JP2011196916A - Measuring vehicle, and road feature measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems wherein, a plurality of laser radars are often used when loading the laser radars on a moving body to irradiate the ground or a wall surface therewith, and measuring the position of a target during movement, if the laser radars are installed simply in parallel, the density at each measuring point has an irregularity according to moving speed, or a density difference of the measuring point becomes large in the direction parallel to traveling and in the direction vertical thereto.SOLUTION: The density irregularity at each measuring point, or the magnitude of the density difference caused by the direction, is reduced, by installing each laser radar at each different angle.

Description

  The present invention relates to a measurement vehicle using a laser radar.

In recent years, products that combine GIS (Geographical Information System) and GPS (Global Positioning System) typified by car navigation systems and the like are remarkably widespread. On the other hand, it is expected that the position information by GIS and GPS will be applied to the safe driving of ITS (Intelligent Transport Systems), and the position information of features on and on the road is considered to be effective information. It has been.
On the other hand, it is desired to improve the accuracy and sophistication of a road management ledger that records information on features around the road. However, because it is necessary to perform surveying with high accuracy in creating a road management ledger that records the position of features on and on the road, such as kiloposts, signs, guardrails, white lines, etc. on a scale of 1/500, A static survey using GPS and a total station that measures distance and angle is performed. On the national road, there may be approximately 2000 features to be measured in a 30 km round-trip section. Therefore, enormous costs and time are required for the advancement and accuracy of road management ledgers nationwide.
Therefore, MMS (Mobile Mapping System) has been attracting attention and research and development for the purpose of reducing information collection time and cost (for example, see Patent Document 1).

WO2008 / 099915

However, in a measurement apparatus using a laser radar as described in Patent Document 1, a one-dimensional laser radar (laser scanner) that scans only in one direction is mounted, and the position of a target is irradiated while moving on the ground or a wall. When trying to measure the laser, there is a problem that when the moving body travels at a high speed, the spot density of the laser decreases or the spot density becomes uneven.

  The present invention has been made in order to solve the problem, and provides a measurement vehicle capable of performing measurement while suppressing a decrease in spot density and uneven spot density even when the vehicle moves at high speed. For the purpose.

  A measurement vehicle according to the present invention scans a laser beam to obtain a laser radar (LRF [Laser Range Finder]) that acquires azimuth / distance data indicating the distance to a road surface and road features around the road surface and its azimuth. Two or more measurement vehicles mounted on the road surface on which the laser radar scans the laser beam is not parallel to the scan line on the road surface on which the other laser radar scans the laser beam. It is.

  According to the measurement vehicle of the present invention, when measuring a feature using a laser radar, even if the vehicle moves at a high speed, measurement is performed while suppressing a decrease in spot density or uneven spot density. can do.

3 is a diagram illustrating a functional configuration of a measurement vehicle 102 according to Embodiment 1. FIG. This is a mounting example in which the laser radars 240a and 240b according to Embodiment 1 are mounted on a top plate. It is the schematic diagram which looked at the measurement vehicle 102 which concerns on Embodiment 1 from upper direction. It is the schematic diagram which looked at the measurement vehicle 102 which concerns on Embodiment 1 from the side. It is the figure which showed the irradiation point of the laser which laser radar 240a, 240b which concerns on Embodiment 1 irradiated to the road surface. This is an example in which a high-density spot and a low-density spot are formed at the irradiation points of the laser radars 240a and 240b according to the first embodiment. This is another example in which the laser radars 241a and 241b according to the first embodiment are mounted on a top plate. It is the figure which showed the point group of the irradiation point of the laser which the laser radars 241a and 241b which concern on Embodiment 1 irradiated to the road surface. It is the figure which showed the point cloud of the laser irradiation point which the laser radars 241a and 241b which concern on Embodiment 1 irradiated to the road surface (when vehicle speed is high). It is the schematic diagram which looked at the measurement vehicle 102 which concerns on Embodiment 2 from upper direction.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a functional configuration of a measurement vehicle 102 and a road feature measurement apparatus (computer) 100 that measures road features using output data output from the measurement vehicle 102 according to the first embodiment. The road feature measurement system is completed by the measurement vehicle 102 and the road feature measurement device (computer) 100. The road feature measuring apparatus (computer) 100 is described in Patent Document 1, and detailed description thereof is omitted here.

  The measurement vehicle 102 in the first embodiment includes an odometry device 200, three gyros 210 (positioning unit, posture detection unit, part of a GPS gyro), and three GPS 220 (positioning unit, posture detection unit, GPS gyro). Part), a camera 230 (imaging part), a laser radar 240a (light scanning part, laser scanner, LRF [Laser Range Finder]) provided in front of the vehicle and radiating laser light toward the front of the vehicle, and provided in the rear of the vehicle. A laser radar 240b (light scanning unit, laser scanner, LRF [Laser Range Finder]) that irradiates laser light backward is provided.

FIG. 2 shows a mounting example in which the GPS 220, the gyro 210, and the laser radars 240 a and 240 b are mounted on the top plate of the measurement vehicle 102. The odometry apparatus 200, the three gyros 210, the three GPS 220, the camera 230, and the two laser radars 240a and 240b (each of which is an example of a measurement sensor) are the top plate of the measurement vehicle 102 (hereinafter referred to as a vehicle). 103 (base). 2 corresponds to the front direction of the vehicle 102. Hereinafter, the Z axis is also referred to as a vehicle axis. The direction of the vehicle axis (+ Z direction) and the front direction of the vehicle coincide with each other, and the vehicle travels in the direction of the vehicle axis.
The odometry apparatus 200 executes an odometry method and calculates distance data indicating the travel distance of the vehicle.
The three gyros 210 calculate angular velocity data indicating the inclination (pitch angle, roll angle, yaw angle) of the vehicle in three axial directions.
The three GPSs 220 calculate positioning data indicating the travel position (coordinates) of the vehicle.
The odometry apparatus 200, the gyro 210, and the GPS 220 measure the position and posture of the vehicle by a GPS / dead reckoning combined calculation.
The camera 230 captures and outputs time-series image data.
One laser radar 240a and one laser radar 240b are installed at the front and the rear of the vehicle body, respectively, irradiating the laser with a predetermined period while licking the optical axis in the lateral direction, and determining the distance to the road surface. The azimuth / distance data (hereinafter referred to as LRF data) shown for the azimuth is calculated.

Next, an outline of the road feature measuring apparatus (computer) 100 that measures road features using the output data output from the vehicle 102 of the present invention will be described.
The road feature measuring apparatus 100 calculates the position of the feature designated by the user based on the distance data, angular velocity data, positioning data, image data, and azimuth / distance data.
The road feature measurement apparatus 100 includes a vehicle position / orientation (3-axis) calculation unit 110, a camera position / orientation calculation unit 130, a camera LOS calculation unit 140, a road surface shape model generation unit 150, a laser radar position / orientation calculation unit 160, and road surface model corresponding points. A search unit 170, a feature identification device 300, an observation data input unit 191, and an observation data storage unit 199 are provided.
The vehicle position / orientation (3-axis) calculation unit 110 calculates the position and orientation of the vehicle (vehicle position / orientation) based on the distance data, the angular velocity data, and the positioning data.
The feature identification device 300 generates a three-dimensional model of a stationary object based on the image data, and generates a road surface shape model of the stationary object by comparing the three-dimensional model of the stationary object with a road surface shape model based on LRF data described later. To do. Further, the feature identifying apparatus 300 groups the laser measurement point groups constituting the road surface shape model, and identifies the type of the feature indicated by each group based on the shape formed by the laser measurement point group. In addition, the feature identifying apparatus 300 superimposes and displays the image, the road surface shape model of the stationary object, and the type of the feature to the user. Then, the feature identifying apparatus 300 inputs a position on the feature image designated by the user as a measurement image point.
The camera position and orientation calculation unit 130 calculates the position and orientation (camera position and orientation) of the camera 230 based on the vehicle position and orientation and the camera mounting offset. The camera attachment offset indicates the amount of deviation of the attachment axis of the camera 230 with respect to the vehicle axis (orthogonal coordinates). The camera mounting offset is a value corresponding to the relationship between the camera 230 and the top plate 103 in FIG.
The camera LOS calculation unit 140 (an example of a vector calculation unit) is an angle of a line-of-sight direction (LOS: Line Of Light) from the camera toward the measurement image point based on the measurement image point and the camera position and orientation specified on the image by the user. (LOS vector) is calculated.
The laser radar position and orientation calculation unit 160 calculates the positions and orientations (laser radar position and orientation) of the laser radars 240a and 240b based on the vehicle position and orientation and the laser radar attachment offset. The laser radar mounting offset indicates the amount of deviation of each of the mounting axes of the laser radars 240a and 240b with respect to the vehicle axis (orthogonal coordinates). The laser radar mounting offset is a value corresponding to the relationship between the laser radar 240a and the top plate 103 and the laser radar 240b and the top plate 103 in FIG. 2, and road surface shape model generation unit 150 in which data of each laser radar is stored. Generates a road surface shape model (three-dimensional point cloud model) indicating the shape (surface, slope, unevenness, etc.) of an uneven road surface on which the vehicle has traveled based on the azimuth / distance data and the laser radar position and orientation.
The road surface model corresponding point searching unit 170 (an example of the feature position calculating unit) calculates the position of the feature designated by the user based on the LOS vector and the road surface shape model for the measurement image point. The road surface model corresponding point searching unit 170 can calculate the feature position with high accuracy by considering the curved surface, slope, unevenness, and the like of the road surface.
Distance data, angular velocity data, positioning data, image data, and azimuth / distance data are used as observation data.
The observation data input unit 191 inputs observation data acquired by the vehicle 102 and stores it in the observation data storage unit 199.
The observation data storage unit 199 stores various data generated based on the observation data acquired by the vehicle 102, the laser radar attachment offset, the camera attachment offset, and the observation data. Each unit included in the road feature measurement device 100 and each unit included in the feature identification device 300 input data to be used from the observation data storage unit 199, perform various processes, and store the generated data in the observation data storage unit 199.
In FIG. 1, the vehicle 102 and the road feature measurement device (computer) are described as different configurations, but the road feature measurement device (computer) is included in the vehicle 102 and has one configuration. It doesn't matter.

  FIG. 3 is a schematic view of the vehicle 102 according to the first embodiment as viewed from above, and illustrates the positional relationship between the two laser radars 240a and 240b mounted on the top plate (base) of the vehicle. . In FIG. 3, the GPS 220 and the gyro 210 other than the laser radar 240 are omitted.

The laser radar 240a is provided in front of the vehicle 102, and irradiates the laser beam 4a in the scanning direction in a predetermined cycle toward the lower direction in front of the vehicle. The laser radar 240a scans the laser beam 4a in a direction substantially perpendicular to the Z axis and obliquely downward with respect to the front direction (+ Z axis (vehicle axis) direction) of the vehicle 102 (see FIG. 4).
Each of 4a_1, 4a_1,..., 4a_n is an irradiation point of the laser beam periodically irradiated on the road surface, and the laser beams are scanned in the order of 4a_1, 4a_1,. The lines (scanning lines) connecting the laser light irradiation points (4a_1, 4a_1,..., 4a_n) are substantially perpendicular to the + Z axis as described above when the road surface is flat. Become.

On the other hand, the laser radar 240b is provided at the rear of the vehicle 102, and irradiates the laser beam 4b downward in the scanning direction with a predetermined period toward the lower side of the rear of the vehicle. The laser radar 240b scans the laser beam 4a in a direction substantially perpendicular to the Z-axis and obliquely downward with respect to the rear direction of the vehicle 102 (the direction opposite to the + Z-axis (vehicle axis)) (see FIG. 4).
Each of 4b_1, 4b_1,..., 4b_n is an irradiation point of laser light periodically irradiated on the road surface, and the laser light is scanned in the order of 4b_1, 4b_1,. The lines (scanning lines) connecting the laser beam irradiation points (4b_1, 4b_1,..., 4b_n) are substantially perpendicular to the Z axis as described above when the road surface is flat. Become.

FIG. 5 is a diagram showing an example of a point group of laser irradiation points irradiated to the road surface by the laser radars 240a and 240b.
As described above, by providing a plurality of laser radars and irradiating the laser radar with the laser light on the road surface to be measured, the laser spot density can be increased.
In addition, since a plurality of laser radars are provided at the front and rear of the vehicle, the layout of the vehicle top plate on which the plurality of measurement sensors are mounted can be facilitated.

However, even in this case, unless the laser radar irradiation timing and the vehicle speed of the plurality of laser radars (laser radars 240a and 240b installed in the front and rear of the vehicle in the example of FIG. 2) are adjusted and controlled. In the spot density of the laser on the road surface, a high density place and a low place are formed.
FIG. 6 is an example of a measurement point group in which a high density place and a low place are formed. FIG. 6 shows the measurement point group (4a, 4b) when the moving speed of the vehicle is fast, and FIG. 7 shows the measurement point group (4a, 4b) when the moving speed is slow. Thus, depending on the speed, such as when the speed is high, unevenness may occur in the portion 20 where the density of the measurement points is high and the portion 21 where the density is low, as shown in the figure. Further, although the point density in the direction perpendicular to the traveling direction is high, there is a problem that the point density in the direction parallel to the traveling direction varies depending on the speed.

  FIG. 7 is another example of the vehicle 102 according to the first embodiment as viewed from above, and illustrates the positional relationship between the two laser radars 241a and 241b mounted on the top board (base). . In FIG. 7, the GPS 220 and the gyro 210 other than the laser radar 241 are omitted.

The laser radar 241a is provided in front of the vehicle 102, and irradiates the laser beam 4a in the scanning direction in a predetermined cycle toward the lower direction in front of the vehicle.
Here, the laser radar 241a scans the laser beam 4a in a direction having an angle θa with respect to the front direction of the vehicle 102 (+ Z axis (vehicle axis) direction).
Each of 4a_1, 4a_1,..., 4a_n is an irradiation point of the laser beam periodically irradiated on the road surface, and the laser beams are scanned in the order of 4a_1, 4a_1,. A line (scanning line) connecting laser light irradiation points (4a_1, 4a_1,..., 4a_n) has an angle θa with respect to the Z axis as described above.

On the other hand, the laser radar 241b is provided on the rear side of the vehicle 102 and irradiates the laser beam 4b in a predetermined direction along the scanning direction toward the lower side of the rear side of the vehicle.
Here, the laser radar 241b scans the laser beam 4b in a direction having an angle θb (≠ θa) with respect to the rear direction (−Z axis direction) of the vehicle 102.
The angle θa and the angle θb are predetermined values. For example, the angle θa and the angle θb can be set by tilting the laser radar 240 on the top plate of the vehicle. The installation conditions installed at an inclination are reflected in the laser radar installation offset.
Each of 4b_1, 4b_1,..., 4b_n is an irradiation point of laser light periodically irradiated on the road surface, and the laser light is scanned in the order of 4b_1, 4b_1,. A line (scanning line) connecting laser beam irradiation points (4b_1, 4b_1,..., 4b_n) has an angle θb (≠ θa) with respect to the −Z axis as described above.

FIG. 8 is a diagram showing a point group of laser irradiation points irradiated on the road surface by the laser radars 241a and 241b.
As shown in FIG. 8, the irradiation points of the laser radar 241a form a point group on a scanning line having an angle θa with respect to the + Z axis. Further, the irradiation point of the laser radar 241b forms a point group on a scanning line having an angle θb with respect to the −Z axis.
Here, since the angle θa and the angle θb are not equal (θa−θb ≠ 0), the scanning line of the laser radar 241a and the scanning line of the laser radar 241b are not parallel (non-parallel), and the laser radars 241a and 241b Each scanning line irradiated with a diamond shape has a diamond shape.

FIG. 9 is a diagram showing a point group of laser irradiation points similarly applied to the road surface by the laser radars 241a and 241b. Here, FIG. 9 is different in that the traveling speed of the vehicle that is mounted with the laser radars 241a and 241b is higher than that in FIG.
As shown in FIG. 9, the irradiation points of the laser radar 241a form a point group on a scanning line having an angle θa with respect to the + Z axis. Further, the irradiation point of the laser radar 241b forms a point group on a scanning line having an angle θb with respect to the −Z axis.
Here, since the angle θa and the angle θb are not equal (θa−θb ≠ 0), the scanning line of the laser radar 241a and the scanning line of the laser radar 241b are not parallel (non-parallel), and the laser radars 241a and 241b Each scanning line irradiated with a diamond shape has a diamond shape.

Comparing FIG. 9 and FIG. 8, it can be seen that even in FIG. 9 where the speed of the vehicle is high, the decrease in spot density and the uneven spot density are suppressed. In particular, when compared with the point group shown in FIG. 6, it can be seen that the unevenness of the point density is suppressed.
Thus, in the measurement vehicle of the present embodiment, even when the vehicle speed becomes high, the size of the rhombus connecting the scanning lines is only smaller than that at the normal speed (FIG. 8), On the road surface, it is difficult to make a place where the laser spot density is high or low, and uneven spot density can be suppressed.

As described above, in the measurement vehicle of the present embodiment, two laser radars are scanned at a predetermined angle θa with one laser beam 4a with respect to the front direction (+ Z axis (vehicle axis) direction) of the vehicle 102. The other unit was installed so that the laser beam 4b scans at a predetermined angle θb (θa ≠ θb) with respect to the rear direction of the vehicle 102 (−Z-axis direction). When the laser beams are installed in this way, the irradiation points of the laser beams irradiated by the two laser radars constitute a point group so as to form a rhombus.
And even if the measurement vehicle of this embodiment is a case where the vehicle moves at a high speed, the laser dot group maintains the rhombus shape, so that the target object can be removed without causing a drop in spot density or uneven spot density. It is possible to measure.

  If the angles θa and θb are not equal values, the effect of the present invention is obtained. However, if θa−θb = 90 ° is basically selected, an appropriate value is selected and set according to the situation. Good.

Embodiment 2. FIG.
In the first embodiment, the two laser radars 241a and 241b are installed near the center of the left and right of the vehicle. However, when the scanning line scanned by the laser beam is tilted as in the first embodiment, the laser radar is installed on the vehicle. You may make it install it by moving to either one from the left-right center.
FIG. 10 is a schematic view of the vehicle 102 according to the second embodiment as viewed from above, and illustrates the positional relationship between the two laser radars 242a and 242b mounted on the top board (base).
As described above, the two laser radars 242a and 242b are offset from the left and right center positions of the vehicle while being tilted, and are installed on the vehicle, thereby reducing the places where the measurement target (in this case, the road surface) is not irradiated with the laser light. be able to.

Embodiment 3 FIG.
In the first and second embodiments, two laser radars 241a and 241b are installed in the front direction of the vehicle and the other one in the rear direction of the vehicle. Two laser radars may be installed. Even when there are other measurement sensors on the vehicle top plate (base) or at the rear of the vehicle and it is difficult to install the laser radar, it is possible to efficiently reduce the spot density and uneven the spot density. It becomes possible to measure without occurring.

  In the first to third embodiments, the case where two laser radars are mounted on the vehicle has been described. Of course, three or more laser radars may be mounted, and more accurate measurement can be performed.

4a Laser point group of laser radar 204a, 4b Laser point group of laser radar 204b, 4a_1, 4a_2, ..., 4a_n Irradiation point of laser radar 204a, 4b_1, 4b_2, ..., 4b_n: Irradiation point of laser radar 204b, 102 (Vehicle), 240a 241a 242a laser radar, 240b 241b 242b laser radar, 20 high density location, 21 low density location.

Claims (5)

A measurement vehicle equipped with two or more laser radars (LRF [Laser Range Finder]) that scans laser light and obtains azimuth / distance data indicating the distance to the road surface and road features around the road surface and the direction thereof. There,
A scanning vehicle on the road surface where one laser radar scans laser light is non-parallel to a scanning line on the road surface scanned by another laser radar. The measurement vehicle according to claim 1, wherein the laser radar is a one-dimensional laser radar that scans only in one direction. 2. The measurement vehicle according to claim 1, wherein at least one laser radar is mounted on the front side and the rear side of the vehicle. 2. The scanning range in which one laser radar scans laser light while the measuring vehicle is moving overlaps the scanning range in which another laser radar scans laser light. 4. The measuring vehicle according to any one of 3 to 3. 5. The measurement vehicle according to claim 1, further comprising: a gyro that acquires angular velocity data indicating inclinations (pitch angle, roll angle, yaw angle) in three axis directions of the measurement vehicle; and the measurement vehicle. GPS (Global Positioning System) that acquires positioning data indicating the travel position of the vehicle,
A calculator that calculates the position of the road feature based on the azimuth / distance data, the angular velocity data, and the positioning data;
A road feature measurement system characterized by comprising:

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