JP4843946B2 - Anti-air sign - Google Patents

Description

  The present invention relates to an anti-air sign, and more specifically, to an anti-air sign suitable for laser ranging.

  As a means for measuring the terrain three-dimensionally, a laser ranging technique called a LiDAR (Light Detection And Ranging) system has attracted attention. The LiDAR system measures the distance to the ground by irradiating laser light on the ground from a laser range finder mounted on an aircraft or satellite, and measures the three-dimensional position of the aircraft and the laser irradiation angle. This is a technique for measuring a three-dimensional position of a laser irradiation target from a measurement result.

Laser ranging technology is effective in mountainous areas where it is difficult for people to enter. In particular, in terrain measurement, a method of installing a reflector and a method of not using a reflector are known. In the reflection type, although a stronger reflected laser beam can be obtained, it is necessary to install the reflector in the measurement target area in advance, and it is necessary to keep the reflector clean. On the other hand, in the non-reflective method, the object can be measured three-dimensionally without the need to previously install a reflector in the measurement target area. Therefore, the non-reflective method is excellent for measuring a wide area.
Patent Document 1 describes an anti-air sign used for photogrammetry. FIG. 3 of Non-Patent Document 1 describes an anti-air mark used for laser surveying.
JP 2004-012395 A Murakami Masayuki, Katsuta Keisuke, Kimura Kokichi, Akiyama Yukihide, Fujiwara Teruyoshi, Miyazaki Mitsuhiro, “High-Density Three-Dimensional Positioning by Airborne Laser Profiling Using Electronic Reference Points”, Proc. 20th Technical Conference Proceedings, Japan) Survey Survey Technology Association, National Survey Technology Convention 98 ', June 19, 1998, pp. 52-59

  Even if it is non-reflective, it is convenient to specify the position if there is any sign. In snowy areas, signs may be buried in the snow, and in this case as well, it must be used as signs. In volcanic ash terrain, it may be buried in volcanic ash.

  In the non-reflective type, a laser distance measuring device that can simultaneously measure reflected light (first pulse) reflected first and reflected light (last pulse) reflected later can be used. For example, the reflection (first pulse) from the branches and leaves of the tree and the reflection from the ground (last pulse) can be measured simultaneously. By using this, the height of trees can be measured.

  In addition, there is a demand for accurate measurement of debris thickness due to snow depth, volcanic ash thickness, and debris flow.

  An object of the present invention is to present an anti-air sign that can be used even if it is partially buried in snow or the like.

  Another object of the present invention is to provide an anti-air sign that allows measurement of snow depth, volcanic ash thickness, and debris thickness.

  An anti-air marker according to the present invention includes a base plate, a braid having a plurality of openings that transmit a laser beam, and a pole that stands on the base plate and holds the braid at a predetermined height from the base plate. It is characterized by that.

  According to the present invention, even if the base plate is buried with snow or the like, the presence and position of the base plate can be identified with a knitting shade by a laser device such as a LiDAR system. Even if snow, volcanic ash, debris, or the like accumulates on the base plate, only a small amount of snow or volcanic ash can accumulate on the knitting shade, and the height position of the knitting shade hardly changes. The thickness of snow or the like can be calculated by measuring the distance between the knitting shade and the surface of snow or the like. That is, snow depth, volcanic ash thickness, and debris thickness can be measured remotely.

  Furthermore, the knitted shade can be reinforced in the event of snow or volcanic ash by providing a reinforcing material that spans between the knitted shade and the pole and reinforces the knitted shade.

  Further, since the outer dimension of the knitting shade is less than half of the outer dimension of the base plate, the three-dimensional coordinates of the knitting shade and the base plate can be measured at a wide angle at which the laser of the laser distance measuring device enters the present embodiment. .

  The knitted shade is composed of a plurality of wires constituting a concentric circle and a plurality of wires extending radially outward from the center of the concentric circle. As a result, it is lightweight, snow and volcanic ash are unlikely to accumulate, and the three-dimensional position can be easily measured with the first pulse of laser light.

  Furthermore, by including a GPS antenna, a GPS receiver that calculates information indicating the position of the GPS antenna from GPS radio waves received by the GPS antenna, and a wireless device that wirelessly transmits the reception result of the GPS receiver The three-dimensional position of the anti-air sign according to the present invention can be accurately determined. When the wireless device receives a command by a radio wave and activates the GPS receiving device, a GPS receiving system that operates with power saving can be realized.

  Furthermore, a GPS antenna, a GPS receiver that calculates information indicating the position of the GPS antenna from GPS radio waves received by the GPS antenna, and a radio device that receives a command from the radio wave and activates the GPS receiver By implementing the above, it is possible to realize a power-saving GPS receiving system capable of accurately determining the three-dimensional position of the anti-air sign of the present embodiment. Since the wireless device has a function of wirelessly transmitting the reception result of the GPS receiving device, the position of the anti-air sign according to the present invention can be referred to whenever necessary.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a perspective view of one embodiment of the present invention. The anti-aircraft mark 10 of this embodiment includes a flat disk-shaped base plate 12, a pole 14 that stands upright on the base plate 12, and a braided cap 16 that covers the top of the pole 14. The pole 14 may penetrate the knitted shade 16. A plurality of reinforcing rods 18 are passed between the pole 14 and the side surface of the braided cap 16, and the braided cap 16 is reinforced so that the braided cap 16 is not easily dropped by snow or volcanic ash.

  The diameter of the base plate 12 is at least twice the diameter of the braided cap 16. Preferably, the length of the pole 14 is at least twice the diameter of the braided cap 16. Thereby, even if the ranging laser pulse is incident on the marker 10 obliquely, the positions of the base plate 12 and the braid 16 can be measured.

  Since both the base plate 12 and the braided cap 16 are circular, the center of the base plate 12 and the braided cap 16, that is, the three-dimensional position of the pole 14 can be determined regardless of the direction of the laser beam. If the number of corners is large to some extent, the braid 16 may be polygonal.

  The length of the pole 14, that is, the height of the braid 16 viewed from the base plate 12, is measured in advance.

  The braid 16 may be a member having a large number of holes through which the laser beam from the laser distance measuring device can pass and a portion that reflects the laser beam. The former is used to measure the position on the ground including the base plate 12 by the last pulse, and the latter is used to measure the position of the braid 16 itself by the first pulse. The knitted shade 16 preferably has a shape in which a wire such as a steel wire is knitted in order to make it less susceptible to the influence of wind. In the present embodiment, the braid 16 is formed by a plurality of wires constituting a concentric circle and a plurality of wires extending radially outward from the center of the concentric circle.

  The anti-air sign 10 of the present embodiment may be dropped from the air. In order to stand up stably, the base plate 12 is made of a heavy and strong material, for example, an iron plate.

  FIG. 2 shows a state of reflection of the distance measuring laser pulse incident on the marker 10 of this embodiment from the vertically upward direction. The laser ranging device 20 mounted on an aircraft such as a helicopter moves to positions 20a, 20b, and 20c.

  The laser pulse emitted from the laser distance measuring device 20 a enters the base plate 12 and is reflected by the base plate 12. Thereby, the three-dimensional position of the base plate 12 is measured.

  The laser pulse emitted from the laser distance measuring device 20 b first enters the braid 16 and is partially reflected by the braid 16 and the rest is reflected by the base plate 12. Each reflected pulse enters the laser distance measuring device 20b as a first pulse and a last pulse, and is used to measure the three-dimensional positions of the braided cap 16 and the base plate 12.

  The laser pulse emitted from the laser distance measuring device 20 c enters the base plate 12 and is reflected by the base plate 12. Thereby, the three-dimensional position of the base plate 12 is measured.

  Since the principle of laser ranging by LiDAR is well known, a description thereof will be omitted.

  FIG. 3 shows an example of a beam spot of a distance measuring laser pulse incident on the marker 10 of this embodiment. The beam spot with the oblique lines shown on the braid 16 is reflected by the braid 16. Further, the beam spot with the oblique lines shown on the base plate 12 is reflected by the base plate 12. A white beam spot illustrated around the base plate 12 is reflected on the ground where the sign 10 is installed.

  When the same measurement is performed when the base plate 12 of the anti-aircraft sign 10 is buried in snow, the net shade 16 can be measured with the first pulse as shown in FIG. 4, and the snow 22 instead of the base plate 12 can be measured with the last pulse. The three-dimensional coordinates of the surface can be measured. Even if snow falls, the snow is only slightly attached to the braid 16 and transmits and reflects the laser beam. From this measurement, the distance Hs between the braid 16 and the surface of the snow 22 can be calculated. The distance H between the base plate 12 and the braid 16 is known. Therefore, the snowfall depth in this case can be calculated as H-Hs. In addition to snowfall, the thickness of volcanic ash and debris, that is, the thickness of volcanic ash and the thickness of debris can be measured.

  FIG. 5 shows a side view of a second embodiment of the present invention. In addition to the embodiment shown in FIG. 1, a GPS reception function and a wireless communication function are added. That is, a GPS antenna 30 that receives GPS radio waves from GPS satellites of a GPS (Global Positioning System) system is installed on the top of the pole 14, and the GPS antennas are received from the GPS radio waves received by the GPS antenna 30 on the base plate 12. A GPS receiver 32 that calculates the position of 30 and a wireless device 34 are arranged. The wireless device 34 transmits the position information received by the GPS receiver 32 to a remote base station or a helicopter flying over the antenna 36 via the antenna 36.

  The GPS receiver 32 only needs to be operated when necessary. In that case, the wireless device 34 activates the GPS receiver 32 in accordance with a command from a remote base station or a helicopter flying over the sky, and calculates a position from the GPS radio wave.

  The wireless device 34 and the GPS receiving device 32 include a power source (secondary battery and a solar cell that charges the secondary battery if necessary) necessary for the above-described operation.

  Although the invention has been described with reference to specific illustrative embodiments, various modifications and alterations may be made to the above-described embodiments without departing from the scope of the invention as defined in the claims. This is obvious to an engineer in the field to which the present invention belongs, and such changes and modifications are also included in the technical scope of the present invention.

1 shows a perspective view of one embodiment of the present invention. It is sectional drawing which shows the propagation example of the laser pulse at the time of the coordinate measurement by a LiDAR system. It is a perspective view which shows the example of the reflective spot of a laser pulse. It is explanatory drawing of the example of a measurement after snowfall. It is a side view of 2nd Example of this invention.

Explanation of symbols

10: Air-to-air sign (this example)
12: Base plate 14: Pole 16: Knitting shade 18: Reinforcing bars 20a, 20b, 20c: Laser distance measuring device 22: Snow 30: GPS antenna 32: GPS receiver 34: Radio device 36: Antenna

Claims (8)

A base plate (12);
A braid (16) having a plurality of openings for transmitting the laser beam;
A pole (14) which stands on the base plate (12) and holds the braided cap (16) at a predetermined height from the base plate (12)
An anti-air sign characterized by comprising:   The anti-aircraft sign according to claim 1, further comprising a reinforcing member (18) that spans between the braid (16) and the pole (14) and reinforces the braid (16). .   The anti-aircraft sign according to claim 1 or 2, wherein the outer dimension of the braided cap (16) is not more than half of the outer dimension of the base plate (12).   The said braid (16) consists of a plurality of wires which constitute a concentric circle, and a plurality of wires which extend radially outward from the center of the concentric circle. Anti-air sign.   Furthermore, a GPS antenna (30), a GPS receiver (32) that calculates information indicating the position of the GPS antenna (30) from GPS radio waves received by the GPS antenna (30), and the GPS receiver (32) The anti-air sign according to any one of claims 1 to 4, further comprising: a wireless device (34) for wirelessly transmitting the reception result. The anti-air sign according to claim 5 , wherein the wireless device (34) receives a command by a radio wave and activates the GPS receiving device (32).   Furthermore, a GPS antenna (30), a GPS receiver (32) that calculates information indicating the position of the GPS antenna (30) from GPS radio waves received by the GPS antenna (30), and a command by radio waves are received. The anti-air sign according to any one of claims 1 to 4, further comprising: a wireless device (34) that activates the GPS receiving device (32).   The anti-air sign according to claim 7, wherein the wireless device (34) wirelessly transmits a reception result of the GPS receiving device (32).

Images