of movement amounts calculated in the course of performing dead reckoning are added, the magnitude of the added correction amount gradually approaches the longitudinal correction amount Δ x as the movement amounts are sequentially added. Therefore, after a sufficient number of movement amounts are accumulated by dead reckoning, the correction of the longitudinal correction amount Δ x is ended.

After the 1-time accumulation of the movement amounts is completed, the integrating unit 150 subtracts the correction amount Δ v · Δ t included in the 1-time movement amount from the longitudinal correction amount, and calculates the longitudinal correction amount after the subtraction. The longitudinal correction amount after the subtraction is used for setting the correction amount in the vehicle speed correction unit 140 next time or later.

In addition, the integrating unit 150 may correct the position of the vehicle by adding the longitudinal correction amount to a value of the ordinate of the vehicle when the longitudinal correction amount is equal to or less than the predetermined threshold value. Here, the predetermined threshold value is determined in consideration of a level at which sudden changes in the steering angle caused by adding the longitudinal correction amount to the value of the ordinate of the vehicle are negligible for the occupant.

For example, in the case where the planned travel route of the vehicle is a straight line, even if the position of the vehicle is corrected by adding the vertical correction amount to the value of the vertical coordinate of the vehicle, the corrected position of the vehicle does not greatly deviate from the planned travel route. Therefore, the predetermined threshold value may be set to be small when the curvature radius of the planned travel route of the vehicle is small, and may be set to be large when the curvature radius of the planned travel route of the vehicle is large.

The lateral position correction unit 160 adds the lateral correction amount to the value of the abscissa of the vehicle to correct the position of the vehicle.

The correction of the vehicle position based on the lateral correction amount by the lateral position correction unit 160 is different from the correction of the vehicle position based on the longitudinal correction amount by the processes of the vehicle speed correction unit 140 and the integration unit 150. Specifically, the vehicle position is corrected by the longitudinal correction amount by correcting the vehicle speed, whereas the vehicle position is corrected by the lateral correction amount directly by correcting the vehicle position.

Since the time at which the lateral correction amount can be calculated tends to be greater than the time at which the longitudinal correction amount can be calculated, the correction of the position of the vehicle based on the lateral correction amount tends to be more frequently performed than the correction of the position of the vehicle based on the longitudinal correction amount, and the lateral correction amount is less likely to become larger than the longitudinal correction amount. Further, since the vehicle speed in the width direction of the vehicle is smaller than the vehicle speed in the front-rear direction of the vehicle, the lateral correction amount tends to be less likely to increase than the longitudinal correction amount. Therefore, even if the position of the vehicle is directly corrected by the lateral correction amount, the steering angle is less likely to change abruptly.

[ procedure of processing of the self-position correcting device ]

Next, a procedure of the self-position correction process by the self-position correction device according to the present embodiment will be described with reference to the flowchart of fig. 2. The self-position correction process shown in fig. 2 is started when the ignition switch of the vehicle is turned on, and is repeatedly executed while the ignition switch is turned on.

In step S01, the object target recognition portion 110 recognizes an object target as a reference for determining the position of the vehicle, and calculates the relative positional relationship between the recognized object target and the vehicle.

In step S03, the longitudinal correction amount calculation unit 120 calculates the longitudinal correction amount, and the lateral correction amount calculation unit 130 calculates the lateral correction amount.

In step S05, the vehicle speed correction unit 140 sets a correction amount for the detected vehicle speed based on the longitudinal correction amount, adds the correction amount to the detected vehicle speed, and calculates the vehicle speed after correction.

In step S07, the integrating unit 150 calculates the movement amount of the vehicle using the calculated corrected vehicle speed, integrates the movement amount, and estimates the position of the vehicle.

In step S09, the lateral position correction unit 160 adds the lateral correction amount to the value of the abscissa of the vehicle to correct the position of the vehicle.

In step S11, the output unit 91 outputs the corrected position of the vehicle.

[ Effect of the embodiment ]

As described above in detail, the self-position correction method and the self-position correction device according to the present embodiment correct the position of the vehicle on the map data by sequentially accumulating the movement amounts of the vehicle and estimating the position of the vehicle on the map data by adding a correction amount, which is set based on a longitudinal correction amount obtained by subtracting a value of a vertical coordinate included in the position of the object detected by the detection unit from a value of a vertical coordinate included in the position of the object registered on the map data, to the vehicle speed and calculating the post-correction vehicle speed, and sequentially accumulating the movement amounts of the vehicle calculated from the post-correction vehicle speed and the yaw rate of the vehicle to estimate the position of the vehicle.

Thus, the longitudinal correction amount is not directly added to the ordinate of the vehicle, and therefore, a sudden change in the steering angle due to the position correction can be suppressed. On the other hand, when dead reckoning is performed, since the correction amount is added to the ordinate of the vehicle by the correction amount of the vehicle speed, and the added correction amount is sequentially accumulated as the movement amount is sequentially added, the magnitude of the added correction amount approaches the longitudinal correction amount, and therefore, the position of the vehicle can be reliably corrected.

The principle of suppressing a sudden change in the steering angle by adding the longitudinal correction amount to the ordinate of the vehicle via the correction amount of the vehicle speed instead of directly adding the longitudinal correction amount to the ordinate of the vehicle can be described with reference to fig. 3 and 5. For example, as shown in fig. 3, a situation in which the vehicle is estimated to be located at a point P1 is assumed. The amount of primary movement during the dead reckoning is calculated based on the vehicle speed and the yaw rate of the vehicle at the point P1, and the vehicle is calculated to move from the point P1 to the point P2 after a predetermined time interval.

Here, when the longitudinal correction amount Δ x is directly added to the ordinate of the vehicle at the point P1 (when all of the longitudinal correction amounts Δ x are added to the ordinate of the vehicle in the step of dead reckoning 1 time), the position of the vehicle is corrected from the point P1 to the point Q1. However, since the amount of movement in the process of dead reckoning 1 time, which is calculated based on the vehicle speed and the yaw rate of the vehicle at the point P1, is not corrected, it is calculated that the vehicle moves from the point Q1 to the point Q2 after a predetermined time interval. Here, the vector starting at the point P1 and ending at the point P2 and the vector starting at the point Q1 and ending at the point Q2 have the same magnitude and direction.

Therefore, when the longitudinal correction amount Δ x is added directly to the ordinate of the vehicle at the point P1, and when the longitudinal correction amount Δ x is large, the position of the vehicle after correction becomes the point Q2 that is greatly deviated from the path (path TR in fig. 3) on which the vehicle should originally travel, and as shown by a curve C2 in fig. 5, there is a possibility that a sudden change in the steering angle occurs. Fig. 5 shows a case where the steering angle changes abruptly from time t1 to time t3 as a result of correction of the longitudinal correction amount at time t 1. As shown by the curve C2, the time rate of change of the steering angle is discontinuous at the time t1, the time t2, and the time t 3.

On the other hand, when the correction amount is added to the ordinate of the vehicle via the correction amount of the vehicle speed, the longitudinal correction amount Δ x is divided and added to the ordinate of the vehicle in a plurality of steps of dead reckoning, and therefore the position of the vehicle after the correction does not become a position greatly deviated from the path (path TR in fig. 3) on which the vehicle should originally travel.

When the correction amount is added to the ordinate of the vehicle by the correction amount of the vehicle speed, as shown by a curve C1 in fig. 5, a sudden change in the steering angle does not occur, and the discontinuity of the time rate of change of the steering angle is suppressed.

In the self-position correction method and the self-position correction device according to the present embodiment, the larger the longitudinal correction amount is, the larger the value obtained by dividing the correction amount by the vehicle speed may be set. Accordingly, the correction amount of the vehicle speed is set to be larger as the longitudinal correction amount is larger or as the vehicle speed is larger, so that it is possible to suppress a sudden change in the steering angle due to the position correction and to shorten the time until the position of the vehicle is corrected. As a result, the position of the vehicle can be corrected in a shorter time than when the correction amount is set so that the value obtained by dividing the correction amount by the vehicle speed is constant regardless of the magnitude of the longitudinal correction amount.

Further, in the self-position correction method and the self-position correction device according to the present embodiment, the correction amount may be set by multiplying the vertical correction amount by a positive predetermined coefficient. Accordingly, the correction amount of the vehicle speed is set to be larger as the longitudinal correction amount is larger, so that it is possible to reduce the time until the position of the vehicle is corrected while suppressing a sudden change in the steering angle due to the position correction. Further, by adjusting the magnitude of the predetermined coefficient, the time until the position of the vehicle is corrected can be controlled.

In the self-position correction method and the self-position correction device according to the present embodiment, when the longitudinal correction amount is equal to or less than the predetermined threshold value, the longitudinal correction amount may be added to a value of the ordinate of the vehicle. Thus, when it is expected that the change in the steering angle caused when the longitudinal correction amount is directly added to the ordinate of the vehicle is sufficiently smaller than the level felt by the occupant, the position of the vehicle can be directly corrected based on the longitudinal correction amount, and the position of the vehicle can be corrected in a shorter time.

Further, in the self-position correction method and the self-position correction device according to the present embodiment, the coordinates of the axis parallel to the vehicle width direction may be used as the abscissa, and the lateral correction amount obtained by subtracting the value of the abscissa included in the position of the object target detected by the detection unit from the value of the abscissa included in the position of the object target registered on the map data may be added to the value of the abscissa of the vehicle. Thus, the vehicle position can be corrected by the lateral correction amount by a method with a smaller calculation load than the correction of the vehicle position by the longitudinal correction amount. In addition, the position of the vehicle can be corrected by the lateral correction amount in a short time.

The functions shown in the above embodiments may be implemented by one or more processing circuits. The processing circuit includes a programmed processor, a circuit, and the like, and further includes a device such as an Application Specific Integrated Circuit (ASIC), a circuit component configured to execute the described functions, and the like.

While the present invention has been described in terms of the embodiments, the present invention is not limited to the descriptions, and various modifications and improvements can be made by those skilled in the art. The discussion and drawings making up a part of this disclosure are not to be construed as limiting the invention. Various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art from this disclosure.

Needless to say, the present invention includes various embodiments and the like not described herein. Therefore, the technical scope of the present invention is determined only by the specific matters of the invention according to the above description and the appropriate scope of the claims.

Description of the symbols

51: map acquisition device

53: GPS receiver

55: radar apparatus

57: video camera

71: vehicle speed sensor

73: inertial measurement sensor

91: output unit

100: controller

110: object target recognition unit

120: longitudinal correction amount calculation unit

130: lateral correction amount calculation unit

140: vehicle speed correction unit

150: integrating part

160: lateral position correction unit