JPS59125008A - Position detecting method of moving body - Google Patents

Abstract

PURPOSE:To measure a position of a moving body by rotating and scanning an optical beam emitted from the moving body, and detecting a reflected light beam from a corner cube provided on three fixed positions. CONSTITUTION:An optical beam which rotates and scans is emitted from a moving body V. A bearing of each corner cube 1, 2 and 3 to the moving body V is detected by photodetecting a reflected light beam from each corner cube 1, 2 and 3. By measuring horizontal angles theta1, theta2 made by those bearings, from those bearings, two circles C1, C2 which use a segment between the corner cubes as a chord are determined clearly, respectively, by a circumferential angle theorem. A position of the moving body V is derived by deriving an intersection point of the two circles. A control computer 10 stores the respective directions of each corner cube 1, 2 and 3, also compares a stored value with an output value of an encoder 9, and controls so as to reduce a rotating speed of a motor 5 in the vicinity of the stored value.

Description

[Detailed Description of the Invention] The invention relates to a method for detecting the position of a moving object such as a vehicle or an aircraft using a light beam. The present invention relates to further improvements to the proposed method for detecting the position of a moving object.

In view of the fact that the conventional method of detecting the position of a moving object requires a large amount of equipment, and that there are restrictions on where it can be used, one of the applicants proposed a simple device with limited implementation. For the purpose of providing possible position detection means, the said %
As indicated in the No. 57-fDj"j, corner cubes are provided at at least three fixed foot positions, and
The moving object is equipped with a light source that emits a rotationally scanning light beam and a photosensitive device, and by detecting the reflected light of the light beam from the corner cubes, the azimuth difference between each corner cube is measured, and the moving object itself Although a method for detecting the digit @ and its M fW +i have been proposed, the invention relates to an improvement for improving the detection accuracy in the method for detecting the digit 16 of a moving body.

13I] In order to detect position #7, the mobile object must
It is necessary to measure the orientation of each corner cube when it is in position, but if the rotational scanning speed of the light beam is slow compared to the moving speed of the moving object, the pressure detection error will increase by that amount. Therefore, it is necessary to increase the rotational scanning speed of the light beam, but the time it takes for the light beam to cross the corner cube cannot be made shorter than the time required to fix the orientation of the corner cube. In particular, when the moving range of the moving object becomes wider, the distance between the moving object and the corner cube increases, resulting in a drawback that the direction of the corner cube cannot be detected.

The object of the invention is to eliminate the above-mentioned drawbacks.

To achieve this objective, the uninvented position detection method rotates and scans a light beam emitted from a moving body, and detects the light emitted from corner cubes provided at at least eight foot positions apart from the moving body. The method detects the orientation of each corner cube with respect to the moving object by detecting the reflected light beam of the light beam, thereby measuring the position of the moving object based on the principle of triangulation. The orientation of each corner cube is sequentially pre-detected by rotating the beam at a low speed, and during subsequent scanning, the emitted light beam is rotated and scanned at a low speed only in the vicinity of the orientation of each corner cube that was previously detected. In the azimuth part, the emitted light beam is configured to rotate and scan at high speed.

In position detection using the uninvented method, to measure the orientation of a corner cube, the rotational scanning speed of the light beam is slowed down only in the vicinity of each corner cube based on the approximate orientation memorized in advance. By doing this, the orientation of the corner cube can be measured without reducing the overall scanning speed, so the position and detection of the moving object can be performed with high accuracy. The orientation of the cube is memorized, and the next scan is performed at low speed in the vicinity of that orientation, so even if the moving object moves, the corner cube can be reliably detected without losing sight of the corner cube. This allows for more accurate position detection.

Hereinafter, embodiments of the non-inventive method will be described based on the drawings.

FIG. 1 is a plan view showing the principle of a method for detecting the position of a moving object such as a vehicle.

In the figure, (1), (2), and (3) are corner cubes installed at known positions in advance, and a light beam incident from any direction is reflected in the direction of incidence.On the other hand, a moving object ( A rotating scanning light beam is emitted from the corner cubes (1), (2), and (3), and by receiving reflected light beams of the emitted light beam from the corner cubes (1), (2), and (3), ) is detected, and from these directions, each corner cube (1) is detected.
.

(2>, (3) horizontal angle (θ1), (θ
By measuring f), two circles (C,) and (C,) whose chords are the line segments between corner cubes are uniquely determined by the principle of triangulation, more specifically, by the circumferential angle theorem. The position of the moving body (g) is determined by finding the intersection point f of the two circles.

Now, as a means for emitting a full rotational scanning light beam, the moving body (G) includes a laser beam generator (4) and a prism (6) rotated by an electric motor (5), as shown in Fig. 2 Gτ. is loaded, and by rotating this prism (6), the laser beam is rotated. This prism (6) is used to reduce the weight of the rotating mass in order to increase responsiveness when controlling the rotational speed.
Prism (6) [A plane mirror may be used instead.

(7) is a half mirror L, and (8) is a light receiver, which is for detecting the reflected light from the corner cubes (1), (2), and (3).

(9) is directly connected to the motor (5), and is an absolute encoder that outputs the direction of the prism (6). The lj4 force of the encoder (9) when detected is input to the position calculation needle W and the machine θη, and this calculation unit calculates the entire position of the moving object (G) itself based on the above-mentioned principle.

The control computer a4 controls the entire rotational speed of the motor, and stores the output value of the encoder (9) when the light receiver (8) detects the foul light, thereby controlling the rotation speed of each corner cube (1). , (2) , (3) A device that stores each direction, compares the stored value with the output value of the encoder (9), and controls the rotational speed of the motor (5) to be reduced near the stored value. It is. Thus, the rotational scanning speed of the light beam is equal to the valley corner cube (1),
It is configured so that it decreases near (2) and (3).

The method of operating this device is that during the first scan, the direction of the corner cube is memorized in advance by rotating the light beam at low speed while the moving object is stopped, and the second and subsequent scans are performed using the above-mentioned method. position detection.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for detecting the position of a moving object according to the present invention, and FIG. 1 is a diagram explaining the principle of the position detection method, and FIG. 2 is a block diagram of a device for detecting the position on the moving object. Concave...Moving object, (1), (2), (3
)...Corner cubep.

Claims (1)

[Claims] Corner cubes (1), (2), which rotate and scan the light boom emitted from the moving body (ω) and are provided at at least three foot positions apart from the moving body (g).
By detecting the reflected light beam of the emitted light beam from (3), the orientation of each corner cube (υ, (2), (3)) with respect to the moving body (g) is detected, and thereby the triangulation This is a method of measuring the position of a moving object based on the principle, and in the first scan, the emitted light beam is rotated and scanned at a low speed to measure the position of each corner cube (1), (2).
), (3) are sequentially detected in advance, and during subsequent scanning, each corner cube (1) detected previously is detected in advance.
, (2), Detection of position of a moving object characterized by rotating and scanning the emitted light beam at low speed only in the vicinity of the directions of (3), and rotating and scanning the emitted light beam at high speed in other directions. Method.