JP4365282B2 - Obstacle detection system and obstacle detection method - Google Patents

Description

  The present invention relates to a system and an obstacle detection method for detecting obstacles at railroad crossings, intersections, and the like.

  Conventionally, an obstacle detection sensor that detects people or cars in a level crossing is installed in the level crossing in order to prevent a level crossing accident. An object detection system is considered.

  FIG. 14 is a diagram showing a conventional level crossing obstacle detection system. In FIG. 14, optical sensors 101 and 102 for detecting obstacles are provided at the entrance and exit of a railroad crossing, and another sensor 103 is provided between the up and down lines 104 to face the sensor across the crossing passage. Three projecting plates 105 to 107 are provided at the positions to be operated.

  The light emitted from the sensor 101 is reflected by the reflecting plate 105, and the reflected light is detected by the light receiving unit of the sensor 101. The light emitted from the sensor 103 is reflected by the reflectors 105 and 107, and the reflected light is detected by the light receiving unit of the sensor 103. The light emitted from the sensor 102 is reflected by the reflectors 107 and 106, and the reflected light is detected by the light receiving unit of the sensor 102.

  In the above obstacle detection system, since an object is detected on a line connecting the sensors 101 to 103 and the reflectors 105 to 107, a relatively large object such as an automobile can be detected. There is a case where it is out of the detection area and cannot be detected.

FIG. 15 is a diagram illustrating a case where an obstacle detection system similar to the above is applied to an intersection.
In FIG. 15, sensors 111 and 112 are installed at two intersections, and four sensors 113 to 116 are installed at each pedestrian crossing. The arrows in FIG. 15 indicate the detection area of each sensor.

This obstacle detection system also has a drawback that it cannot detect the person 117 walking off the sidewalk because the detection area of the sensors 111 to 116 is narrow.
In order to eliminate the drawbacks of the linear detection method as described above, for example, in Patent Document 1, a millimeter wave sensor is installed on a rotatable drive unit, and the millimeter wave sensor is rotated to rotate the millimeter wave sensor. It describes the detection of obstacles.
JP 2000-326850 A

However, there is a problem in that the cost of components increases when the durability of the drive unit that rotates the obstacle detection sensor used outdoors is increased.
An object of the present invention is to make it possible to detect an obstacle within a certain range without increasing the component cost of the sensor.

  FIG. 1 is an explanatory diagram of the principle of the present invention. The present invention is an obstacle detection system for detecting obstacles existing within a certain range, and a plurality of sensors having a detection area having directivity are formed so as to form detection areas within a predetermined range by changing detection directions. Coordinate calculation means 2 that calculates the sensor unit 1 that is arranged and a point corresponding to the measurement distance of the sensor on the axis extending in the same direction as the detection direction of each of the sensors 1a to 1d of the sensor unit 1 as the coordinates of the detected object. The determination unit 3 that determines that an object whose distance between the coordinate calculated this time by the coordinate calculation unit 2 and the coordinate calculated a predetermined time ago is equal to or less than a predetermined value is determined to be the same by the determination unit 3. A speed calculation means 4 for calculating the speed of the detected object, and a time required for the object to go out of a certain range from the current position of the object and the speed calculated by the speed calculation means 4 Calculated time and a warning means 5 for performing a warning when a predetermined time or more.

  According to this invention, the two-dimensional coordinates are calculated based on the measurement distance of the object detected by each sensor, and the position of the object is more accurately determined by specifying the same object from the previous measurement result and the current measurement result. Can be detected. Then, the presence or absence of an obstacle can be determined based on the detected position of the object, and a warning can be given when an obstacle exists.

  Another obstacle detection system according to the present invention is an obstacle detection system for detecting an obstacle existing within a certain range, and detects a predetermined range by changing the detection direction of a sensor having a detection area having directivity. When an object is detected at the same distance by two sensor units arranged so as to form an area and a part of the detection area of the adjacent sensor overlaps with two sensors that overlap a part of the detection area When a point corresponding to the measurement distance of the sensor on the first axis extending in the detection direction within the overlapping area of the two sensors is calculated as the coordinates of the detected object, and the object is not detected at the same distance by the two sensors Includes a coordinate calculation means for calculating a point corresponding to a measurement distance on an axis different from the first axis, which extends in the detection direction of each sensor, as coordinates of the detected object; and A determination unit that determines an object having a distance between a coordinate calculated this time and a coordinate calculated a predetermined time before the predetermined value as the same object, and a speed calculation that calculates a speed of the object determined to be the same by the determination unit A warning means for calculating a time required for the object to go out of a certain range from the current position of the object and the speed calculated by the speed calculation means, and for giving a warning when the calculated time is equal to or longer than a predetermined time; Is provided.

  According to this invention, when an object is detected at the same distance by two sensors in which a part of the detection area overlaps, the point corresponding to the measurement distance on the first axis in the overlap area is detected. By calculating as the dimensional coordinates, for example, the position of the object can be detected more accurately using a one-dimensional sensor. As a result, obstacles within a certain range can be detected without increasing the component cost of the sensor unit.

  For example, the sensor unit corresponds to the sensor unit 11 in FIG. 3, the first axis in the overlap area corresponds to the intermediate axis 52 in FIG. 8, and the axis different from the first axis corresponds to the sensor in FIG. This corresponds to the main shaft 53.

  According to another aspect of the obstacle detection system of the present invention, the coordinate calculation unit is configured so that, when an object is detected at the same distance by two sensors in which the positions of the detection areas overlap, the coordinates are calculated on the central axis of the overlapping area of the detection areas. If the point corresponding to the measured distance is calculated as the coordinates of the detected object and the object is not detected at the same distance, the point corresponding to the measured distance on the main axis in the detection area of each sensor is calculated. Calculate as coordinates.

  With this configuration, when an object is detected at the same distance by two sensors, a point on the central axis of the overlapping area of the detection area is calculated as the coordinates of the detected object. It is possible to distinguish between an object inside and an object in other areas.

  Another aspect of the obstacle detection system of the present invention is a crossing obstacle detection system, wherein the sensor unit is installed at one of four corners of a detection area so that an object in the crossing can be detected.

  According to the present invention, obstacles within a certain range can be detected without increasing the component cost of the sensor unit. Further, by partially overlapping the detection areas of the sensors and specifying the objects detected in the overlapping areas, the position of the objects can be detected more accurately, and the obstacle detection accuracy can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a diagram illustrating a configuration of an obstacle detection system that detects an obstacle in a railroad crossing according to the embodiment of this invention.
In FIG. 2, the sensor unit 11 includes a plurality of one-dimensional sensors such as a fan beam sensor having a directivity detection area with different detection directions so that an object within a certain range can be detected. The sensor unit 11 has fan beam sensors (hereinafter referred to as sensors) 11a to 11e having different detection directions arranged in the horizontal direction. Each of the sensors 11a to 11e has a conical detection area with the sensor as the origin, and forms a predetermined range of detection area in the entire sensor unit 11 by slightly shifting the detection direction.

  The processing device 12 calculates the coordinates of each object from the distances to the objects measured by the sensors 11a to 11e, and identifies the object from the coordinates of the object detected a predetermined time ago and the coordinates of the object detected this time. In addition, the movement speed is obtained from the coordinates of the object, and it is estimated whether a detection object such as a person or car can go out of the railroad crossing before the railroad crossing breaker gets off. If it is estimated that it will not be possible, a warning will be sent to the pedestrian, driver, or driver of the approaching train at the railroad crossing. The processing device 12 can be realized by a device using a personal computer or a dedicated device incorporating a CPU.

  FIG. 3 is a diagram illustrating a detection area of the sensor unit 11 used in the crossing obstacle detection system. In the sensor unit 11, a plurality of sensors 11a to 11e are arranged side by side in the horizontal direction (or vertical direction) in FIG. The detection area of each of the sensors 11a to 11e shown in FIG. 3 extends in a conical shape with the sensor as the origin, for example, a detection area 21a of the sensor 11a, a detection area 21b of the sensor 11b, a detection area 21dc of the sensor 11c, The detection area 21d of the sensor 11d and the detection area 21e of the sensor 11e are continuously formed as a whole of the sensor unit 11 to form a fan-shaped detection area as shown in FIG.

  Although not shown in FIG. 3, the sensors 11 a to 11 e are arranged so that adjacent sensors and a part of the detection areas 21 a to 21 e overlap each other, and an object existing in the overlapping area is two adjacent sensors. Is detected.

Next, FIG. 4 is a flowchart of processing for specifying objects detected by the sensors 11a to 11e.
First, the distances to the objects measured by the sensors 11a to 11e are written in the measurement result table 31 shown in FIG. 5 (FIG. 4, step 11).

  FIG. 5 is a diagram showing the measurement result table 31. As shown in FIG. 5, the measurement result table 31 stores the measurement distance of the object and the coordinate number of the coordinate table 32 described later in association with the IDs of the sensors 11a to 11e. The coordinates of the object can be obtained from this coordinate number.

Next, X and Y coordinates are calculated from the measured distance of the first sensor (in this case, sensor 11a), and the calculated coordinates are written in the coordinate table 31 at time t in FIG. 6 (FIG. 4, step 12).
Here, the method of calculating the X and Y coordinates in step S12 will be described with reference to FIG. When the object 42 is detected at the point of distance d1 by the sensor, the point of distance d1 from the origin (sensor installation position) on the main axis (center axis of the detection area) 41 of the sensor fan beam is measured distance d1. As the coordinates of the object 42. Next, from the angle θ of the main shaft 41 with respect to the X axis, the X coordinate X1 and the Y coordinate Y1 of the point of the distance d1 on the main shaft 41 are obtained from X1 = d1 × cos θ and Y1 = d1 × sin θ.

  FIG. 6 is a diagram showing the configuration of the coordinate table 32. The coordinate table 32 stores the X coordinate, Y coordinate, and coordinate number of the object detected by the process of step S12 in association with each other. And the coordinate number of this coordinate table 32 is matched and memorize | stored with the measurement distances d1a-d3a, d1b-d12 ... d1f of each sensor 11a-11e of the measurement result table 31.

  Since the coordinate number of the object detected by the specific sensor, for example, the coordinate number of the object detected at the position of the distance d1a by the sensor 11a is known from the measurement result table 31, the coordinate number of the object detected from the coordinate table 32 at time t is displayed. Corresponding coordinate values can be determined.

Next, it is determined whether or not the detection of all the sensors 11a to 11e is completed (FIG. 4, step 13).
When the detection of all the sensors 11a to 11e is not completed, the process proceeds to step S14 and the following processing is executed.

  First, it is checked from the measurement result table 31 whether or not the same value as the measurement distance of the next sensor exists as the measurement distance of the adjacent sensor (the previous sensor). For example, if the currently detected sensor is the sensor 11b, it is checked whether or not the same measurement distance exists in the sensor 11a immediately before the sensor 11b. If the same measurement distance exists, It is estimated that an object in the sensor overlap area is detected by two sensors. Then, the X coordinate and Y coordinate of the point corresponding to the measurement distance of the sensor on the central axis of the overlapping area are calculated, and the coordinate value corresponds to the corresponding coordinate number in the coordinate table 32 (corresponding to the same measurement distance of the two sensors). Update the coordinate value of the coordinate number).

  On the other hand, when the same value does not exist in the measurement distance of adjacent sensors in the measurement result table 31, the X coordinate and Y coordinate of the point corresponding to the measurement distance on the main axis of the sensor are calculated, and the X coordinate, Y Coordinates and coordinate numbers are added to the coordinate table 32. Further, the measurement distance and the coordinate number are added to the measurement result table 31.

  FIG. 8 is an explanatory diagram of a method for calculating the coordinates of the overlapping area of the sensors. Hereinafter, a case where an object is detected at substantially the same distance d1 by the sensor 11a and the sensor 11b and a case where an object at the same distance is not detected will be described. Note that, since the sensors 11a to 11e are arranged side by side in the horizontal direction, even if they are the same object, the measurement distances do not exactly match each other, but the difference in the measurement distances is processed within the detection error range.

  When the measurement distances of the adjacent sensors 11a and 11b in the measurement result table 31 are compared and the same measurement distance exists, it is assumed that an object exists in the overlapping area 51 of the two sensors 11a and 11b. Then, a point P (d1) at a distance d1 from the origin on the intermediate shaft 52 passing through the center of the overlapping area 51 and extending in the detection direction of the sensors 11a and 11b is obtained as the position of the object. Further, the coordinate values X2 and Y2 in the X, Y coordinate system are obtained from the distance d1 from the origin of the point P (d1) in the polar coordinate system and the angle α formed by the intermediate axis 52 and the X axis. Then, the coordinate number corresponding to the distance d1 of the sensor 11a is obtained from the measurement result table 31, and the coordinate value of the corresponding coordinate number in the coordinate table 32 is updated to the coordinate values X2 and Y2.

  On the other hand, when the same measurement distance value does not exist in the two adjacent sensors 11a and 11b in the measurement result table 31, measurement of the point on the main axis 53 of the fan beam of the sensor 11b is performed as in the description of FIG. The X coordinate and Y coordinate of the point corresponding to the distance are calculated, and the coordinate value is added to the coordinate table 32.

  Returning to FIG. 4, in the next step S15, the distance is calculated from the coordinate value of the current coordinate table 32 and the coordinate value of the coordinate table 32 at the time of the previous detection, and the coordinate numbers within the predetermined value are associated with each other. Are identified as the same object.

FIG. 9 is a diagram showing an object management table 33 for managing whether or not the objects detected by the sensors 11a to 11e at the respective times are the same object.
In step S15 described above, an object whose difference between the previous coordinate value in the coordinate table 32 (for example, time t1) and the current coordinate value in the coordinate table 32 (for example, time t2) is within a predetermined value (or less than a predetermined value). Are identified as the same object (object). Then, the coordinate number of the corresponding coordinate value in the coordinate table 32 at this time (time t2) of the object determined to be the same object is set in the object management table 33 as the coordinate number of the object at time t2.

  As a result, the coordinate of each time of the object can be known from the coordinate number of each time in the object management table 33, so that the movement distance and speed of the object can be calculated by the processing described later.

Next, FIG. 10 is a flowchart of a process for giving a warning when there is an obstacle in the crossing.
First, the object management table 33 is examined to identify an object that currently exists (S21 in FIG. 10).

  Next, the oldest coordinate, coordinate number, and time of the object are obtained from the object management table 33, and the coordinates corresponding to the coordinate number are obtained from the coordinate table 32 (S22).

Next, the coordinate number of the current time of the same object is obtained from the object management table 33, and the coordinates corresponding to the coordinate number are obtained from the coordinate table 32 (S23).
Next, the speed in the Y-axis direction is calculated from the difference between the Y coordinate value of the current time and the past time and the time difference (S24). In the crossing fault detection system of the embodiment shown in FIG. 3, since it is assumed that the pedestrian and the vehicle move in the Y-axis direction (upward or downward as viewed from the front of FIG. 3), the Y-axis The moving speed is calculated from the moving distance in the direction and the time difference therebetween.

Next, the remaining moving distance until the object comes out of the crossing is calculated from the current position and the moving direction (S25).
Next, the time required for the object to go out of the crossing is calculated from the remaining moving distance and the speed of the object (S26).

Next, it is determined whether or not the time obtained by adding the required time to the current time is later in time than the time (danger time) at which the crossing barrier is closed (S27).
If the time obtained by adding the required time to the current time is temporally before the time when the crossing breaker closes (S27, NO), the process returns to step S23 and the above-described processing is repeated.

  On the other hand, when the time obtained by adding the required time to the current time is later in time than the time when the crossing breaker gets off (S27, NO), the process proceeds to step S28, and the pedestrian, driver, or approach in the crossing. Warn the train driver that he may not be able to get out of the railroad crossing before the breaker goes down.

  According to the first embodiment described above, the sensors 11a to 11e having the detection areas with directivity are arranged so that the detection areas of the adjacent sensors partially overlap, and are estimated to exist in the overlapping detection areas. The one-dimensional sensor detects the object existing in the detection area that does not overlap with the detected object by replacing the coordinates of the main axis of each sensor 11a to 11e or the point on the intermediate axis of the overlapping area of each sensor 11a to 11e. Can be converted into two-dimensional coordinates. By using a plurality of one-dimensional sensors 11a to 11e with different detection directions in this way and eliminating the need for a drive mechanism for rotating the sensors, the component cost of the sensor unit 11 can be reduced. Further, since there is no drive mechanism for rotating the sensor, the life of the sensor unit 11 is extended.

  In the first embodiment, the width of the detection area of each sensor 11a to 11e may be relatively narrow, and the detection area where an object can be detected only by one sensor 11a to 11e may be set narrow. In this case, the position of the object can be obtained more accurately by distinguishing between the case where the object is detected by only one sensor and the case where the object is detected at the same measurement distance by the two sensors.

Next, FIG. 11 is a diagram illustrating a detection area of the sensor of the obstacle detection system according to the second embodiment of this invention.
This 2nd Embodiment has shown the example applied to the system which detects the obstruction of an intersection. In FIG. 11, a sensor unit 11 in which sensors 11 a to 11 e having different detection directions are arranged in a horizontal direction is arranged at one of the four corners of an intersection, and detection with directivity is performed at opposite positions on both sides of a crosswalk at the intersection. A sensor 61 having an area is arranged.

  According to the second embodiment, the same effects as those of the first embodiment described above can be obtained in the detection of obstacles at intersections. In the detection of pedestrians on a pedestrian crossing, the sensors 61 are arranged opposite to each other so that the detection areas overlap each other, so that the two sensors 61 can detect an object on the pedestrian crossing. Detection accuracy can be increased.

  Next, FIG. 12 is a diagram illustrating a detection area of the sensor unit according to the third embodiment of this invention. In the third embodiment, the sensors are arranged to face each other so that the detection areas overlap.

  The sensor units 71 and 72 are arranged to face the vicinity of the two corners of the four corners of the fixed detection range 73 shown by the thick line in FIG. Each of the sensor units 71 and 72 includes three sensors 71a to 71c and 72a to 72c, respectively, in which the main axes of the sensor beams are shifted by a predetermined angle. Three sensors 71 a to 71 c are arranged side by side in the horizontal direction to constitute a sensor unit 71. Similarly, three sensors 72 a to 72 c are arranged side by side in the horizontal direction to constitute a sensor unit 72.

  In FIG. 12, the detection area 70a of the sensor 71a and the detection area 70a 'of the sensor 72a located at a position facing the sensor 71a are mostly overlapped. Further, most of the detection area 70b of the sensor 71b and the detection area 70b 'of the sensor 72b located at the position facing the sensor 71b also overlap. Further, most of the detection area 70c of the sensor 71c and the detection area 70c 'of the sensor 72c at a position facing the sensor 71c are overlapped.

Here, a determination method for determining whether or not the objects measured by the sensors 71b and 72b arranged opposite to each other are the same object will be described with reference to FIG.
The beam divergence angle of the sensor 71b is φb, the beam divergence angle of the sensor 72b is φb ′, and the distance between the sensors 71b and 72b is d.

If the measurement distance of the object detected by the sensor 71b is d1 and the measurement distance of the sensor 72b is d2, it is determined whether or not the objects are the same depending on whether or not the value of d1 + d2 satisfies the following condition.
d ≦ d1 + d2 ≦ d + f (φ) (1)
Here, f (φ) is a smaller value of f (φb) = 2 × d × sin (φb / 2) and f (φb ′) = 2 × d × sin (φb ′ / 2). .

  The objects at the measurement distance that satisfy the condition of the above expression (1) are estimated as the same object. Then, the X and Y coordinates of the point on the main axis of the beam corresponding to the measurement distance d1b of another object or an object estimated as the same object are calculated, and the coordinate number corresponding to the measurement distance is acquired from the measurement result table 31. . Then, the calculated coordinates are written as the coordinate values of the corresponding coordinate numbers in the coordinate table 32 of FIG. Further, the distance is calculated from the coordinate table 32 of the current time and the coordinate value of the coordinate table 32 at the time of the previous detection, and the objects with the coordinate numbers within the fixed distance are determined as the same object. With these processes, it is possible to specify whether or not the objects are the same object from the distance between the objects detected by the two sensors facing the detection area.

  In addition, as a method for specifying an object from the measurement distances of two sensors arranged opposite to each other so that the detection areas are overlapped, for example, draw circles having the measurement distances as radii with the positions of the two sensors as the origin. The coordinates of the intersection of the circles may be calculated, and when the calculated intersection coordinates exist in the detection areas of the two sensors, the coordinates may be specified as the detection position of the object. Then, by determining whether or not the object is the same from the position of the object measured last time and the position of the object measured this time, it can be obtained more accurately from the position of the object.

  According to the third embodiment described above, the position of the object is estimated by measuring the distance to the object with two of the sensors 71a to 71c and 72a 'to 72c' arranged opposite to each other. Furthermore, it is possible to accurately determine whether or not they are the same object (object) by comparing the position of the object measured last time and the position of the object measured this time. Thereby, it can be predicted more accurately whether an object in the level crossing can go out of the level crossing before the breaker goes down.

The present invention is not limited to the embodiment described above, and may be configured as follows, for example.
(1) In the third embodiment, the same object is detected by the sensors installed at the opposing positions. However, the detection range of the adjacent sensor is partly as in the first embodiment. It may be set to overlap, and the detection ranges of the three sensors may partially overlap.

With this configuration, it is possible to more accurately estimate the position of the object and more accurately determine whether or not they are the same object.
(2) The sensor to be used is not limited to a fan beam sensor, and any sensor may be used as long as it is a one-dimensional sensor having a directivity detection area. For example, a millimeter wave sensor or other wavelength sensor can be used.

(Appendix 1) An obstacle detection system for detecting obstacles existing within a certain range,
A sensor unit in which a plurality of sensors having a detection area with directivity are arranged to form a detection area in a predetermined range by changing the detection direction;
Coordinate calculation means for calculating a point corresponding to the measurement distance of the sensor on the axis extending in the same direction as the detection direction of each sensor of the sensor unit as the coordinates of the detected object;
A determination unit that determines an object having a distance between a coordinate calculated this time by the coordinate calculation unit and a coordinate calculated a predetermined time before a predetermined value as the same object;
Speed calculating means for calculating the speed of the object determined by the determining means;
Warning means for calculating a time required for the object to go out of a predetermined range from the current position of the object and the speed calculated by the speed calculating means, and for giving a warning when the calculated time is a predetermined time or more; Obstacle detection system comprising:

(Appendix 2) An obstacle detection system for detecting obstacles existing within a certain range,
A plurality of sensor units arranged so as to form a detection area of a predetermined range by changing the detection direction of a sensor having a detection area having directivity, and a part of the detection areas of adjacent sensors overlap;
When an object is detected at the same distance by two sensors partially overlapping the detection area, a point corresponding to the measurement distance of the sensor on the first axis extending in the detection direction within the overlapping area of the two sensors is Calculated as the coordinates of the detected object, and if the object is not detected at the same distance by the two sensors, a point corresponding to the measurement distance on the axis different from the first axis extending in the detection direction of each sensor is Coordinate calculation means for calculating the coordinates of the detected object;
A determination unit that determines an object having a distance between a coordinate calculated this time by the coordinate calculation unit and a coordinate calculated a predetermined time before a predetermined value as the same object;
Speed calculating means for calculating the speed of the object determined by the determining means;
Warning means for calculating a time required for the object to go out of a predetermined range from the current position of the object and the speed calculated by the speed calculating means, and for giving a warning when the calculated time is a predetermined time or more; Obstacle detection system comprising:

(Supplementary note 3) In the obstacle detection system according to supplementary note 2,
In the case where an object is detected at the same distance by two sensors in which a part of the detection area overlaps, the coordinate calculation means detects the object corresponding to the measurement distance on the central axis of the overlapping area of the detection area If no object is detected at the same distance, a point corresponding to the measurement distance on the main axis of the detection area of each sensor is calculated as the coordinates of the detected object.

(Supplementary note 4) In the obstacle detection system according to supplementary note 2 or 3,
The obstacle detection system is a system for detecting an obstacle in a level crossing, and the sensor unit is installed at one of the four corners of a detection area so that an object in the level crossing can be detected.

(Additional remark 5) It is an obstacle detection method which detects the obstacle which exists in a fixed range,
Using a sensor unit in which a plurality of sensors having a detection area with directivity are arranged so as to form a detection area in a predetermined range by changing the detection direction,
A point corresponding to the measurement distance of the sensor on the axis extending in the same direction as the detection direction of each sensor of the sensor unit is calculated as the coordinates of the detected object,
An object whose distance between the coordinates calculated this time and the coordinates calculated before a predetermined time is equal to or less than a predetermined value is determined as the same object,
Calculate the velocity of objects determined to be the same,
An obstacle detection method that calculates a time required for the object to go out of a certain range from the current position of the object and the calculated speed, and issues a warning when the calculated time is a predetermined time or more.

(Appendix 6) In the obstacle detection system described in Appendix 2,
Each sensor of the sensor unit has a detection area extending in a semicircular shape, and has an overlapping area of detection areas between adjacent sensors.

(Appendix 7) An obstacle detection system for detecting obstacles existing within a certain range,
A first sensor unit in which a plurality of sensors having detection areas with directivity are arranged so as to form detection areas within a predetermined range by changing the detection direction;
A second sensor unit comprising a plurality of sensors arranged at positions facing the first sensor unit and having a detection area that substantially overlaps the detection area of each sensor of the first sensor unit;
When the measurement distance of the object detected by the two sensors in which the detection areas of the first and second sensor units substantially overlap each other satisfies a specific distance condition, the measurement distance on the axis extending in the detection direction of the two sensors Coordinate calculation means for calculating corresponding points as the coordinates of the detected object;
A determination unit that determines an object having a distance between a coordinate calculated this time by the coordinate calculation unit and a coordinate calculated a predetermined time before a predetermined value as the same object;
Speed calculating means for calculating the speed of the object determined by the determining means;
A fault comprising warning means for calculating a time required for the object to go out of a predetermined range from the current position of the object and the speed calculated by the speed calculating means, and for giving a warning when the calculated time is equal to or longer than the predetermined time Object detection system.

(Supplementary note 8) In the obstacle detection system according to supplementary note 7,
The coordinate calculation means calculates, as the coordinates of the detected object, the coordinates of the intersection determined by the two measurement distances of the two sensors whose detection areas substantially overlap with respect to the positions of the first sensor unit and the second sensor unit. To do.

It is a principle explanatory view of the present invention. It is a figure which shows the structure of an obstruction detection system. It is a figure which shows the detection area of the sensor of 1st Embodiment. It is a flowchart of the process which specifies an object. It is a figure which shows a measurement result table. It is a figure which shows a coordinate table. It is explanatory drawing of the calculation method of a coordinate. It is explanatory drawing of the calculation method of the coordinate of an overlap area. It is a figure which shows an object management table. It is a flowchart of a warning process. It is a figure which shows the detection area of the sensor of 2nd Embodiment. It is a figure which shows the detection area of the sensor of 3rd Embodiment. It is explanatory drawing of the determination method of whether it is the same object. It is a figure which shows the conventional obstacle detection system of a level crossing. It is a figure which shows the obstacle detection system of the conventional intersection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sensor unit 2 Coordinate calculation means 3 Judgment means 4 Speed calculation means 5 Warning means 11 Sensor unit 12 Processing apparatus

Claims (5)

An obstacle detection system for detecting obstacles existing within a certain range,
A sensor unit in which a plurality of sensors having a detection area with directivity are arranged to form a detection area in a predetermined range by changing the detection direction;
Coordinate calculation means for calculating a point corresponding to the measurement distance of the sensor on the axis extending in the same direction as the detection direction of each sensor of the sensor unit as the coordinates of the detected object;
A determination unit that determines an object having a distance between a coordinate calculated this time by the coordinate calculation unit and a coordinate calculated a predetermined time before a predetermined value as the same object;
Speed calculating means for calculating the speed of the object determined to be the same by the determining means;
A fault comprising warning means for calculating a time required for the object to go out of a certain range from the current position of the object and the speed calculated by the speed calculation means, and for giving a warning when the calculated time is a predetermined time or more Object detection system. An obstacle detection system for detecting obstacles existing within a certain range,
A plurality of sensor units arranged so as to form a detection area of a predetermined range by changing the detection direction of a sensor having a detection area having directivity, and a part of the detection areas of adjacent sensors overlap;
When an object is detected at the same distance by two sensors partially overlapping the detection area, a point corresponding to the measurement distance of the sensor on the first axis extending in the detection direction within the overlapping area of the two sensors is Calculated as the coordinates of the detected object, and if the object is not detected at the same distance by the two sensors, a point corresponding to the measurement distance on the axis different from the first axis extending in the detection direction of each sensor is Coordinate calculation means for calculating the coordinates of the detected object;
A determination unit that determines an object having a distance between a coordinate calculated this time by the coordinate calculation unit and a coordinate calculated a predetermined time before a predetermined value as the same object;
Speed calculating means for calculating the speed of the object determined to be the same by the determining means;
A fault comprising warning means for calculating a time required for the object to go out of a certain range from the current position of the object and the speed calculated by the speed calculation means, and for giving a warning when the calculated time is a predetermined time or more Object detection system.   The coordinate calculation means detects a point corresponding to the measurement distance on the central axis of the overlapping area of the detection areas of the two sensors when the object is detected at the same distance by the two sensors whose detection area positions overlap. The coordinates of the detected object are calculated, and when the object is not detected at the same distance, a point corresponding to the measurement distance on the main axis of the detection area of each sensor is calculated as the coordinate of the detected object. Obstacle detection system.   The said obstacle detection system is a system which detects the obstruction in a level crossing, The said sensor unit is installed in one of the four corners of a detection area so that the object in a level crossing can be detected. Obstacle detection system. An obstacle detection method for detecting obstacles existing within a certain range,
Using a sensor unit in which a plurality of sensors having a detection area with directivity are arranged so as to form a detection area in a predetermined range by changing the detection direction,
A point corresponding to the measurement distance of the sensor on the axis extending in the same direction as the detection direction of each sensor of the sensor unit is calculated as the coordinates of the detected object,
An object whose distance between the coordinates calculated this time and the coordinates calculated before a predetermined time is equal to or less than a predetermined value is determined as the same object,
Calculate the velocity of objects determined to be the same,
An obstacle detection method that calculates a time required for the object to go out of a certain range from the current position of the object and the calculated speed, and issues a warning when the calculated time is a predetermined time or more.

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