JP6494538B2 - Limit measuring device and limit measuring program - Google Patents

Description

  The present invention relates to a technique for detecting the presence of an object within a limit distance around a vehicle.

In railways, building limits are set to ensure the safety of vehicle operation. The building limit is a range in which it is prohibited to install a building or the like that obstructs the operation of the vehicle, and is a range determined based on the rail. After construction work such as railway tracks, building limits are measured and it is confirmed that there are no objects such as buildings within the building limits.
Similarly, on the road, it is necessary to confirm that there is no object in the dangerous range in view of the vehicle width and vehicle height of the traveling vehicle.

As a method of confirming that there are no objects within the building limits, a method of attaching a whisker-like part to the vehicle and confirming that physical contact between the beard-like part and an object such as a building did not occur was used. . In addition, a method of measuring a distance one by one to an object around the vehicle using a measure or a laser has been used.
However, in the method of confirming that physical contact does not occur, the apparatus is large-scale, and there is a danger when physical contact is made. Also, the method of measuring the distance to the object one by one is inefficient and inaccurate.

  Patent Document 1 describes MMS (Mobile Mapping System). In MMS, a vehicle equipped with a laser scanner is run, and the laser scanner scans the surroundings where the vehicle has traveled, thereby obtaining a laser point cloud indicating surrounding objects traveled by the vehicle.

Japanese Patent Laid-Open No. 2015-096824

The laser point cloud acquired by MMS has position information. Therefore, the distance to each point of the laser point group can be calculated, and it can be confirmed that there is no object within the construction limit. However, in this, as a post-processing after the vehicle has traveled and the laser point cloud data has been accumulated, the distance measurement processing, three-dimensional processing, and recognition processing of each point are performed by the computer. It will be confirmed that there is no object within the limits. Therefore, it is not possible to immediately confirm that there is no object within the building limits while driving the vehicle.
When there is an object within the construction limits, there is a case where an action such as removing the object is required immediately. For this reason, there is a disadvantage in the method of confirming that there is no object within the building limit by post-processing using MMS.

  It is an object of the present invention to make it possible to confirm that there is no object within a limit distance such as a building limit immediately and safely while driving the vehicle.

The limit measuring apparatus according to the present invention is:
A storage device that stores a limit distance from a reference point for each of a plurality of directions on a vertical plane perpendicular to the traveling direction of the vehicle;
While the vehicle is running, an object is placed at a position within the limit distance in which the distance from the reference point is stored in the storage device in each direction on the vertical plane using a laser scanner attached to the vehicle. A detection unit for detecting that there is,
A notification unit that notifies when the detection unit detects that the object is present.

  In the present invention, a limit distance is set, and an object within the limit distance is detected using a laser scanner while the vehicle is traveling. Thereby, it can be confirmed that there is no object within the limit distance immediately and safely while the vehicle is running.

1 is a configuration diagram of a limit measurement device 10 according to Embodiment 1. FIG. Explanatory drawing of the limit distance 121 which concerns on Embodiment 1. FIG. FIG. 3 is a diagram showing a state in which the limit measurement device 10 according to the first embodiment is mounted on a vehicle 20. FIG. 3 is a schematic explanatory diagram of the operation of the limit measurement device 10. FIG. 6 is a schematic explanatory diagram of an operation of detecting that an object is within a limit distance 121. 5 is a flowchart showing the operation of the limit measurement device 10. Explanatory drawing about the detection of the reference point 22. FIG. Explanatory drawing when the rail 23 inclines. The block diagram of the limit measuring apparatus 10 in case the function of each part is implement | achieved by hardware.

Embodiment 1 FIG.
*** Explanation of configuration ***
With reference to FIGS. 1 to 3, the configuration of the limit measuring apparatus 10 according to the first embodiment will be described.
The limit measurement device 10 is a computer and is mounted on the vehicle 20. In the first embodiment, the vehicle 20 is a railroad vehicle.
The limit measurement device 10 includes a processor 11, a storage device 12, and a laser scanner 13. The processor 11 is connected to other hardware via a signal line, and controls these other hardware.

The limit measurement apparatus 10 includes a detection unit 111 and a notification unit 112 as functional configurations. The functions of the detection unit 111 and the notification unit 112 are realized by software.
The storage device 12 stores a program that realizes the functions of the respective units of the limit measurement device 10. This program is read into the processor 11 and executed by the processor 11. Thereby, the function of each part of limit measuring device 10 is realized. Further, the limit distance 121 is stored in the storage device 12.

The limit distance 121 according to the first embodiment will be described with reference to FIG.
The limit distance 121 is a distance from the reference point 22 that is determined for each of a plurality of directions on the vertical plane 21 perpendicular to the traveling direction of the vehicle 20, and indicates a building limit in the first embodiment. In the first embodiment, the reference point 22 is the rail 23 on which the track-rail vehicle travels.

The processor 11 is an IC that performs processing. IC is integrated
Abbreviation for Circuit. Specifically, the processor 11 is a CPU, a DSP, or a GPU. CPU is an abbreviation for Central Processing Unit. DSP is an abbreviation for Digital Signal Processor. GPU is an abbreviation for Graphics Processing Unit.

  Specifically, the storage device 12 is a RAM and an HDD. RAM is an abbreviation for Random Access Memory. HDD is an abbreviation for Hard Disk Drive. The storage device may be configured by other hardware such as a ROM and a flash memory. ROM is an abbreviation for Read Only Memory.

The laser scanner 13 is a device that detects information such as three-dimensional coordinates, color information, and reflection intensity of an object around the vehicle 20 by irradiating a laser beam and receiving reflected light.
In the first embodiment, the laser scanner 13 is installed at the front or rear of the vehicle 20 so as to irradiate the laser in a direction perpendicular to the traveling direction of the vehicle 20, that is, in a direction perpendicular to the ground. To do. In FIG. 2, the four-wheeled vehicle 24 on which the laser scanner 13 is mounted is placed on a railroad vehicle that is the vehicle 20. In FIG. 2, the laser scanner 13 is installed at the rear of the four-wheeled vehicle 24 so as to irradiate the laser in a direction perpendicular to the ground. That is, the laser scanner 13 is installed so as to irradiate a laser on the vertical surface 21. The laser scanner 13 is installed so that the irradiated laser is not shielded.
Further, in the first embodiment, it is assumed that the laser scanner 13 can irradiate a laser in the range of 360 degrees on the vertical surface 21.

  Information, data, signal values, and variable values indicating the results of processing of each function realized by the processor 11 are stored in the storage device 12 or a register or cache memory in the processor 11. In the following description, information, data, signal values, and variable values indicating the results of processing of the functions realized by the processor 11 are described as being stored in the storage device 12.

  It is assumed that a program for realizing each function realized by the processor 11 is stored in the storage device 12. However, this program may be stored in a portable storage medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD.

  In FIG. 1, only one processor 11 is shown. However, a plurality of processors 11 may be provided, and a plurality of processors 11 may execute programs that realize each function in cooperation with each other.

*** Explanation of operation ***
With reference to FIGS. 4 to 5, the operation of the limit measurement apparatus 10 according to the first embodiment will be described.
The operation of the limit measurement apparatus 10 according to the first embodiment corresponds to the limit measurement method according to the first embodiment. The operation of the limit measurement apparatus 10 according to the first embodiment corresponds to the process of the limit measurement program according to the first embodiment.

With reference to FIG. 4, the outline | summary of operation | movement of the limit measuring apparatus 10 is demonstrated.
The limit measuring apparatus 10 irradiates a laser on the vertical surface 21 by a laser scanner 13 mounted on the vehicle 20 while the vehicle 20 is traveling, and thus an object such as a building around the vehicle 20 from the reference point 22. The distance to is specified sequentially. Then, the limit measurement device 10 notifies the worker when the specified distance is within the limit distance 121. Thereby, the worker can know that there is an object within the limit distance 121 in real time while the vehicle 20 is traveling.

With reference to FIG. 5, an outline of an operation for detecting that an object is within the limit distance 121 will be described.
The laser scanner 13 sequentially irradiates the laser on the vertical surface 21 while shifting by a certain angle. Therefore, it is possible to specify the distance to the object around the vehicle 20 for every fixed angle. However, noise often enters the distance detected by the laser scanner 13. For this reason, if the distance from the reference point 22 calculated from the distance detected by the laser scanner 13 to the object is within the limit distance 121, it is assumed that the object is simply located at the position within the limit distance 121. Misdetections will increase.
Therefore, the limit measuring apparatus 10 determines that the normal period in which the object is recognized to exist is present when the difference between the two distances measured continuously is within the reference distance for the reference number or more. Then, when the distance measured during the normal period is within the limit distance 121, the limit measurement device 10 detects that there is an object at a position within the limit distance 121. In other words, the limit measurement device 10 determines that noise is included when the difference between the two distances measured in succession is within the reference distance and does not continue beyond the reference number, and the distance specified between them is Do not use for object detection.
In the first embodiment, it is assumed that the reference distance is 0.1 m (meter) and the reference number is 5.

With reference to FIG. 6, the operation of the limit measuring apparatus 10 will be described in detail.
The process shown in FIG. 6 is executed while the vehicle 20 is traveling. The process shown in FIG. 6 is continuously executed until an end input is received from the worker.

In the detection process of step S <b> 1, the detection unit 111 uses the laser scanner 13 attached to the vehicle 20, and the limit distance 121 in which the distance from the reference point 22 in each direction on the vertical plane 21 is stored in the storage device 12. It detects that there is an object in the position.
The detection process in step S1 is divided into processes from step S11 to step S16.

In the laser irradiation process of step S11, the detection unit 111 causes the laser scanner 13 to irradiate a laser in a certain direction on the vertical surface 21, and specifies a distance to an object around the vehicle 20 in that direction.
Specifically, the detection unit 111 measures the distance from the laser irradiation port of the laser scanner 13 to the object from the time difference between the time when the laser is irradiated by the laser scanner 13 and the time when the reflected light is received. . Then, the detection unit 111 calculates the distance from the reference point 22 to the object based on the position of the laser irradiation port and the position of the reference point 22 and the measured distance. The detection unit 111 writes the calculated distance in the storage device 12.

In the adjacent distance determination process in step S12, the detection unit 111 determines the distance from the reference point 22 identified in the latest step S11 to the object, and the distance from the reference point 22 identified in step 11 before that to the object. Is read from the storage device 12. Then, the detection unit 111 determines whether or not the difference between the two read distances is within the reference distance. It is assumed that the reference distance is stored in advance in the storage device 12. As described above, in the first embodiment, the reference distance is 0.1 m.
If the difference between the two distances is within the reference distance, the detection unit 111 advances the process to step S13. On the other hand, if the difference between the two distances is not within the reference distance, the detection unit 111 advances the process to step S16.

  In the continuous count process in step S13, the detection unit 111 updates the counter value stored in the storage device 12 to a value obtained by adding 1. It is assumed that the counter value is initialized to 1 at the start of the processing of FIG.

In the continuous determination process in step S <b> 14, the detection unit 111 reads the counter value from the storage device 12. Then, the detection unit 111 determines whether or not the counter value is greater than or equal to the reference number. It is assumed that the reference number is stored in advance in the storage device 12. As described above, the reference number is 5 in the first embodiment.
If the counter value is greater than or equal to the reference number, the detection unit 111 advances the process to S15. On the other hand, when the counter value is less than the reference number, the detection unit 111 returns the process to S11.

In the limit distance determination process in step S15, the detection unit 111 reads the distance from the reference point 22 identified in step S11 to the object from the storage device 12. Further, the detection unit 111 reads the limit distance 121 in the direction in which the laser is irradiated in step S11 from the storage device 12. Then, the detection unit 111 determines whether or not the read distance is within the read limit distance 121.
In addition, when the count value is equal to the reference number, the detection unit 111 reads the distance specified in step S11 from the storage device 12 for the past reference number of times (the past five times in the first embodiment). It is determined whether the distance is within the limit distance 121 in the corresponding direction. On the other hand, if the count value is larger than the reference number, the distance specified most recently in step S11 is read from the storage device 12, and it is determined whether or not the read distance is within the limit distance 121.
If it is determined that the distance is within the limit distance 121, the detection unit 111 outputs the detection information 31 to the notification unit 112, and the process proceeds to step S2. On the other hand, if it is determined that the detection unit 111 is outside the limit distance 121, the process returns to step S11.

  In the count reset process in step S <b> 16, the detection unit 111 sets 1 to the counter value stored in the storage device 12.

In the notification process of step S2, when the detection information 111 is output from the detection unit 111, the notification unit 112 writes the detection information in the storage device 12 and notifies the worker.
Specifically, the notification unit 112 outputs notification information 32 such as sound, light, and a message to notify the worker that an object located within the limit distance 121 has been detected.

*** Effects of Embodiment 1 ***
As described above, the limit measurement apparatus 10 according to the first embodiment sets the limit distance 121 and detects an object within the limit distance 121 using the laser scanner 13 while the vehicle 20 is traveling. Accordingly, it can be confirmed that there is no object within the limit distance 121 immediately and safely while the vehicle 20 is traveling.

  In particular, the limit measurement apparatus 10 according to the first embodiment detects an object within the limit distance 121 after removing the detection noise of the laser scanner 13. Thereby, erroneous detection can be prevented.

*** Supplement of Embodiment 1 ***
Supplement (1) Detection of Reference Point 22 Detection of the reference point 22 will be described with reference to FIGS. 7 and 8. 7B and 7C, the position of the vehicle 20 when the vehicle 20 is in a normal state is indicated by a broken line.
The detection unit 111 detects the position of the reference point 22 every time in step S11. Specifically, the detecting unit 111 detects the position of the reference point 22 by detecting the rail 23 from the distance to an object around the vehicle 20 specified in the past, that is, the laser point group. In step S <b> 11, the detection unit 111 calculates the distance from the reference point 22 to the object based on the detected position of the reference point 22. In step S15, the detection unit 111 specifies the limit distance 121 to be read based on the detected position of the reference point 22 and the direction of laser irradiation in step S11.
The reason why the position of the reference point 22 is detected every time is to prevent the determination using the wrong limit distance 121. If the position of the reference point 22 is fixed with respect to the position of the vehicle 20, as shown in FIG. 7B, the vehicle 20 is compared with a case where the vehicle 20 is in a normal state as shown in FIG. When the vehicle is inclined and when the vehicle 20 is traveling at a position shifted as shown in FIG. 7C, the limit distance 121 of the shifted position is used. Therefore, the detection unit 111 detects the position of the reference point 22 each time, and specifies the inclination and position of the vehicle 20 from the position of the laser irradiation port and the position of the reference point 22. Then, the distance from the reference point 22 to the object is calculated, and the limit distance 121 to be used is specified. Accordingly, it is possible to accurately detect an object located within the limit distance 121 regardless of the traveling state of the vehicle 20.

  As shown in FIG. 8, the rail 23 serving as the reference point 22 may be inclined. In this case, the limit distance 121 is set by rotating a point group that defines the limit distance 121 according to the detected inclination of the rail 23. It should be noted that the inclination of the rail 23 and the inclination of the railroad vehicle, which is the vehicle 20, are irrelevant. become.

Supplement (2) Restriction on detection A thin object that falls between laser points detected by the irradiated laser is not detected.
As described above, the laser scanner 13 irradiates the laser while shifting the vertical surface 21 by a certain angle. Therefore, an object that enters between a laser point detected by a certain laser and a laser point detected by the next irradiated laser is not detected. Further, an object that enters between laser points in the traveling direction of the vehicle 20 is not detected.
If the rotation speed of the laser is slowed, the deviation of the laser irradiation angle becomes small, and the interval between the laser points in the rotation direction becomes narrow. However, if the rotation speed of the laser is slowed at the same traveling speed, the interval between the laser spots becomes wider in the traveling direction of the vehicle 20. Therefore, if the interval between the laser points in the traveling direction is also reduced, the traveling speed of the vehicle 20 needs to be reduced. That is, if the rotation speed of the laser is slow and the traveling speed of the vehicle 20 is slow, the distance between the laser points in the rotation direction and the traveling direction becomes narrow, and even a thin plate-like object can be easily detected.
Specifically, assuming that 5000 points are detected when the rotational speed of the laser is 200 rps, the deviation of the laser irradiation angle is 0.072 deg. Therefore, the interval between the laser points at 2 m ahead is 2.5 mm (millimeter). As described above, when the reference number for excluding noise is 5, the minimum detection width is 12.5 mm or more. When the laser rotation speed is 50 rps, the minimum detection width can be about 3 mm.
Further, when the rotational speed of the laser is 200 rps and the traveling speed of the vehicle 20 is 40 km / h (kilometers / hour), the interval between the laser points in the traveling direction is 5.6 cm (centimeter). When the rotational speed of the laser is 50 rps and the traveling speed of the vehicle 20 is 40 km / h, the distance between the laser points in the traveling direction is 22 cm.

Supplement (3) Installation of Laser Scanner 13 In the above description, the laser scanner 13 is installed so as to irradiate a laser in a direction perpendicular to the traveling direction of the vehicle 20. By installing the laser scanner 13 in this way, the distance measured based on the laser is the distance on the vertical plane 21 that defines the limit distance 121, and thus the measured distance needs to be converted to the distance on the vertical plane 21. There is no. Therefore, the processing load is small. Further, even if the posture of the vehicle 20 is disturbed, the influence on the distance to be measured is small.
However, the laser scanner 13 may be installed so as to irradiate the laser in a direction slightly shifted from the vertical plane 21 in the traveling direction of the vehicle 20. Even in this case, if the measured distance is converted into the distance in the vertical plane 21, it can be detected that an object is located at a position within the limit distance 121.
If the laser scanner 13 is installed so as to irradiate the laser in a direction slightly deviated from the vertical plane 21 in the traveling direction of the vehicle 20, a thin object may be detected as long as the object is perpendicular to the traveling direction. There is.

Supplement (4) Laser Irradiation Range In the above description, it is assumed that the laser scanner 13 can irradiate a laser in a range of 360 degrees. However, the laser scanner 13 may be capable of irradiating the laser only in the range of 180 degrees. In this case, only the range of 180 degrees is the object detection range. Of course, two laser scanners 13 capable of irradiating laser only in the range of 180 degrees may be mounted so that the laser can be irradiated in the range of 360 degrees.

Supplement (5) Type of Vehicle 20 In the above description, the vehicle 20 is assumed to be a track-and-rail vehicle. However, the vehicle 20 may be another vehicle such as an automobile. In the case where the vehicle 20 is an automobile, the limit distance 121 is not a building limit, but causes a problem in the safe driving of the automobile when considering the vehicle width and height of the automobile that is allowed to travel on the road. A range may be set. This makes it possible to detect obstacles caused by events such as wire drooping and tree growth.
Further, if the distance between the laser point groups is calculated instead of determining whether or not there is an object at the position within the limit distance 121, the lane width can be calculated in real time from the width between the white lines on the road. Similarly, the height and width in the tunnel can be calculated. Thereby, the maximum width and the maximum height of the vehicle 20 that can pass through a road or a tunnel can be specified.

*** Other configurations ***
In the first embodiment, each function of the limit measurement device 10 is realized by software. However, as a modification, each function of the limit measurement device 10 may be realized by hardware. This modification will be described with respect to differences from the first embodiment.

With reference to FIG. 9, the configuration of the limit measurement apparatus 10 when the functions of the respective units are realized by hardware will be described.
When the function of each unit is realized by hardware, the limit measurement apparatus 10 includes a laser scanner 13 and a processing circuit 14. The processing circuit 14 is a dedicated electronic circuit that realizes the functions of the respective units of the limit measurement device 10 and the functions of the storage device 12.

The processing circuit 14 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA, an ASIC, or an FPGA. GA is an abbreviation for Gate Array. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array.
The function of each part may be realized by one processing circuit 14, or the function of each part may be distributed to a plurality of processing circuits 14.

  As another modification, some functions may be realized by hardware, and other functions may be realized by software. That is, some of the functions of the limit measurement device 10 may be realized by hardware, and other functions may be realized by software.

  The processor 11, the storage device 12, and the processing circuit 14 are collectively referred to as “processing circuitry”. That is, the function of each part is realized by a processing circuit. That is, even if the limit measuring apparatus 10 has the configuration shown in FIGS. 1 and 9, the functions of the respective units are realized by the processing circuitry.

  In addition, the limit measurement device 10 may include other devices such as a camera, a positioning signal receiver, an IMU, and an odometer. And the limit measurement apparatus 10 may acquire data, such as the position of the vehicle 20 and the surrounding image data, by these apparatuses.

  10 limit measuring device, 11 processor, 12 storage device, 13 laser scanner, 14 processing circuit, 111 detection unit, 112 notification unit, 20 vehicle, 21 vertical plane, 22 reference point, 23 rail, 31 detection information, 32 notification information.

Claims (4)

A storage device that stores a limit distance from a reference point for each of a plurality of directions on a vertical plane perpendicular to the traveling direction of the vehicle;
The distance from the reference point in each direction on the vertical plane is stored in the storage device using a laser scanner that is attached to the vehicle and emits laser while gradually shifting the irradiation angle while the vehicle is running. A detection unit that detects that an object is located at a position within the limit distance, and sequentially measures the distance in the direction on the vertical plane according to the angle at which the laser is irradiated by the laser scanner. When the distance measured within a normal period in which the difference between the two measured distances is within the reference distance is equal to or greater than the reference number and is within the limit distance, the object is positioned at the position within the limit distance. A detection unit for detecting that there is,
A limit measurement device comprising: a notification unit that notifies when the detection unit detects that the object is present. The detection unit detects a position of the reference point, and calculates a distance from the reference point to the object from a distance to the object measured by the laser scanner based on the detected position of the reference point. The limit measuring apparatus according to 1. The limit measuring apparatus according to claim 2, wherein the reference point is a point determined based on a rail on which the vehicle travels. For each of a plurality of directions on a vertical plane perpendicular to the traveling direction of the vehicle, a storage device storing a limit distance from the reference point is used.
The distance from the reference point in each direction on the vertical plane is stored in the storage device using a laser scanner that is attached to the vehicle and emits laser while gradually shifting the irradiation angle while the vehicle is running. Detection processing for detecting the presence of an object at a position within the limit distance, and sequentially measuring the distance in the direction on the vertical plane in accordance with the angle irradiated with the laser by the laser scanner. When the distance measured within a normal period in which the difference between the two measured distances is within the reference distance is equal to or greater than the reference number and is within the limit distance, the object is positioned at the position within the limit distance. A detection process to detect that there is,
A limit measurement program for causing a computer to execute notification processing for notifying that the presence of the object is detected by the detection processing.

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