JP6790951B2 - Map information learning method and map information learning device - Google Patents

Description

The present invention relates to a map information learning method and a map information learning device.

As a technique for estimating the position of a moving vehicle, the vehicle position estimation device described in Patent Document 1 is known. This vehicle position estimation device obtains the amount of movement of the vehicle using vehicle speed information, and estimates the current position of the vehicle from the amount of movement. On the other hand, at the point where the detailed map information exists, the point where the scene obtained by the in-vehicle camera and the detailed map information match is identified by using the road alignment information such as the white line extracted from the detailed map and the landmark information. Then, a highly accurate vehicle position is obtained. When the vehicle position estimation device generates detailed map information, the vehicle position estimation device refers to the altitude information to obtain the lane boundary line information extracted from the image taken by the in-vehicle camera, and the lane boundary information of the three-dimensional coordinate point sequence. Convert to.

Japanese Unexamined Patent Publication No. 2005-265494

The self-position of the vehicle can be estimated by so-called odometry, which determines the moving distance and direction of the vehicle according to the rotation angle and the rotation angular velocity of the left and right wheels.
For example, if there is an altitude difference in the traveling path of the vehicle, a difference occurs between the traveling distance along the road surface and the traveling distance on the two-dimensional map. The elevation difference of the travel path is one of the factors of the odometry error that occurs between the self-position estimated by the odometry and the self-position on the two-dimensional map.
This odometry error can be corrected by collating the position information of the landmarks around the road stored in the map data in advance with the detected positions of the landmarks detected around the vehicle.

However, if the landmark position information is stored excessively densely, the amount of the landmark position information exceeds the amount of the recording medium that can be mounted on the vehicle, so that the landmark position information cannot be learned over a wide range.
An object of the present invention is to learn the location information of landmarks at appropriate intervals.

In the map information learning method according to one aspect of the present invention, the difference between the first mileage, which is the length of the traveling locus of the vehicle, and the second mileage, which is the length of the traveling locus on the two-dimensional map. The distance difference is calculated, the landmarks around the vehicle are detected, and the distance interval for recording the position information of the landmarks in the map data is determined according to the distance difference.

According to one aspect of the present invention, landmark position information can be learned at appropriate distance intervals.

It is a figure which shows the schematic configuration example of the operation support apparatus which concerns on 1st Embodiment. It is a block diagram which shows an example of the functional structure of the controller shown in FIG. It is explanatory drawing of an example of a map information learning method. It is a flowchart of an example of the map information learning method which concerns on 1st Embodiment. It is a flowchart of an example of a modification of a map information learning method. It is explanatory drawing of the detection range of a landmark. It is a block diagram which shows an example of the functional structure of the controller which concerns on 2nd Embodiment. It is a flowchart of an example of the map information learning method which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments of the present invention shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the structure, arrangement, and the like of components. Is not specified as the following. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims stated in the claims.

(First Embodiment)
(Constitution)
See FIG. The driving support device 1 includes a self-position estimation device 2 according to an embodiment of the present invention, a vehicle traveling controller 50, and a vehicle control actuator group 51.
The self-position estimation device 2 estimates the position of the vehicle equipped with the driving support device 1 (hereinafter, simply referred to as "vehicle") on the two-dimensional map, and also determines the position of the landmark used for estimating the position of the vehicle. learn.

A landmark is a structure around a road, and may be a three-dimensional object such as a road sign, a traffic light, a pedestrian bridge, a guide board, or a building. It may be a display.
The self-position estimation device 2 is an example of a map information learning device according to one aspect of the present invention.

The self-position estimation device 2 includes an ambient environment sensor group 10, a vehicle sensor group 20, a communication device 30, a map storage unit 31, a GPS (Global Positioning System) receiver 33, a second map 34, and an altitude database. A 35 and a controller 40 are provided. In addition, in FIG. 1, FIG. 2, FIG. 7, and the following description, the altitude database is referred to as “elevation DB”.

The controller 40 communicates with the ambient environment sensor group 10, the vehicle sensor group 20, the communication device 30, the map storage unit 31, the GPS receiver 33, the second map 34, and the altitude database 35 by wire communication or wireless communication. Information can be sent and received.
The map storage unit 31 can send and receive data, signals, or information to and from the communication device 30 by wired communication or wireless communication.

The ambient environment sensor group 10 is a sensor group that detects the ambient environment of the vehicle, for example, an object around the vehicle. For example, the ambient environment sensor group 10 may include a photographing device 11 and a distance measuring device 12. The photographing device 11 and the distance measuring device 12 detect the surrounding environment of the vehicle such as an object existing around the vehicle, a relative position between the vehicle and the object, and a distance between the vehicle and the object.
The photographing device 11 may be, for example, a stereo camera. The photographing device 11 may be a monocular camera, or may photograph the same object from a plurality of viewpoints with the monocular camera and calculate the distance to the object.

The range finder 12 may be, for example, a laser range finder (LRF) or a radar.
The photographing device 11 and the distance measuring device 12 output the detected ambient environment information to the controller 40. Further, the photographing device 11 and the distance measuring device 12 also output the surrounding environment information to the vehicle traveling controller 50 that performs the driving support control or the automatic driving control of the vehicle.

The vehicle sensor group 20 includes a sensor that detects a driving operation performed by the driver, a sensor that detects a running state of the vehicle, and other sensors 28. Sensors that detect driving operations performed by the driver include an accelerator sensor 21, a steering sensor 22, and a brake sensor 23. The sensor for detecting the traveling state of the vehicle includes a vehicle speed sensor 24, an acceleration sensor 25, a gyro sensor 26, and a wheel speed sensor 27.

The accelerator sensor 21 detects the accelerator opening degree of the vehicle and outputs the information of the accelerator opening degree to the controller 40 and the vehicle traveling controller 50. For example, the accelerator sensor 21 detects the amount of depression of the accelerator pedal of the vehicle as the accelerator opening degree.
The steering sensor 22 detects the steering angle of the steering wheel and outputs the detected steering angle information to the controller 40 and the vehicle traveling controller 50.

The brake sensor 23 detects the amount of brake operation by the driver and outputs the information of the detected amount of operation to the controller 40 and the vehicle traveling controller 50. For example, the brake sensor 23 detects the amount of depression of the brake pedal of the vehicle as the amount of brake operation.
The vehicle speed sensor 24 calculates the speed of the vehicle and outputs the calculated vehicle speed information to the controller 40 and the vehicle traveling controller 50.

The acceleration sensor 25 detects the acceleration in the front-rear direction and the acceleration in the vehicle width direction of the vehicle, and outputs the information of these accelerations to the controller 40 and the vehicle traveling controller 50.
The gyro sensor 26 detects the traveling direction of the vehicle and outputs the traveling direction information to the controller 40 and the vehicle traveling controller 50.
The wheel speed sensor 27 detects the wheel speed of the vehicle and outputs the wheel speed information to the controller 40 and the vehicle traveling controller 50.
Information of the accelerator opening degree, steering angle, brake operation amount, vehicle speed, acceleration, traveling direction, and wheel speed output from the vehicle sensor group 20 may be referred to as "vehicle state information".

The communication device 30 communicates with a communication device outside the vehicle. For example, the communication device 30 performs vehicle-to-vehicle communication with another vehicle, road-to-vehicle communication with a device installed on the shoulder of the road, or wireless communication with an information server installed outside the vehicle. By doing this, various information can be obtained from an external device.

The map storage unit 31 includes a first map 32 which is two-dimensional map data used for driving support of a vehicle by the driving support device 1. The map storage unit 31 may be, for example, a car navigation system or a map database.
The first map 32 is a lane level that includes road markings such as white lines, stop lines, pedestrian crossings, and road surface marks on the road, and point sequence information indicating the positions of steps such as curbs and medians that indicate road edges. It is map data.

The first map 32 may include point sequence information indicating the positions of landmarks around the road. The point sequence information indicating the position of the landmark has a three-dimensional coordinate value corresponding to the three-dimensional shape of the landmark, and the value indicating the position on the two-dimensional map is used as the two-dimensional coordinate value indicating the horizontal position. Have.
The map storage unit 31 may acquire the first map 32 from the outside via the communication device 30, or may periodically receive the latest map information to update the first map 32. The map storage unit 31 may store the track actually traveled by the vehicle in the first map 32 as map information.

The GPS receiver 33 detects the position of the vehicle by receiving the satellite positioning signal transmitted from the GPS satellite. The GPS receiver 33 outputs the detected vehicle position information to the controller 40.
The second map 34 is two-dimensional map data used to complement the first map 32. For example, in the second map 34, the self-position estimation device 2 has learned in an area where the point sequence information is not stored in the first map 32 or an area where the stored point sequence information is small and is not sufficient for vehicle position detection. It may be used to store map information.

For example, the second map 34 may record point sequence information indicating the position of the landmark learned by the self-position estimation device 2. This point sequence information has a three-dimensional coordinate value corresponding to the three-dimensional shape of the landmark, and has a value indicating a position on a two-dimensional map as a two-dimensional coordinate value indicating a horizontal position.
The altitude DB 35 stores the altitude data of each point in a predetermined geographical range.

The controller 40 is an electronic control unit that executes a process of estimating the position of the vehicle on a two-dimensional map and a process of learning the position of a landmark used for estimating the position of the vehicle. The controller 40 includes a processor 41 and peripheral components such as a storage device 42. The processor 41 may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit).

The controller 40 may be realized by a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the controller 40 may have a programmable logic device (PLD: Programmable Logic Device) such as a field-programmable gate array (FPGA).

The storage device 42 may include any of a semiconductor storage device, a magnetic storage device, and an optical storage device. The storage device 42 may include a memory such as a register, a cache memory, a ROM (Read Only Memory) and a RAM (Random Access Memory) used as the main storage device.
The storage device 42 stores a computer program that is executed on the processor 41 to cause the controller 40 to execute the vehicle position estimation process and the landmark learning process.

The vehicle travel controller 50 is an electronic control unit that controls the travel of the vehicle according to the driving operation of the occupant detected by the vehicle sensor group 20. Further, the vehicle driving controller 50 is based on the current position of the vehicle estimated by the self-position estimation device 2, the surrounding environment detected by the surrounding environment sensor group 10, and the first map 32 stored in the map storage unit 31. Provides driving support such as automatic driving of vehicles, emergency stop, and obstacle avoidance.

The vehicle travel controller 50 includes a processor and peripheral parts such as a storage device. The processor may be, for example, a CPU or an MPU.
The vehicle traveling controller 50 may be realized by a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the vehicle travel controller 50 may have a programmable logic device such as a field programmable gate array.
The storage device may include any of a semiconductor storage device, a magnetic storage device, and an optical storage device. The storage device may include a memory such as a register, a cache memory, a ROM and a RAM used as a main storage device.

The vehicle travel controller 50 controls the travel of the vehicle by driving the vehicle control actuator group 51. The vehicle control actuator may include, for example, a steering actuator 52, an accelerator opening actuator 53, and a brake control actuator 54.
The steering actuator 52 controls the steering direction and steering amount of the steering of the vehicle. The accelerator opening actuator 53 controls the accelerator opening of the vehicle. The brake control actuator 54 controls the braking operation of the vehicle braking device.

The vehicle travel controller 50 drives the vehicle control actuator group 51 based on the current position of the vehicle estimated by the self-position estimation device 2 at the time of driving support of the vehicle, thereby determining the timing of occurrence of the vehicle behavior of the vehicle. Control the amount of vehicle behavior generated.
For example, the vehicle travel controller 50 determines the timing of changing the accelerator opening amount, the timing of changing the steering amount of the steering wheel, and the timing of operating the brake device based on the current position of the vehicle. For example, the vehicle travel controller 50 changes the accelerator opening amount, the steering amount, and the braking amount by the braking device based on the current position of the vehicle.

An example of the functional configuration of the controller 40 is shown in FIG. The controller 40 includes an odometry calculation unit 60, a trajectory calculation unit 61, a white line detection unit 62, a landmark detection unit 63, a matching unit 64, a landmark correction unit 65, a trajectory correction unit 66, and a landmark recording. A unit 67 is provided.
The functions of the odometry calculation unit 60, the trajectory calculation unit 61, the white line detection unit 62, the landmark detection unit 63, the matching unit 64, the landmark correction unit 65, the trajectory correction unit 66, and the landmark recording unit 67 are stored in the storage device 42. This is realized by executing the stored computer program on the processor 41.

The odometry calculation unit 60 calculates the movement amount and the movement direction of the vehicle per unit time by using the vehicle state information obtained from the vehicle sensor group 20 and the positioning information of the GPS receiver 33.
The trajectory calculation unit 61 calculates the traveling locus of the vehicle on the road using the movement amount and the movement direction calculated by the odometry calculation unit 60. In calculating the traveling locus of the vehicle, a traveling locus model obtained in advance by learning the traveling locus on the road and a vehicle model of the vehicle may be used.

The white line detection unit 62 uses road markings such as white lines, stop lines, pedestrian crossings, and road surface marks on the road, curbs indicating road edges, medians, etc., based on changes in the surrounding environment information obtained from the surrounding environment sensor group 10. Detects the position of the step (hereinafter referred to as "white line, etc.").
The landmark detection unit 63 detects the position of the landmark around the road from the change in the ambient environment information obtained from the ambient environment sensor group 10. Landmarks include, for example, utility poles, signs, posts, buildings, those that exist around the vehicle and can be detected as straight lines, and those that can be detected as 90-degree edges. The landmark detection unit 63 may detect landmarks within a predetermined range around the vehicle. For example, the landmark detection unit 63 may detect landmarks within a predetermined distance from the vehicle. The landmark detection unit 63 outputs point sequence information indicating the position of the detected landmark to the landmark correction unit 65 and the trajectory correction unit 66.

The matching unit 64 estimates the position of the vehicle on the two-dimensional map by collating the position of the white line or the like detected by the white line detecting unit 62 with the position of the white line or the like stored in the first map 32. When the first map 32 includes the landmark score sequence information, the matching unit 64 uses the landmark score sequence information detected by the landmark detection unit 63 and the landmark score sequence stored in the first map 32. The landmark of the vehicle on the two-dimensional map may be estimated by collating with the information. The matching unit 64 outputs the estimated position information on the two-dimensional map of the vehicle to the landmark correction unit 65.

The landmark correction unit 65 calculates the position of the landmark detected by the landmark detection unit 63 on the two-dimensional map based on the position on the two-dimensional map of the vehicle estimated by the matching unit 64. For example, the landmark correction unit 65 is a land detected by the landmark detection unit 63 based on the position on the two-dimensional map of the vehicle and the relative positional relationship between the vehicle and the landmark detected by the landmark detection unit 63. The position of the mark on the two-dimensional map may be calculated.

The landmark correction unit 65 can calculate the position of the landmark on the two-dimensional map that is not stored in the first map 32. The landmark correction unit 65 outputs the point sequence information indicating the calculated position of the landmark on the two-dimensional map to the landmark recording unit 67.
The trajectory correction unit 66 corrects the traveling locus of the vehicle calculated by the trajectory calculation unit 61 based on the position on the two-dimensional map of the vehicle estimated by the matching unit 64, and estimates the position of the vehicle on the two-dimensional map. To do. When making corrections, the vehicle locus model described above may be used.
Further, the trajectory correction unit 66 re-estimates the position on the two-dimensional map such as the white line detected by the white line detection unit 62 based on the estimated position of the vehicle, corrects the traveling locus again, and estimates the position of the vehicle. The accuracy may be improved.

In an area where the point sequence information is not stored in the first map 32 or an area where the stored point sequence information is too small to detect the position of the vehicle, the trajectory correction unit 66 uses the landmark detection unit 63 to detect the landmark. The position of the vehicle on the two-dimensional map is estimated by collating the position of the mark with the position of the landmark stored in the second map 34.
The trajectory correction unit 66 corrects the traveling locus of the vehicle calculated by the trajectory calculation unit 61 based on the estimated position on the two-dimensional map of the vehicle, and estimates the position of the vehicle on the two-dimensional map.

The trajectory correction unit 66 re-estimates the position of the landmark detected by the landmark detection unit 63 on the two-dimensional map based on the estimated vehicle position, corrects the traveling locus again, and corrects the vehicle position estimation accuracy. May be improved.
The trajectory correction unit 66 outputs self-position information indicating the estimated position of the vehicle on the two-dimensional map to the vehicle travel controller 50.

The landmark recording unit 67 records the point sequence information indicating the position of the landmark on the two-dimensional map output by the trajectory correction unit 66 on the second map 34. For example, the landmark recording unit 67 stores the landmark point sequence information in an area where the point sequence information is not stored in the first map 32 or an area where the stored point sequence information is small and is not sufficient for vehicle position detection. Record on the second map 34. For example, the landmark recording unit 67 records the point sequence information of the landmarks that are not stored in the first map 32 on the second map 34.

Landmark recording unit 67, a first running distance L _{odm-calculated} by odometry calculation unit _60, i.e. the length of the running locus traveling along the road surface is the length on the two-dimensional map of the travel locus The first distance difference D1 = | L _map −L _odm |, which is the difference from the second mileage L _map , is calculated.
The landmark recording unit 67 determines the distance interval between points that detect landmarks around the vehicle and record the landmark sequence information on the second map 34 according to the first distance difference D1.
For example, the landmark recording unit 67 records the point sequence information of the landmark on the second map 34 every time the vehicle travels at an interval (distance) determined based on the first distance difference D1.

The landmark recording unit 67 includes a second mileage calculation unit 70, a condition determination unit 71, and a recording unit 72.
The second traveling distance calculating unit 70, a first travel distance L _{odm-calculated} by odometry calculation unit 60, and the positioning information of the GPS receiver 33, based on the altitude data stored in the elevation DB 35, two-dimensional travel locus The second mileage L _map , which is the length on the _map, is calculated.
Incidentally, odometry calculation unit 60 corresponds to the first travel distance calculating section that calculates a first travel distance L _odm-.

See FIG. Vehicle 80 mounting the driving support device 1 is traveling on the point A at time t _0, during the period from the time t ₀ to time t _i, it is assumed that moving from point A to point B.
The second traveling distance calculating unit 70, at time _{t 0} and time _{t i,} obtains the coordinates of point A and point B on the basis of the positioning information of the GPS receiver 33, respectively. The second mileage calculation unit 70 acquires the altitudes of the points A and B from the altitude DB 35 based on the coordinates of the points A and B. The second mileage calculation unit 70 calculates the altitude difference H between the point A and the point B.

The second mileage calculation unit 70 calculates the angle θ between the road surface and the horizontal plane between the points A and B and the second mileage L _map by the following equations (1) and (2). ..
θ = Sin ^-1 (H / L _odm )… (1)
L _map = L _odm × cos θ… (2)

See FIG. Condition determining unit 71, a first travel distance L _odm-the length of the travel locus of the vehicle odometry calculation unit 60 is calculated, and the second traveling distance L _map is the length on the two-dimensional map of the travel locus The first distance difference D1 = | L _map- L _odm |, which is the difference between the two, is calculated.
The condition determination unit 71 determines whether or not the vehicle has traveled a distance determined based on the first distance difference D1.

For example, the condition determination unit 71 determines whether or not the vehicle has traveled a distance determined based on the first distance difference D1 and either the first mileage _{Lodm or} the second mileage L _map. Good.
For example, the condition determination unit 71 determines whether or not the vehicle has traveled a distance in which either the first mileage _{Lodm or} the second mileage L _map is maximized while the first distance difference D1 is equal to or less than the predetermined threshold value Th1. May be determined.
Further, for example, in the condition determination unit 71, the vehicle sets a distance at which either one of the first mileage _Lodm and the second mileage L _map reaches a predetermined value while the first distance difference D1 is equal to or less than the predetermined threshold value Th1. It may be determined whether or not the vehicle has traveled.

The recording unit 72 records the point sequence information of the landmarks detected by the landmark detection unit 63 on the second map 34 according to the determination result of the condition determination unit 71.
For example, the recording unit 72 may record the landmark point sequence information on the second map 34 each time the condition determination unit 71 determines that the vehicle has traveled a distance determined based on the first distance difference D1. That is, the recording unit 72 records the landmark point sequence information on the second map 34 at intervals determined based on the first distance difference D1.

For example, the recording unit 72 determines that the vehicle has traveled a distance determined based on the first distance difference D1 and either the first mileage _{Lodm or} the second mileage L _map. Each time, the point sequence information of the landmark may be recorded on the second map 34. That is, the recording unit 72 _displays the landmark point sequence information on the second map at intervals determined based on the first distance difference D1 and either the first mileage _{Lodm or} the second mileage L _map. Record to 34.

For example, the recording unit 72 determines that the vehicle has traveled a distance that maximizes either the first mileage _{Lodm or} the second mileage L _map while the first distance difference D1 is equal to or less than the predetermined threshold Th1. Each time 71 determines, the point sequence information of the landmark may be recorded on the second map 34. That is, the recording unit 72 keeps the first distance difference D1 at or less than the predetermined threshold value Th1 at intervals at which either the first mileage _{Lodm or} the second mileage L _map becomes maximum, and the landmark point sequence information. May be recorded on the second map 34.
Further, for example, in the recording unit 72, the condition determination unit 71 determines that one of the first mileage _Lodm and the second mileage L _map has reached a predetermined value while the first distance difference D1 is equal to or less than the predetermined threshold value Th1. Each time the determination is made, the landmark point sequence information may be recorded on the second map 34.
If recording point sequence information of the landmark at such intervals, odometry error occurring between the second traveling distance L _map on the first travel distance L _odm-and two-dimensional map along the road by the altitude difference Th1 You can use landmarks to correct the odometry error so that it is within. In the present embodiment, although the odometry error generated between the second traveling distance L _map on the first travel distance L _odm-and two-dimensional map by the altitude difference as an example, not necessarily limited thereto. In addition, odometry error occurs due to tire slippage, unevenness of the road surface, etc., and therefore, this embodiment can be implemented in response to such cases.

For example, the interval for recording the landmark point sequence information may be determined by the following processing.
If point sequence information of the landmark at time t ₀ is recorded in the second map 34, odometry calculation unit 60, the position of the vehicle at time t ₀ and counting point of the first travel distance L _odm-. Odometry calculation unit 60 calculates a first travel distance _{L odm-from} counting point to the first time _{t (i-1).} Further, odometry calculation unit 60, the counting point, calculates a first travel distance _{L odm-up} to the second time _{t i} following the first time _{t (i-1).}

The second mileage calculation unit 70 calculates the second mileage L _map , which is the length on the two-dimensional map of the travel locus from the starting point to the first time t _(i-1) . Further, the second traveling distance calculating unit 70 calculates a second running distance _{L map} from counting point to the second time _{t i.}
Condition determining unit 71 calculates the first distance difference at the first time _{t (i-1) D1 (} i-1), a first distance difference D1 _i at the second time _{t i,} respectively.
Recording unit 72 obtains the point sequence information of the landmark detected landmark detection unit 63 in the first time t _(i-1) and a second time t _i from the landmark correcting unit 65.

Condition determining unit 71, a first distance difference at the first time _{t (i-1) D1 (} i-1) is not less threshold Th1 or less, and the first distance difference D1 _i at the second time _{t i} is the threshold Th1 Judge whether it is large or not. When the first distance difference D1 _(i-1) is equal to or less than the threshold Th1 and the first distance difference D1 _i is larger than the threshold Th1, the first distance difference D1 is the threshold Th1 at the first time t _(i-1) . Either one of the first mileage _Lodm and the second mileage L _map becomes the maximum as follows.

When the first distance difference D1 _(i-1) is equal to or less than the threshold Th1 and the first distance difference D1 _i is larger than the threshold Th1, the recording unit 72 has the landmark detection unit 63 at the first time t _(i-1) . The point sequence information of the landmarks detected in is recorded in the second map 34.
After recording the landmark on the second map 34, the odometry calculation unit 60 sets the position of the vehicle at the first time t _{(i-1) as} the starting point of the first mileage _Lodm .
By repeating the above processing, the landmark becomes the second at an interval in which either the first mileage _{Lodm or} the second mileage L _map is maximized while the first distance difference D1 remains equal to or less than the predetermined threshold value Th1. Recorded on map 34.

(motion)
Next, an example of the map information learning method according to the first embodiment will be described. See FIG. Step S1~S8 shown in FIG. 4, the time _{t i (i = 1,2,3, ...} ) to visit in a predetermined cycle (for example, every 100m seconds) respectively executed in.

Odometry calculation unit 60 in step S1 calculates the length of the travel path of the vehicle from the counting point of the first travel distance _{L odm-until} time _{t i} as the first traveling distance _{L odm-.}
Second traveling distance calculating unit 70 in step S2 calculates the altitude difference H between the point of counting point and time t _i of the first travel distance L _odm-.
Second traveling distance calculating unit 70 in Step S3 calculates the second traveling distance _{L map} until time _{t i} from counting point of the first travel distance _{L odm-.}

Landmark detection unit 63 in Step S4 detects the position of the landmarks near the road at time t _i. The recording unit 72 acquires the point sequence information of the landmarks detected by the landmark detection unit 63 at the time ti from the landmark correction unit 65.
Condition determining unit 71 in step S5 calculates the first distance difference D1 _i at time _{t i.}

Condition determining unit 71 in step S6, the time _{t (i-1)} a first distance difference in _{D1 (i-1)} is not less threshold Th1 or less, and the first distance difference D1 _i at time _{t i} is larger than the threshold Th1 Judge whether or not.
When the first distance difference D1 _(i-1) is equal to or less than the threshold Th1 and the first distance difference D1 _i is larger than the threshold Th1 (step S6: Y), the process proceeds to step S7. When the first distance difference D1 _i is equal to or less than the threshold Th1 (step S6: N), the process proceeds to step S8.

In step S7, the recording unit 72 records the point sequence information of the landmarks detected by the landmark detection unit 63 at the time t _(i-1) on the second map 34. Odometry calculation unit 60, the position of the vehicle at time _{t (i-1)} to the counting point the first travel distance _{L odm-.} After that, the process proceeds to step S8.
In step S8, the landmark recording unit 67 determines whether or not the learning of the landmark on the second map 34 should be completed.

For example, the landmark recording unit 67 may determine that learning of the landmark should be terminated when the ignition switch of the vehicle is turned off. Further, for example, it may be determined that the learning of the landmark should be completed when the vehicle enters the area where the point sequence information is stored in the first map 32.
When it is determined that the landmark learning should be completed (step S8: Y), the process ends. If it is not determined that the landmark learning should be completed (step S8: N), the process returns to step S1.

(Effect of the first embodiment)
The landmark recording unit 67 determines the difference between the first mileage _Lod , which is the length of the vehicle's travel locus, and the second mileage L _map , which is the length of the travel locus on the two-dimensional map. A certain first distance difference D1 is calculated. The landmark recording unit 67 determines the distance interval between points that detect landmarks around the vehicle and record the landmark sequence information on the second map 34 according to the first distance difference D1.
As a result, the location information of the landmark can be learned at an appropriate distance interval. In addition, since the landmark position information can be recorded at appropriate distance intervals, the position of the own vehicle can be accurately specified.

Further, the recording unit 72 records the position information of the landmarks detected around the vehicle on the second map 34 each time the vehicle travels a distance determined based on the first distance difference D1.
The first distance difference D1 reflects the odometry error caused by the altitude difference of the traveling path. Therefore, by recording the landmarks at intervals determined based on the first distance difference D1, the interval for recording the landmark position information can be determined according to the odometry error caused by the altitude difference of the travel path. become able to.
Therefore, the position information of the landmark used for correcting the odometry error caused by the altitude difference of the traveling path can be learned at an appropriate distance interval.

For example, if a vehicle is conventionally driven at a speed of 36 km / h, 33 frames per second are photographed with two stereo cameras, 30 landmarks are recorded per frame, and the data size per point is 10 KB, 1 km. It was necessary to record the amount of data of 1 GB per unit.
According to the present invention, for example, when the recording interval of landmarks is determined so as to suppress the first distance difference D1 within 10 cm on a traveling road having an inclination of 5 degrees, it is sufficient to record the landmarks at 40 points per 1 km on a two-dimensional map. .. Therefore, the amount of data to be recorded is 13.2 MB, which can be reduced to 1/75.
The landmark information is not necessarily limited to the point sequence, and may be any information that can identify the landmark. Further, the landmark information does not necessarily have to be recorded on the map, but may be recorded so that the location information can be specified. In addition, landmark information does not need to be recorded during traveling, and if it can be recorded at distance intervals between points, the timing of recording is not limited.

The recording unit 72 is the position of the landmark detected around the vehicle at a distance interval determined based on the first distance difference D1 and one of the first mileage _Lodm and the second mileage L _map. The information may be recorded on the second map 34.
For example, the recording unit 72 is a vehicle when either one of the first mileage _Lodm and the second mileage L _map reaches a predetermined predetermined value while the first distance difference D1 is equal to or less than the predetermined threshold value Th1. The location information of the landmarks detected around the second map 34 may be recorded.
By defining the landmark recording interval in this way, the interval can be set so that the landmark recording interval is as long as possible while suppressing the odometry error. This makes it possible to reduce the amount of data required for recording landmarks.

The second mileage calculation unit 70 may calculate the second mileage L _map based on the altitude difference H of the travel path of the vehicle. The condition determination unit 71 may calculate the first distance difference D1 between the first mileage _Lodm and the second mileage L _map . That is, the second mileage calculation unit 70 and the condition determination unit 71 may calculate the first distance difference D1 based on the altitude difference H of the travel path of the vehicle.
The first distance difference D1 can be calculated relatively easily and accurately based on the altitude difference H.

The second mileage calculation unit 70 may measure the altitude difference H using the satellite positioning signal and the altitude DB 35. The elevation difference is very small within the error range of the satellite positioning signal. Therefore, the altitude difference H can be accurately obtained by measuring the altitude difference H using the satellite positioning signal and the altitude DB 35.
The map data for recording the location information of the landmark is the second map 34 which complements the first map 32 used for the traveling support of the vehicle. However, the recording unit 72 may record the location information of the landmark on the first map 32.
By supplementing the first map 32 with the second map 34 in which the landmarks are learned by individual vehicles, the area where the point sequence information is not stored in the first map 32 and the area where the stored point sequence information is small and the vehicle Even if there is an area that is not sufficient for position detection, the odometry error can be corrected within the range required for individual vehicles.

(Modification example)
(1) When the landmark recording interval is set so that the odometry error caused by the altitude difference is equal to or less than the threshold Th1, a threshold Th2 sufficiently smaller than the threshold Th1 is set, and the distance at which the first distance difference D1 exceeds the threshold Th2 is set. Each time the vehicle travels, the position information of the landmarks detected around the vehicle may be recorded on the second map 34. That is, landmarks may be recorded on the second map 34 at intervals where the first distance difference D1 exceeds the threshold Th2.

See FIG. Step S10~S17 shown in FIG. 5, the time _{t i (i = 1,2,3, ...} ) to visit in a predetermined cycle (for example, every 100m seconds) respectively executed in.
The processing of steps S10 to S14 is the same as the processing of steps S1 to S5 of FIG.
Step condition determination unit 71 step S15, the first distance difference D1 _i at time _{t i} is determined whether the threshold is greater than Th2.
When the first distance difference D1 _i is larger than the threshold value Th2 (step S15: Y), the process proceeds to step S16. When the first distance difference D1 _i is equal to or less than the threshold Th2 (step S15: N), the process proceeds to step S17.

Step S16 the recording unit 72 in records point sequence information of the landmark detected landmark detection unit 63 at time t _i to the second map 34. Odometry calculation unit 60, the position of the vehicle at time _{t i} to counting point of the first travel distance _{L odm-.} After that, the process proceeds to step S17.
The process of step S17 is the same as the process of step S8 of FIG.
In this modified example as well, similarly to the effect of the first embodiment, it becomes possible to determine the interval for recording landmarks according to the odometry error caused by the altitude difference of the traveling path.
Therefore, the position information of the landmark used for correcting the odometry error caused by the altitude difference of the traveling path can be learned at an appropriate distance interval.

(2) The second mileage calculation unit 70 may measure the altitude difference H using the gyro sensor 26. By using the gyro sensor 26, it is possible to determine the interval for recording landmarks without using the altitude DB 35. The same applies to the second embodiment described later.

(3) Landmarks may not be detected due to causes such as occlusion. As a result, when the vehicle travels a distance determined based on the first distance difference D1, the landmark detection unit 63 may not be able to detect landmarks within a predetermined range around the vehicle.
Therefore, if the landmark within a predetermined range around the vehicle cannot be detected when the vehicle travels a distance determined based on the first distance difference D1, the recording unit 72 detects the landmark in the area around the predetermined range. The location information of the landmark may be recorded on the second map 34. The same applies to the second embodiment described later.

See FIG. When the landmark in the predetermined range 81 around the vehicle 80 cannot be detected, the landmark detection unit 63 detects the landmark detected in the region 82 of the predetermined width W around the predetermined range 81.
The recording unit 72 records the position information of the landmark detected in the area 82 on the second map 34.
As a result, even if the landmark detection unit 63 cannot detect a landmark within a predetermined range 81 when the vehicle 80 travels a distance determined based on the first distance difference D1, the landmark used for correcting the odometry error. The mark can be recorded. Therefore, the accumulation of odometry error can be prevented.

(4) The threshold values Th1 and Th2 may be fixed values. It may be a value that fluctuates dynamically. The larger the thresholds Th1 and Th2, the wider the interval for recording landmarks, and the easier it is for odometry error to accumulate. The smaller the thresholds Th1 and Th2, the narrower the interval for recording landmarks and the less likely it is that odometry errors will accumulate. That is, the accuracy of estimating the position of the vehicle is high.

For example, the condition determination unit 71 may change the threshold values Th1 and Th2 according to the operating environment. For example, in an environment where driving difficulty is high, the thresholds Th1 and Th2 may be reduced to improve the estimation accuracy of the vehicle position, and for example, deviation from the lane or approach to the edge of the lane may be prevented. In an environment where the driving difficulty level is low, the threshold values Th1 and Th2 may be increased to reduce the amount of data recorded on the second map 34. The same applies to the second embodiment described later.

For example, the condition determination unit 71 may change the threshold values Th1 and Th2 according to the season. For example, in winter, when the difficulty of driving tends to be high, such as when the road surface freezes, the threshold values Th1 and Th2 may be made smaller than in summer.
For example, the condition determination unit 71 may change the threshold values Th1 and Th2 depending on the location. For example, in places where congestion occurs, such as near a specific store or facility or at an intersection, it is required to estimate the position of the vehicle with high accuracy in order to ensure safety.

Therefore, the condition determination unit 71 determines whether or not the vehicle is traveling in a place where congestion is expected by referring to the first map 32, and if the vehicle is traveling in a place where congestion is expected, a threshold value is obtained. Th1 and Th2 may be reduced.
Further, for example, the condition determination unit 71 may change the threshold values Th1 and Th2 according to the type and shape of the road on which the vehicle travels. For example, the threshold values Th1 and Th2 may be made smaller while traveling on a curve than when traveling on a straight road. The thresholds Th1 and Th2 may be made smaller while traveling on a highway than when traveling on a general road. The thresholds Th1 and Th2 may be smaller while traveling at an intersection than when traveling on a road.

(5) When the second mileage L _map, which is the length on the two-dimensional map, is known, the landmark recording unit 67 travels along the road surface based on the second mileage L _map and the altitude difference H. The first mileage _Lodm , which is the length of the above, may be calculated, and the first distance difference D1 = | L _map- L _odm | may be calculated.
The landmark recording unit 67 may include a first mileage calculation unit that calculates the first mileage _Lodm based on the following equations (3) and (4).
θ = Tan ^-1 (H / L _map )… (3)
L _odm = L _map / cos θ… (4)
The same applies to the second embodiment described later.

(Second Embodiment)
Subsequently, the self-position estimation device 2 of the second embodiment will be described. In the second embodiment, the second map 34 calculates the coefficient G to be multiplied to the first travel distance L _odm-to correct the odometry errors generated in the first traveling distance L _{odm-calculated} based on the rotational speed of a wheel Record. Hereinafter, the coefficient G is referred to as "odometry gain G".
Odometry calculation unit 60 corrects the odometry error by multiplying the odometry gain G to the first travel distance L _odm-.

For example, it odometry gain G can be a factor for calculating the second traveled distance L _map is multiplied by the first traveling distance L _odm-.
Odometry calculation unit 60 corrects the odometry error to calculate a second travel distance L _map by multiplying the odometry gain G as shown in the following equation (5) to the first travel distance L _odm-.
L _map = G × L _odm … (5)

Each time the condition determination unit 71 determines that the vehicle has traveled a distance determined based on the first distance difference D1, the landmark recording unit 67 calculates the odometry gain G and records it on the second map 34.

See FIG. 7. The functional configuration of the controller 40 according to the second embodiment is similar to the functional configuration shown in FIG. 2, and the same reference numerals are given to similar components.
The controller 40 includes a third mileage calculation unit 90. The landmark recording unit 67 includes an odometry gain calculation unit 91.
The functions of the third mileage calculation unit 90 and the odometry gain calculation unit 91 are realized by executing the computer program stored in the storage device 42 on the processor 41.

The third mileage calculation unit 90 acquires the detection result of the surrounding environment of the vehicle from the surrounding environment sensor group 10. The third mileage calculation unit 90 calculates the length of the traveling locus of the vehicle along the road surface based on the detection result of the surrounding environment. The length of the traveling locus calculated by the third mileage calculation unit 90 is referred to as the third mileage L _hi .
For example, the third mileage calculation unit 90 may calculate the third mileage L _hi based on the white line or the like extracted from the detection result of the ambient environment sensor group 10 or the landmark, and the ambient environment sensor group 10 may calculate. The third mileage L _hi may be calculated by visual odometry based on the detection result of.

The third mileage calculation unit 90 outputs the third mileage L _hi to the landmark recording unit 67. The third mileage L _hi is the length of the traveling locus of the vehicle along the road surface as in the case of the first mileage _Lodom . However, since the third mileage L _hi is calculated from the detection result of the ambient environment sensor group 10, the accuracy is generally higher than that of the first mileage _Lodm calculated based on the number of rotations of the wheels.

The odometry gain calculation unit 91 calculates the odometry gain G.
Odometry gain calculation unit 91, for example, first travel distance _{L odm-,} second running distance _{L map,} may calculate the odometry gain G based on the third traveling distance _{L hi.} For example, the odometry gain calculation unit 91 may calculate odometry gains such as G = L _map / L _odm and G = L _hi / L _odm .
The odometry gain calculation unit 91 may further calculate the odometry gain G in consideration of parameters such as the slope of the road surface, the speed, and the road shape.

The odometry gain calculation unit 91 calculates the odometry gain G and records it on the second map 34 each time the condition determination unit 71 determines that the vehicle has traveled a distance determined based on the first distance difference D1.
In the second embodiment, the odometry gain calculation unit 91 has a second distance difference D2 = | L _map −L _hi |, which is a difference between the third mileage L _hi and the second mileage L _map, and the first Every time the vehicle travels a distance determined based on the distance difference D1, the odometry gain G is calculated and recorded on the second map 34.

For example, one of the first mileage _Lodom , the second mileage L _map , and the third mileage L _hi is maximized while the first distance difference D1 is equal to or less than the predetermined threshold Th1, or the second distance difference D2. The odometry gain G is calculated each time the vehicle travels a distance that maximizes any one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi while keeping the predetermined threshold Th3 or less. Then, it is recorded on the second map 34.
That is, one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi is maximized while the first distance difference D1 is equal to or less than the predetermined threshold Th1 or the second distance difference D2. The odometry gain G is calculated at the interval at which any one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi is maximized while keeping the predetermined threshold Th3 or less, and the second map 34 Record in.
Further, for example, any one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi reaches a predetermined value while the first distance difference D1 is equal to or less than the predetermined threshold Th1 or the second When any of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi reaches a predetermined value while the distance difference D2 is equal to or less than the predetermined threshold Th3, the odometry gain G is calculated. Record on the second map 34.

Similarly, the recording unit 72 determines whether any of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi is maximized while the first distance difference D1 is equal to or less than the predetermined threshold Th1. Alternatively, each time the vehicle travels a distance that maximizes one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi while the second distance difference D2 remains equal to or less than the predetermined threshold Th3. , The point sequence information of the landmark is recorded on the second map 34.
That is, one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi is maximized while the first distance difference D1 is equal to or less than the predetermined threshold Th1 or the second distance difference D2. The point sequence information of the landmarks is displayed on the second map 34 at intervals where any one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi is maximized while keeping the predetermined threshold Th3 or less. Record to.
Further, for example, any one of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi reaches a predetermined value while the first distance difference D1 is equal to or less than the predetermined threshold Th1. When any of the first mileage _Lodm , the second mileage L _map , and the third mileage L _hi reaches a predetermined value while the two distance difference D2 is equal to or less than the predetermined threshold Th3, the point sequence information of the landmark. Is recorded on the second map 34.

In this way, the odometry gain G is calculated and recorded together with the landmark at the interval at which the second distance difference D2 between the third mileage L _hi and the second mileage L _map becomes the threshold value Th3 or less. This makes it possible to correct by landmarks before the error between the third mileage L _hi calculated based on the detection result of the surrounding environment and the second mileage L _map on the two-dimensional map becomes excessive. Therefore, it is possible to prevent the correction error of the odometry gain G from becoming large due to the correction amount by the odometry gain G becoming excessive.

Further, the odometry gain G is calculated and recorded together with the landmark at the interval at which the first distance difference D1 between the first mileage _Lodm and the second mileage L _map becomes equal to or less than the threshold Th1. Error of the first travel distance L _odm-becomes possible correction by landmarks before becoming excessive thereby a odometry calculated based on the rotation of the wheel. Therefore, it is possible to prevent the correction error of the odometry gain G from becoming large due to the correction amount by the odometry gain G becoming excessive.

For example, the interval for recording the odometry gain G and the landmark may be determined by the following processing.
If odometry gain G and landmark at time t ₀ is recorded in the second map 34, odometry calculation unit 60, the position of the vehicle at time t ₀ and counting point of the first travel distance L _odm-. Further, the third mileage calculation unit 90 sets the position of the vehicle at time t _{0 as} the starting point of the third mileage L _hi .

Odometry calculation unit 60 calculates a first travel distance _{L odm-from} counting point to the first time _{t (i-1).} Further, odometry calculation unit 60, the counting point, calculates a first travel distance _{L odm-up} to the second time _{t i} following the first time _{t (i-1).}
The third mileage calculation unit 90 calculates the third mileage L _hi from the starting point to the first time t _(i-1) . The third travel distance calculating section 90 calculates the third travel distance _{L hi} from counting point to the second time _{t i.}

The second traveling distance calculating unit 70 calculates a second running distance _{L map} from counting point from the first time _{t (i-1)} to and counted point to the second time _{t i,} respectively.
Condition determining unit 71 calculates the first distance difference at the first time _{t (i-1) D1 (} i-1), a first distance difference D1 _i at the second time _{t i,} respectively.
Condition determining unit 71 calculates a second distance difference at the first time _{t (i-1) D2 (} i-1), the second distance difference D2 _i in the second time _{t i,} respectively.
Recording unit 72 obtains the point sequence information of the landmark detected landmark detection unit 63 in the first time t _(i-1) and a second time t _i from the landmark correcting unit 65.

Odometry gain calculating unit 91, at the first time _{t (i-1),} the first travel distance _{L odm-and} second traveling distance _{L map} at the first time _{t (i-1),} or the first traveling distance _{L odm-and} Based on the third mileage L _hi , the odometry gain G for correcting the odometry error occurring at the first time t _(i-1) is calculated. Similarly odometry gain calculation unit 91 calculates the odometry gain G for correcting the odometry error caused in the second time t _i.

Condition determining unit 71, a first distance difference at the first time _{t (i-1) D1 (} i-1) is not less threshold Th1 or less, and the first distance difference D1 _i at the second time _{t i} is the threshold Th1 Is it large, or is the second distance difference D2 _{(i-1) at} the first time t _(i-1) equal to or less than the threshold Th3, and the second distance difference D2 _{i at} the second time t _i is greater than the threshold Th3? Judge whether or not.
Odometry gain calculation unit 91, a first distance difference at the first time _{t (i-1) D1 (} i-1) is not less threshold Th1 or less, and the first distance difference D1 _i at the second time _{t i} is the threshold value Th1 When the condition determination unit 71 determines that the value is larger, the odometry gain G calculated at the first time t _(i-1) is recorded in the second map 34. The first time _{t (i-1)} second distance difference in _{D2 (i-1)} is the threshold value Th3 or less, and a second greater than the second distance difference D2 _i is the threshold value Th3 at time _{t i} and the condition determination section 71 Is also determined, the odometry gain G calculated at the first time t _(i-1) is recorded on the second map 34.

Recording unit 72, a first distance difference at the first time _{t (i-1) D1 (} i-1) is not less threshold Th1 or less, and the first distance difference D1 _i at the second time _{t i} is larger than the threshold Th1 When the condition determination unit 71 determines, the point sequence information of the landmarks detected by the landmark detection unit 63 at the first time t _(i-1) is recorded in the second map 34. The first time _{t (i-1)} second distance difference in _{D2 (i-1)} is the threshold value Th3 or less, and a second greater than the second distance difference D2 _i is the threshold value Th3 at time _{t i} and the condition determination section 71 Is also determined, the point sequence information of the landmarks detected by the landmark detection unit 63 at the first time t _(i-1) is recorded in the second map 34.
After recording the landmark on the second map 34, the odometry calculation unit 60 sets the position of the vehicle at the first time t _{(i-1) as} the starting point of the first mileage _Lodm . The third mileage calculation unit 90 sets the position of the vehicle at the first time t _{(i-1) as} the starting point of the third mileage L _hi .

Subsequently, an example of the map information learning method according to the second embodiment will be described. See FIG. Step S20~S30 shown in FIG. 8, the time _{t i (i = 1,2,3, ...} ) to visit in a predetermined cycle (for example, every 100m seconds) respectively executed in.
The processing of steps S20 to S22 is the same as the processing of steps S1 to S3 of FIG.
Third travel distance calculating unit 90 in step S23 calculates the length of the travel path of the vehicle from the counting point of the third traveling distance L _hi to time t _i as the third traveling distance L _hi.

The process of step S24 is the same as the process of step S4 of FIG.
Odometry gain calculating unit 91 in step S25 calculates the odometry gain G at time _{t i.}
The process of step S26 is the same as the process of step S5 of FIG.
Condition determining unit 71 in step S27 calculates a second distance difference D2 _i at time _{t i.}
Condition determining unit 71 in step S28, the time _{t (i-1)} a first distance difference in _{D1 (i-1)} is not less threshold Th1 or less, and the first distance difference D1 _i at time _{t i} is larger than the threshold Th1 Or, it is determined whether or not the second distance difference D2 _{(i-1) at the} time t _(i-1) is equal to or less than the threshold Th3 and the second distance difference D2 _{i at} the time t _i is larger than the threshold Th3. ..

Processing when the first distance difference D1 _{(i-1) at} time t _(i-1) is equal to or less than the threshold Th1 and the first distance difference D1 _{i at} time t _i is larger than the threshold Th1 (step S28: Y). Proceeds to step S29. Even when the second distance difference D2 _{(i-1) at} time t _(i-1) is equal to or less than the threshold Th3 and the second distance difference D2 _{i at} time t _i is larger than the threshold Th3 (step S28: Y). The process proceeds to step S29. In other cases (step S28: N), the process proceeds to step S30.

In step S29, the recording unit 72 records the point sequence information of the landmarks detected by the landmark detection unit 63 at the time t _(i-1) on the second map 34. The odometry gain calculation unit 91 records the odometry gain G calculated at time t _(i-1) on the second map 34.
The odometry calculation unit 60 sets the position of the vehicle at the first time t _{(i-1) as} the starting point of the first mileage _Lodm . The third mileage calculation unit 90 sets the position of the vehicle at the first time t _{(i-1) as} the starting point of the third mileage L _hi .
The process of step S30 is the same as the process of step S8 of FIG.

(Effect of the second embodiment)
Odometry calculation unit 60 calculates the first traveling distance L _odm-based on the rotation speed of a wheel. Odometry gain calculation unit 91, an odometry gain G is multiplied to the first travel distance L _odm-to correct an error generated in the first traveling distance L _odm-, the distance determined on the basis of the first distance difference D1 vehicle travels Each time, the position information of the landmarks detected around the vehicle and the odometry gain G are recorded on the second map 34.

For example odometry gain G can be a factor to be multiplied to the first travel distance _{L odm-for} calculating a second travel distance _{L map} from the first travel distance _{L odm-.}
As a result, the position correction by the odometry gain G becomes possible until the position correction by the landmarks recorded at the intervals determined based on the first distance difference D1 is performed, so that the estimation accuracy of the vehicle position can be improved. Can be done.

The condition determination unit 71 calculates the first distance difference D1, which is the difference between the first mileage _Lodm and the second mileage L _map . The condition determination unit 71 is a second distance difference, which is the difference between the third mileage L _hi , which is the length of the vehicle's travel locus calculated based on the detection result of the surrounding environment of the vehicle, and the second mileage L _map. Calculate D2.
Each time the vehicle travels a distance determined based on the first distance difference D1 and the second distance difference D2, the odometry gain G is calculated to obtain the landmark position information and the odometry gain G detected around the vehicle. Record on the second map 34.

This makes it possible to correct by landmarks before the error between the third mileage L _hi calculated based on the detection result of the surrounding environment and the second mileage L _map on the two-dimensional map becomes excessive. Therefore, it is possible to prevent the correction error of the odometry gain G from becoming large due to the correction amount by the odometry gain G becoming excessive.
The error of the first travel distance L _odm-becomes possible correction by landmarks before becoming excessive is odometry calculated based on the rotation of the wheel. Therefore, it is possible to prevent the correction error of the odometry gain G from becoming large due to the correction amount by the odometry gain G becoming excessive.
Further, the odometry gain G is recorded at an interval determined by the first distance difference D1, which is the difference between the first mileage _Lodm and the second mileage L _map . As a result, the odometry gain G can be recorded at an appropriate interval, so that the appropriate odometry gain G can be set while suppressing the amount of data, and the moving distance of the own vehicle can be calculated accurately. become able to. The odometry gain G does not need to be recorded on the map, and the recording method and medium are not limited as long as the position information of the position where the odometry gain G is used can be specified.

(Modification example)
(1) Similar to the first embodiment, the vehicle _sets the maximum distance of either the first mileage _{Lodm or} the second mileage L _map while the first distance difference D1 is equal to or less than the predetermined threshold Th1. Each time the vehicle travels, the odometry gain G may be calculated and the position information of the landmark and the odometry gain G may be recorded on the second map 34.
Further, a threshold value Th2 sufficiently smaller than the threshold value Th1 is set, and every time the vehicle travels a distance in which the first distance difference D1 exceeds the threshold value Th2, the odometry gain G is calculated to obtain the landmark position information and the odometry gain G. It may be recorded on the second map 34.
Further, a threshold value Th4 sufficiently smaller than the threshold value Th3 is set, and every time the vehicle travels a distance in which the second distance difference D2 exceeds the threshold value Th4, the odometry gain G is calculated to obtain the landmark position information and the odometry gain G. It may be recorded on the second map 34.
(2) Similar to the modified example of the first embodiment, the condition determination unit 71 may change the threshold value Th3 according to the operating environment.

It goes without saying that the present invention includes various embodiments not described here. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention relating to the reasonable claims from the above description.

1 ... Driving support device, 2 ... Self-position estimation device, 10 ... Surrounding environment sensor group, 11 ... Imaging device, 12 ... Distance measuring device, 20 ... Vehicle sensor group, 21 ... Accelerator sensor, 22 ... Steering sensor, 23 ... Brake Sensor, 24 ... Vehicle speed sensor, 25 ... Acceleration sensor, 26 ... Gyro sensor, 27 ... Wheel speed sensor, 28 ... Other sensor, 30 ... Communication device, 31 ... Map storage, 32 ... First map, 33 ... GPS receiver , 34 ... 2nd map, 35 ... altitude DB, 40 ... controller,
41 ... Processor, 42 ... Storage device, 50 ... Vehicle running controller, 51 ... Vehicle control actuator group, 52 ... Steering actuator, 53 ... Accelerator opening actuator, 54 ... Brake control actuator, 60 ... Odometry calculation unit, 61 ... Trajectory calculation Unit, 62 ... White line detection unit, 63 ... Landmark detection unit, 64 ... Matching unit, 65 ... Landmark correction unit, 66 ... Trajectory correction unit, 67 ... Landmark recording unit, 70 ... Second mileage calculation unit, 71 ... condition judgment unit, 72 ... recording unit, 80 ... vehicle, 90 ... third mileage calculation unit, 91 ... odometry gain calculation unit

Claims (14)

Sensors detect landmarks around the vehicle
The controller
The distance difference, which is the difference between the first mileage, which is the length of the traveling locus of the vehicle, and the second mileage, which is the length of the traveling locus on the two-dimensional map, is calculated.
The distance interval for recording the detected position information of the landmark is determined according to the distance difference.
A map information learning method characterized by this. The map information learning method according to claim 1, wherein the controller records position information of landmarks detected around the vehicle at distance intervals determined based on the distance difference. The map information learning method according to claim 2, wherein the controller records the position information of the landmark when the distance difference exceeds a predetermined threshold value as the distance interval. The controller is characterized in that it records the position information of the landmark at a distance interval determined based on the distance difference and one of the first mileage and the second mileage. The map information learning method described in 2. When either one of the first mileage and the second mileage reaches a predetermined value as the distance interval while the distance difference is equal to or less than a predetermined threshold value, the controller controls the vehicle. The map information learning method according to claim 4, wherein the location information of landmarks detected in the surroundings is recorded. The controller
The first mileage is calculated based on the number of rotations of the wheels.
Record the coefficient used to correct the error that occurs in the first mileage .
The map information learning method according to any one of claims 1 to 5, wherein the map information learning method is characterized. The map information learning method according to claim 6, wherein the coefficient is a coefficient to be multiplied by the first mileage in order to calculate the second mileage from the first mileage. The map information learning method according to claim 6 or 7, wherein the controller records the coefficient at a distance interval determined based on the distance difference. The controller
The first distance difference, which is the difference between the first mileage and the second mileage, is calculated.
The second distance difference, which is the difference between the third mileage, which is the length of the traveling locus of the vehicle, and the second mileage, which is calculated based on the detection result of the surrounding environment of the vehicle, is calculated.
The coefficient is recorded at a distance interval determined based on the first distance difference and the second distance difference .
The map information learning method according to claim 6 or 7, characterized in that. The map information learning method according to any one of claims 1 to 9, wherein the controller calculates the distance difference based on the altitude difference of the traveling path of the vehicle. The map information learning method according to claim 10, wherein the controller measures the altitude difference using a satellite positioning signal and an altitude database, or a gyro sensor. The map information learning method according to any one of claims 1 to 11, wherein the recording of the location information of the landmark is used for complementing the map data used for the traveling support of the vehicle. The claim is characterized in that when a landmark within a predetermined range around the vehicle is not detectable, the controller records the position information of the landmark detected in a region of a predetermined width around the predetermined range. The map information learning method according to any one of 1 to 12. Sensors that detect landmarks around the vehicle,
The distance difference, which is the difference between the first mileage, which is the length of the traveling locus of the vehicle, and the second mileage, which is the length of the traveling locus on the two-dimensional map, is calculated by the sensor. A controller that determines a distance interval for recording the detected position information of the landmark in a predetermined storage device according to the distance difference.
A map information learning device characterized by being equipped with.

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