JP2013011454A - Apparatus and method for detecting road surface unevenness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for detecting road surface unevenness, that is capable of detecting unevenness on a road surface by utilizing an electromagnetic wave radiating from an object.SOLUTION: An apparatus 1 for detecting road surface unevenness comprises: an antenna 2 for detecting an electromagnetic wave radiating from an object; a reference level setting part 3 that detects a region in which a change of reception power of the electromagnetic wave is equal to or less than a predetermined value, as a road surface region, and that sets a reference level on the basis of the reception power of the road surface region; an increase and decrease region detecting part 4 for detecting a region in which the reception power of the electromagnetic wave increases from the reference level to the predetermined value or more and then decreases to the reference level, as an increase and decrease region; an unevenness height detecting part 5 for detecting a height of the unevenness on the basis of an amplitude of the reception power; and an unevenness width detecting part 6 for detecting a width of the unevenness on the basis of a width of the increase and decrease region in a horizontal direction; and an unevenness detecting part 7 for detecting the increase and decrease region as the unevenness on the road surface, when there exist increase and decrease regions between the road regions.

Description

  The present invention relates to a road surface unevenness detecting device and a road surface unevenness detecting method for detecting unevenness on a road surface by receiving electromagnetic waves radiated from an object.

  Conventionally, a technique for detecting the state of a road surface by measuring an electromagnetic wave radiated from the road surface has been developed, and Patent Document 1 is disclosed as an example. The radio radiometer type road surface condition grasping device disclosed in Patent Document 1 measures the radiation beam from the road surface and the radiation beam from the sky, and obtains the difference between the road surface radiation temperature and the sky radiation temperature to grasp the road surface condition. Was.

JP 2004-177188 A

 However, the road surface condition detected by the radio radiometer type road surface condition grasping device disclosed in Patent Document 1 described above only detects the road surface wetness such as dryness, wetness, and freezing of the road surface. There was a problem that some irregularities could not be detected.

 Therefore, the present invention has been proposed in view of the above-described circumstances, and a road surface unevenness detection apparatus and a road surface unevenness detection method capable of detecting unevenness on a road surface using electromagnetic waves radiated from an object. The purpose is to provide.

  A road surface unevenness detection apparatus according to the present invention includes an antenna that detects electromagnetic waves radiated from an object with a plurality of elements, a reference level setting unit that sets a reference level based on received power in a road surface region, and an electromagnetic wave received by the antenna. An increase / decrease area detection unit that detects an increase / decrease area as an increase / decrease area when the received power increases from the reference level to a predetermined value or more and then decreases to the reference level. And an unevenness detecting unit for detecting the upper unevenness.

  According to the road surface unevenness detection apparatus and the road surface unevenness detection method according to the present invention, an area where the reception power of the electromagnetic wave received by the antenna increases from the reference level to a predetermined value or more and then decreases to the reference level is detected as an increase / decrease area, Since this increase / decrease area is detected as unevenness on the road surface, the unevenness on the road surface can be detected using electromagnetic waves radiated from the object.

It is a block diagram which shows the structure of the road surface unevenness | corrugation detection apparatus which concerns on 1st Embodiment to which this invention is applied. It is a block diagram which shows the structure of the modification of the road surface unevenness detection apparatus which concerns on 1st Embodiment to which this invention is applied. It is a flowchart which shows the process sequence of the unevenness | corrugation detection process by the road surface unevenness detection apparatus which concerns on 1st Embodiment to which this invention is applied. It is a figure which shows the received power received with the antenna of the road surface unevenness | corrugation detection apparatus which concerns on 1st Embodiment to which this invention is applied. It is a figure for demonstrating the detection method of the rudder on the road surface by the road surface unevenness | corrugation detection apparatus which concerns on 2nd Embodiment to which this invention is applied. It is a figure for demonstrating the detection method of the rumble strip on the road surface by the road surface unevenness | corrugation detection apparatus which concerns on 3rd Embodiment to which this invention is applied. It is a figure for demonstrating the detection method of the Dotsbotts on the road surface by the road surface unevenness | corrugation detection apparatus which concerns on 4th Embodiment to which this invention is applied.

  Hereinafter, first to fourth embodiments to which the present invention is applied will be described with reference to the drawings.

[First Embodiment]
[Configuration of road surface unevenness detection device]
FIG. 1 is a block diagram showing a configuration of a road surface unevenness detection apparatus according to this embodiment. As shown in FIG. 1, a road surface unevenness detection apparatus 1 according to this embodiment includes an antenna 2 that detects an electromagnetic wave radiated from an object that is scanned in a horizontal direction and a vanishing point direction, and an electromagnetic wave received by the antenna 2. A reference level setting unit 3 that detects a region where the power change is within a predetermined value as a road surface region and sets a reference level based on the received power of the road surface region, and the received power of the electromagnetic wave received by the antenna 2 is a reference level. An increase / decrease area detection unit 4 that detects an area that increases from a predetermined value to a reference level and then decreases to a reference level as an increase / decrease area, and an uneven height that detects the height of the unevenness on the road surface based on the amplitude of received power in the increase / decrease area If there is an increase / decrease area between the detection section 5, the uneven width detection section 6 that detects the uneven width on the road surface based on the horizontal width in the increase / decrease area, and the increase / decrease area. A concave-convex detecting part 7 detects an area as unevenness on the road surface, and a storage unit 8 that stores information necessary for processing for detecting irregularities on the road surface.

  Here, the road surface unevenness detecting apparatus 1 according to the present embodiment can be mounted on a vehicle, and the antenna 2 is directed in the traveling direction of the vehicle, so that the unevenness in the traveling direction of the vehicle, that is, a road or an obstacle on the road surface. It is a device for detecting. When the antenna 2 receives an electromagnetic wave radiated from unevenness on the road surface, the received power of the electromagnetic wave shows a change that increases once to a predetermined value or more and then decreases to a reference level. Therefore, the road surface unevenness detection apparatus 1 according to the present embodiment detects such an area as an increase / decrease area, and recognizes the increase / decrease area as an unevenness on the road surface when the increase / decrease area is between the road surface areas. .

  The antenna 2 includes an array antenna in which a plurality of antennas are arrayed, a mechanical scan mechanism, and a lens. For example, an array antenna having a number of elements of 1 column × 20 rows can be scanned at high speed in the azimuth direction within a range of ± 30 degrees. The mechanical scanning mechanism and the configuration satisfying the receiving angle resolution of 1 degree. The wavelength of the electromagnetic wave received by the antenna 2 is set to 1/10 or less of the height of the unevenness on the road surface to be detected. For example, when the unevenness with a height of 5 cm is set as the detection target, the antenna The wavelength of the electromagnetic wave received at 2 is set to detect an electromagnetic wave having a frequency of 5 mm or less, that is, a frequency of 60 GHz or more. Thus, by setting the wavelength of the received electromagnetic wave of the antenna 2 according to the height of the unevenness to be detected, the unevenness can be detected with higher accuracy. Furthermore, as shown in FIG. 2, a plurality of antennas 2 may be installed to receive electromagnetic waves having different frequencies. As a result, it is possible to accurately detect irregularities having different heights. However, the number of antennas 2 need not be two, and may be three or more. It should be noted that a plurality of array antennas may be provided to simultaneously acquire a two-dimensional image so that the mechanical scanning mechanism is omitted.

  The reference level setting unit 3 is for setting the received power level (reference level) of the road surface area serving as a reference, detects the road surface area, calculates the average value, and sets the received power as the reference level. To do. In detecting the road surface area, the fact that the received power of the electromagnetic wave radiated from a flat object such as the road surface has a feature that the change is within a certain range is used, and the road surface area is within a predetermined value (for example, 5%). And the average value is obtained to set the reference level. Other than this method, a road surface area may be detected, and a statistical value such as an average value or a median value of received power in the area may be determined as a reference level.

  The increase / decrease area detector 4 monitors the change in received power of the electromagnetic wave received by the antenna 2 and increases / decreases the area where the received power increases from the reference level once to a predetermined value (for example, 5%) or more and then decreases to the reference level. Detect as a region.

  The unevenness height detection unit 5 obtains the difference between the maximum received power and the reference level in the increase / decrease area, detects the difference in received power, and calculates the height of the unevenness on the road surface based on the received power difference. And ask.

  The unevenness width detection unit 6 detects the width of the increase / decrease area in the horizontal direction, and calculates and obtains the width of the unevenness on the road surface based on the width of the increase / decrease area.

  The unevenness detection unit 7 detects an increase / decrease area existing between the road surface areas in the detected increase / decrease area as an unevenness on the road surface. When the antenna 2 is scanned in the horizontal direction, a large number of increase / decrease areas are detected. Among these increase / decrease areas, the increase / decrease areas within the road surface area are detected as irregularities on the road surface. The unevenness detection unit 7 acquires vehicle information such as the rotation angle of the steering wheel, the accelerator opening, and the brake amount, and corrects the height, width, position, etc. of the unevenness.

  The storage unit 8 stores information necessary for the unevenness detection process, and stores, for example, the frequency of the electromagnetic wave detected by the antenna 2, the angle of view of the antenna 2, the field of view, the resolution, the attachment parameters, and the like.

[Procedure for unevenness detection processing]
Next, the procedure of unevenness detection processing by the road surface unevenness detection apparatus 1 according to the present embodiment will be described with reference to the flowchart of FIG.

  As shown in FIG. 3, in step S101, the antenna 2 is scanned in the horizontal direction to receive an electromagnetic wave radiated from the object. Here, an example of the received power of the received electromagnetic wave is shown in FIG. FIG. 4A is a diagram showing received power when there is no unevenness, and FIG. 4B is a diagram showing received power when there is unevenness.

  As shown in FIG. 4, when there is no unevenness, the received power of the received electromagnetic wave is within a certain range, but when there is unevenness, the received power increases greatly and then decreases again.

  Next, in step S <b> 102, the reference level setting unit 3 determines a received power level (hereinafter referred to as a reference level) of the road surface area serving as a reference. For example, the road surface area is set as an area that satisfies the received power such that the change in the received power is within a predetermined value (5%) as shown in FIG. And the average value of the received power in this road surface area is set as a reference level. Other than this method, a road surface area may be specified, and a reference level may be set using a statistical method such as an average value of received power in the area or an intermediate value of maximum and minimum values, or correction for each pixel.

  Next, in step S103, the increase / decrease area detection unit 4 detects, as an increase / decrease area, an area where the received power decreases from the reference level to a predetermined value or more, for example, 5% or more, and then decreases to the reference level. For example, in FIG. 4B, three increase / decrease areas 31 to 33 are detected.

  Next, in step S104, the unevenness height detection unit 5 obtains the difference between the maximum value of the received power in the increase / decrease area and the reference level, and detects the difference in received power. For example, in FIG. 4B, the difference between the received power is detected by obtaining the difference between the maximum value Max of the received power in the increase / decrease area 31 and the reference level. The unevenness height detection unit 5 detects the height of the unevenness on the road surface based on the detected amplitude of the received power, but the received power amplitude changes according to the height and depth of the unevenness. The height and depth of the unevenness can be obtained from the difference in power and the wavelength of the electromagnetic wave.

  Next, in step S105, the unevenness width detection unit 6 obtains the unevenness width on the road surface from the horizontal width in the increase / decrease area. For example, the number of pixels of the horizontal width w in the increase / decrease area 31 shown in FIG. 4 is counted, and the uneven width is calculated from this count value. Since the scanning range in which the antenna 2 is scanned in the horizontal direction is determined in advance, by storing the movement amount of the scanning range and the total number of pixels in the storage unit 8 in advance, the width w with respect to the total number of pixels in the scanning range is set. The unevenness width can be calculated from the ratio of the number of pixels.

  Next, in step S106, when the detected increase / decrease area is between the road surface areas, the unevenness detection unit 7 recognizes and detects the increase / decrease area as unevenness on the road surface. For example, when the antenna 2 is scanned in the horizontal direction, an obstacle or a building outside the road that is not on the road surface may be detected as an increase / decrease area. Therefore, in order not to detect such an object outside the road, the unevenness detection unit 7 detects only an increase / decrease area within the road surface area as an unevenness on the road surface.

  When the unevenness on the road surface is detected in this way, the unevenness detecting unit 7 outputs the unevenness detected by the unevenness height detecting unit 5 and the unevenness width detected by the unevenness width detecting unit 6 to output the present embodiment. The unevenness detection processing by the road surface unevenness detection apparatus 1 according to is completed.

[Effect of the first embodiment]
As described above in detail, according to the road surface unevenness detection apparatus 1 according to the present embodiment, the region in which the reception power of the electromagnetic wave received by the antenna 2 increases from the reference level to a predetermined value or more and then decreases to the reference level. Since it detects as an increase / decrease area | region and detects this increase / decrease area | region as an unevenness | corrugation on a road surface, the unevenness | corrugation on a road surface can be detected using the electromagnetic waves radiated | emitted from an object. Further, in the conventional method disclosed in Patent Document 1, the difference between the road surface observation output and the sky observation output is obtained to grasp the road surface condition. Etc.) and the surrounding environment (shade, building, etc.), it was difficult to accurately grasp the road surface condition. However, according to the road surface unevenness detection apparatus 1 according to the present embodiment, since the reference level is set based on the received power of the road surface region, it is accurately affected under any conditions without being affected by the weather and surrounding environment. Unevenness on the road surface can be detected.

  Further, according to the road surface unevenness detecting apparatus 1 according to the present embodiment, an area where the change in received power of the electromagnetic wave received by the antenna is within a predetermined value is detected as a road surface area, so that the reference level can be accurately set. And unevenness on the road surface can be detected more accurately.

  Furthermore, according to the road surface unevenness detecting apparatus 1 according to the present embodiment, the width of the increase / decrease area in the horizontal direction is detected, and the width of the unevenness on the road surface is detected based on the width of the increase / decrease area. The width of the unevenness on the road surface can be measured using the electromagnetic waves that are generated.

  Further, according to the road surface unevenness detecting apparatus 1 according to the present embodiment, the difference between the maximum received power and the reference level in the increase / decrease area is obtained to detect the received power difference, and the road surface is determined based on the received power difference. Since the height of the unevenness on the top is detected, the height of the unevenness on the road surface can be measured using electromagnetic waves radiated from the object.

  Furthermore, according to the road surface unevenness detection apparatus 1 according to the present embodiment, the wavelength of the electromagnetic wave received by the antenna 2 is set to 1/10 or less of the height of the unevenness on the road surface to be detected. Unevenness on the road surface can be detected accurately and reliably.

  In addition, according to the road surface unevenness detection device 21 according to the present embodiment, since a plurality of antennas 2 are installed to receive electromagnetic waves having different frequencies, it is possible to accurately detect unevenness having different heights. Become.

[Second Embodiment]
Next, a second embodiment to which the present invention is applied will be described with reference to the drawings. Detailed description of the same parts as those in the first embodiment will be omitted.

  The road surface unevenness detection apparatus according to the present embodiment is characterized by detecting a rut from unevenness on a road surface.

  First, the antenna 2 is scanned in the horizontal direction to obtain the unevenness detection result as shown in FIG. In the detection result shown in FIG. 5, the uneven | corrugated row | line | columns 42 and 43 in which the point 41 which shows the unevenness | corrugation on a road surface were formed continuously in the vanishing point direction are detected.

  Here, when the unevenness detector 7 detects two unevenness rows as shown in FIG. 5, the unevenness detector 7 acquires the width of each unevenness constituting the unevenness row. Since the width of each concavo-convex has already been detected by the concavo-convex width detector 6, it can be acquired without newly measuring. Furthermore, the unevenness detector 7 measures the distance between the two uneven rows 42 and 43. The method for measuring the distance between the concave and convex rows 42 and 43 can be measured in the same manner as the method for detecting the width of the concave and convex by the concave and convex width detector 6.

  Next, the unevenness detecting unit 7 determines whether or not the measured distance between the uneven rows 42 and 43 is a value close to the distance between the tires of the vehicle (for example, about 1 to 2 m), and is further on the road surface. It is determined whether or not the width of each unevenness 41 is a value close to the tire width (for example, 50 cm or less). When the distance between the uneven rows 42 and 43 is a value close to the distance between the tires of the vehicle, and the width of each unevenness 41 on the road surface is a value close to the tire width, the uneven rows 42, 43 is detected as a rut. Since the distance between the tires and the tire width of the vehicle are stored in the storage unit 8 in advance, it is possible to easily detect the rut by reading out the values from the storage unit 8 and comparing them.

[Effects of Second Embodiment]
As described above in detail, according to the road surface unevenness detecting apparatus according to the present embodiment, two uneven rows in which unevenness on the road surface is continuous in the vanishing point direction are detected, and the distance between the uneven rows is a vehicle tire. When the width of the unevenness on the road surface is close to the tire width, the unevenness row is detected as a rut when the width of the unevenness on the road is close to the tire width. Can be detected.

[Third Embodiment]
Next, a third embodiment to which the present invention is applied will be described with reference to the drawings. Detailed description of the same parts as those of the first and second embodiments described above will be omitted.

  The road surface unevenness detecting apparatus according to this embodiment is characterized in that a rumble strip is detected from unevenness on a road surface.

  First, the antenna 2 is scanned in the horizontal direction to obtain the unevenness detection result as shown in FIG. In the detection result shown in FIG. 6, the uneven | corrugated aggregate | assembly 52-54 in which about 3 points 51 which show the unevenness | corrugation on a road surface were formed continuously in the horizontal direction is detected.

  Here, when the unevenness detecting unit 7 detects a plurality of unevenness sets as shown in FIG. 6, the unevenness detecting unit 7 measures the distances between the multiple unevenness sets 52 to 54. The method for measuring the distance between the concave / convex sets 52 to 54 is the same as the method of detecting the width of the concave / convex by the concave / convex width detecting unit 6, and first counts the number of pixels between the concave / convex sets in the vanishing point direction to determine the total number of pixels in the scanning range The distance between the concavo-convex sets is measured from the ratio to.

  And the unevenness | corrugation detection part 7 determines whether the distance between the unevenness | corrugation sets 52-54 is a predetermined space | interval (about 10-20 cm) in a vanishing point direction, and the unevenness | corrugation sets 52-54 are predetermined in a vanishing point direction. If the intervals are continuous, the set of irregularities is detected as a rumble strip. Further, in addition to the distance between the unevenness sets, the height of each unevenness detected by the unevenness height detecting unit 5 may be acquired, and it may be determined whether or not the height of each unevenness is about 10 cm. . And if it recognizes as a rumble strip when the height of each unevenness becomes about 10 cm in addition to the distance between the unevenness sets, it is possible to prevent misrecognition and detect the rumble strip more reliably. . Since the predetermined interval and the height of the unevenness are stored in the storage unit 8 in advance, the rumble strip can be easily detected by reading each value from the storage unit 8 and comparing it.

[Effect of the third embodiment]
As described above in detail, according to the road surface unevenness detecting apparatus according to the present embodiment, a set of unevenness in which a predetermined number of unevenness on the road surface continues in the horizontal direction is detected, and this unevenness set is predetermined in the vanishing point direction. When the concavo-convex set is detected as a rumble strip, the rumble strip on the road surface can be detected using electromagnetic waves radiated from the object.

[Fourth Embodiment]
Next, a fourth embodiment to which the present invention is applied will be described with reference to the drawings. Detailed description of the same parts as those in the first to third embodiments described above will be omitted.

  The road surface unevenness detection apparatus according to the present embodiment is characterized in that Dotsbotts are detected from unevenness on a road surface. Dotsbotts are metal protrusions that are installed on European and American roads instead of white lines, and have a disk shape with a diameter of about 20 cm.

  First, the antenna 2 is scanned in the horizontal direction to obtain the unevenness detection result as shown in FIG. In the detection result shown in FIG. 7, the uneven | corrugated row | line | column 62 in which the point 61 which shows the unevenness | corrugation on a road surface was formed continuously in the vanishing point direction is detected.

  Here, when the concavo-convex detection unit 7 detects the concavo-convex column 62 as shown in FIG. Get the width of each bump.

  Then, the unevenness detection unit 7 determines whether or not the widths and heights of the plurality of unevennesses on the road surface are close to the preset width (about 20 cm) and height (about 10 cm) of the Dotsbotts. When the widths and heights of the plurality of projections and depressions become values close to the width and height of the Dotsbotts, the projections and depressions 62 are detected as Dotsbotts. Since the width and height of the Dotsbots are stored in the storage unit 8 in advance, the Dotsbotts can be easily detected by reading out the values from the storage unit 8 and comparing them.

[Effect of Fourth Embodiment]
As described above in detail, according to the road surface unevenness detection apparatus according to the fourth embodiment to which the present invention is applied, the unevenness line in which unevenness on the road surface is continuous in the vanishing point direction is detected, and the unevenness line is configured. When the width and height of each unevenness is close to the preset width and height of the Dotsbots, the uneven rows are detected as Dotsbots. Can be detected.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and even if it is a form other than this embodiment, as long as it does not depart from the technical idea of the present invention, it depends on the design and the like. Of course, various modifications are possible.

DESCRIPTION OF SYMBOLS 1, 21 Road surface unevenness detection apparatus 2 Antenna 3 Reference level setting part 4 Increase / decrease area | region detection part 5 Concavity and convexity detection part 6 Concavity and convexity width detection part 7 Concavity and convexity detection part 8 Memory | storage part

Claims (10)

An antenna that detects electromagnetic waves radiated from an object with multiple elements;
Reference level setting means for setting a reference level based on received power in the road surface area;
Increase / decrease area detection means for detecting, as an increase / decrease area, an area where the received power of the electromagnetic wave received by the antenna increases from the reference level to a predetermined value or more and then decreases to the reference level;
A road surface unevenness detection device comprising: unevenness detecting means for detecting the increase / decrease region as unevenness on the road surface when the increase / decrease region exists between the road surface regions.   The road surface unevenness detection apparatus according to claim 1, wherein the reference level setting unit detects, as the road surface area, an area where a change in received power of an electromagnetic wave received by the antenna is within a predetermined value.   The unevenness width detecting means for detecting the width of the increase / decrease area in the horizontal direction and detecting the width of the unevenness on the road surface based on the width of the increase / decrease area is further provided. The road surface unevenness detection apparatus according to claim 1.   An unevenness height detecting means for detecting a difference in received power by obtaining a difference between a maximum value of received power in the increase / decrease area and the reference level, and detecting the height of the unevenness on the road surface based on the difference in received power. The road surface unevenness detection apparatus according to claim 1, further comprising:   The unevenness detecting means detects an unevenness set in which unevenness on the road surface is continued by a predetermined number in the horizontal direction, and when the unevenness set is continuous at a predetermined interval in the vanishing point direction, The road surface unevenness detection device according to any one of claims 1 to 4, wherein the unevenness set is detected as a rumble strip.   The unevenness detecting means detects two uneven rows in which the unevenness on the road surface is continuous in the vanishing point direction, and the distance between the unevenness rows becomes a value close to the distance between tires of the vehicle, and the unevenness on the road surface The road surface unevenness detection apparatus according to any one of claims 3 to 5, wherein when the width of the vehicle becomes a value close to the tire width, the unevenness row is detected as a rut.   The unevenness detecting means detects an unevenness row in which unevenness on the road surface is continuous in the vanishing point direction, and the width and height of the unevenness constituting the unevenness row are set in advance to the width and height of the Dotsbotts. The road surface unevenness detection device according to any one of claims 4 to 6, wherein when the values are close to each other, the unevenness row is detected as Dotsbots.   8. The antenna according to claim 1, wherein a wavelength of an electromagnetic wave to be received is set to 1/10 or less of a height of unevenness on a road surface to be detected. Road surface unevenness detection device.   The road surface unevenness detection apparatus according to claim 1, wherein a plurality of the antennas are installed, and the plurality of antennas receive electromagnetic waves having different frequencies. A road surface unevenness detection method for detecting electromagnetic waves radiated from an object with a multi-element antenna and detecting unevenness on the road surface,
A reference level setting step for setting a reference level based on the received power in the road surface area;
Increase / decrease area detection step for detecting an area where the received power of the electromagnetic wave received by the antenna increases from the reference level to a predetermined value or more and then decreases to the reference level as an increase / decrease area;
A road surface unevenness detecting method comprising: detecting unevenness as an unevenness on the road surface when the increase / decrease area exists between the road surface areas.

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