Warning system

Abstract

To make it possible to issue a warning when a vehicle mistakenly enters a working area that is set up along a traffic lane of a road.SOLUTION: A warning system 1 comprises: a three-dimensional measuring region sensor 30 that irradiates a measuring beam towards a traffic lane adjacent to a working area, that repeatedly executes measurement processing to measure a position of a vehicle by receiving reflected light from the vehicle traveling in the traffic lane, and that outputs the acquired positional information of the vehicle; and a determination unit 32a that determines whether or not the vehicle has mistakenly entered a working area, based on the positional information of the vehicle output from the three-dimensional measuring region sensor 30.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a warning system that issues a warning when a vehicle mistakenly enters a work area that is defined as a part of a road on which the vehicle is traveling. [Background technology]

[0002] When road repairs or the like are to be carried out on a portion of a road on which vehicles travel, a work area is demarcated on that portion of the road, and workers carry out various tasks within that work area. While work is being carried out in the work area, ordinary vehicles are traveling in other areas of the road. There is a risk that these ordinary vehicles may mistakenly enter the work area, and warning systems that warn of vehicles entering such work areas on the road are known (see, for example, Patent Documents 1 and 2).

[0003] The warning systems in Patent Documents 1 and 2 are equipped with a three-dimensional range sensor that outputs vehicle position information, and are configured to determine whether or not there is a high possibility that the vehicle will erroneously enter the work area based on the time-series position information of the vehicle output from this three-dimensional range sensor. Patent Documents 1 and 2 assume that the work area is divided into an arc-shaped area, and therefore the three-dimensional range sensor irradiates measurement light upstream of the work area to identify the front of the vehicle and then determines whether or not there is a high possibility that the vehicle will erroneously enter the work area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-39689 [Patent Document 2] Japanese Patent Publication No. 2021-114169 Summary of the Invention [Problem to be solved by the invention]

[0005] Depending on the type of work being done on the road, a long work area may be set up along the road lane, and the length of the work area may reach several hundred meters to several kilometers. When setting up such a long work area, multiple triangular cones are usually placed at predetermined intervals along the lane to divide the work area.

[0006] However, the distance between adjacent traffic cones is large enough for a vehicle to pass through, so there is a risk that a vehicle may enter the work area between the traffic cones.

[0007] In this regard, in the warning systems of Patent Documents 1 and 2, the 3D range sensor only detects vehicles approaching from upstream of the work area, making it difficult to detect vehicles in the middle or downstream parts of a long work area of ​​several hundred meters or more.

[0008] The present disclosure has been made in consideration of such points, and its purpose is to make it possible to issue an alarm when a vehicle mistakenly enters a work area set along a lane of a road. [Means for solving the problem]

[0009] To achieve the above object, one aspect of the present disclosure can be based on a warning system that warns of a vehicle's entry into a work area set along a road extension direction. The warning system includes a three-dimensional range sensor that repeatedly performs a measurement process of irradiating a measurement light over a predetermined range in the extension direction toward a portion of a lane adjacent to the work area that is located to the side of the work area and measuring the position of the vehicle by receiving light reflected from the vehicle traveling on the lane, and outputs the acquired vehicle position information, a determination unit that determines whether the vehicle has erroneously entered the work area based on the vehicle position information output from the three-dimensional range sensor, and a warning device that issues a warning when the determination unit determines that the vehicle has erroneously entered the work area.

[0010] With this configuration, the 3D range sensor emits measurement light over a predetermined range in the direction of the road toward the side of the work area, making it possible to detect vehicles traveling in lanes adjacent to the work area even in the middle of the work area. This makes it possible to detect vehicles that have mistakenly entered the work area not only in the upstream part of the work area but also in the middle part.

[0011] The determination unit sets a virtual dividing line that extends along the extension direction and divides the work area, and determines that the vehicle has erroneously entered the work area when at least a portion of the vehicle crosses the dividing line based on the vehicle position information output from the 3D range sensor. This makes it possible to accurately determine that the vehicle has erroneously entered the work area.

[0012] The three-dimensional range sensor may be configured to detect partition members for partitioning the work area. In this case, the determination unit may execute a search process to search for the partition members based on data output from the three-dimensional range sensor, and set a line passing through the partition members found by the search process as the virtual partition line.

[0013] The determination unit may use the search process to search for a first partitioning element closest to the 3D range sensor, a second partitioning element located upstream of the first partitioning element on the road, and a third partitioning element located downstream of the first partitioning element on the road, and set a line passing through the first partitioning element, the second partitioning element, and the third partitioning element as the virtual partitioning line. This allows the virtual partitioning line to correspond to the partitions of the actual work area.

[0014] The determination unit can also set the virtual division line to have a predetermined width in the height direction.

[0015] The warning system may further include an imaging unit that images a vehicle traveling in a lane adjacent to the work area. In this case, the determination unit may be configured to determine, based on the image captured by the imaging unit, whether the vehicle in the image is an authorized vehicle that has been permitted to enter the work area, and, if determined to be an authorized vehicle, not to determine that the authorized vehicle has entered the work area as an erroneous entry.

[0016] The warning system may further include a detector that receives radio waves transmitted from a transmitter attached to an authorized vehicle that has been permitted to enter the work area. In this case, the determination unit may be configured to determine whether the vehicle is authorized to enter the work area based on the radio wave reception result by the detector, and if it is determined to be an authorized vehicle, not to determine that the authorized vehicle has entered the work area as an erroneous entry. [Effects of the Invention]

[0017] As described above, the measurement light from the 3D range sensor is projected toward the lane adjacent to the work area set along the lane of the road, so an alarm can be issued if a vehicle mistakenly enters the work area. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a plan view of a road illustrating a state in which an alarm system according to a first embodiment of the present invention is used. [Figure 2] FIG. 2 is a diagram showing the measurement range of the three-dimensional range sensor at the time of setting. [Figure 3] FIG. 3 is a block diagram of the alarm system according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a side view showing a virtual dividing line. [Figure 5] FIG. 5 is a block diagram of an alarm system according to a second embodiment of the present invention. [Figure 6]FIG. 6 is a plan view of a road illustrating a state in which the alarm system according to the second embodiment of the present invention is used. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0020] (Embodiment 1) FIG. 1 is a plan view of a road 3 illustrating the use of a warning system 1 according to a first embodiment of the present invention. The warning system 1 is installed on the road 3 or a side road, etc., and is intended to warn of the entry of a general vehicle 7 into a work area 5 pre-defined on the road 3. The road 3 has three lanes 9a, 9b, and 9c, each traveling in the same direction. A work area 5 for road construction and other work is defined along the length of the road 3, for example, in the leftmost lane 9a as viewed in the direction of travel. In FIG. 1, the work area 5 is indicated by dotted diagonal lines. In the work area 5, road repair work, equipment installation work, equipment maintenance work, wiring and piping work, etc. are carried out. The number of lanes may be two, four, or more. The work area 5 is defined over any length at any location where work is required. In this embodiment, a case will be described in which the work area 5 is continuously provided over a long area of ​​several hundred meters or more, for example, one or several kilometers. The general vehicle 7 also includes motorcycles.

[0021] Vehicles traveling in each of the lanes 9a, 9b, and 9c travel in the same direction. Between the lanes 9a, 9b, and 9c, lane boundary lines 11 are drawn, extending in the direction of the extension of the road 3 (left and right in FIG. 1). The right side of FIG. 1 is the upstream side of the road 3, and the left side of FIG. 1 is the downstream side of the road 3. Therefore, general vehicles 7 travel from the right side to the left side in FIG. 1.

[0022] A plurality of triangular cones (dividing members) 13 are placed on the road 3 to divide the work area 5. The triangular cones 13 are lined up along the lane boundary line 11 between the lanes 9a and 9b. In the example shown in FIG. 1, the triangular cones 13 are placed on the lane boundary line 11, but this is not limitative and the triangular cones 13 may be placed at a position offset from the lane boundary line 11 in the width direction of the road 3. The work area 5 may also be divided by members other than the triangular cones 13.

[0023] Symbol C in Figure 2 indicates the distance between adjacent cones 13. The distance between cones 13 can be set to, for example, about 20 m, but is not limited to this. Generally, the distance between cones 13 is set to allow entry of a general vehicle 7 (shown in Figure 1). For this reason, as shown in Figure 1, there is a possibility that a general vehicle 7 traveling in lane 9b adjacent to the work area 5 may, for some reason, enter the work area 5 between adjacent cones 13. The warning system 1 detects that a general vehicle 7 has entered the work area 5 from a portion of the lane 9b adjacent to the work area 5 that is located to the side of the work area 5, and issues a warning as necessary.

[0024] 3 is a block diagram of the alarm system 1. The alarm system 1 includes a three-dimensional range sensor 30, a camera 31, a control device 32, and a speaker 33. Power is supplied to the alarm system 1 from a power source 40. The power source 40 may be a battery, a commercial power source, or a generator. The power source 40 may constitute a part of the alarm system 1.

[0025] For example, a so-called 3D-LiDAR is used as the three-dimensional range sensor 30. The three-dimensional range sensor 30 and a control device 32 are connected, and measurement data acquired by the three-dimensional range sensor 30 is input to the control device 32.

[0026] Although not shown, the three-dimensional range sensor 30 includes a laser light emitting unit that emits laser light (measurement light) of a wavelength outside the visible light over a wide area, a light receiving unit that receives the laser light irradiated from the laser light emitting unit that is reflected from an object, and a measurement unit that measures the position of the object and the distance from the three-dimensional range sensor 30 based on the laser light received by the light receiving unit, and the configuration of each unit is conventionally well known, so detailed description will be omitted. The three-dimensional range sensor 30 can be one with a horizontal viewing angle of 360° or 180°, for example, but it is also possible to use a combination of multiple sensors with narrower viewing angles.

[0027] Symbol D in FIG. 2 schematically indicates the measurable distance (also referred to as the measurement range) in the extension direction of the road 3 by the 3D range sensor 30 near the 3D range sensor 30. The 3D range sensor 30 repeatedly performs a measurement process to measure the position of the general vehicle 7 by emitting measurement light over a predetermined range in the extension direction of the road 3 toward a portion of the lane 9b adjacent to the work area 5 that is located to the side of the work area 5, and receiving light reflected from the general vehicle 7 traveling on the lane 9b, and outputs the acquired position information of the general vehicle 7. At a location a distance A away from the 3D range sensor 30 in the direction approaching the lane 9b, the measurable distance in the extension direction of the road 3 by the 3D range sensor 30 is D', which is shorter than distance D. For example, if distance D is 70 m and distance A is 3.5 m, distance D' can be calculated as follows.

[0028] arccos(3.5 / 70)=87.134 Distance D'=70×sin(87.134)=69.912m In this embodiment, as shown in Figure 1, laser light is emitted toward a portion of lane 9b on road 3 that is located to the side of work area 5, and the position of general vehicle 7 traveling in lane 9b and the distance from 3D range sensor 30 must be measured by receiving the light reflected from the general vehicle 7 traveling in lane 9b. Therefore, a 3D range sensor 30 having a field of view that can measure that range must be selected.

[0029] The vertical viewing angle of the 3D range sensor 30 may be approximately 10° to 30°, but in this embodiment, the vertical viewing angle may be narrower, and the sensor may be capable of measuring only the horizontal direction, or only a narrow range of approximately 1 to 3° above and 1 to 3° below the horizontal direction. The upper limit of the range of the 3D range sensor 30 is preferably 150 m or more, and more preferably capable of measuring long distances of 200 m or 300 m.

[0030] If the length of the work area 5 is longer than the measurement range of the 3D range sensor 30, multiple 3D range sensors 30 may be installed at intervals from each other in the extension direction of the road 3. In this case, the intervals between the 3D range sensors 30 lined up in the extension direction of the road 3 are set so that no areas are created where it is impossible to detect general vehicles 7. In other words, by setting the installation positions of the 3D range sensors 30 so that the measurement ranges of the upstream 3D range sensors 30 and the downstream 3D range sensors 30 partially overlap each other, it is possible to detect the erroneous entry of general vehicles 7 throughout the entire range of the work area 5.

[0031] The 3D range sensor 30 is configured to repeatedly perform a measurement process of measuring the position of an object by receiving light reflected from the object. The 3D range sensor 30 can also measure the position of a stationary object in the same manner, so it can also detect stationary objects. An example of a stationary object is a triangular cone 13 installed on the road 3, but is not limited to this.

[0032] The cycle of the measurement process of the 3D range sensor 30 is called, for example, a sampling cycle or frame rate, and may be preset for each model of the 3D range sensor 30 or may be changeable by the user. For example, the sampling cycle can be set between 5 Hz and 30 Hz. If the object is a general vehicle 7, the 3D range sensor 30 can repeatedly execute a measurement process to measure the position of the general vehicle 7, and the acquired position information is output to the control device 32. At this time, the acquired position information can be temporarily stored in a buffer memory (not shown) of the 3D range sensor 30 and then output to the control device 32 in chronological order. Temporarily storing the acquired position information in the 3D range sensor 30 is called buffering. Position information of stationary objects other than moving objects is also buffered in the same way.

[0033] A specific example of position information is coordinate information. For example, when a laser beam is irradiated onto a certain point on an object, the 3D range sensor 30 can obtain the three-dimensional coordinates of the point (X, Y, Z) by measuring the laser beam reflected from the point, with the light receiving unit as the origin.

[0034] The camera 31 is an imaging unit for capturing images of general vehicles 7 traveling in the lane 9b adjacent to the work area 5. The type of camera 31 is not particularly limited, but for example, a 360° camera capable of capturing images of a 360° range around the vehicle 7 can be used. The camera 31 may be, for example, a video camera capable of capturing video, or a camera that captures still images in response to the input of a predetermined imaging trigger. The camera 31 has a capture area set to include the area being measured by the 3D range sensor 30. The camera 31 is connected to a control device 32, and image data captured by the camera 31 is input to the control device 32.

[0035] The speaker 33 is an example of an alarm device that issues an alarm when a determination unit (described later) determines that the general vehicle 7 has erroneously entered the work area 5. The speaker 33 is connected to the control device 32. When an operation signal is output from the control device 32, the speaker 33 emits a warning sound wave (alarm sound). The speaker 33 may be, for example, a speaker that emits sound waves in the audible range, or may be an ultrasonic speaker. In the case of an ultrasonic speaker, when the sound waves emitted from the ultrasonic speaker hit the general vehicle 7, the components that make up the general vehicle 7 vibrate, causing the occupants to hear a warning sound.

[0036] A lighting device or the like may be provided as a warning device instead of or in addition to the speaker 33. When the determination unit 32a determines that the general vehicle 7 has mistakenly entered the work area 5, the lighting device can be turned on to warn the occupants of the general vehicle 7.

[0037] The emission of an alarm sound or light can also be directed at workers performing various tasks within the work area 5. For example, by installing a speaker 33, a lighting device, or the like near the worker, when the determination unit 32a determines that a general vehicle 7 has mistakenly entered the work area 5, the worker can be notified of this. This can also cause the worker to evacuate from the work area 5. Note that multiple alarm devices may be provided. Another example of an alarm device is an individual alarm unit attached to the worker's helmet. The individual alarm unit is configured to be able to receive an operation signal from the control device 32 via wireless communication, and when it receives an operation signal from the control device 32, it acts as if it is hitting the helmet, thereby generating sound and vibration to alert the worker.

[0038] 2 is configured, for example, by a small personal computer or the like, and includes a determination unit 32a, a storage unit 32b, and a communication unit 32c. The determination unit 32a is configured by a central processing unit, a ROM, a RAM, and the like that the personal computer has. The central processing unit executes a program to realize the functions of the determination unit 32a. The determination unit 32a may be configured by a combination of hardware such as the central processing unit, ROM, and RAM and software such as a program or application.

[0039] The storage unit 32b can be configured with, for example, a RAM, a ROM, a hard disk drive, an SSD (Solid State Drive), etc. The control device 32 operates according to a program stored in the storage unit 32f.

[0040] The communication unit 32c is configured to be able to communicate with the administrator terminal 50. The communication unit 32c can communicate with the administrator terminal 50 via, for example, a public communication line. The communication unit 32c transmits the determination result by the determination unit 32a to the administrator terminal 50, so that the determination result can be displayed on the display unit 50a of the administrator terminal 50. For example, if the determination unit 32a determines that a general vehicle 7 has erroneously entered the work area 5, the display unit 50a of the administrator terminal 50 displays, using text, illustrations, or the like, that the general vehicle 7 has erroneously entered the work area 5. This allows the administrator to be notified that the general vehicle 7 has erroneously entered the work area 5.

[0041] The determination unit 32a of the control device 32 acquires the coordinate data of each point output from the 3D range sensor 30. The determination unit 32a detects whether or not a moving object exists within the field of view (measurement range) of the 3D range sensor 30 based on the coordinate data of each point output from the 3D range sensor 30. This method is a conventionally used moving object determination method, and if there is no change in the coordinate data of each point output from the 3D range sensor 30 at predetermined time intervals, it determines that no moving object exists, and if there is a change, it determines that a moving object exists there. The size and shape of the moving object can also be estimated.

[0042] Since the warning system 1 is a system installed on the road 3, it can be estimated that most of the objects detected as moving objects by the control device 32 are ordinary vehicles 7. Therefore, although the coordinate data output from the 3D range sensor 30 includes data other than the position information of ordinary vehicles 7, the control device 32 can distinguish between the coordinate data that led to the detection of a moving object and other coordinate data, and use the coordinate data that led to the detection of a moving object as the position information of the ordinary vehicle 7.

[0043] The determination unit 32a determines whether the general vehicle 7 has mistakenly entered the work area 5 based on the position information of the general vehicle 7 output from the three-dimensional range sensor. In making this determination, the determination unit 32a sets a virtual dividing line L1 that extends along the extension direction of the road 3 and divides the work area 5, as shown in Figure 1. The virtual dividing line L1 can be set away from the road surface of the road 3 in the height direction.

[0044] With the virtual lane marking L1 set, the determination unit 32a determines that the general vehicle 7 has erroneously entered the work area 5 when at least a part of the general vehicle 7 crosses the lane marking L1 and enters the work area 5 based on the position information of the general vehicle 7 output from the three-dimensional range sensor 30. Note that the determination unit 32a may also determine that the general vehicle 7 has erroneously entered the work area 5 when the entire general vehicle 7 crosses the lane marking L1 and enters the work area 5.

[0045] The virtual lane marking L1 may be set by the user of the warning system 1, but in this embodiment, the determination unit 32a can automatically set the virtual lane marking L1. When setting the virtual lane marking L1, the user performs a predetermined operation to put the warning system 1 into setting mode. In setting mode, the 3D range sensor 30 measures the range measurement. At this time, general vehicles 7 are prevented from passing through. Therefore, the 3D range sensor 30 acquires measurement data of the road 3, traffic cones 13, etc. included in the range measurement.

[0046] The determination unit 32a acquires data output from the three-dimensional range sensor 30. Then, the determination unit 32a executes a search process to search for the triangular cones 13 based on the data output from the three-dimensional range sensor 30. Because the triangular cones 13 have a distinctive shape, it is possible to search for the triangular cones 13 by registering an image of the triangular cone as a master image and using conventionally known image processing techniques. Because the triangular cones 13 are lined up in the extension direction of the road 3, it is possible to search for multiple triangular cones 13 by the search process.

[0047] As shown in Fig. 2, the range of the search process is set to a range of width E from a point that is a distance B away from the installation location of the 3D range sensor 30 toward the lane 9b. In Fig. 2, the area between two dashed lines is schematically shown as the search range. Taking into account the side road, distance B is approximately 3.5 m to 5.5 m, but it varies depending on the standards of the road 3, etc. Width E can be set to include the area where the triangular cones 13 are installed, and is, for example, approximately 1 m to 3 m.

[0048] As a result of the search process, the determination unit 32a sets a line passing through the searched multiple triangular cones 13 as a virtual demarcation line L1. When setting the virtual demarcation line L1, if the multiple triangular cones 13 are arranged in a substantially straight line, a straight-line approximation line passing through the multiple triangular cones 13 can be set as the virtual demarcation line L1. The virtual demarcation line L1 is automatically registered and is used in the determination process when determining that a general vehicle 7 has mistakenly entered the work area 5.

[0049] The determination unit 32a can calculate a straight-line approximation line to set as the virtual demarcation line L1 if it can find at least two triangular cones 13, but it may also search for three or more triangular cones 13. Specifically, the determination unit 32a performs a search process within the search range to find the first triangular cone 13A closest to the 3D range sensor 30, the second triangular cone 13B located upstream of the first triangular cone 13A on the road 3, and the third triangular cone 13C located downstream of the first triangular cone 13A on the road 3. The determination unit 32a sets the line passing through the first triangular cone 13A, the second triangular cone 13B, and the third triangular cone 13C as the virtual demarcation line L1. Note that it is also possible to search for a fourth triangular cone or a fifth triangular cone and set the line passing through them as the virtual demarcation line L1.

[0050] FIG. 4 is a side view showing the virtual demarcation line L1. As shown in FIG. 4, the determination unit 32a sets the virtual demarcation line L1 to have a predetermined width in the height direction. The width of the virtual demarcation line L1 can be set, for example, in the range of 0.3 m or more, or 0.5 m or more. The width of the virtual demarcation line L1 can also be set, for example, in the range of 1.5 m or less, or 2.0 m or less.

[0051] Based on an image captured by the camera 31, the determination unit 32a determines whether or not a vehicle in the image is an authorized vehicle that has been permitted to enter the work area 5. That is, since construction-related vehicles, emergency vehicles, and the like are authorized vehicles that have been permitted to enter the work area 5, even if an authorized vehicle enters the work area 5, it does not constitute erroneous entry. However, since it is difficult to determine whether or not a vehicle is authorized based only on the data output from the 3D range sensor 30, the determination unit 32a uses the image captured by the camera 31 to determine whether or not the vehicle is authorized.

[0052] Specifically, the character information of the license plate of the permitted vehicle is stored in advance in the memory unit 32b or the like. The determination unit 32a acquires the character information of the license plate contained in the image captured by the camera 31 through image processing. The vehicle captured by the camera 31 and the vehicle identified by the data output from the 3D range sensor 30 can be associated with each other based on their respective times and positions. The determination unit 32a performs a comparison process to determine whether the character information of the license plate contained in the image matches the character information of the license plate of the permitted vehicle. If the comparison process shows a match, the determination unit 32a determines that the vehicle is a permitted vehicle that has been permitted to enter the work area 5. If the vehicle is determined to be a permitted vehicle, the determination unit 32a does not determine that the permitted vehicle has entered the work area as an erroneous entry, and therefore no alarm is issued. If the two do not match, the determination unit 32a determines that the vehicle is a general vehicle 7. Note that the camera 31 may be omitted.

[0053] (Effects of the embodiment) As described above, according to this embodiment, the position of the general vehicle 7 can be identified using the 3D range sensor 30. At this time, the 3D range sensor 30 emits measurement light over a predetermined range in the extension direction of the road 3 toward a portion of the lane 9b adjacent to the work area 5 that is located to the side of the work area 5, so that the general vehicle 7 traveling on the lane 9b can be detected even in the middle of the work area 5. This makes it possible to detect when the general vehicle 7 has erroneously entered the work area 5 not only in the upstream part of the work area 5 but also in the middle part. Then, if it is determined that the general vehicle 7 has erroneously entered the work area 5, an alarm can be immediately issued to notify the general vehicle 7.

[0054] (Embodiment 2) 5 and 6 illustrate an alarm system 1 according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in that a beacon detector (detector) 38 is provided instead of the camera 31, but other parts are the same as the first embodiment. Therefore, the same parts as the first embodiment will be denoted by the same reference numerals and their description will be omitted, and only the different parts will be described in detail. The second embodiment may further include a camera 31.

[0055] 6, an authorized vehicle 70 that is permitted to enter the work area 5 is equipped with a beacon (transmitter) 70a that emits radio waves at a predetermined frequency. The beacon detector 38 is a device that receives the radio waves emitted from the beacon 70a attached to the authorized vehicle 70, and is connected to the control device 32. The detection range of the beacon detector 38 is set to be equal to or smaller than the measurement range of the three-dimensional range sensor 30.

[0056] The determination unit 32a determines whether the vehicle is an authorized vehicle 70 that has been permitted to enter the work area 5, based on the radio wave reception results from the beacon detector 38. Specifically, when the beacon detector 38 receives radio waves transmitted from a beacon 70a attached to the authorized vehicle 70, it determines that the vehicle located near the control device 32 is an authorized vehicle 70 that has been permitted to enter the work area 5. On the other hand, when the beacon detector 38 does not receive radio waves transmitted from the beacon 70a, the determination unit 32a determines that the vehicle located near the control device 32 is an ordinary vehicle 7 that has not been permitted to enter the work area 5. If it is determined that the vehicle is an authorized vehicle 70, the determination unit 32a does not determine that the authorized vehicle 70 has entered the work area 5 as an erroneous entry.

[0057] The above-described embodiments are merely examples in all respects and should not be construed as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention. [Industrial Applicability]

[0058] As described above, the warning system according to the present disclosure can be used, for example, when a work area is partitioned off in part of a road on which a vehicle travels and various types of work are carried out. [Explanation of symbols]

[0059] 1. Alarm system 3 road 5 Working area 30 3D range sensor 31 Camera (imaging unit) 32a Judgment part 33 Speaker (alarm device) 38 Beacon Detector 70a Beacon (transmitter)

Claims

1. A warning system that warns of a vehicle entering a work area set along an extension direction of a road, a three-dimensional range sensor that repeatedly performs a measurement process of irradiating a measurement light over a predetermined range in the extension direction toward a portion of a lane adjacent to the work area that is located to the side of the work area, and measuring the position of a vehicle traveling on the lane by receiving light reflected from the vehicle, and outputs the acquired vehicle position information; a determination unit that determines whether the vehicle has mistakenly entered the work area based on the position information of the vehicle output from the three-dimensional range sensor; an alarm device that issues an alarm when the determination unit determines that the vehicle has erroneously entered the work area.

2. 2. The alarm system of claim 1, The determination unit sets a virtual dividing line that extends along the extension direction and divides the work area, and determines that the vehicle has mistakenly entered the work area if at least a portion of the vehicle crosses the dividing line based on the vehicle's position information output from the three-dimensional range sensor.

3. 3. The alarm system of claim 2, the three-dimensional range sensor is configured to be able to detect a partition member for partitioning the work area, The determination unit executes a search process to search for the partition members based on the data output from the three-dimensional range sensor, and sets a line passing through the multiple partition members searched for by the search process as the virtual partition line.

4. 4. The alarm system of claim 3, An alarm system in which the determination unit searches for a first partition member closest to the three-dimensional range sensor, a second partition member located upstream of the first partition member on the road, and a third partition member located downstream of the first partition member on the road, and sets a line passing through the first partition member, the second partition member, and the third partition member as the virtual partition line.

5. 4. The alarm system of claim 3, The determination unit sets the virtual dividing line to have a predetermined width in the height direction.

6. 2. The alarm system of claim 1, An imaging unit is further provided for imaging vehicles traveling in a lane adjacent to the work area, The determination unit determines whether the vehicle in the image captured by the imaging unit is an authorized vehicle that has been granted permission to enter the work area, based on the image captured by the imaging unit, and if it is determined to be an authorized vehicle, does not determine that the authorized vehicle's entry into the work area is an erroneous entry.

7. 2. The alarm system of claim 1, The vehicle further includes a detector that receives radio waves transmitted from a transmitter mounted on an authorized vehicle that is authorized to enter the work area, The judgment unit determines whether the vehicle is an authorized vehicle that has been granted permission to enter the work area based on the radio wave reception results from the detector, and if it is determined to be an authorized vehicle, the warning system does not determine that the authorized vehicle's entry into the work area is an erroneous entry.

Images