JP2850156B2 - Radio wave reflection type buried object detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground object and an exploration device for exploring a reinforcing bar in a reinforced concrete structure, and more particularly, to a radio wave reflection type embedded object utilizing a reflected wave of an electromagnetic wave. It relates to an exploration device.

[Conventional technology]

Conventionally, the transmitting and receiving antennas are mounted on a carriage having wheels for movement, the electromagnetic wave is transmitted and received while moving the carriage, and the position of the carriage at which the maximum reception level can be obtained is the position directly above the buried object. And had In addition, since the dielectric constant of the medium in which the buried object exists is unknown, the depth of the buried object cannot be measured. Therefore, a hyperbolic approximation method has been used.
(Refer to Japanese Patent Application No. 62-99099) [Problem to be Solved by the Invention] In the moving range of the bogie in the conventional technology, the surface immediately above the buried object has severe irregularities, water is accumulated, and there are steps. In a situation where there is a building, and it is not suitable for the movement of the bogie, it is impossible to measure the position of the buried object using the conventional apparatus and method.

The present invention seeks to provide a device that can simultaneously measure the position on the surface and the depth from the surface of the position of the buried object without moving the exploration device directly above the buried object even under the conditions described above. is there.

[Means for solving the problem]

The present invention has been made for the purpose of solving the above-described problems, and in a buried object exploration device including a transmitting antenna for electromagnetic waves and a receiving antenna for receiving a reflected wave of the electromagnetic waves from the buried object, one place of a bogie. A rotatable receiving antenna provided, and an angle sensor for detecting a rotation angle of the receiving antenna are provided, and a point directly above the buried object from the distance between the measuring antenna and the angle of the receiving antenna at two different measurement points. And measuring depth.

(Operation)

The receiving antenna receives the electromagnetic waves reflected from the transmitting antenna when the electromagnetic waves strike the buried object. Since the receiving antenna is rotatable, it can be rotated so as to receive the reflected wave at the maximum level at two different measurement points. Each time it is rotated in this way, its rotation angle is detected by an angle sensor. The distance between two different measurement points is known. Therefore, the position and the depth directly above the buried object can be obtained by the geometric calculation from the two rotation angles at the two measurement points and the distance between the measurement points. The receiving antenna may be rotated automatically or manually, and the transmitting antenna and the receiving antenna may be the same or different antennas.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. 1 and 2 are configuration diagrams of a radio wave reflection type buried object detecting apparatus according to the present invention. FIG. 1 is a side view, and FIG. 2 is a view taken in the direction of arrow A in FIG.

In FIGS. 1 and 2, 1 is a truck, 2 is a transmitting antenna for electromagnetic waves, 10 is an electromagnetic wave transmitted from the transmitting antenna 2, and a part 10a of this electromagnetic wave is reflected by the buried object 11 and reflected. The received electromagnetic wave 10b is received by the receiving antenna 3 provided at one place on the truck, and the receiving level becomes maximum at a position where the receiving antenna 3 is automatically or manually rotated by an angle θ with respect to a horizontal plane. Note that the receiving antenna 3 can also serve as the transmitting antenna 2. Reference numeral 5 denotes an angle sensor that detects an angle θ with respect to the XY plane (horizontal plane) of the receiving antenna 3. 4 is the Z axis of the receiving antenna 3 (XY
This is an angle sensor that detects an angle φ that is rotated with respect to a reference point by an angle sensor around an axis (perpendicular to the plane). Reference numeral 6 denotes a data processing device, and reference numerals 7 and 8 denote wires for sending data of the angles φ and θ from the rotation sensors 4 and 5 to the data processing device. FIG. 3 is a three-dimensional view illustrating the rotation angle of the receiving antenna.

Next, the principle of calculation by the data processing device 6 will be described with reference to FIG. The receiving level of the receiving antenna 3 becomes maximum at an angle θ ₁ at a distance X ₁ from the point 12 directly above the buried object 11, and the bogie is moved △ X while maintaining the rotation angle φ about the Z axis at this time. , similarly to the above receiving antenna 3 from directly above the point 12 in X ₂ of buried objects the reception level at the angle theta ₂ is to become the maximum.
Now, let D be the depth from the surface 13 to the buried object.
Assuming that the height from to the receiving antenna 3 is H, the following equation holds.

tan θ ₁ = X ₁ / (D + H) (1) tan θ ₂ = X ₂ / (D + H) (2) X ₁ = X ₂ + △ X (3) Equation (1) is replaced by equation (1). Tan θ ₁ = (X ₂ + X) / (D + H) (4) By transforming (4), X ₂ = (D + H) × tan θ _1- △ X (5) (5) Substituting the equation into equation (2), tan θ ₂ = tan θ _1- {X / (D + H) (6) By modifying (6), D = {X / (tan θ ₁ -tan θ ₂ ) -H} substituting ... (7) (7) D of formula (5) to D of formula, X ₂ is obtained.

Thus, the position on the surface 13 directly above the buried object 11
12 can be obtained (the distance of X ₂ can be obtained). Further, the depth D from the surface 13 can be obtained.

〔The invention's effect〕

Since the present invention is configured as described above, (1) the position of the buried object can be known three-dimensionally regardless of the value of the dielectric constant of the medium in which the buried object exists.

(2) The practical value of the present invention is extremely high because the position of a buried object can be known three-dimensionally irrespective of the presence / absence of irregularities on the surface near the buried object, water pools, steps, and the presence or absence of a building.

[Brief description of the drawings]

1 and 2 are configuration diagrams of a radio wave reflection type buried object detecting apparatus according to the present invention. FIG. 1 is a side view, and FIG. 2 is A in FIG.
FIG. 3 is a three-dimensional view for explaining a rotation angle of the receiving antenna, and FIG. 4 is an explanatory view of a principle calculated by the data processing device. 1: Bogie, 2: Transmitting antenna, 3: Receiving antenna, 4: Angle sensor, 5: Angle sensor, 6: Data processing device, 10: Electromagnetic wave, 11:
Buried object, 12: Point directly above the buried object, θ, θ ₁ , θ ₂ : Angle of receiving antenna, φ: Angle of receiving antenna, D: Depth of buried object, H: Height of receiving antenna, ΔX : Distance between measurement points

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01S 7/00-7/42 G01S 13/00-13/95 G01V 3/12

Claims (4)

(57) [Claims] A buried object exploring apparatus comprising: a transmitting antenna for electromagnetic waves; and a receiving antenna for receiving a reflected wave of the electromagnetic waves from the buried object. Radio wave reflection, wherein an angle sensor for detecting a rotation angle of the object is provided, and a point just above the buried object and a depth are measured from an angle of the receiving antenna and a distance between the measurement points at two different measurement points. Type buried object detection device. 2. The radio wave reflection type buried object detecting apparatus according to claim 1, wherein the receiving antenna is automatically or manually rotated. 3. The radio wave reflection type buried object exploration apparatus according to claim 2, wherein transmission and reception of the electromagnetic wave are performed by different antennas. 4. The radio wave reflection type buried object detection apparatus according to claim 2, wherein transmission and reception of the electromagnetic wave are performed by the same antenna.