JPS61145410A - Position surveying apparatus of moving body - Google Patents

Abstract

PURPOSE:To enable positive and accurate surveying operation of a position of a ship, by projecting simultaneously an image of each mark onto image sensors using a lens system. CONSTITUTION:A position surveying apparatus 11 of a moving body is laid on an operation ship 15 and marks 17, 19, 21 set on the ground are sighted from a moving operation site range 13. By this arrangement, images developed of the marks 17, 19, 21 on the image sensor 31 are converted to electric signals and they are emitted as image signals corresponding to luminous intensity levels and become binarized image signals after comparison with the threshold values by the initial processing means 35. By the image signals corresponding to each mark 17, 19, 21, each center of gravity (d), (e), (f) is obtained by an image processing and calculating means 37. The calculating means 37 processes arithmetically deviation of these values from the center point (g) on the sensor 31 and that (e) of the central line 19 and included angles alpha, beta between marks 17, 19 and those between marks 19, 21 are obtained. Here, the calculating means 37 transmits a signal to an automatic colimation mechanism 41 in such a way that a deviation of the center point (g) on the sensor 31 from the center of gravity (e) of the mark 19 may be minimized and the optical axis of a lens 33 is adjusted and the co-ordinate informations of the ship position are obtained by processing the included angles alpha, beta by the calculating means 37.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a position surveying device for a moving body used for surveying the position of a work boat, etc.

(Prior Art) Conventionally, the position of a work boat, etc. has generally been measured using optical equipment as follows. In other words, there is a method of determining the ship's position by using a sextant to measure at least three markers at known positions on land, finding the included angle between each marker, and measuring both sides of the three points in triangulation. This method uses reflected distance measuring light to measure the distance to each reference standard with a light wave range finder to determine the ship's position.

(Problems to be Solved by the Invention) However, the former ship positioning method does not simultaneously measure the included angle between each marker.

Measurement errors are likely to occur in the included angle between each standard due to the movement or oscillation of the workboat, and the latter method measures distance by receiving reflected distance light from a reflector serving as a reference standard, so light waves cannot be measured. Even if the rangefinder is equipped with an automatic reference device, the distance measurement light emitted from the light wave rangefinder has a narrow divergence angle, so the distance measurement light may come off the reflector due to the movement of a work boat or something similar, resulting in automatic reference. There was a problem in that distance measurement could not be performed while the reflector was being captured by the camera, that is, continuous distance measurement could not be performed.

The present invention has been made with attention to these points, and it is an object of the present invention to provide a position surveying device for a moving body that can perform ship position surveying work reliably and has small measurement errors.

(Means for Solving the Problems) Therefore, in the present invention, a position measuring device for a moving object is equipped with an image sensor in which a large number of light receiving elements are arranged in a grid pattern, and at least three markers installed at known positions. a lens system that projects an image of the building onto the image sensor, and converts an image signal corresponding to the luminous intensity level of the projected image of each building output from the image sensor into an image signal that is binarized into a bright and dark pattern. an initial processing means, and arithmetically determines the included angle between each of the marks based on the binary image signal outputted by the initial processing means, and calculates each included angle by the three-point diagonal method of triangulation. and image processing calculation means for specifying the position of the moving object.

(Function) In the mobile object positioning device of the present invention configured as described above, three targets installed at known positions on land are simultaneously imaged on the image sensor by the lens system, and projected onto the image sensor. The image of each building is processed by the initial processing means 1 image processing calculation means, etc., and the initial processing means binarizes the level image signal corresponding to the image of each building projected onto the image sensor into a bright and dark pattern. The included angle between each mark is calculated from this binary image signal using an image processing calculation means, and the included angle is calculated by the three-point double angle method of triangulation to move the target. This system identifies the position of the body, and uses a lens system to simultaneously project the images of each building onto the image sensor, so depending on the slight movement or oscillation of the work vessel, the image of each building may not be displayed on the image sensor. There is almost no chance of losing sight of the ship because it is out of the effective field of view, which makes the work of surveying the ship's position easier.Furthermore, since the images of each building are observed simultaneously on the image sensor, one task is easy. This makes it possible to provide a positioning device for a moving object that has small errors due to ship movement, oscillation, etc.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a position measuring device for a moving body according to the present invention, and FIG. 2 is an explanatory diagram showing the positional relationship between the position measuring device for a moving body and three markers. In the drawing, 11 is a positioning device for a mobile body installed on a work boat 15 floating in a work movement area 13 on the sea;
, 19°21 is a marker installed on land. Here, this marker 17.19.21 is equipped with a light source, such as a halogen lamp, that has enough brightness to distinguish against background light, and is installed horizontally at intervals of about 100 to 1000 m. and its installation location is accurately known.

Further, 31 is an image sensor, 33 is a lens system, 35 is an initial processing means, and 37 is an image processing calculation means.

39 is a display, 41 is an automatic collimation mechanism, and the position measuring device 11 of the moving body is formed by these.

The image sensor 31 is made up of countless tiny photodiodes 4
3 are arranged in a high-density lattice arrangement on a plane, and the details are shown in FIG. The lens system 33 is arranged in front of the image sensor 31, and its horizontal field of view angle θ is covered within the effective field of view of the image sensor 31. Therefore, the three marks 17, 19, 21 within the horizontal field of view of this lens system 33
is reliably projected onto the image sensor 31, and each mark 17,
19.21 The included angles α and β are the image sensor 3, respectively.
This approximately corresponds to the number of photodiodes 43 in the horizontal direction of 1. At this time, the automatic sighting mechanism 41
The lens system 33 functions to adjust the optical axis of the lens system 33 so that the image thereof is always formed approximately at the center of the image sensor 31.

The image sensor 31 detects each building 1 projected in this way.
Images 7, 19, and 21 are converted into electrical signals for each photodiode 43, and sent out as image signals corresponding to the luminous intensity level. Here, if the horizontal viewing angle θ of the lens system 33 is 90'' and the number of photodiodes 43 arranged in the horizontal direction of the effective viewing angle of the image sensor 31 is 2000, then the resolution of the included angle between each target is is approximately 0.045°.

Further, the initial processing means 35 and the image processing calculation means 37 are realized by one microcomputer, and the initial processing means 35 is implemented by the luminous intensity level of the image of each building 17, 19, 21 output from the image sensor 81. The image signal corresponding to the
Convert to an off-value binary image signal. This initial processing means 35 has a function of automatically adjusting the threshold value to a value such that the light emitted by each building 17, 19, 21 and other background light can always be clearly distinguished. This automatic adjustment of the threshold value is performed by a correction signal fed back from an image processing calculation means 37, which will be described later.

The image processing calculation means 37 calculates each building 17, 19, 21 based on the value converted image signal processed by the initial processing means 35.
From the number of photodiodes between the images of
, β are calculated arithmetically, and each included angle α, β and each building 17, 1
The position information of 9 and 21 is subjected to calculation using the three-point diagonal method of triangulation to specify the position of the work boat 15 within the work movement area 13 on the sea. This ship position coordinate information is sent to the display 39 and displayed. Also, at this time, the automatic aiming mechanism 41
The control signal and the threshold correction signal of the initial processing means 35 are also calculated at the same time and fed back to the automatic collimation mechanism 41 or the initial processing means 35.

The mobile body position surveying device 11 configured in this manner is loaded onto a work boat 15 and measures a reference mark 17, 19, or 21 installed at a predetermined position on land from within the work movement area 13. As a result, the target 17 is imaged on the image sensor 31.
, 19.21 is converted into an electrical signal and output as an image signal corresponding to the luminous intensity level. The image signal corresponding to this luminous intensity level is compared with a threshold value by the initial processing means 3S and becomes a binary image signal. Since the image signals corresponding to the images of each building 17, 19, and 21 are extracted as areas a, b, and c that have a certain extent as shown by the black dots in FIG. The center of gravity points d, e, and f are determined using statistical methods such as the following. At this time, if the area mentioned above is too large, or if marks other than 11 marks 17, 19, and 21 are extracted, or if each mark 17, 1
9. If all of the threshold values cannot be extracted, a correction signal for automatically adjusting the threshold value is fed back to the initial processing means 35.

The image processing calculation means 37 calculates each building 17.1 obtained in this way.
Center of gravity points d, e, f of images 9 and 21 and image sensor 3
Question 17.19 and mark 19,
The included angles α, β, between 21. , Yu, 1, Iuni, Yakga, □
Yo. If the deviation between the 7° point g and the centroid point e of the central marker 19 becomes large, errors will occur in the obtained included angles α and β.
The image processing calculation means 37 sends a signal to the automatic collimation mechanism 41 to adjust the optical axis of the lens system 33 so that the above-mentioned deviation is reduced. The image processing calculation means 37 further performs calculations on the included angles α and β obtained in this way using the three-point diagonal method of triangulation to obtain coordinate information of the position of one work boat. This coordinate information is sent to the display 39 and displayed.

Although the present invention has been described in detail according to the illustrated embodiment, the present invention is not limited thereto, and is applicable not only to the positioning of work boats on the sea but also to the positioning of work carts etc. moving on land. It's possible.

For example, the image sensor may include a COD, BBD, etc. in addition to a photodiode as a light receiving element of the image sensor, and the initial processing means and image processing calculation means may be separated from each other. It may be constructed with dedicated hardware, or if the marker uses coherent light such as a laser and a polarizing filter is placed in the lens system to collect and process data at different polarization planes.

Even if there is extremely high brightness noise light, it can be reliably distinguished from the target image. In addition, the threshold value in the initial processing means may be adjusted manually by taking into account the background illuminance such as the weather and time of the day. If it is possible to direct the lens, it is also possible to omit the automatic collimation mechanism of the lens system.

(Effects of the Invention) The present invention is constructed as described above, and uses a lens system to simultaneously project images of each building onto the image sensor. It is almost impossible for the image of the ship to fall outside the effective field of view of the image sensor and be lost, making the work of surveying the ship's position extremely easy.Furthermore, the images of each ship can be observed simultaneously on the image sensor. Because of this, it is possible to obtain excellent effects such as almost eliminating errors due to movement, oscillation, etc. of a single work boat.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a position measuring device for a moving body according to the present invention, FIG. 2 is an explanatory diagram showing the positional relationship between the position measuring device for a moving body and three markers, and FIG. The figure is a front view schematically showing an example of an image sensor. 11...Positioning device for moving object, 17,19゜21...Standard, 31...Image sensor, 33...Lens system, 35... . . . Initial processing means, 37 . . . Image processing calculation means, 41 .
...Automatic sighting mechanism. Figure 1 Figure 2

Claims (3)

[Claims] (1) An image sensor in which a large number of light-receiving elements are arranged in a grid, a lens system that projects images of at least three markers installed at known positions onto the image sensor, and an image output from the image sensor. an initial processing means for converting an image signal corresponding to the luminous intensity level of the projected image of each target into a binary image signal in a bright/dark pattern; The position of a moving body, comprising image processing calculation means for arithmetically determining the included angle between each mark and performing calculations on each included angle using the three-point diagonal method of triangulation to specify the position of the moving body. Surveying equipment. (2) The lens system is provided with an automatic collimation mechanism for controlling the optical axis direction so that the central image of the target image projected onto the image sensor is focused on the center of the image sensor. A position measuring device for a moving body according to claim (1). (3) The initial processing means is equipped with an automatic threshold adjustment mechanism for binarizing the image signal corresponding to the luminous intensity level of the image of each target output by the image sensor into an image signal of a light and dark pattern. A position measuring device for a moving body according to claim (1).