JP2016224854A - Autonomous travel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce wrong detection by securely recognizing a state of a road surface in a travel direction.SOLUTION: An autonomous travel device comprises: a travel control part which controls a drive member; and a distance detection part which emits predetermined light to a predetermined front space in a travel direction, receives reflected light reflected by a body present in the front space and a road surface, and detects distances to the body and road surface. The distance detection part comprises a scan control part which makes a scan in the emission direction of the light so that a predetermined plurality of measurement points in the front space are irradiated with the light, and further comprises a road surface determination part which makes the scan in the emission direction of the light by the scan control part so as to determine a state of the road surface in the travel direction upon the basis of change in the number of measurement points whose distances are detected by the distance detection part within a certain time when the light irradiating the plurality of measurement points is reflected by the body and the road surface.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an autonomous traveling device, and more particularly to an autonomous traveling device that travels along a predetermined route while avoiding an obstacle or the like in order to carry an object, monitor a building periphery, or the like.

Today, autonomous traveling devices that move autonomously are used, such as a transport robot that transports luggage and a monitoring robot that monitors the situation in and around buildings and in predetermined sites.
In such an autonomous traveling device, a camera or a distance image sensor is used to detect an obstacle existing on the moving route and avoid the obstacle, and a step is detected to have a large step. I try not to enter the area.

For example, in Patent Document 1, using a distance image sensor that measures distance using reflected light from an object, obstacle detection that detects an obstacle and a floor surface based on the reflected light intensity and the measured distance is performed. A system has been proposed.
Further, in Patent Document 2, road surface data is acquired using a range sensor such as an ultrasonic sensor or a laser sensor for a floor surface region in a moving direction of a moving body, and a movable region and a non-movable region are acquired based on the road surface data. A system has been proposed in which possible areas are identified and obstacles are accurately recognized.
Furthermore, in Patent Document 3, a distance image sensor for short distance and long distance is provided, the distance to the floor surface and the obstacle obliquely below the traveling direction is measured, and the measurement distance and the plane equation are used. Distance measuring systems that detect the presence of dents and obstacles on the floor have been proposed.

JP 2009-168751 A JP 2012-220227 A JP 2014-21625 A

However, in the conventional obstacle detection system, when the autonomous traveling device travels outdoors, the detection accuracy of the obstacle changes depending on the road surface condition and the weather, and the obstacle or the step cannot be detected or erroneously detected. There was a thing.
Therefore, when traveling outdoors, it is desirable to use a detection method that does not erroneously detect an obstacle or the like even if there is a change in the condition of the road surface.
Therefore, the present invention has been made in view of the above circumstances, and provides an autonomous traveling device that can reduce road surface conditions such as steps and holes existing on the road surface and false detection of obstacles and the like. The task is to do.

  The present invention provides a traveling control unit that controls a driving member, and emits predetermined light to a predetermined front space in the traveling direction, and receives reflected light reflected by an object and a road surface existing in the front space. A distance detection unit that detects a distance to the object and the road surface, and the distance detection unit emits the light toward a plurality of predetermined measurement points in the front space. The distance detection is performed when light emitted toward the plurality of measurement points is reflected by the object and the road surface by scanning the light emission direction by the scanning control unit. An autonomous traveling device is provided, further comprising a road surface determination unit that determines a state of a road surface in a traveling direction based on a change in the number of measurement points whose distance is detected by the unit within a certain time.

  The distance detecting unit includes a light emitting unit that emits light and a light receiving unit that receives light, and a light receiving confirmation unit that confirms that the reflected light is received by the light receiving unit; A light receiving distance that is a distance between the light emitting unit and the plurality of measurement points by using a time difference between the time when the light is emitted and the time when the reflected light is confirmed to be received by the light receiving unit. A light receiving distance calculating unit that calculates a light receiving distance, and the road surface determining unit includes an object at a measurement point where the reflected light is confirmed to be received by the light receiving confirmation unit, and the reflected light is received. It is characterized in that it is determined that there is no object at a measurement point that has not been confirmed.

Further, the road surface determination unit determines that the road surface in the traveling direction is a flat road surface when the number of measurement points from which the distance is detected has hardly changed for a predetermined time or more.
In addition, when the vehicle is traveling, the road surface determination unit has a hole area on the road surface in the traveling direction when the number of measurement points where the distance is detected shows a decreasing tendency for a predetermined time or more. It is determined that it is present.
In addition, in a state where the vehicle is traveling, the road surface determination unit is configured to decrease or increase the number of stations from which the distance is detected for a predetermined time from a state in which a certain number of stations from which the distance is detected exists After showing the tendency, it is determined that the road surface in the traveling direction has changed to a road surface having a different light reflectance when there is almost no change in the number of measurement points different from the fixed number of measurement points. And
Further, the distance detection unit uses a LIDAR that emits a laser to a two-dimensional space or a three-dimensional space in a predetermined distance measurement region and measures distances at a plurality of measurement points in the distance measurement region. To do.

  According to the present invention, the measuring point whose distance is measured by using the light reflected by the object and the road surface by emitting the light while scanning toward the measuring point in the predetermined front space in the traveling direction. Since the road surface condition in the traveling direction is determined based on the change in the number of roads within a certain time, it is possible to reliably recognize the road surface condition or the like to proceed from now on, and to reduce false detections. .

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of one Example of the autonomous traveling apparatus of this invention. It is explanatory drawing of the structure relevant to driving | running | working of the autonomous running apparatus of this invention. It is a block diagram of a configuration of an embodiment of the autonomous mobile device of the present invention. It is a schematic explanatory drawing of one Example of the distance detection part of this invention. It is a schematic explanatory drawing of the scanning direction of the laser radiate | emitted from the distance detection part of this invention. It is the schematic explanatory drawing which looked at the irradiation area of the laser of this invention from the upper direction and back. It is explanatory drawing of one Example about the determination process of the road surface which the autonomous running apparatus of this invention drive | works. It is explanatory drawing of one Example about the determination process of the road surface which the autonomous running apparatus of this invention drive | works. It is explanatory drawing of one Example about the determination process of the road surface which the autonomous running apparatus of this invention drive | works. It is explanatory drawing of one Example about the determination process of the road surface which the autonomous running apparatus of this invention drive | works. It is explanatory drawing of one Example about the determination process of the road surface which the autonomous running apparatus of this invention drive | works. It is explanatory drawing of one Example of weighting of the number of measurement points. It is explanatory drawing of one Example of the weighting based on the distance difference of the horizontal direction between measurement points.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by description of the following examples.
<Configuration of autonomous traveling device>
In FIG. 1, the external view of one Example of the autonomous running apparatus of this invention is shown.
In FIG. 1, an autonomous traveling device 1 of the present invention is a vehicle having a function of autonomously moving while avoiding an obstacle based on predetermined route information.
Further, the autonomous mobile device 1 has various functions such as a transportation function, a monitoring function, a cleaning function, a guidance function, a reporting function, a road guide, and a farming function (mowing, tilling, harvesting) in addition to the moving function. Also good.
In the following embodiments, an autonomous traveling device having a monitoring function capable of autonomously traveling in a predetermined outdoor monitoring area or passage and monitoring the monitoring area or the like will be mainly described.

In the external view of FIG. 1, the autonomous traveling device 1 (hereinafter also referred to as a vehicle) mainly includes a vehicle body 10, four wheels (21, 22), a monitoring unit 2, and a control unit 3.
The monitoring unit 2 is a part having a function of confirming a moving area and a road surface state and a function of monitoring a monitoring target. For example, a distance detection unit 51 for confirming a state of a moving front space, a current traveling state It includes a position information acquisition unit 55 that acquires position information, a camera, and the like.
The control unit 3 is a part that executes a traveling function, a monitoring function, and the like of the autonomous traveling device of the present invention, and includes, for example, a control unit 50, a communication unit 58, a road surface determination unit 59, a storage unit 70, and the like as will be described later. Is done.

  In the present invention, in particular, when the distance detection unit 51 is used to self-run while checking the state of the front of the vehicle body 10 in the traveling direction, and it is detected that an obstacle, a step, a hole, etc. are present ahead. In order to prevent it from colliding with an obstacle or being stuck in a hole and becoming unable to move, the path is changed by performing operations such as rest, rotation, retreat, and forward movement.

FIG. 2 is an explanatory diagram of a configuration related to traveling of the autonomous traveling device of the present invention.
FIG. 2A is a right side view of the vehicle 1, and the right front wheel 21 and the rear wheel 22 are indicated by phantom lines. FIG. 2B is a cross-sectional view taken along the line B-B in FIG. Front wheels (21, 31) are arranged on the front surface 13 of the vehicle body 10, and rear wheels (22, 32) are arranged on the rear surface 14.
A belt-like cover 18 is installed on each side surface 12R, 12L of the vehicle body 10 and extends along the front-rear direction of the vehicle body 10. Below the cover 18 are provided axles 21a, 31a and axles 22a, 32a that rotatably support the front wheels 21, 31 and the rear wheels 22, 32, respectively. Each axle 21a, 31a, 22a, 32a is independently rotatable when not coupled by a power transmission member.

  Belts 23 and 33, which are power transmission members, are provided on the pair of front wheels (21, 31) and rear wheels (22, 32) on the left and right, respectively. Specifically, a sprocket 21 b is provided on the axle 21 a of the right front wheel 21, and a sprocket 22 b is provided on the axle 22 a of the rear wheel 22. Between the front wheel sprocket 21b and the rear wheel sprocket 22b, for example, a belt 23 provided with a protrusion that meshes with the sprocket is provided on the inner surface side. Similarly, a sprocket 31b is provided on the axle 31a of the left front wheel 31, and a sprocket 32b is provided on the axle 32a of the rear wheel 32. Between the sprocket 31b of the front wheel and the sprocket 32b of the rear wheel, As with the belt 23, a belt 33 is wound around.

Accordingly, the pair of front and rear wheels (21 and 22, 31 and 32) on the left and right sides are connected and driven by the belts (23 and 33), so that one of the wheels may be driven. For example, the front wheels (21, 31) may be driven. When one wheel is a driving wheel, the other wheel functions as a driven wheel that is driven without slipping by a belt that is a power transmission member.
As a power transmission member for connecting and driving a pair of left and right front wheels and rear wheels, in addition to using a sprocket and a belt provided with a projection that meshes with the sprocket, for example, using a sprocket and a chain that meshes with the sprocket. Also good. Furthermore, if slip is acceptable, a pulley and a belt having a large friction may be used as the power transmission member. However, the power transmission member is configured so that the rotational speeds of the driving wheel and the driven wheel are the same.
In FIG. 2, the front wheels (21, 31) correspond to drive wheels, and the rear wheels (22, 32) correspond to driven wheels.

  Two motors, an electric motor 41R for driving the right front and rear wheels 21 and 22 and an electric motor 41L for driving the left front and rear wheels 31 and 32, are provided on the front wheel side of the bottom surface 15 of the vehicle body 10. ing. A gear box 43R is provided as a power transmission mechanism between the motor shaft 42R of the right electric motor 41R and the axle 21a of the right front wheel 21. Similarly, a gear box 43L is provided as a power transmission mechanism between the motor shaft 42L of the left electric motor 41L and the axle 31a of the left front wheel 31. Here, the two electric motors 41R and 41L are arranged in parallel so as to be symmetrical with respect to the center line in the traveling direction of the vehicle body, and the gear boxes 43R and 43L are also arranged on the left and right outer sides of the electric motors 41R and 41L, respectively. It is installed.

  The gear boxes 43R and 43L are composed of a plurality of gears, shafts, and the like, and are assembly parts that transmit the power from the electric motor to the axle that is the output shaft by changing the torque, the rotation speed, and the rotation direction. A clutch for switching the shutoff may be included. The left and right rear wheels 22 and 32 are pivotally supported by bearings 44R and 44L, respectively, and the bearings 44R and 44L are disposed close to the right side surface 12R and the left side surface 12L of the bottom surface 15 of the vehicle body 10, respectively. .

  With the above configuration, the pair of front and rear wheels 21 and 22 on the right side in the traveling direction and the left and right front and rear wheels 31 and 32 can be driven independently. That is, the power of the right electric motor 41R is transmitted to the gear box 43R via the motor shaft 42R, and the rotational speed, torque, or rotational direction is changed by the gear box 43R and transmitted to the axle 21a. The wheel 21 is rotated by the rotation of the axle 21a, and the rotation of the axle 21a is transmitted to the rear shaft 22b via the sprocket 21b, the belt 23, and the sprocket 22b, and the rear wheel 22 is rotated. Transmission of power from the left electric motor 41L to the front wheels 31 and the rear wheels 32 is the same as the operation on the right side described above.

And when the rotation speed of two electric motors 41R and 41L is the same, if the gear ratio (reduction ratio) of each gearbox 43R and 43L is made the same, the autonomous mobile device 1 will move forward or backward. . When changing the speed of the autonomous mobile device 1, the gear ratios of the gear boxes 43R and 43L may be changed while maintaining the same value.
When changing the traveling direction, the gear ratios of the gear boxes 43R and 43L are changed so that the rotation speeds of the right front wheel 21 and the rear wheel 22 and the left front wheel 31 and the rear wheel 32 are rotated. It only has to make a difference. Furthermore, by changing the rotation direction of the output from each gear box 43R, 43L, the turning direction of the left and right wheels can be reversed to enable stationary turning around the vehicle body center.

  When the autonomous traveling device 1 is turned stationary, the steering mechanism for changing the angle of the front and rear wheels is not provided. Therefore, the larger the distance between the front and rear wheels (wheel base), the greater the resistance applied to the wheels. A large driving torque is required for turning. However, since the gear ratios in the gear boxes 43R and 43L are variable, a large torque can be applied to the wheels only by reducing the rotation speed of the wheels during turning.

  For example, when the gear ratio in the gear box 43R is 10 for the number of gear teeth on the motor shaft 42R, 20 for the number of teeth on the intermediate gear, and 40 for the gear on the side of the axle 21b, the rotational speed of the axle 21b Is ¼ of the rotational speed of the motor shaft 42R, but four times the torque is obtained. And, by selecting a gear ratio that further reduces the rotation speed, a larger torque can be obtained, so that it is possible to turn even on road surfaces with large resistance related to wheels such as rough terrain and sand. .

  Further, since the gear boxes 43R and 43L are provided between the motor shafts 42R and 42L and the axles 21a and 31a, vibrations from the wheels 21 and 31 are not directly transmitted to the motor shaft. Further, clutches for transmitting and disconnecting (cutting off) power are provided in the gear boxes 43R and 43L, and when the electric motors 41R and 41L are not energized, the electric motors 41R and 41L side and the axles 21a and 31a serving as drive shafts It is desirable to block power transmission between the two. As a result, even if a force is applied to the vehicle body 10 when the vehicle stops and the wheels rotate, the rotation is not transmitted to the electric motors 41R and 41L. Therefore, no back electromotive force is generated in the electric motors 41R and 41L. There is no possibility of damaging the circuits of 41R and 41L.

In this way, the left and right pair of front and rear front wheels and rear wheels are connected by a power transmission member, and the four wheels are driven so as to be driven by two electric motors arranged on the front wheel side. In addition, it is not necessary to provide a dedicated rear wheel gear box between the electric motor and the rear wheel, and the installation space for the rear wheel dedicated electric motor and gear box can be reduced. .
As described above, the two electric motors 41R and 41L are arranged on the front wheels 21 and 31 side of the bottom surface 15 of the vehicle body 10 on the left and right sides in the traveling direction, and further the gear box 43R on the left and right sides of the electric motors 41R and 41L. 43L, but only the bearings 44R and 44L are arranged on the rear wheels 22 and 32 side of the bottom surface 15. Therefore, the bottom surface 15 of the vehicle body 10 is placed on the bottom surface 15 of the vehicle body, for example, from the center position. A wide accommodation space 16 can be secured up to the end.

  Each electric motor 41R, 41L uses, for example, a battery 40 such as a lithium ion battery as a power source, and the battery 40 is installed in the accommodation space 16. Specifically, the battery 40 has a rectangular parallelepiped shape, for example, and can be placed at a substantially central position of the bottom surface 15 as shown in FIG. In addition, the rear surface 14 of the vehicle body 10 is preferably configured to be openable and closable with respect to the upper surface or the bottom surface 15, for example, so that the battery 40 can be easily inserted into and removed from the accommodation space 16. As a result, a large-capacity battery 40 for realizing long-time running can be mounted in the housing space 16 of the vehicle body 10, and work such as replacement, charging, and inspection of the battery 40 can be easily performed from the rear surface 14. It becomes possible. Furthermore, since the battery 40 can be disposed on the bottom surface 15, an electric vehicle capable of running stably with a low center of gravity of the vehicle body 10 can be obtained.

FIG. 3 shows a block diagram of a configuration of an embodiment of the autonomous traveling device of the present invention.
3, the autonomous traveling device 1 of the present invention mainly includes a control unit 50, a distance detection unit 51, a light reception confirmation unit 52, a light reception distance calculation unit 53, a camera 54, a position information acquisition unit 55, a travel control unit 56, and wheels. 57, a communication unit 58, a road surface determination unit 59, a rechargeable battery 60, and a storage unit 70.
The autonomous mobile device 1 is connected to the management server 5 via the network 6, autonomously travels based on instruction information and the like sent from the management server 5, and transmits the acquired monitoring information and the like to the management server 5.
As the network 6, any currently used network can be used. However, since the autonomous mobile device 1 is a moving device, it is possible to use a network capable of wireless communication (for example, a wireless LAN). preferable.

As a wireless communication network, the Internet open to the public or the like may be used, or a dedicated line wireless network in which devices that can be connected are limited may be used. As a wireless transmission method in a wireless communication path, various wireless LANs (Local Area Network) (with or without WiFi (registered trademark) authentication), ZigBee (registered trademark), Bluetooth (registered trademark) LE (Low Energy), etc. A method conforming to the above standard may be mentioned, and it may be used in consideration of a wireless reachable distance, a transmission band, etc. For example, a mobile phone network may be used.
The management server 5 mainly includes a communication unit 91, a monitoring control unit 92, and a storage unit 93. The communication unit 91 is a part that communicates with the autonomous mobile device 1 via the network 6 and preferably has a wireless communication function.
The monitoring control unit 92 is a part that executes movement control for the autonomous traveling device 1, information collection function and monitoring function of the autonomous traveling device 1, and the like.
The storage unit 93 stores information for instructing movement to the autonomous mobile device 1, monitoring information (reception monitoring information 93a, etc.) sent from the autonomous mobile device 1, a program for monitoring control, and the like. It is.

The control unit 50 of the autonomous mobile device 1 is a part that controls the operation of each component such as the travel control unit 56, and is mainly realized by a microcomputer including a CPU, a ROM, a RAM, an I / O controller, a timer, and the like. The
The CPU organically operates various hardware based on a control program stored in advance in a ROM or the like, and executes the traveling function, the road surface determination function, and the like of the present invention.

The distance detection unit 51 is a part that detects the distance from the current position of the vehicle to the object and the road surface existing in the forward space in the traveling direction. Here, when the vehicle travels outdoors, the object is, for example, a three-dimensional object such as a building, a pillar, a wall, a protrusion, a rock, a parked car, a human, an animal, or a traveling vehicle. means.
The distance detection unit 51 emits predetermined light to a predetermined front space in the traveling direction, and then receives the reflected light reflected by the object and the road surface existing in the front space, and detects the distance to the object and the road surface. . Specifically, the distance detecting unit 51 mainly determines a light emitting unit 51a that emits light, a light receiving unit 51b that receives light reflected by an object, and a light emitting direction in two or three dimensions. And a scanning control unit 51c to be changed.

FIG. 4 shows an explanatory diagram of an embodiment of the distance detector 51 of the present invention.
Here, the laser 51d emitted from the light emitting unit 51a is reflected by the object 100, and a part of the laser that has returned back and forth by the light receiving distance L0 is received by the light receiving unit 51b.

Lasers, infrared rays, visible light, ultrasonic waves, electromagnetic waves, and the like can be used as radiated for sensing, but it is preferable to use lasers because of high weather resistance and high ranging accuracy. .
Also, today, LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging: rider) is used as a distance detection sensor, but this may be used as the distance detection unit 51.
The LIDAR is a device that emits a laser to a two-dimensional space or a three-dimensional space in a predetermined distance measurement region and measures distances at a plurality of measurement points in the distance measurement region.
The LIDAR detects the reflected light reflected by the object after the laser is emitted from the light emitting unit 51a, and calculates the light receiving distance L0 from the time difference between the emission time and the light receiving time, for example.

If the laser emitted from the light emitting unit 51a hits a non-moving object separated by a distance L0, the laser beam travels by a distance (2L0) corresponding to twice the distance L0 from the tip of the light emitting unit 51a to the object surface. Light is received by the light receiving portion 51b.
The time when the laser is emitted and the time when the laser is received are shifted by a time T0 required for the laser to travel the distance (2L0). That is, there is a time difference. By using the time difference T0 and the speed of light, the light receiving distance L0 can be calculated.

FIG. 4 shows a case where the distance detecting unit 51 is not moved, and shows a case where the laser emitted from the light emitting unit 51a travels on the same optical path.
Therefore, when the reflected light reflected by one point of the object 100 is received, only the distance between the tip of the light emitting unit 51a and one point of the object is calculated.

The scanning control unit 51c is a part that scans the light emission direction so that light is emitted toward a plurality of predetermined measurement points in the front space in the traveling direction, and changes the direction of the distance detection unit 51 at regular intervals. By gradually changing, the optical path along which the emitted laser travels is moved little by little.
The LIDAR 51 calculates the distance to the object by changing the laser emission direction by a predetermined scanning pitch within a predetermined two-dimensional space in the horizontal direction (horizontal two-dimensional scanning). When calculating the distance three-dimensionally, the laser emission direction is changed by a predetermined scanning pitch in the vertical direction, and the above two-dimensional scanning in the horizontal direction is further performed to calculate the distance.

FIG. 5 is a schematic explanatory diagram of the scanning direction of the laser emitted from the distance detection unit (LIDAR) 51.
FIG. 6 shows a view of the irradiation region of the laser emitted from the distance detector (LIDAR) 51 (FIG. 6A) and a view seen from the rear (FIG. 6B). Show.
In FIG. 5, one point indicates a position (hereinafter referred to as a measurement point) where the laser hits on a two-dimensional plane (vertical plane) in a vertical direction at a position separated by a predetermined distance.

For example, when the direction of the distance detection unit 51 is changed so that the emission direction of the laser emitted from the light emitting unit 51a of the distance detection unit 51 is moved to the right by a predetermined scanning pitch in the horizontal direction, the laser is moved in the horizontal direction. It hits the vertical plane of the next position (measurement point) shifted to the right by the scanning pitch.
If an object exists at the position of the vertical plane, a part of the reflected light of the laser reflected at each measurement point is received by the light receiving unit 51b.
In this manner, when the laser irradiation direction is shifted sequentially by a predetermined scanning pitch in the horizontal direction, the laser is irradiated to a predetermined number of measurement points. As described above, the distance is calculated by confirming whether or not the reflected light is received at each of the plurality of measurement points.

FIG. 6A shows an explanatory diagram of an example in which the laser irradiation direction is shifted in the horizontal direction by the scanning pitch and the laser is scanned in the left-right direction (that is, the horizontal direction) in the figure.
For example, as shown in FIG. 6A, when the laser is irradiated in the rightmost direction, if there is an object in that direction, the light receiving distance L0 is calculated by receiving the reflected light from the object. The

Further, as shown in FIG. 5, when the laser scanning direction is the vertical direction, for example, when the laser emission direction is shifted upward by a predetermined scanning pitch in the vertical direction, the laser is vertical. It hits the vertical plane of the next position (measurement point) shifted in the upward direction by the scanning pitch.
After shifting the laser emission direction by one scanning pitch in the vertical upward direction, as shown in FIG. 6A, if the laser irradiation direction is shifted in the horizontal direction, the laser beam is shifted upward by 1 from the previous measurement point. A laser beam is irradiated to a measurement point at a position shifted by the scanning pitch.
In this way, by sequentially performing a horizontal laser scan and a vertical laser scan, the laser is irradiated to a predetermined three-dimensional space, and if an object exists in the three-dimensional measurement space, The distance to the object is calculated.

In the two-dimensional scanning, the laser scanning direction is described as the horizontal direction, but the present invention is not limited to this, and the laser emitting direction may be changed in the vertical direction.
When irradiating a laser to a three-dimensional measurement space, after performing two-dimensional scanning in the vertical direction, the same two-dimensional scanning in the same vertical direction may be sequentially performed by shifting the scanning direction by a predetermined scanning pitch in the horizontal direction.

FIG. 6B is a schematic explanatory diagram of laser measurement points irradiated on the three-dimensional space when the laser is scanned in the horizontal direction and the vertical direction.
If there is no object in the direction of one measuring point where the laser is emitted, the laser travels on the optical path as it is, the reflected light is not received, and the distance cannot be measured.
Conversely, when reflected light is received with respect to a laser emitted to a certain measurement point, a distance is calculated, and it is recognized that an object exists at a position separated by the calculated distance.
FIG. 6B shows that reflected light is detected at the six measurement points in the lower right part, and that some object (such as an obstacle) exists in the area including these six measurement points. Is recognized.

When the laser 51d is incident on the light receiving unit 51b of the distance detecting unit 51, an electrical signal corresponding to the received light intensity of the laser is output.
The light receiving confirmation unit 52 is a part for confirming that the reflected light is received by the light receiving unit 51b. Specifically, when the laser 51d is received by the light receiving unit 51b, the electricity output from the light receiving unit 51b. Check the signal.
For example, when an electrical signal having an intensity equal to or greater than a predetermined threshold is detected, it is determined that the laser has been received, and the control unit 50 is notified that the laser has been received.
Conventionally used laser light emitting elements are used for the light emitting part 51a, and laser light receiving elements for detecting a laser are used for the light receiving part 51b.

The light reception distance calculation unit 53 uses the time difference T0 between the emission time of the laser emitted from the light emitting unit 51a and the light reception time when it is confirmed that the reflected light is received by the light receiving unit 51b. This is a part for calculating a light receiving distance L0 which is a distance between a plurality of measurement points.
For example, when the control unit 50 obtains the current time using a timer and the laser emission time and the light reception time when the light reception confirmation unit 52 confirms the light reception are given to the light reception distance calculation unit 53, the light reception distance calculation unit 53 receives the light. The distance calculation unit 53 calculates the light receiving distance L0 using the time difference T0 between the two times and the laser speed. The functions of the light reception confirmation unit 52 and the light reception distance calculation unit 53 are executed mainly by the CPU performing software processing based on a predetermined program.

The camera 54 is a part that mainly captures an image ahead of the vehicle in the traveling direction, and the image to be captured may be a still image or a moving image. The captured image is stored as input image information 73 in the storage unit 70 and transferred to the management server 5 as necessary.
Further, not only one camera but also a plurality of cameras may be provided. For example, four cameras may be fixedly installed to shoot the front, left, right, and rear of the vehicle body, and the shooting direction of each camera may be changed. You may prepare.
Further, when the vehicle travels outdoors, when the weather is good and the photographing area is sufficiently bright, the state of the obstacle or the road surface may be detected by analyzing an image photographed by the camera.

The position information acquisition unit 55 is a part for acquiring information (latitude, longitude, etc.) indicating the current position of the vehicle. For example, the current position information 74 is obtained by using GPS (Global Position System). You may get it.
While comparing the acquired current position information 74 with the route information 75 stored in advance in the storage unit 70, the direction in which the vehicle should travel is determined and the vehicle is allowed to travel autonomously.
In order to make the vehicle autonomously travel, it is preferable to use information obtained from all of the above-described distance detection unit 51, camera 54, and position information acquisition unit 55, or use information obtained from at least one of them. May be autonomously driven.
In particular, even when the weather is bad and a clear image cannot be captured by the camera, or even when a GPS signal cannot be received, by calculating the light reception distance from the information acquired by the distance detection unit 51, any object (failure) If there is a thing, a person, etc.) or there is a step or hole on the road surface, and if it is not appropriate to go straight, change the course from the information of the position where the detected step exists Can do.
Further, as the position information acquisition unit 55, other satellite positioning systems currently used may be used as in the case of GPS. For example, using Japan's Quasi-Zenith Satellite System (QZSS), Russian GLONASS (Global Navigation Satellite System), EU Galileo, China Hokuto, India IRNSS (Indian Regional Navigational Satellite System) May be.

The traveling control unit 56 is a part that controls the driving member, and mainly controls the rotation of the wheels 57 corresponding to the driving member to cause the vehicle to automatically travel by causing a linear traveling, a rotating operation, and the like. The drive member includes a wheel, a caterpillar and the like.
The wheel 57 corresponds to four wheels (21, 22, 31, 32) as shown in FIGS.
Further, as described above, of the wheels, the left and right front wheels (21, 31) may be drive wheels, and the left and right rear wheels (22, 32) may be driven wheels that are not rotationally controlled.
In addition, encoders (not shown) are provided on the left and right wheels of the drive wheels (21, 31), respectively, and the travel distance of the vehicle is measured by the rotation speed, rotation direction, rotation position, and rotation speed of the wheels to control traveling. May be.

The communication unit 58 is a part that transmits / receives data to / from the management server 5 via the network 6. As described above, it is preferable to have a function of connecting to the network 6 by wireless communication and communicating with the management server 5.
The road surface determination unit 59 is a part that determines the state of the road surface in the direction in which the vehicle is to travel by using the acquired various information.
That is, when the light emitted toward a plurality of measurement points is reflected by the object and the road surface by scanning the light emission direction by the scanning control unit 51c, the distance detection unit 51 detects the distance. Based on the change in the score within a certain period of time, it is determined whether the road surface is in the traveling direction and the object is present in the traveling direction.

Since the distance is measured for the measurement point where it is confirmed that the reflected light is received by the light reception confirmation unit 52, it is determined that some object or road surface exists in that direction. Further, since a distance is not measured for a measurement point where it is not confirmed that the reflected light has been received, it is determined that there is no object or road surface.
For example, there are obstacles on the road surface in the direction of travel based on the presence or absence of the measurement distance, the position of the measurement point where the distance was measured, and the change in the number of measurements where the distance was measured. It is determined whether there is a step or a hole on the road surface.
The function of the road surface determination unit 59 is mainly executed by the CPU performing software processing based on a predetermined program.

The rechargeable battery 60 is a part that supplies power to each functional element of the vehicle 1, and is a part that mainly supplies power for performing a travel function, a distance detection function, a road surface determination function, and a communication function.
For example, rechargeable batteries such as lithium ion batteries, nickel metal hydride batteries, Ni-Cd batteries, lead batteries, and various fuel cells are used.
In addition, a battery remaining amount detection unit (not shown) is provided to detect the remaining capacity (battery remaining amount) of the rechargeable battery, and whether or not to return to a predetermined charging facility based on the detected battery remaining amount. When the remaining battery level is less than the predetermined remaining level, the battery may be automatically returned to the charging facility.

  The storage unit 70 is a part that stores information and programs necessary for executing each function of the autonomous mobile device 1, and includes a semiconductor storage element such as a ROM, a RAM, a flash memory, a storage device such as an HDD, an SSD, Other storage media are used.

  In the storage unit 70, for example, measurement distance information 71, detection point information 72, input image information 73, current position information 74, route information 75, transmission monitoring information 76, and the like are stored.

The measurement distance information 71 is the light reception distance L 0 calculated by the light reception distance calculation unit 53. One light receiving distance L0 means a distance measured at one measuring point in a predetermined distance measuring region.
The detected measurement point information 72 stores the light receiving distance L0 at each measurement point belonging to a predetermined distance measurement region, and is stored in association with the position information of each measurement point. For example, when there are m measuring points in the horizontal direction and n measuring points in the vertical direction, the light receiving distances L0 corresponding to the total of m × n measuring points are stored.

  In addition, if there is an object (obstacle, road surface, pillar, etc.) that reflects the laser in the direction of each measurement point and the reflected light from the object can be received, the light receiving distance L0 to that object is stored. The However, since no reflected light is received when there is no object in the measuring point direction, for example, information indicating that measurement could not be performed is stored as the detected measuring point information 72 instead of the light receiving distance L0.

  Further, since the vehicle 1 is normally moving, the laser is emitted into a predetermined distance measurement region at a constant time interval while moving. For example, when there are m × n measuring points in the distance measurement region, the laser is scanned in the horizontal direction and the vertical direction while moving, and at a certain time interval, the m × n measuring points are measured. The light receiving distance L0 is measured.

The light receiving distances L0 at m × n measuring points measured in a certain time zone are stored in the storage unit 70, and this m × n light receiving distances L0 are referred to as detection measuring point information of one frame. . For example, if m × n light receiving distances L0 at a certain time T1 are stored as the detected station information 72 of the T1 frame, then at a time T2 (= T1 + Ta) after a certain time (Ta) has elapsed. The m × n light receiving distances L0 are stored as the detected station information 72 of the T2 frame.
As will be described later, the detected station information 72 is used for road surface state determination processing, obstacle detection processing, mapping of the surrounding environment, obstacle avoidance, and the like.

  The input image information 73 is image data taken by the camera 54. When there are a plurality of cameras, it is stored for each camera. The image data may be either a still image or a moving image. The image data is used to determine the course of the vehicle and is transmitted to the management server 5 as one of the transmission monitoring information 76.

  The current position information 74 is information indicating the current position of the vehicle acquired by the position information acquisition unit 55. For example, it is information consisting of latitude and longitude acquired using GPS. This information is used, for example, to determine the course of the vehicle.

  The route information 75 is stored in advance as a map of a route on which the vehicle should travel. For example, when the route and area to be moved are fixedly determined in advance, the route information 75 is stored as fixed information from the beginning. However, when it is necessary to change the route, information transmitted from the management server 5 via the network 6 may be stored as new route information.

  The transmission monitoring information 76 is various monitoring information acquired during traveling, and is information transmitted to the management server 5 via the network 6. This information includes, for example, image data taken by the camera 54, moving image data, terrain data, obstacle data, road surface information, warning information, and the like.

<Example of road surface determination processing>
FIGS. 7 to 11 are explanatory views of an embodiment of the road surface determination process in the autonomous mobile device of the present invention.
(Embodiment 1)
Here, a case where the number of measurement points whose distances are detected by the distance detection unit 51 has hardly changed for a predetermined time or more and it is determined that the road surface in the traveling direction is a flat road surface is shown.
FIG. 7 shows an explanatory diagram of a state where a flat road surface that normally travels is detected.
FIG. 7A shows a case where the autonomous traveling device 1 travels rightward on a flat road surface. In addition, a laser is emitted to a distance measurement region (laser irradiation range) including a road surface ahead in the traveling direction by LIDAR which is the distance detection unit 51. When the laser hits an object such as an obstacle or road surface in the distance measurement area, the laser beam is reflected by the object, and a part of the reflected light returns to the LIDAR and is received.

The light reception distance L0 measured for all the measurement points in the distance measurement area at a certain time is stored as detection measurement information 72 of one frame. As described above, when the object does not exist at the position corresponding to the measurement point, the light receiving distance L0 is not measured. However, when the object exists at the position corresponding to the measurement point, the laser reflected from the measurement point is not detected. Since the light is received, the light receiving distance L0 is measured.
Therefore, the number of measurement points at which the light receiving distance L0 is measured for one frame (referred to as the number of measurement points CN in the distance measurement area) is counted. As shown below, in this invention, the state of the road surface is determined by using the number CN of measurement points in the distance measurement area.

FIG. 7B shows a relationship graph between the number of measurement points CN in the distance measurement region and the frame.
Since one frame shows one time zone of a distance measured at a certain time interval, the horizontal axis in FIG. 7B corresponds to time. Moreover, the vertical axis | shaft of FIG.7 (b) is the number CN of points in a distance measurement area | region.
In FIG. 7B, when the vehicle 1 is traveling on a flat road surface, the reflected light obtained from the distance measurement region irradiated with the laser is considered to be approximately the same, so the light receiving distance L0. The number of measurement points CN at which is measured is almost the same in every frame.

  For example, as shown in FIG. 7B, the number of measurement points CN is approximately 200 for all frames. Therefore, the road surface determination unit 59 creates a graph as shown in FIG. 7B using the stored detected station information 72, and when the station number CN does not change in a certain number of consecutive frames, Alternatively, when the change in the number of measurement points CN is within a predetermined threshold width W, it is determined that the currently running road surface is a “flat road surface”.

(Embodiment 2)
Here, in the state where the vehicle is traveling, when the number of measurement points from which the distance is detected shows a decreasing tendency for a predetermined time or more, and there is a hole area on the road surface in the traveling direction A case of determination will be described.
FIG. 8 is an explanatory diagram of a road surface detection state when a hole is present on the road surface in the traveling direction.
FIG. 8A shows a case where a hole region exists on the road surface in the direction in which the vehicle travels.
At this time, when the emitted laser is scanned in the vertical direction, there are a state where a road surface is detected and a state where a hole region is detected.
As in FIG. 7, when a flat road surface is detected, reflected light from the road surface is received, so that a predetermined number of measurement points can be obtained per frame.
However, when the laser is irradiated to the hole region, the laser proceeds as it is toward the hole, so that the reflected light cannot be obtained or only the reflected light having a weak reflected light intensity can be obtained.

As shown in FIG. 8 (a), when a hole area exists in the laser irradiation range, the reflected light is received by the laser reflected on the road surface, but the reflected light by the laser traveling toward the hole area is obtained. The number of measurement points at which the distance per frame is measured is smaller than the number of measurement points measured on a flat road surface.
Assuming that the vehicle 1 is moving in the direction of the hole area, the number of measurement points at which the distance can be measured gradually decreases, and if the entire laser irradiation range becomes the hole area, almost no reflected light can be obtained. Therefore, the number of stations is almost zero.
FIG. 8B shows a change in the number of measurement points in the distance measurement area for each frame when a hole area exists in the traveling direction as described above.

In FIG. 8B, since the number of measurement points CN is constant at approximately 200 until around 11 frames, it is determined that the vehicle is traveling on a flat road surface.
After that, after 11 frames, the number of measurement points CN gradually decreases, and the number of measurement points is almost zero around 26 frames.
That is, during traveling, when the number of measurement points CN decreases and becomes zero as a certain time elapses, it is determined that a hole is present on the road surface in the traveling direction.
If there is a hole, if the vehicle continues to run as it is, it may get stuck in the hole and become unable to move. For example, when a decreasing tendency of the number of measurement points is detected from frame 11 to frame 21, the traveling direction It is determined that there is a hole in the immediate vicinity, and the travel is stopped immediately at the time of the frame 22 instead of proceeding to the 26th frame. Alternatively, when the distance of the frame 22 is measured, the advancing direction may be changed so as to avoid the front hole, or it may be returned to the original direction after rotating.

(Embodiment 3)
FIG. 9 is an explanatory diagram of a road surface detection state when a convex step exists on the road surface in the traveling direction.
FIG. 9A shows a case where the front wheel of the vehicle 1 rides on a convex step.
In this case, the irradiation range of the laser emitted from the LIDAR 51 is slightly upward as compared to traveling on a flat road surface. The higher the height of the step, the more the laser irradiation range will be directed upward, and the number of lasers that will hit and reflect the road surface will be reduced, so that the road surface will be less likely to be detected.
Therefore, since the reflected light from the road surface becomes difficult to be received, the number of measurement points CN decreases.
If the step is flat in the direction of travel after the vehicle has climbed the step and is long enough for both the front and rear wheels to ride, the laser irradiation range will be the same as when traveling on a flat road surface. The score CN increases, and the number is the same as when traveling on a flat road surface.

Furthermore, if the vehicle travels, the front wheels descend from the step, and only the rear wheels are on the step, the car body tilts forward, so the laser irradiation range is when driving on a flat road surface. Compared to the downward direction.
Therefore, since more road surfaces are included in the laser irradiation range, it becomes easier to detect the road surface, and more reflected light reflected by the road surface is received, so that it travels on a flat road surface. The number of measurement points CN increases as compared with the case where there is.
After that, when the rear wheel descends from the step, if the road surface is flat, the number of measurement points CN is almost the same as when traveling on a flat road surface.

FIG. 9B shows an example of a change in the number of measurement points from when the vehicle has climbed the step as described above until it gets off the step.
As shown in FIG. 9B, the number of measurement points CN decreases from around frames 6 to 8, and then the number of measurement points CN increases until around frame 12.
When such a change in the number of measurement points CN is detected, it is determined that there is a step on the road surface and the vehicle has climbed the step.
In addition, after that, once it is detected that the number of measurement points CN becomes a constant value, the number of measurement points CN increases from frame 18 to around 23, and that the number of measurement points CN again becomes a constant value after frame 24. It is determined that the road surface has changed to a flat road surface again after the vehicle has passed the step.

When the change in the number of measurement points CN as shown in FIG. 9 (b) is measured, it is detected that there is a convex step on the road surface. continue.
The height of the step can be detected by utilizing the change in the number of measurement points.
If the detected step height is about 7 cm and the step is lower than the predetermined height that can be traveled, the travel may be continued as it is, but conversely, the step is higher than the predetermined height. If it is determined that there is, the traveling may be stopped, or the driving wheel may be reversely rotated to return to the original direction.

(Embodiment 4)
FIG. 10 shows an explanatory diagram of a road surface detection state when there is a concave step on the road surface in the traveling direction.
FIG. 10A shows a case where there is a concave step region in front of the traveling direction.
The laser emitted toward the concave step region hits the surface of the step, but travels a longer distance than a flat road surface.
Therefore, even if there is reflected light that hits the step and returns, the intensity of the laser is considered to be small, and reflected light having an intensity smaller than a predetermined threshold intensity is received by the light receiving unit 51b. Even if the light is received, the light reception confirmation unit 52 does not determine that the reflected light has been received.
That is, when it is determined that there is no reflected light, the laser that hits the concave stepped region is determined as a measuring point where the distance could not be measured.
Therefore, as the vehicle travels toward the stepped region, more stepped regions are included in the laser irradiation range, so the number of measured points CN is gradually greater than the number of measured points measured on a flat road surface. It will decrease to.

After that, if the vehicle proceeds on the stepped area as it is and becomes a flat road surface over the step, the number of measurement points CN gradually increases, and the laser irradiation range includes only the flat road surface including no step. In this case, the number of measurement points CN is almost the same as the number of measurement points measured on a flat road surface.
FIG. 10B shows an example of the change state of the number of measurement points when there is a concave stepped region in the traveling direction as described above.

As shown in FIG. 10B, the number of measurement points CN gradually decreases from the frames 9 to 17 as the stepped region is included in the laser irradiation range.
Thereafter, when the vehicle travels, the stepped region deviates from the laser irradiation range, and more flat road surfaces are detected, the number of measurement points CN increases from frame 17 to around 26.
Thus, when the tendency which increases after the number of measurement points decreases and becomes a fixed number is detected, it is determined that the vehicle has traveled a concave step and the road surface has changed to a flat road surface again.

(Embodiment 5)
Here, after the vehicle is running, after a certain number of points from which distance has been detected exists, the number of points from which distance has been detected has been decreasing or increasing for a predetermined time. The case where it is determined that the road surface in the traveling direction has changed to a road surface having a different light reflectivity when there is almost no change in the number of measurement points different from the predetermined number of measurement points will be described.
FIG. 11 is an explanatory diagram of a road surface detection state when the road surface is flat but the vehicle travels toward a road surface having a different reflectance.
In FIG. 11 (a), the reflectance of the laser on the road surface on the left side and the road surface on the right side is greatly different with respect to the traveling direction of the vehicle, and the road surface on the right side is the road surface on the left side. It is assumed that the reflectance is smaller than that.

For example, it is assumed that the road surface on the left side is a road surface mainly made of a stone material having small irregularities on the surface, and the road surface on the right side is a road surface obtained by flattening the surface like marble.
In this case, even if the distance from the LIDAR 51 is the same, the left road surface is more uneven, so that a large amount of reflected light returns toward the LIDAR 51 and is easily received, but the right road surface has little reflected light itself. Alternatively, it is considered that there is little reflected light returning in the direction of LIDAR 51 even if there is reflected light.
Thus, when there is a change in the road surface state, the number of measurement points changes when the vehicle travels near the boundary between the two road surfaces.

As shown in FIG. 11B, when only the left flat road surface is detected, a larger fixed number of measurement points CN is measured up to around frame 6.
However, when the vehicle travels to the vicinity of the boundary between both road surfaces, the flat road surface with a small reflectance on the right side is included in the laser irradiation range, so that the reflected light detected in the frames 6 to 11 decreases. As a result, the number of measurement points CN also tends to decrease.
Further, when the vehicle travels in the right direction, the left road surface is not detected, and only the right flat road surface is detected, for example, the decrease in the number of measurement points CN stops after the frame 11 and the left side. The measurement number CN having a substantially constant value, which is smaller than the number of measurement points measured on the road surface, is measured.

As shown in FIG. 11 (b), the flatness of the road surface does not change, but when the reflectance of the road surface on which the vehicle travels changes, the number of measurement points CN changes, and after a certain time has elapsed, The number of measurement points CN becomes a substantially constant value.
When a change in the number of measurement points CN as shown in FIG. 11B is detected, it is determined that the flatness is the same, but the road surface state is different.
Thus, by detecting that the state of the road surface has changed, it is possible to detect that the vehicle has traveled to an area including the road surface that should not travel.
FIG. 11B shows a case where the traveling road surface is changed from a road surface having a slightly high light reflectance to a road surface having a slightly low reflectance. On the contrary, the number of measurement points from which the distance is detected is as follows. When the number of measurement points reaches a certain number after showing an increasing tendency, it is determined that the road surface on which the vehicle travels has changed from a road surface with a slightly low light reflectance to a road surface with a slightly high reflectance.

Road conditions and obstacles can be determined by analyzing the images taken with the camera, but if it is raining or snowing, there are holes in the images taken with the camera. Such a road surface state may not be determined.
When the road surface state cannot be determined from the image from the camera, the determination of the road surface state using distance detection is an effective means because the influence of the change in weather is small as in the present invention.
However, in order to determine the state of the road surface in more detail and accurately, it is preferable to make a comprehensive determination using both distance detection and a camera image.

(Embodiment 6)
In the above embodiment, the number of measurement points at the position where the distance is measured is counted. However, when counting the number of measurement points, the number of measurement points themselves may be weighted corresponding to the position of the measurement point.
That is, when the distance is measured at a position N, when counting the number of points, the number of the position N is counted as “1”. For example, the weight of the position N is “1.5”. In this case, the number of measurement points at the position N is counted as 1.5.
That is, assuming that the weighting factor is K1, the weighting factor K1 is used instead of 1 when the value of the weighting factor K1 is changed for each position of the station and the number of stations is counted.
In this way, if the count value of the number of measurement points is weighted according to the position of the measurement point, the detection sensitivity can be easily changed by changing the setting of the weighting coefficient. There is an advantage that it is easy to accurately detect the shape.
For example, when the road surface on which the vehicle travels is considered as the reference plane, and the position of the measurement point is higher than the road surface, the weight coefficient K1 of the measurement point is set to a numerical value greater than 1, and the position of the measurement point is the road surface. If the height is the same, K1 = 1, and if the position of the measuring point is lower than the road surface, K1 <1.

FIG. 12 is an explanatory diagram of an embodiment of weighting of the number of measurement points.
FIG. 12A shows that the weighting reference plane is the road surface.
FIG. 12B shows a graph of an example showing the relationship between the weighting factor K1 and the height of the measuring point. The horizontal axis of the graph is the weighting factor K1, the vertical axis indicates the height of the station, and the higher the station is, the larger the weighting factor K1 is set in proportion to the station height. Is shown.
That is, the weighting factor K1 of the station existing above the road surface is made larger than 1, and the weighting factor K1 of the station existing below the road surface is made smaller than 1.

Here, since the distance from the light emitting unit to the measuring point is calculated, the height of each measuring point is calculated by converting the direction and distance data of the laser emitted from the light emitting unit into XYZ coordinates. It can be obtained by paying attention to the coordinates.
When such weighting is adopted, for example, since the station existing in the hole is at a position lower than the road surface, a weighting coefficient K1 smaller than 1 is used as the number of stations, and no weighting is performed. Is counted as a smaller number of stations.
As a result, when the number of measurement points is weighted, the detection sensitivity can be set freely for each height depending on how the weighting coefficient is set, compared to when weighting is not performed. Can be detected. For example, when the deceleration rate is set in proportion to the count value, traveling is easily interrupted if it is always stopped when a hole is detected. On the other hand, the weight reduction makes it possible to control the body more smoothly if the shallow hole has a smaller deceleration rate and a deeper hole is set larger.
Here, the deceleration rate is a rate at which the speed is suppressed with respect to the raw speed command to the travel control unit, and travel speed = deceleration rate × raw speed command.

(Embodiment 7)
In the sixth embodiment, the case where the number of measurement points where the distance is measured is weighted and the weighting coefficient K1 is made different according to the height of the measurement points is shown.
Here, a case will be described in which weighting corresponding to a difference in distance between measurement points is performed in the forward direction (depth direction) in which the vehicle travels.
When scanning the laser in the vertical direction while running on a flat road surface, if the light emitting portion 51a is shifted upward by a predetermined pitch, the linear distance from the light emitting portion 51a to the laser hitting the road surface becomes long. The distance measured by the reflected light that hits the road surface and becomes longer is longer.

FIG. 13 shows an explanatory diagram of an embodiment of weighting based on a distance difference measured at a traveling point in the forward direction.
FIG. 13A shows a case where the vehicle travels in the right direction, and the difference in the horizontal direction (L1 to L8) between the position of each measurement point (P1 to P9) and the adjacent measurement points. Is shown.
The distance from the light emitting part measured at the measurement point P1 closest to the vehicle to the measurement point P1 is the shortest, and the distance from the light emission part measured at the measurement point P9 farthest from the vehicle to the measurement point P9 is the longest.

As shown in FIG. 13 (a), there is a hole area, and the points P1 to P4 were the same height as the road surface, but the points P5, P6 and P7 were in the hole area. Suppose that the position is lower than the road surface.
At this time, if the scanning pitch in the vertical upward direction is a constant value, the horizontal distance difference between the adjacent measurement points becomes longer in principle, but the measurement point P4 on the road surface and the measurement in the hole area. The horizontal distance difference L4 from the point P5 is considerably longer than when the measurement point P5 is on the road surface.
Further, as the depth of the hole increases, the position of the measurement point in the hole region shifts to the right in the drawing, so that the horizontal distance difference from the previous measurement point becomes longer.
In FIG. 13 (a), the measurement points P5 and P6 exist in the hole region, but the horizontal distance difference L5 between the measurement points P5 and P6 indicates that there is no hole region and the measurement points P5 and P6. Is longer than the distance difference in the horizontal direction when it is assumed that it is on the road surface.

Therefore, as shown in FIG. 13B, weighting is applied to the horizontal distance difference between adjacent measurement points.
FIG.13 (b) has shown the example of the relationship graph of the weighting coefficient K2 and the distance difference of the horizontal direction between adjacent measuring points.
The horizontal axis of FIG.13 (b) shows the weighting coefficient K2, and the vertical axis | shaft has shown the distance difference Ln (L1-L8) of the horizontal direction.
Here, when the distance difference Ln is zero, the weighting factor K2 is 1, and the weighting factor K2 is proportionally increased as the distance difference Ln increases.
In the case of FIG. 13A, the weighting coefficient K2 is obtained for each of the eight horizontal distance differences (L1 to L8) calculated for the nine measuring points based on the graph of FIG. 13B. , Evaluation value = distance difference × weighting coefficient (K2).
In the case of FIG. 13A, the evaluation values obtained from the eight distances (L1 to L8) vary greatly between the measurement points L4 and L5, and the evaluation values increase at the measurement points L5 and L6. At the subsequent measuring points L7 and L8, the distance difference is small, and the evaluation value is conversely small.
On the other hand, when weighting is not performed, it is just a count of the measuring points, so the same deceleration rate is obtained no matter how deep the hole is. That is, when weighting is not performed, the deceleration rate is constant even for deep holes, whereas when weighting is performed as described above, the deceleration rate changes depending on the weighting. When we approach the same terrain by comparing the case of counting only the stations that have entered the detection area with the case of entering the detection area and having a count weight based on the distance difference evaluation value Since it can be seen that the method of deceleration in the distance vs. speed graph has changed, weighting has the effect that the deceleration rate can be changed according to the depth of the hole.
As described above, in addition to the change in the number of measurements, the evaluation value as described above is calculated, and by examining the change tendency of the evaluation value, it is easier and clearer in which part the hole region exists, Can be detected.

DESCRIPTION OF SYMBOLS 1 Autonomous traveling apparatus, 2 Monitoring unit, 3 Control unit, 5 Management server, 6 Network, 10 Car body, 12R Right side, 12L Left side, 13 Front, 14 Rear, 15 Bottom, 16 Storage space, 18 Cover, 21 Front wheel, 21a axle, 21b sprocket, 22 rear wheel, 22a axle, 22b sprocket, 23 belt, 31 front wheel, 31a wheel, 31b sprocket, 32 rear wheel, 32a wheel, 32b sprocket, 33 belt, 40 battery, 41R electric motor, 41L electric motor Motor, 42R motor shaft, 42L motor shaft, 43R gear box, 43L gear box, 44R bearing, 44L bearing, 50 control unit, 51 distance detection unit (LIDAR), 51a Light part, 51b Light receiving part, 51c Scan control part, 52 Light reception confirmation part, 53 Light reception distance calculation part, 54 Camera, 55 Position information acquisition part, 56 Travel control part, 57 Drive wheel, 58 Communication part, 59 Road surface judgment part, 60 rechargeable battery, 70 storage unit, 71 measurement distance information, 72 detection point information, 74 current position information, 75 route information, 76 transmission monitoring information, 91 communication unit, 92 monitoring control unit, 93 storage unit, 93a reception monitoring information

Claims (6)

A travel control unit for controlling the drive member;
A distance detection unit that emits predetermined light to a predetermined front space in the traveling direction, receives reflected light reflected by an object and a road surface existing in the front space, and detects a distance to the object and the road surface And
The distance detection unit includes a scanning control unit that scans an emission direction of light so that the light is irradiated toward a plurality of predetermined measurement points in the front space,
The number of measurement points whose distance is detected by the distance detection unit when the light emitted toward the plurality of measurement points is reflected by the object and the road surface by scanning the light emission direction by the scanning control unit. An autonomous traveling device, further comprising a road surface determination unit that determines a state of a road surface in the traveling direction based on a change within a predetermined time. The distance detection unit includes a light emitting unit that emits light, and a light receiving unit that receives light,
A light receiving confirmation unit for confirming that the reflected light is received by the light receiving unit;
Using the time difference between the time when the light is emitted from the light emitting unit and the time when the reflected light is confirmed to be received by the light receiving unit, the distance between the light emitting unit and the plurality of measurement points A light receiving distance calculation unit for calculating a light receiving distance which is
The road surface determination unit is provided for a measurement point where it is confirmed that the reflected light is received by the light reception confirmation unit, and an object exists for the measurement point where the reflected light is not received. The autonomous traveling device according to claim 1, wherein it is determined that no object exists.   The road surface determination unit determines that the road surface in the traveling direction is a flat road surface when the number of measurement points from which the distance has been detected is substantially unchanged for a predetermined time or longer. 2. The autonomous traveling device according to 2.   In a traveling state, the road surface determination unit determines that a hole area exists on the road surface in the traveling direction when the number of measurement points where the distance is detected shows a decreasing tendency for a predetermined time or more. The autonomous traveling device according to claim 1, wherein the autonomous traveling device is determined.   In a traveling state, the road surface determination unit has a tendency that the number of stations from which the distance is detected decreases or increases by a predetermined time from a state in which a certain number of stations from which the distance is detected exists. After being shown, it is determined that the road surface in the traveling direction has changed to a road surface having a different light reflectivity when there is almost no change in the number of measurement points different from the predetermined number of measurement points. The autonomous traveling device according to claim 1 or 2.   The distance detection unit uses a LIDAR that emits a laser to a two-dimensional space or a three-dimensional space in a predetermined distance measurement region and measures distances at a plurality of measurement points in the distance measurement region. Item 6. The autonomous traveling device according to any one of Items 1 to 5.