JP2018054328A - Machine for mine work and obstacle detection device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an obstacle detection technique suitable for a machine for mine work.SOLUTION: A machine for mine work comprises: a high power radar device; a low power radar device; and an obstacle detection device for determining whether or not there is an obstacle using detection results from the high power radar device and detection results from the low power radar device. The high power radar device and the low power radar device are mounted on the machine for mine work so that a detection area 121d of the high power radar device and a detection area 122a of the low power radar device are overlapped. The obstacle detection device determines the kind of obstacles at the position where a detection area 121b of the high power radar device and a detection area of the low power radar device are overlapped using both the detection results of the high power radar device and the detection results of the low power radar device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a mining work machine and its obstacle detection device, and more particularly to an obstacle detection technique for a mining work machine operating in an off-road environment.

  As an example of a driving control technology for an automobile, Patent Document 1 states that “when the distance between the vehicle and the preceding vehicle detected by the radar device becomes a predetermined value or less, automatic braking is performed or a warning is issued to the driver, thereby generating interference. To prevent moving objects such as preceding vehicles, and to detect stationary objects against the threshold level of the reflected wave reception level of radar devices such as laser radar devices and pulse radar devices. Set the threshold of the reception level of the reflected wave high in a predetermined area, so that it is possible to prevent the vehicle from being detected as an obstacle by detecting a gate or an object falling on the road that does not interfere with the vehicle. A technology that can prevent unnecessary automatic braking and warning from being performed on a road falling object (summary excerpt) is disclosed.

  Patent Document 2 states that “in a vehicular radar apparatus having a light emitting element for a long distance range and a light emitting element for a short distance range, the optical axis of the short distance light emitting element is slightly offset above the horizontal direction. , To prevent the transmission signal for short distances from being reflected on the road surface (summary excerpt).

JP 2008-102591 A Japanese Patent Laid-Open No. 8-082679

  There is an obstacle detection technique in which a sensor such as a millimeter wave radar is mounted on a mining work machine, for example, a transport vehicle, and it is determined whether there is an obstacle ahead of the traveling direction of the host vehicle. In general, a millimeter wave radar is attached to a relatively low position such as a bumper portion or a mirror portion of a vehicle so that a metal portion of the vehicle to be detected as an obstacle is included in an irradiation range of electromagnetic waves emitted by the millimeter wave radar. However, work machines run on uneven road surfaces compared to automobiles, so the vehicle height is high, so the installation position of the millimeter wave radar is high, and there is a strong tendency that the metal part of the vehicle does not exist within the electromagnetic wave irradiation range. Become. In particular, a vehicle that exists in the vicinity of a large mining work machine can capture only a part of the vehicle, such as a window glass or a ceiling, depending on the direction and height of the vehicle, and the received intensity of reflected waves is high. It may be as low as road surface irregularities.

  Since the technique of Patent Document 1 detects a non-obstacle such as road surface unevenness or an uphill as an obstacle and does not give a false alarm, the detection result of the received intensity corresponding to the reflected wave from the road surface is excluded. When the technique 1 is applied to a work machine, it may not be possible to detect a vehicle in the vicinity of the work machine, and there is a problem that the obstacle detection technique for a passenger car cannot be applied to the work machine as it is.

  In the technique of Patent Document 2, the pulse signal output direction of the short-distance transmission means is slightly offset upward with respect to the horizontal direction, so that the installation position of the millimeter wave radar is as high as 4 m from the road surface, for example. When applied to the above, there is a problem that the irradiation range height of the electromagnetic wave of the short-distance sending means is further increased and an obstacle on the road cannot be caught.

  This invention is made | formed in view of the said subject, and it aims at providing the obstacle detection technique suitable for the working machine for mines.

  In order to achieve the above object, a mining work machine equipped with at least two or more radar devices that detect obstacles ahead in the traveling direction, which emits electromagnetic waves with a narrow irradiation angle and high output intensity, From one or more high-power radar devices for long-distance use, at least one low-power radar device for short-range use that emits an electromagnetic wave having a wide irradiation angle and low output intensity, and each of the high-power radar devices And an obstacle detection device that determines the presence or absence of an obstacle using the detection result of each of the low-power radar devices and the detection region of each high-power radar device. The low-power radar device is attached to the mining work machine at a position where the detection areas of the low-power radar device overlap, and the obstacle detection device detects the low-power radar device that overlaps the detection region of each high-power radar device. The type of obstacle detected in the area is determined based on the reception intensity of the reflected wave generated when the electromagnetic wave irradiated by the high-power radar device and the low-power radar device is reflected by the obstacle. To do.

  According to the present invention, it is possible to provide an obstacle detection technique suitable for a mining work machine. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

Schematic configuration diagram of a dump truck according to the first embodiment The figure which shows the installation position of the 1st millimeter wave radar and the 2nd millimeter wave radar (top view) FIG. 4 is a diagram showing a detection area of a millimeter wave radar mounted on a dump truck, where (a) is a detection area of a first millimeter wave radar, (b) is a detection area of a second millimeter wave radar, and (c) is The state where the detection areas of the first millimeter wave radar and the second millimeter wave radar are overlapped is shown. Functional block diagram of obstacle detection device Flow chart showing the flow of processing of the obstacle detection device Block diagram showing the functional configuration of an obstacle detection device mounted on an autonomous traveling dump truck The figure which shows the relationship between the reception strength of the low power radar and the high power radar and the judgment threshold of the obstacle / non-obstacle Schematic configuration diagram of a dump truck according to the second embodiment The block diagram which shows schematic structure of the millimeter wave radar which concerns on 2nd embodiment. Diagram showing the relationship between the high and low signals of the reference pulse signal and the detection area at that time The figure which shows the example which overlapped the detection area of three radar apparatuses

  Hereinafter, embodiments of a mining work machine and an obstacle detection device according to the present invention will be described with reference to the drawings. Throughout the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted. Hereinafter, a dump truck will be described as an example of a mining work machine, but the present invention can be applied regardless of the type of the mining work machine such as a wheel loader or a hydraulic excavator.

<First embodiment>
The first embodiment is an embodiment in which obstacle detection is performed by mounting a first millimeter wave radar and a second millimeter wave radar including a high output radar and a low output radar on a dump truck. FIG. 1 is a schematic configuration diagram of a dump truck according to the first embodiment. FIG. 2 is a diagram (top view) showing the mounting positions of the first millimeter wave radar and the second millimeter wave radar. FIG. 3 is a diagram illustrating a detection region of the millimeter wave radar mounted on the dump truck. Here, high-power radar is a long-range radar that emits electromagnetic waves with a narrow irradiation angle and high output intensity, and low-power radar is a short-range radar that emits electromagnetic waves with a wide irradiation angle and low output intensity. is there. Each of the first millimeter-wave radar and the second millimeter-wave radar is a radar device in which a long-range radar device and a short-range radar device are integrated. In the present embodiment, the type of obstacle detected in the detection area of the low-power radar device that overlaps the detection area of the high-power radar device is generated by reflecting the electromagnetic wave irradiated from the high-power radar device. This is characterized in that the received wave is discriminated using the received intensity of the reflected wave and the received intensity of the reflected wave generated when the obstacle reflects the electromagnetic wave irradiated from the stationary output radar device. In the above, “detected in the detection region of the low-power radar device that overlaps the detection region of the high-power radar device” is detected in the detection region of the high-power radar device that overlaps the detection region of the low-power radar device. "In other words, it is synonymous.

  A dump truck 10 shown in FIG. 1 includes a vehicle body 11, a front wheel 12, a rear wheel 13, and a vessel 14 on which a load is mounted. A first millimeter wave radar 21 and a second millimeter wave radar 22 are installed in front of the vehicle body 11 as radars for detecting obstacles.

  As shown in FIG. 2, a millimeter wave radar mounting jig 30 is installed on the bumper 111 of the vehicle body 11. The attachment jig 30 includes a left inclined surface 31 that is inclined from the front center of the attachment jig 30 toward the left end of the vehicle body, and a right inclined surface 32 that is inclined from the front center of the attachment jig 30 toward the rear right end of the vehicle body. The first millimeter wave radar 21 is attached to the left inclined surface 31, and the second millimeter wave radar 22 is attached to the right inclined surface 32. Therefore, the first millimeter wave radar 21 is attached to the vehicle body 11 with the central axis of the detection area of the first millimeter wave radar 21 tilted to the left with respect to the front in the traveling direction. Similarly, the second millimeter wave radar 22 is attached to the vehicle body 11 with the central axis of the detection area of the second millimeter wave radar 22 tilted to the right with respect to the front in the traveling direction.

  Millimeter wave radars are often used for work machines operating at mines because of their high robustness against environmental changes such as dust, fog, rain, and lighting changes. Millimeter wave radar generally irradiates electromagnetic waves with a wavelength range of several millimeters to several tens of millimeters, and measures the time until the reflected wave returns and the relative distance to the reflection target by measuring the Doppler shift amount. Relative speed can be detected. Further, the millimeter wave radar can obtain a reception intensity representing a reception level of the reflected wave. In general, the reception intensity is high when the reflection target is a metal object, and the road surface unevenness that is non-metal has a low reception intensity. Therefore, vehicles having metal tend to have high reception intensity. By using this characteristic, it is possible to separate road surface irregularities that are non-obstacles and vehicles that are obstacles from objects detected by the millimeter wave radar.

  However, the installation position of the millimeter wave radar is increased, and the metal part of the vehicle is less likely to be present within the electromagnetic wave irradiation range. Tend to be. Therefore, in the present embodiment, the first millimeter wave radar 21 and the second millimeter wave radar 22 are used together, and the detection accuracy of the short-range vehicle is improved using the detection result from each millimeter wave radar.

  Therefore, as shown in FIG. 3A, the first millimeter-wave radar 21 and the second millimeter-wave radar 22 divide the detection area radially into three, and the central detection areas 121b and 121d are used for detecting obstacles at a long distance. An electromagnetic wave having a relatively strong intensity with respect to the traveling direction of the dump truck 10 is applied to the narrow angle region so as to obtain an appropriate output. Each divided small area is assigned an address that uniquely indicates this, and the received intensity and the address in this small area are associated with each other and output to the obstacle detection apparatus 200. The strong intensity (high output) is preferably an output intensity at which a reflected wave from the road surface can be received.

  On the other hand, the left detection areas 121a and 122a and the right detection areas 121c and 122c emit electromagnetic waves having relatively weak intensity with respect to the side so that the output is suitable for detecting a wide range of obstacles at a short distance. Irradiate. That is, the first millimeter-wave radar 21 and the second millimeter-wave radar 22 are a high-power radar device that outputs high-power electromagnetic waves in a narrow-angle region and a low-power radar that outputs low-power electromagnetic waves in a wide-angle region. And a device. The low output mentioned here is preferably an output intensity at which the difference in received intensity between the reflected wave from the non-metal part of the vehicle and the reflected wave from the road surface becomes relatively small. In the present embodiment, a specific output method is not limited, but for example, a millimeter wave radar having an antenna switching type multi-beam antenna may be used.

  Generally, the left detection areas 121a and 122a and the right detection areas 121c and 122c, which are wide-angle areas where electromagnetic waves are weak, are reflected from the road surface as compared with the central detection areas 121b, 122b, 121d and 122d which are narrow-angle areas where electromagnetic waves are strong. It tends to be difficult to detect waves. This is because the power density of the electromagnetic wave irradiated in inverse proportion to the square of the distance from the antenna decreases, and the received intensity of the reflected wave from the road surface unevenness becomes weak and difficult to detect. Accordingly, the left detection areas 121a and 122a and the right detection areas 121c and 122c tend to be harder to detect road surface irregularities than other areas, and thus the vehicle and the road surface irregularities tend to be easily separated. On the other hand, the center detection areas 121b, 121d, 122b, and 122d are easier to detect road surface unevenness than the left detection areas 121a and 122a and the right detection areas 121c and 122c, and it tends to be difficult to separate the vehicle and road surface unevenness.

  By utilizing the fact that the separation characteristics of the road surface and the vehicle differ according to the detection area in this way, in this embodiment, as shown in FIG. 3C, the narrow-angle area of the detection area of the first millimeter wave radar 21 The wide-angle area of the detection area of the second millimeter wave radar 22 is installed so as to overlap each other. That is, the center detection area 121 b of the first millimeter wave radar 21 is installed so as to overlap the left detection area 122 a of the second millimeter wave radar 22. Further, the center detection area 122 b of the second millimeter wave radar 22 is installed so as to overlap the right detection area 121 c of the first millimeter wave radar 21. Then, based on the difference in detection characteristics of each millimeter wave radar, it is determined whether the detected object is a vehicle or a road surface unevenness, thereby improving the separation performance between the road surface and the vehicle. Details of this processing will be described in the explanation of functional blocks of the obstacle detection apparatus 200.

  With reference to FIGS. 4-7, the structure and operation | movement of the obstruction detection apparatus mounted in the dump truck are demonstrated. FIG. 4 is a block diagram showing a functional configuration of the obstacle detection device mounted on the manned dump truck. FIG. 5 is a flowchart showing the flow of processing of the obstacle detection apparatus. FIG. 6 is a block diagram showing a functional configuration of the obstacle detection device mounted on the autonomous traveling dump truck. FIG. 7 is a diagram illustrating the relationship between the reception intensity of the low-power radar and the high-power radar and the obstacle / non-obstacle determination threshold value.

  As shown in FIG. 4, the dump truck 10 includes an obstacle detection device 200, and a first millimeter wave radar 21, a second millimeter wave radar 22, and a vehicle speed sensor 130 are connected to the input end of the obstacle detection device 200. Is done. An alarm device 160 is connected to the output terminal of the obstacle detection device 200 via the vehicle control device 110.

  The obstacle detection apparatus 200 includes a preprocessing unit 201, a moving body determination unit 202, a reliability acquisition unit 203, a reliability setting value storage unit 204, a vehicle presence determination unit 205, and an obstacle information output unit 206. The obstacle information output unit 206 outputs information necessary for performing a collision avoidance operation when there is a moving object or a stationary object that needs collision avoidance. When the dump truck 10 is a so-called manned dump truck that travels according to the driving operation of the operator, the collision avoidance operation here corresponds to a process of issuing an alarm to the operator. In addition, when the dump truck 10 is an autonomous traveling dump truck that autonomously travels according to a control command from a control server connected via a wireless communication line, the dump truck 10 decelerates to a braking device mounted on the autonomous traveling dump truck. Processing for outputting a braking instruction signal for performing a stopping operation, and processing for outputting a steering instruction signal for performing a steering operation at a steering angle capable of avoiding an obstacle with respect to a steering device mounted on an autonomous traveling dump truck Is applicable.

  The obstacle detection device 200 is configured to include hardware including a CPU (Central Processing Unit) and a storage device (RAM, ROM, HDD), and software that implements the above-described units, and software stored in the storage device. It is an electronic control unit (ECU: Engine Control Unit) realized by loading and executing the CPU. The obstacle detection apparatus 200 determines whether the obstacle (detected body) detected by the first millimeter wave radar 21 and the second millimeter wave radar 22 mounted on the vehicle body 11 is an obstacle to be subjected to the collision avoidance action. It has a function of making a determination based on the relative distance to the obstacle, the relative speed, the received intensity, and the vehicle motion information obtained from the vehicle speed sensor 130 output by the one millimeter wave radar 21 and the second millimeter wave radar 22. Hereinafter, the details of each function of the obstacle detection apparatus 200 will be described in the order of the steps in FIG.

The preprocessing unit 201 acquires information on the relative position, relative speed, and reception intensity up to the obstacle output from the first millimeter wave radar 21 and the second millimeter wave radar 22 (step S501), and is determined in advance. A process of converting the coordinates into the vehicle coordinate system of the dump truck 10 is executed (step S502). Then, based on the relative position and relative speed of the obstacle coordinate-converted into the vehicle coordinate system, a process of grouping data sets determined to have detected the same obstacle is executed (step S503). Any method may be used for the grouping process. For example, the relative position of the obstacle detected by the first millimeter wave radar 21 is X1, the relative velocity is V1, and the obstacle detected by the second millimeter wave radar 22 is used. If the relative position is X2 and the relative speed is V2, the data set in which (Equation 1) is satisfied may be determined as the data of the same obstacle. ΔXth and ΔVth are position differences (distance differences) for determining whether or not the obstacles detected by the first millimeter wave radar 21 and the second millimeter wave radar 22 are the same. The threshold value or threshold value of the speed difference may be set in consideration of measurement errors of the millimeter wave radar and the vehicle speed sensor 130.
| X1-X2 | <= ΔXth and | V1-V2 | <= ΔVth (Formula 1)

The moving body determination unit 202 performs a process of calculating the absolute speed Va of the obstacle based on the relative speeds V1 and V2 of the obstacle and the own vehicle speed Vo acquired from the vehicle speed sensor 130 (step S504). For example, (Equation 2) may be used to calculate the absolute speed. Here, Vm is the relative speed of the obstacle detected by the millimeter wave radar, Vo is the vehicle speed detected by the vehicle speed sensor 130, and Va is the absolute speed of the obstacle. Vm is the relative velocity V1 or V2 of the obstacle. For example, the larger one of V1 and V2 may be adopted.
Va = Vm + Vo (Formula 2)

Next, the moving body determination unit 202 determines whether the obstacle is moving or stationary based on the calculated absolute velocity Va of the obstacle (step S505). Specifically, when (Equation 3) is satisfied, the obstacle is determined as a stationary body (step S507), and when it is not satisfied, the obstacle is determined as a moving body (step S506). Vth is a speed threshold provided for determining whether or not the object is a moving body, and may be set in consideration of measurement errors of the millimeter wave radar and the vehicle speed sensor 130.
Va <Vth (Formula 3)

The reliability acquisition unit 203 acquires the reliability for determining whether the obstacle is a collision avoidance target according to the reception intensity of the reflected wave from the obstacle determined to be a stationary body and the detection area where the obstacle is detected. Is performed (step S508). For example, the reliability may be set as a probability value obtained by the Bayes formula shown in (Expression 4). Here, R1 and R2 represent the reception strengths of the first millimeter wave radar 21 and the second millimeter wave radar 22, respectively. A1 and A2 represent the addresses of the detection areas of the first millimeter wave radar 21 and the second millimeter wave radar 22, and it is assumed that a unique number is assigned to each detection area of the millimeter wave radar shown in FIG. H1 and H2 represent assumptions, H1 represents a vehicle, and H2 represents a vehicle. In the present embodiment, the collision avoidance target is a vehicle. Therefore, (Expression 4) calculates a probability value indicating whether or not the detected data is a vehicle from the reception intensity and the detection area detected by the first millimeter wave radar 21 and the second millimeter wave radar 22. 1 when the probability of being a vehicle is high, and 0 when low.

  The reliability calculated by (Equation 4) is calculated in advance based on the respective detection data of the first millimeter wave radar 21 and the second millimeter wave radar 22 collected before the operation in the mine environment where the dump truck 10 is operated. The calculated data may be stored in a memory (corresponding to the reliability setting value storage unit 204) in the obstacle detection apparatus 200. By setting the reliability according to (Equation 4), it is possible to more accurately determine the presence of the vehicle based on the conditional posterior probability.

  The reliability setting value storage unit 204 represents a memory that stores the reliability calculated in advance, and the reliability acquisition unit 203 stores the reliability setting value according to the received intensity of the reflected wave from the detected obstacle and the detection area. The reliability may be acquired from the unit 204.

  The reliability setting is not limited to (Equation 4). For example, the probability value may be calculated based on an average value or a variance value of the reception intensity for a predetermined time instead of the reception intensity value. . In addition, a cumulative average value or a variance value after detecting an obstacle may be used, or a statistic other than the average value or the variance value may be used. According to these statistical values and the setting of reliability used, the calculation algorithm can be made simpler than (Equation 4).

  An important point in the present embodiment is that a probability value is set according to a combination of detection areas of each millimeter wave radar, and other conditions may be added or changed as necessary. Further, the reliability may be updated while the dump truck 10 is operating in the mine environment. For example, when the dump truck passes the position of the obstacle detected by the first millimeter wave radar 21 or the second millimeter wave radar 22, it is determined that the obstacle is not a vehicle, and the value of (Equation 4) is updated. Good.

The vehicle presence determination unit 205 determines whether the obstacle detected by the first millimeter wave radar 21 and the second millimeter wave radar 22 is a collision avoidance target based on the reliability obtained by the reliability acquisition unit 203. Is performed (step S509). If the reliability obtained by the reliability acquisition unit 203 is P and the preset threshold value is Pth, if (Equation 5) holds, the obstacle is determined to be a collision avoidance target. The value of the threshold value Pth is set in consideration of the frequency of erroneous collision avoidance processing due to erroneous detection. The threshold value Pth is a reliability indicating an existence probability determined according to the type of obstacle, and when the reliability P is higher than this, it is determined that the obstacle is of a type corresponding to the reliability. Here, a threshold value Pth for determining the vehicle is used.
P> = Pth (Formula 5)

  The obstacle information output unit 206 is configured to output the relative position and relative velocity data of the obstacle determined as the moving object by the moving object determination unit 202 and the relative position and relative speed of the obstacle determined as the vehicle by the vehicle presence determination unit 205. A process of outputting the speed data to the vehicle control device 110 as a collision avoidance target is performed (step S511). The vehicle control device 110 can issue an alarm to the operator using the alarm device 160 based on the collision avoidance target data received from the obstacle detection device 200.

  In the case of an autonomous traveling dump truck, as shown in FIG. 6, the autonomous traveling control unit 170 outputs the braking amount to the autonomous traveling control unit 150 that performs control for autonomous traveling in accordance with the control command from the control server. Or a steering angle is calculated, and a braking instruction signal for applying a braking operation according to the braking amount is output to the braking device 171 or a steering instruction signal is output to the steering motor 172.

  As shown in FIG. 7, when the reflectance of the metal part of the vehicle> the reflectance of the non-metal part of the vehicle> the reflectance of the road surface, the value of the reception intensity of the high-power radar is highest in the metal part of the vehicle, Then the non-metal part and the road surface. The value of the reception intensity of the low-power radar is also in the same order. However, in the case of the low-power radar, the difference in the value of the reception intensity is not as great as that of the high-power radar because the output intensity is low. Therefore, for the output result of the high-power radar, it is possible to classify both using the judgment threshold value of the obstacle such as the vehicle and the non-obstacle such as the road surface. On the other hand, it is difficult to classify both using a determination threshold value for an obstacle such as a vehicle and a non-obstacle such as a road surface. Moreover, since commercially available millimeter-wave radar has built-in threshold values for obstacles and non-obstacles, the user cannot change the threshold values appropriately according to the usage situation.

  In contrast, according to the present embodiment, when a vehicle is in the vicinity of the mining work machine, the detection result of the low-power radar that can easily distinguish the road surface from the vehicle, and the obstacle that can be detected with higher reception intensity Combined with the output radar detection result, it is judged whether the detected object is an obstacle (vehicle) or not, so even if only the part of the vehicle where the reflection intensity is low is detected, it will be mistaken for the road surface It can be determined that there is no vehicle.

  As shown in Fig. 3 (a) or Fig. 3 (b), there are several commercially available millimeter-wave radars with low-power wide-angle areas and high-power detection areas in narrow-angle areas. The vehicle in the vicinity of the work machine can be detected without making a mistake with the road surface. That is, it is possible to provide an obstacle detection technique suitable for a mining work machine using a commercially available product.

<Second embodiment>
In the second embodiment, a low-power radar and a high-power radar are integrally configured, and the low-power radar and the high-power radar are alternately output to detect the low-power radar at a certain time interval (radar switching cycle). This is an embodiment in which the area and the detection area of the high-power radar are overlapped. Hereinafter, a second embodiment will be described with reference to FIGS. FIG. 8 is a schematic configuration diagram of a dump truck according to the second embodiment. FIG. 9 is a block diagram showing a schematic configuration of the millimeter wave radar according to the second embodiment. FIG. 10 is a diagram showing the relationship between the high and low signals of the reference pulse signal and the detection area at that time.

  As shown in FIG. 8, in the second embodiment, a single third millimeter-wave radar (corresponding to an output switching radar device) that alternately outputs low-power radar and high-power data to the front surface of the vehicle body 11 of the dump truck 10. ) 23 is mounted.

  As shown in FIG. 9, the third millimeter wave radar 23 includes a reference pulse transmission unit 231 (timing generator) that generates a reference pulse that determines the output timing of the radar, and a control unit that controls the operation of the third millimeter wave radar 23. 232, a high-power radar transmitter 233 that outputs a high-power radar, a low-power radar transmitter 234 that outputs a low-power radar, and a receiver 235 that includes an antenna that receives a reflected wave of the radar.

  FIG. 10 shows the relationship between the reference pulse and the radar output state of the third millimeter wave radar 23 at that time. The control unit 232 counts the input signal (reference pulse) transmitted from the reference pulse transmission unit 231 to the control unit 232 and calculates the time. The control unit 232 alternately transmits millimeter waves from the high-power radar transmission unit 233 and the low-power radar transmission unit 234 every time the designated time elapses. For example, when the reference pulse signal is high, a high-power radar is transmitted, and the detection area at that time is 123H. When the reference pulse signal is low, a low-power radar is transmitted, and the detection area at that time is 123L. When the moving distance of the dump truck 10 is negligible compared to the radar switching period, for example, the radar switching period is in the milli-SEC order, whereas when the dump truck speed is in the hourly order, the high output radar Since the moving distance of the dump truck is negligible during one switching period with the low-power radar, the overlapping area 123b between the detection area 123H of the high-power radar and the detection area 123L of the low-power radar is the same area within that time. Can be regarded as being detected by both the high-power radar and the low-power radar.

  According to the present embodiment, using a single millimeter wave radar capable of transmitting radars having different output characteristics, a vehicle in the vicinity of the mining work can be detected separately from the road surface as in the first embodiment.

  Furthermore, according to the present embodiment, since one millimeter wave radar may be attached to the front surface of the dump truck body, when a plurality of millimeter wave radars are installed so that their detection areas overlap as in the first embodiment. Compared with this, it is possible to easily perform the installation work of the millimeter wave radar.

  The embodiment of the present invention has been described above. The present invention is not limited to being realized as the embodiment. For example, in setting the reliability, more than one type of hypothesis H may be set, not only the hypothesis H that is a vehicle of H1 but a vehicle of H2. For example, you may increase the object which should be determined as alarm objects, such as a pedestrian, a bank, and a falling rock. In addition to the reception intensity of the reflected wave from the obstacle, the distribution shape of multiple obstacles detected by the millimeter wave radar is obtained from the relative position variation, and the parameter that expresses the distribution shape (for example, when considered as an elliptical shape) The reliability may be set based on the length of the major axis and the minor axis of the ellipse.

  Further, when there are a plurality of hypotheses in the vehicle presence determination unit 205, the hypothesis having the largest probability value may be determined to be true, and the determined obstacle type may be notified to the obstacle information output unit 206. Thus, for example, when an obstacle detected by the millimeter wave radar is determined to be a pedestrian, the vehicle control device can output an alarm different from that determined to be a vehicle, and an alarm corresponding to the type of the obstacle is output. Can be put out.

  In addition, when a wireless communication device is installed in the dump truck 10 and the reliability is updated, the result is notified to the control server via the vehicle control device 110 and the communication device so that it can be shared with other dump trucks. May be. Furthermore, the reliability may be updated by receiving the reliability updated by another dump truck.

  Furthermore, the method of overlapping the detection areas is not limited to the above embodiment. For example, one low-power radar device and two high-power radar devices, and a total of three (or three or more) radars may be mounted on the mining work machine. For example, as shown in FIG. 11, the detection area of the low-power radar device may be overlapped with a_L, and the detection areas of the two high-power radar devices may be overlapped with b_H and c_H. The output of each radar may be one radar device having one low-power laser detection area and two high-power radar detection areas, or the other low-power laser detection area being two high. There may be one output radar detection area. And you may comprise so that the detection area of the high output radar of the radar apparatus from which the output of these detection areas differs may overlap with the detection area of the low output radar. As described above, the number of radar devices and the breakdown of the detection regions of one radar device (the number of detection regions of a high-power radar and the number of detection regions of a low-power radar) are not limited to the above embodiment, and the high output Obstacle detection devices that determine the type of an obstacle by spatially or temporally overlapping a detection area of a radar and a detection area of a low-power radar are widely included in the present invention.

10: dump truck, 21: first millimeter wave radar, 22: second millimeter wave radar, 23: third millimeter wave radar, 200: obstacle detection device

Claims (8)

A mining work machine equipped with at least two or more radar devices that detect obstacles ahead in the traveling direction,
At least one long-distance high-power radar device that emits electromagnetic waves with a narrow irradiation angle and high output intensity;
At least one low-power radar device for short-range irradiation that emits electromagnetic waves having a wide irradiation angle and low output intensity;
An obstacle detection device for determining the presence or absence of an obstacle using the detection result from each of the high-power radar devices and the detection result from each of the low-power radar devices,
The detection area of each high-power radar device is attached to the mining work machine at a position where the detection areas of at least one or more low-power radar devices overlap.
The obstacle detection device detects the type of obstacle detected in the detection region of the low-power radar device overlapping the detection region of each high-power radar device, and radiates the electromagnetic waves emitted by the high-power radar device and the low-power radar device. Is determined based on the received intensity of the reflected wave generated by being reflected by the obstacle,
Mining work machine characterized by that. The mining work machine according to claim 1,
A first radar device including the high-power radar device and the low-power radar device; and a second radar device configured separately from the first radar device and including the high-power radar device and the low-power radar device. Prepared,
The first radar device and the second radar device are arranged such that a detection region of the high-power radar device included in the first radar device overlaps a detection region of the low-power radar device included in the second radar device. Attach to the mining work machine at
Mining work machine characterized by that. The mining work machine according to claim 1,
The obstacle detection device includes a combination of a detection area and a reception intensity of the high-power radar device and the low-power output when each of the high-power radar device and the low-power radar device detects an object to be detected. If the reliability set in advance according to the combination of the detection area of the radar device and the received intensity is acquired, and the reliability is greater than the reliability indicating the existence probability determined according to the type of obstacle, The detected object is determined to be an obstacle of a type corresponding to the reliability.
Mining work machine characterized by that. The mining work machine according to claim 3,
The obstacle detection device divides the detection region of the high-power radar device and the low-power radar device into a plurality of small regions, and sets the reliability according to the combination with the reception intensity in the small region,
Mining work machine characterized by that. The mining work machine according to claim 3,
The obstacle detection device divides a detection region of the high-power radar device and the low-power radar device into a plurality of small regions, and has a reliability according to a combination of an average value and a dispersion value of reception intensity within a predetermined time. Set
Mining work machine characterized by that. The mining work machine according to claim 1,
The high-power radar device and the low-power radar device are designed to irradiate an electromagnetic wave with a wide output angle and a wide output angle and a low output intensity of a high-power radar for long-distance irradiating an electromagnetic wave with a narrow irradiation angle and high output intensity. Configured using an output switching radar device that alternately switches the output timing of a low-power radar for
Mining work machine characterized by that. The mining work machine according to claim 1,
The high-power radar device transmits a radar having an output intensity capable of receiving a reflected wave from the road surface,
The low-power radar device transmits a radar having an output intensity with a relatively small difference in reception intensity between a reflected wave from a non-metal part of a vehicle and a reflected wave from a road surface
The obstacle detection device determines whether the obstacle is a vehicle;
Mining work machine characterized by that. At least one high-power radar device for long-distance irradiation that irradiates electromagnetic waves with a narrow irradiation angle and high output intensity, and at least one low-range radiation for irradiation with electromagnetic waves with a wide irradiation angle and low output intensity An obstacle detection device that determines the type of an obstacle ahead in the traveling direction of a mining work machine on which the two or more radar devices are mounted, based on detection results of at least two or more radar devices including an output radar device. Because
The detection area of each high-power radar device is attached to the mining work machine at a position where the detection areas of at least one or more low-power radar devices overlap.
The obstacle detection device detects the type of obstacle detected in the detection region of the low-power radar device overlapping the detection region of each high-power radar device, and radiates the electromagnetic waves emitted by the high-power radar device and the low-power radar device. Is determined based on the received intensity of the reflected wave generated by being reflected by the obstacle,
An obstacle detection device characterized by that.