JP2018054290A - Obstacle detection device for transportation vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable detection of obstacles which might inhibit traveling stability on a road surface of a traveling road, even when a transportation vehicle travels at high speed during traveling of the vehicle.SOLUTION: An obstacle detection device is provided on a dump truck 1, and is constituted so that a scanning interval before and after the scanning line of a laser pulse is changed in accordance with the traveling speed by emitting the laser pulse from a laser pulse emitting device 34 toward the road surface at the front position in the traveling direction to receive reflected light from the road surface, and scanning the irradiation position of the laser pulse in a direction crossing the traveling direction of the dump truck 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an obstacle detection device for a transportation vehicle for detecting an obstacle on a traveling path in a transportation vehicle such as a dump truck operating in a mine.

  If an obstacle such as an object or a person that obstructs traveling, or another vehicle is located in front of the traveling vehicle, the vehicle must travel while avoiding these obstacles. For this reason, it has been widely known that a sensor is attached to a front part of a vehicle to monitor the front. For example, Patent Document 1 discloses a distance measuring device using a laser sensor.

  This known distance measuring device is mounted on a vehicle, emits a laser pulse toward the front position with respect to the traveling direction of the vehicle, receives the reflected light, and measures the time from transmission to reception of this laser pulse. By doing so, the distance of the obstacle is measured.

Japanese Patent No. 3351696

  In Patent Document 1 described above, the vehicle is a vehicle that is running or stopped on a general road, and is a person such as a passerby on the road of the vehicle. That is, the detection target has a certain height, and the irradiated laser pulse is in a substantially horizontal direction in order to improve the line of sight as much as possible.

  By the way, in a transport vehicle such as a dump truck that uses a mine as an operating field, the vehicle travels at a high speed to some extent, and obstacles such as rocks that obstruct travel are present on the travel path. there is a possibility. In particular, since dump trucks loaded with excavated material frequently travel, there is a possibility that the load will spill from the vessel (loading platform), and obstacles such as rocks may enter the travel path later. Therefore, when the dump truck travels, it must travel so as to avoid these obstacles, and when a large obstacle is in the front position in the traveling direction, the dump truck must be stopped.

  Based on the above, it is necessary to detect the presence of obstacles that hinder the operation of the dump truck on the road surface on which the dump truck travels. If there is a risk of spillage due to impact, even if there are obstacles that can be overcome, especially when there is a load on the vessel, the obstacle should be avoided. It may be necessary to travel or the vehicle must be stopped. Moreover, this obstacle detection is performed while the dump truck is running. Therefore, since the detection target is a projecting object from the road surface of the traveling road, the laser pulse needs to be emitted toward the road surface, and how far away from the vehicle the information of the position is required and how much is required. It is necessary to make it possible to arbitrarily set whether to detect the height of the protruding object according to the configuration of the dump truck, the type of the load in the vessel, the traveling speed of the vehicle, and other situations.

  The present invention has been made in view of the above points, and detects obstacles on the road surface of a traveling road that may hinder traveling stability even when the vehicle is traveling at a high speed while traveling. Its purpose is to make it possible.

    In order to achieve this object, the present invention is a laser that is provided in a transportation vehicle and that irradiates a laser pulse toward a road surface at a front position in the traveling direction of the transportation vehicle and receives reflected light from the road surface. Apparatus, laser pulse scanning means for scanning the irradiation position of the laser pulse from the laser apparatus in a direction intersecting the traveling direction of the transporting vehicle, the traveling speed V of the transporting vehicle, and the scanning end point position to the scanning end position The scanning interval between the scanning lines of the preceding and following laser pulses is measured on the basis of the measurement period time Th consisting of the scanning time until and the period until the start of the next scanning period. Scanning interval adjustment means for changing the measurement cycle time Th so that the scanning interval does not exceed a predetermined value even if the speed changes.

  The laser device includes a laser device that emits laser pulses and a light receiving sensor that receives scattered light of laser light from a road surface. Further, when the optical path of the laser beam is bent, a reflection mirror is arranged in the middle of the optical path, and the angle of the reflection mirror is controlled. It is desirable that the reflected light from the road surface be collected by a condenser lens and incident on the light receiving sensor.

  The road surface is scanned with a laser pulse emitted from the laser device. In the travel path of the transport vehicle, when the direction orthogonal to the travel direction of the vehicle is the X direction and the travel direction is the Y direction, the X direction defines the road width of the travel path. The laser pulse scanning means defines a scanning range in the X direction, and a road width when the transporting vehicle travels is set. The laser pulse scanning means swings the laser device back and forth or rotates it in one direction. When a reflection mirror is disposed in the optical path of the laser beam, the laser pulse can be scanned by reciprocatingly rotating the reflection mirror, and a linear or belt-like scanning line is set. Here, the scanning lines are not limited to those orthogonal to the traveling direction of the vehicle, but may be oblique to the direction orthogonal to the traveling direction. A system that performs inspection / monitoring by irradiating a laser pulse forward in the traveling direction of the vehicle in this manner is called a LIDAR (Light Detection and Ranging) system.

  As described above, a predetermined range at the front position in the traveling direction of the transporting vehicle is scanned with the laser pulse, and it is possible to detect whether there is an obstacle based on the LIDAR system. Therefore, when a virtual grid connecting the laser spots is set on the road surface, the size of the obstacle that can be detected changes based on the size of the mesh (mesh) that constitutes the grid. The size of the obstacle to be detected is generally determined based on the stability when the obstacle is overtaken when the transport vehicle is running. Based on the size of the object, the lengths of the mesh in the X and Y directions are determined.

  Here, when the traveling speed V of the transport vehicle, the measurement period time Th including the scanning time from the scanning start point position to the scanning end point position and the period until the start of the next scanning period, the above-described mesh is formed. Regarding the X direction and the Y direction, the interval in the X direction is determined by the pulse interval of the pulse laser emitted from the laser device. On the other hand, the interval in the Y direction varies depending on the traveling speed V of the transport vehicle. That is, the interval in the Y direction is shortened when the transporting vehicle is traveling at a low speed, and is long when traveling at a high speed. Therefore, the scanning interval V × Th between the front and rear scanning lines changes according to the traveling speed of the transporting vehicle. The scanning interval adjusting means is for adjusting the pitch interval in the Y direction of the scanning line according to the traveling speed of the transporting vehicle. By the adjustment by the scanning interval adjusting means, an obstacle having a set size can be reliably detected. Here, the interval in the Y direction may be changed according to the change in the speed of the transporting vehicle. However, when the upper limit speed of the transporting vehicle is determined, the Y direction interval is based on the upper limit speed. The pitch interval can be fixed.

  During travel of the transport vehicle, it is possible to reliably detect obstacles that may impede travel stability even when the vehicle is traveling at high speed on the road surface of the travel path.

  The problems, configurations, and effects of the invention described above and other than those described above will be further clarified by embodiments of the present invention described below with reference to the drawings.

It is an external view which shows the dump truck which operates in a mine as an example of the vehicle for conveyance. It is explanatory drawing which shows typically the mine site where a dump truck operates. It is a principle block diagram of the obstacle detection on a road surface. It is structure explanatory drawing of the obstruction detection apparatus integrated in a dump truck. It is explanatory drawing which shows the scanable range of a laser apparatus. It is explanatory drawing which shows the irradiation range of the laser pulse from the obstacle detection apparatus of FIG. It is explanatory drawing about the scanning interval of the X and Y direction of a laser pulse. It is explanatory drawing which shows the structure for deriving | resolving the resolution about an obstruction. It is explanatory drawing which shows the pitch space | interval of a laser spot. It is operation | movement explanatory drawing which shows the state which is performing the obstacle inspection of the road surface by a dump truck. It is a schematic block diagram of an obstacle detection system. It is operation | movement explanatory drawing about the position of the obstruction at the time of driving | running | working of a dump truck, and the operation | movement which avoids it. It is explanatory drawing of the obstruction detection processing operation at the time of driving | running | working of a dump truck. It is a flowchart figure which shows an obstruction detection process. It is a configuration explanatory view of a dump truck showing a second embodiment of the present invention. FIG. 16 is a plan view of FIG. 15.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an obstacle detection device for a transport vehicle according to the present invention, which is configured as a dump truck operating in a mine, will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of the dump truck 1, and FIG. 2 schematically shows the state of a mine site as an example of the operation field of the dump truck 1. The dump truck 1 is for transporting ores and earth and sand excavated in a mine, and its operation field is off-road with poor traveling conditions and travels in the presence of rocks and gravel.

  The dump truck 1 includes a vehicle main body 1a and a vessel 1b. A driver's cab 2 is installed in the vehicle main body 1a, and has a front wheel 3 and a rear wheel 4 respectively provided on the left and right as traveling means. The front wheel 3 is a driven wheel and the rear wheel 4 is a driving wheel. .

  The operator's cab 2 is provided with an upper deck 5 in the vehicle main body 1a for the operator to board. The upper deck 5 is installed on the front side of the vehicle main body 1a, and its width dimension is the vehicle main body 1a. Spans the entire width of. A pair of building structures 6R and 6L are disposed at the lower center position of the upper deck 5, and an air cleaner 7 is disposed at an intermediate position thereof. The air cleaner 7 is provided with a plurality of filter elements and is configured to capture dust and the like in the air.

  In FIG. 2, reference numeral 10 denotes a mining site, and a hydraulic excavator 11 for performing mining work is operating in the mining site 10. A traveling path 12 extends from the mining site 10, and the traveling path 12 is not shown in the figure, but the ore transporting path 13 toward the ore accumulation field and the earth and sand transporting path 14 toward the earth discharging field are branched. Is formed.

  The dump truck 1 is carried into the mining site 10, and earth and sand, ore, and the like are loaded on the vessel 1 b from the excavator 11 and travel along the travel path 12. When the ore is loaded, it is transferred from the ore transport path 13 to the ore depository. Further, when earth and sand are loaded on the vessel 1b, the vehicle travels toward the earth and sand transport path 14. Whichever route is taken, the load is discharged from the vessel 1b at the ore accumulation site and the earth removal site.

  In the field where the dump truck 1 is operating, a plurality of dump trucks 1 are operating, and the operation of these dump trucks 1 is managed by a management device provided in the traffic control center 15. Bidirectional transmission of information is possible between the dump truck 1 and the traffic control center 15 by wireless communication. For this purpose, an antenna 16 is provided at a predetermined position in the travel path 12 and the traffic control center 15. Further, each dump truck 1 can acquire its own position information from a communication satellite (GPS) 17.

  In the travel path 12, the dump truck 1 travels from the mining site 10 to the ore transport path 13 and the earth and sand transport path 14 and to the return path to the mining site 10 side. The other dump trucks 1 will pass each other. For this purpose, the traveling path 12 is divided into an outbound path and a return path. However, usually no median strip is provided at the boundary. In addition, a cliff or the like is located at the end of the road width of the travel path 12, and as a result, the travel path 12 is roughly set with a road width on the forward path and the return path. Therefore, in the following description, the side ends of the forward path and the return path of the traveling path 12 are referred to as road shoulders, respectively.

  When the dump truck 1 travels on the travel path 12 (including the ore transport path 13 and the earth and sand transport path 14), there is no obstacle on the road surface in order to improve travel stability and enable smooth travel. It is necessary to do so. In the mine, since there is no pavement or the like, the road surface is uneven and there may be rocks and the like. Therefore, it is necessary to monitor the condition of the road surface. In particular, it is necessary to determine whether or not there is an obstacle that makes it impossible to travel to the front position in the traveling direction of the dump truck 1 or affects traveling stability. . Moreover, if there is an obstacle, it may be necessary to run or stop to avoid it. Therefore, it is necessary to detect whether or not there is an obstacle on the road surface in front of the traveling direction in the dump truck 1, and the obstacle detection mechanism 20 using the LIDAR system shown in FIG. 3 is used.

  The obstacle detection mechanism 20 detects whether or not an obstacle exists in the test area 21. In the figure, reference numeral 22 denotes a laser device that emits laser pulses at a predetermined interval, reference numeral 23 denotes a laser pulse scanning mechanism that scans the laser pulse over a predetermined range, and reference numeral 24 denotes a light receiving sensor.

  When the test region 21 is an area having a predetermined spread in the X direction and the Y direction, the laser beam emitted from the pulse laser device 22 has its optical path bent by the laser pulse scanning mechanism 23 and then the test region 21. Will be scanned. Therefore, the laser pulse scanning mechanism 23 has the reflection mirror 23a, and the laser pulse is irradiated to the test region 21 by the reflection mirror 23a. In order for the laser pulse to scan the entire test region 21, the reflection mirror 23a can be tilted or rotated in two orthogonal axes, that is, in the X direction and the Y direction. Specifically, it has a rotating shaft 23X extending in the vertical direction, and the laser pulse is scanned in the X direction of the region 21 to be examined by rotationally driving the rotating shaft 23X by a motor or the like (not shown). . In addition, the inside of the test region 21 can be scanned in the Y direction by driving the rotation shaft 23Y extending in the horizontal direction. The laser pulse that has scanned the test region 21 is condensed by the condenser lens 25 and is incident on the light receiving sensor 24.

  The light receiving sensor 24 receives the scattered light of the reflected light from the test region 21. If the test region 21 has irregularities, the scattered light changes, so that it is possible to determine the presence, size, shape, and the like of an obstacle protruding from the road surface based on the amount of light scattered by the light receiving sensor 24.

  By using the obstacle detection mechanism 20 described above, it is possible to detect the condition of the road surface at the front position in the traveling direction of the dump truck 1. That is, depending on the condition of the road surface, the dump truck 1 may not be able to travel, and the dump truck 1 may not be able to go straight and a steering operation may be required. In this way, when the dump truck 1 is in a state where it cannot go straight, an avoidance operation such as stopping or performing a steering operation is performed. For this purpose, the obstacle detection mechanism 20 can be used. The irradiation position of the laser pulse by the detection mechanism 20 is set obliquely in front of the road surface, and covers the entire road width in which the dump truck 1 can travel.

  When the obstacle detection mechanism 20 is incorporated in the dump truck 1, it is configured as an obstacle detection unit 30 in which the mechanisms are integrated, and a specific example is shown in FIG. As shown in FIG. 1, the obstacle detection unit 30 in the dump truck 1 is disposed at an upper position of the mounting portion of the air cleaner 7 at a position between the building structures 6 </ b> R and 6 </ b> L. The obstacle detection device 30 has a configuration in which the laser holding unit 32 and the rotation driving unit 33 are mounted on the upper and lower sides of the support plate 31 at positions separated by a predetermined interval. A laser pulse incident / exit region is secured in between. A pulse laser emitting device 34 is attached to the laser holding unit 32. The rotation drive unit 33 is provided with a rotating body 35 that is driven to rotate by a motor (not shown). The rotating body 35 is provided with a half mirror 36 and a light receiving sensor 37.

  The optical path from the laser pulse emitting device 34 and the rotation center of the rotation drive unit 33 are substantially coincident with each other. A part of the pulse laser emitted from the laser pulse emitting device 34 is reflected by the half mirror 36 to be covered. Irradiation is directed toward the inspection area. The reflected light from the surface of the test region is scattered, but a part of the scattered light is transmitted through the half mirror 36. The scattered light that has passed through the half mirror 36 is received by a light receiving sensor 37, and a condensing lens is attached to the light receiving sensor 37.

  Here, as shown in FIG. 5, the obstacle detection unit 30 has a blind spot in the direction facing the support plate 31, but can irradiate laser light over a wide angle range excluding this blind spot range. Is. Since the detection of the obstacle is limited to the road width on the road surface of the traveling road 12, the rotating body 35 by the rotation drive unit 33 is rotated in one direction to scan the entire road surface of the traveling road 12. Is possible. However, it may be reciprocally rotated by a predetermined angle.

  By scanning the road surface with a laser beam, the presence or absence of an obstacle is detected on the road surface. For this purpose, the obstacle detection unit 30 is driven while the dump truck 1 travels, and the rotator 35 is driven. The laser pulse is emitted from the laser pulse emitting device 34 while rotating. As a result, the road surface of the traveling road 12 is scanned as shown in FIG. Here, when the traveling direction of the vehicle is the Y direction and the road width direction is the X direction, the scanning interval of the laser pulses is the pitch interval of the laser spots in the X direction. On the other hand, the pitch interval of the laser spots in the Y direction varies depending on the traveling speed of the vehicle. That is, when the vehicle travels at a high speed, the pitch interval of the laser spots in the Y direction is widened, and when the vehicle travels at a low speed, the pitch interval is widened.

In a general LIDAR system, as shown in FIG. 7, laser irradiation and detection are repeated at a constant time interval ΔT when the laser pulse irradiation direction is rotated at a constant angular velocity ω and traveled at a speed V. Therefore, measurement is obtained for each constant angular resolution Δθ. Assuming that ΔT is constant, if the measurement period Th is the time from laser irradiation in a certain angle θ direction to the next laser pulse irradiation in the same angle θ direction at t = T ₀ , the measurement period Th And the measurement resolution Δθ have a relationship of Δθ · Th = 2π · ΔT. That is, there is an inversely proportional relationship between Th and Δθ.

  Here, in FIG. 8 and FIG. 9, the distance in two directions between the measurement points P1-P2, P1-P1 ′, P2-P2 ′ (the distance ΔY in the traveling direction and the distance ΔX in the direction orthogonal to the traveling direction) is used. Sometimes, the distance ΔY is an interval between the measurement cycles Th, and is based on the traveling speed V of the dump truck 1 and the rotational speed of the rotating body 35 by the rotational drive unit 33, and the rotational speed of the rotational drive unit 33 is constant. If there is, the measurement cycle Th that changes depending on the traveling speed V of the dump truck 1 corresponds to ΔY. 8A, when the height from the road surface of the laser pulse emitting device 34 is H, the pitch interval is ρ, the laser irradiation direction is θ, and the measurement resolution is Δθ. As shown in b), the pitch interval in the X direction of the laser spot on the road surface, that is, the distance ΔX is calculated based on H / cosρ | tanθ−tan (θ + Δθ) |.

Here, as shown in FIGS. 9 and 10, the maximum values ΔX _{MAX and} ΔY _MAX of the distances ΔX and ΔY during traveling of the dump truck 1 take the road shoulder or the position in the vicinity thereof. Therefore, regarding the size of the obstacle to be detected on the road surface, even if the dump truck 1 has the maximum traveling speed, if the size of the position indicated by E in FIG. _{If MAX} · ΔY _MAX is within a predetermined range, it is set so that it can be reliably detected.

The evaluation value E is not limited to E = ΔX _{MAX ·} ΔY _MAX , but E = ΔX _MAX + ΔY _MAX, or a method of evaluating the larger one of ΔX _MAX and ΔY _MAX , etc., and should be selected according to the purpose. . From the above, in order to detect the obstacle B having a predetermined size while the dump truck 1 is traveling, the laser pulse emission driven by the rotation drive unit 33 of the obstacle detection unit 30 according to the traveling speed is detected. The rotational speed of the device 34 is adjusted. As a result, the obstacle B having a desired size can be detected. The traveling speed of the dump truck 1 can be calculated based on data obtained from a self-position measuring device 42 described later. These constitute scanning interval adjusting means. Here, in the following description, the obstacle B is described as having a configuration in which the scanning interval is set based on the size of the obstacle B. In short, the scanning interval is prevented from changing depending on the traveling speed of the dump truck 1. However, it is not necessarily based only on the size of the obstacle B, and the scanning interval can be set in consideration of other factors.

  Next, the configuration of the obstacle detection system will be described based on FIG. In the same figure, 40 is a schematic block diagram of an obstacle detection system. The obstacle detection system 40 is a system for detecting whether or not an obstacle B having a predetermined size or more exists on the road surface of the traveling road 12. Here, it is for ensuring the stability at the time of driving | running | working of the dump truck 1, the obstruction B is located on the road surface, and the front wheel 3 or the rear wheel 4 is this obstruction B (refer FIG. 10). If the vehicle is of a size that makes it impossible to travel, traveling is stopped, but the vehicle may be able to travel while avoiding the obstacle B by a steering operation.

  By the way, as shown in FIG. 12, in the travel path 12, when the area where the dump truck 1 travels straight is defined as area S, if area L and area R exist on both left and right sides of area S, area T , R has an obstacle B located in front of the dump truck 1, and collides with the obstacle B when traveling straight, but as indicated by arrow T or arrow S, area T or area If the steering operation is performed in the direction S, it may be possible to travel without the front wheels 3 and the rear wheels 4 getting on the obstacle B. Accordingly, when the obstacle detection system 40 mounted on the dump truck 1 detects an obstacle B of a predetermined size in front of the dump truck 1 in the traveling direction, the obstacle detection system 40 can travel while avoiding the obstacle B. In the case where the steering operation is performed and there is an obstacle B that cannot be traveled, the vehicle is stopped by operating the brake.

  Therefore, in the system configuration for detecting the obstacle shown in FIG. 11, reference numeral 40 denotes a measurement system for measuring the relative position of the obstacle B with respect to the vehicle body 1a. The measurement system 40 and the traffic control center 15 are connected by wireless communication. Signals can be exchanged.

  40 includes the obstacle measuring unit 41 shown in FIG. 4 in order to detect an obstacle. Further, based on the self-position measuring unit 42 for measuring the position and posture of the vehicle main body 1a, the relative position of the obstacle B, the road surface width, and the presence of the oncoming vehicle, the traveling direction and traveling speed of the vehicle main body 1a are determined. A vehicle body motion control unit 43 to be changed is provided. Furthermore, the communication part 44 for performing communication between the traffic control centers 15 is provided.

  The obstacle measurement unit 41 includes an obstacle detection unit unit 30, an obstacle measurement unit 41 a that measures the relative position of the obstacle B with respect to the dump truck 1 based on the measurement result by the obstacle detection unit 30, a road surface An obstacle storage unit 41b is provided as a storage unit for storing obstacle data related to obstacle positions and obstacle shapes in the external coordinate system around A.

  The obstacle detection unit 30 is connected to the obstacle measurement unit 41a, and the obstacle measurement unit 41a is connected to the obstacle storage unit 41b. As shown in FIG. 1, the obstacle detection unit 30 has an intersection line L as a scanning direction that is a straight line formed by measurement points on the road surface A to which the laser light emitted from the obstacle detection unit 30 reaches. Each is set along the width direction of the road surface A (the road width X direction). Further, the obstacle detection unit 30 scans the measurement points on the road surface A by gradually changing the irradiation direction of the laser light at a predetermined angle, for example, every 0.25 degrees. The distance to the road surface A at every predetermined angle is measured on the scanning surface of the laser beam by the detection unit 30.

  Further, the obstacle measuring unit 41 includes a comparison unit 41c that compares the obstacle information detected by the obstacle detection unit 30 with the obstacle data stored in the obstacle storage unit 41b. Based on the comparison, the attribute information of the obstacle data such as whether the obstacle is a stationary obstacle such as an installation object or a dynamic obstacle such as a vehicle is updated.

  The self-position measuring unit 42 is a steering angle of a wheel speed measuring unit 42a for measuring, for example, the rotational speed of the front wheel 3 of the vehicle main body 1a and a handle (not shown) provided in the cab 2 of the vehicle main body 1a. Based on the rotational speed result measured by the steering angle measurement unit 42b and the wheel speed measurement unit 42a and the steering angle result measured by the steering angle measurement unit 42b, the traveling speed of the vehicle main body 1a, the front wheel 3 And a self-position calculating device 42c for calculating the position and orientation of the vehicle main body 1a in a coordinate system fixed to the ground. The wheel speed measuring unit 42a is, for example, a speed sensor for detecting the rotational speed of the front wheel 3. The steering angle measurement unit 42b is a displacement sensor or the like that can detect the steering angle of the steering wheel.

  The self-position measuring side part 42 includes a self-position correcting device 42d for correcting the self-position of the vehicle main body 1a. The self-position correcting device 42d is for measuring the position and posture of the vehicle body 1a with higher accuracy, and is configured by, for example, an inertial measurement device (IMU), a GPS (Global Positioning System), or the like. ing. The wheel speed measuring unit 42a, the steering angle measuring unit 42b, and the self-position correcting device 42d are respectively connected to the self-position calculating device 42c.

  The vehicle body motion control unit 43 includes a braking device 43a that reduces or stops the traveling speed of the vehicle main body 1a, a drive torque limiting device 43b that limits a rotational torque command value for the rear wheel 4 of the dump truck 1, A steering control device 43c for avoiding the obstacle B, a data storage unit 43d in which map data such as the route of the traveling road, the road width of the road surface A, and oncoming vehicle information is stored, the braking amount by the braking device 43a, and the driving A vehicle control device 43e for calculating a limit amount by the torque limit device 43b and a control amount by the steering control device 43c is provided. The vehicle control device 23e limits the braking amount and driving torque by the braking device 43a for the purpose of limiting the distance and traveling speed of the vehicle main body 1a to the obstacle B based on the map data stored in the data storage unit 43d. A limit amount by the device 43b and a control amount by the steering control device 23c are calculated.

  The brake device 43a is a mechanical brake having a mechanical structure such as a disc brake for braking the rotation of the rear wheel 4, for example. The drive torque limiting device 43b is a retarder brake such as an electric brake that applies an electric resistance to the rotation of the rear wheel 4 to brake the rotation. As the map data stored in the data storage unit 43d, road shoulder information such as a road shoulder shape provided on the side of the traveling road is also stored. The vehicle control device 43e receives map data stored in the data storage unit 43d, self-location information calculated by the self-position calculation device 42c, and obstacle information measured by the obstacle measurement unit 41a. The The vehicle control device 43e is connected to each of the braking device 43a, the drive torque limiting device 43b, and the steering control device 43c.

  The communication unit 44 is connected to the self-position calculating unit 42c, and transmits the self-position information of the dump truck 1 calculated by the self-position calculating unit 42c to the traffic control center. The communication unit 44 is connected to the obstacle storage unit 41b and the data storage unit 43d, and transmits the obstacle position data stored in the obstacle storage unit 41b and the map data stored in the data storage unit 43d to the communication unit. 44 is configured to be able to output via 44.

  The traffic control center 15 includes a communication device 51 for transmitting and receiving information to and from the communication unit 44 mounted on the dump truck 1, and an obstacle data storage in which an obstacle map such as an obstacle shape of the travel path is stored. Obstacle comparison as a comparison unit that compares the obstacle information transmitted from the communication unit 44 of the dump truck 1 to the communication device 51 with the obstacle map stored in the obstacle data storage unit 52 When the obstacle information is different from the obstacle map as a result of comparison between the device 53 and the obstacle comparison device 53, a change data storage unit 54 for storing obstacle change information of the obstacle information is provided. Is provided.

  Next, obstacle detection processing by the measurement system 40 will be described with reference to FIGS. 11 and 12. FIG. 13 is a diagram showing obstacle detection by the obstacle detection unit 30 of the dump truck 1, wherein (a) is a schematic perspective view showing a scanning state by a laser pulse PL at the time of obstacle detection, and (b) is a diagram. It is a graph which shows the obstacle detection position P. Here, (a) of FIG. 13 shows a state where the dump truck 1 is traveling while detecting the obstacle B on the traveling path, and the broken line in (a) of FIG. The obstacle position calculated | required in the unit 30 and the obstacle measurement part 41 is shown. FIG. 14 is a flowchart showing obstacle detection processing by the dump truck 1.

  First, the obstacle detection unit 30 measures the obstacle B on the road surface of the traveling road 12, and acquires distance data about the position of the road surface and the obstacle B (step S1, hereinafter simply referred to as "S1"). Show.) Based on the distance measurement data acquired in S1, as shown in FIGS. 13A and 13B, an intersection line L intersecting the scanning surface and the road surface A by the obstacle detection unit 30 is measured on the shoulder. Calculated by the unit 41a (S2).

After that, the obstacle measurement unit 41 sets the measurement point that is separated from the intersection line L calculated in S2 by a predetermined distance H or more as the obstacle measurement point Pn (in FIG. 13, P1, P2, and P3 are obstacles). (S3). When an obstacle having a predetermined size and shape is detected at the obstacle measurement point Pn while the dump truck 1 is traveling (S4), the obstacle is calculated from the relative position of the obstacle measurement point Pn and the current position of the dump truck 1. The absolute position of the object measurement point Pn is calculated (S5). Here, the current position of the dump truck 1 is measured based on the communication satellite 17. Then, the absolute position of the obstacle measurement point Pn is stored in the obstacle storage unit 41b (S6).
On the other hand, based on the rotational speed result measured by the vehicle speed measuring unit 42a and the steering angle result measured by the steering angle measuring unit 42b, the traveling speed of the dump truck 1 corrected by the self-position correcting device 42d, the front wheels 3, the position and posture of the dump truck 1 in a coordinate system fixed to the ground are calculated by the self-position calculator 42 c and the self-position is estimated. The shortest distance to the obstacle from the position of the dump truck 1 calculated by the self-position calculating unit 42c and the positions of the obstacles around the dump truck 1 stored in the obstacle storage unit 41b is a predetermined distance. It is determined whether it is larger than the distance D (S7).

  In S7, it is determined whether the distance between the position obtained by the self-position calculating unit 42c and the position of the obstacle around the dump truck 1 stored in the obstacle storage unit 41b is larger than the predetermined distance D. In the case of (YES in S7), the obstacle detection process shown in FIG. 14 ends. On the other hand, in S7, it is determined that the distance between the position obtained by the self-position calculating unit 42c and the position of the obstacle around the dump truck 1 stored in the obstacle storage unit 41b is smaller than the predetermined distance D. If it is determined that there is a danger of colliding with an obstacle, it is determined whether or not the dump truck 1 can be run while avoiding the obstacle. Judgment is made (step 8). If avoidance is possible, the dump truck 1 is caused to take an avoidance action by steering or the like (step 9). When it is determined that the avoidance operation cannot be performed, the braking device 43a and the drive torque limiting device 43b of the vehicle body motion control unit 43 are controlled to stop the traveling of the dump truck 1 (step 10).

  Furthermore, a grid map in the X direction and Y direction of the laser spot is created on the traveling road, and the presence or absence of obstacles on the traveling road surface is managed by this grid map, so that the number of undetected grids is minimized. The resolution Δθ (or measurement cycle ΔT) is set. By recording this grid information, it becomes possible to efficiently manage and maintain the road surface. Further, since the dump truck 1 travels on substantially the same traveling road surface, grid information at the same position on the same traveling road surface is repeatedly obtained from the same dump truck 1 and the plurality of dump trucks 1. Moreover, the dump truck 1 travels back and forth, and can scan the same position even if the position scanned during the forward travel is the return path. Therefore, it is also possible to acquire grid information of a part that reciprocates on the traveling road surface. If the grid information is set to be accumulated, the grid map becomes more complete, and the unknown detection area can be minimized.

  Next, FIG.15 and FIG.16 is a schematic block diagram which shows the dump truck 1 which concerns on 2nd Embodiment of invention. Similar to the first embodiment, the dump truck 1 includes a vehicle main body 1a and a vessel 1b as a working portion provided on the vehicle main body 1a so as to be able to be raised and lowered, and a driver's cab above the vehicle main body 1a. 2 is provided. And it is set as the structure provided with the right-and-left front wheel 3 and the rear wheel 4 supported so that driving | running | working is possible. In addition, a pair of building structures 6L and 6R are provided at a predetermined interval in the lower central portion of the upper deck 5, and a heat exchange device such as a radiator is installed between the building structures 6L and 6R. Yes. In order to detect the relative position of a part of the obstacle B existing on one side in the traveling direction of the vehicle main body 1a, for example, in the front in the traveling direction, there is a total of two units between the building structural parts 6L and 6R. Obstacle detection units 30L and 30R are respectively attached.

  In the second embodiment, as in the first embodiment, an obstacle is detected by the LIDAR system. In this case, the two obstacle detectors 30L and 30R are connected to the traveling direction of the dump truck 1. Instead of scanning the laser pulses in the orthogonal direction, the scanning lines XL and XR are set in an oblique direction. In this case, the scanning lines XL and XR intersect at a predetermined position, and the obstacle detection is performed on the scanning line XL from the intersection position Q on the basis of the intersection position Q. Obstacle detection is performed from the intersection position Q to the other road shoulder, that is, the right road shoulder, up to the road shoulder, that is, the left road shoulder.

Paying attention to the maximum of the two distances between the measurement points on the obstacle detection area (distance ΔY in the traveling direction and distance ΔX in the direction perpendicular to the traveling direction), the evaluation value E = ΔX _MAX Although ΔY _MAX is an evaluation function, not only the angular resolution Δθ (or measurement period ΔT) but also the scan line Xl, XR is appropriately determined by determining the crossing angle α at the crossing position Q, thereby reducing a smaller obstacle. It can be reliably detected.

  In addition, this invention is not limited to embodiment mentioned above, Various deformation | transformation aspects are included. For example, the above-described embodiments are for explaining the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to only having all the configurations described.

DESCRIPTION OF SYMBOLS 1 Dump truck 1a Vehicle main body 1b Vessel 2 Driver's cab 6L, 6R Building structure 12 Running path 30 Obstacle detection unit 33 Rotation drive unit 34 Laser pulse emitting device 35 Rotating body 37 Light receiving sensor 40 Obstacle detection system 41 Obstacle measurement Unit 42 self-position measuring unit 42a wheel speed measuring unit 42b steering angle measuring unit 43 vehicle body motion control unit

Claims (4)

A laser device that is provided in a transport vehicle, irradiates a laser pulse toward a road surface at a forward position in the traveling direction of the transport vehicle, and receives reflected light from the road surface;
Laser pulse scanning means for scanning the irradiation position of the laser pulse from the laser device in a direction crossing the traveling direction of the transporting vehicle;
Based on the traveling speed V of the transporting vehicle and the measurement cycle time Th consisting of the scan time from the scan start point position to the scan end point position and the cycle until the start of the next scan period, A scanning interval adjusting means for changing the measurement cycle time Th so that the scanning interval does not exceed a predetermined value even if the traveling speed of the transporting vehicle changes. Vehicle obstacle detection device.   The height of the laser device from the road surface is H, the pitch interval is ρ, the laser irradiation direction is θ, the measurement resolution is Δθ, and the pitch of the laser spot on the road surface H / cosρ | tanθ−tan (θ + Δθ) | 2. The obstacle detection for a transportation vehicle according to claim 1, wherein the measurement cycle time Th is changed so that a measurement mesh size composed of the scanning interval V × Th does not exceed a predetermined value. apparatus.   By recording obstacles on the road surface in a grid map and storing grid map data each time the measurement of the road surface is repeated, the measurement cycle time Th is reduced so as to reduce the unknown detection area of the grid map. The obstacle detection device for a transport vehicle according to claim 1, wherein the obstacle detection device is configured to be changed.   2. The transport vehicle according to claim 1, wherein a pair of the laser devices are arranged on both the left and right sides of the transport vehicle so as to irradiate the laser pulse so as to intersect the scanning direction of the laser pulse. Obstacle detection device.

Images