JPS61114112A - Weight deciding method - Google Patents

Abstract

PURPOSE:To measure the weight of a body to be measured continuously without using a weight sensor nor contacting the object body by projecting a slit pattern from slantingly above and below the object body which moves. CONSTITUTION:The slit projectors C1 and C2 are arranged slantingly above and below the object body Q and slit light beams projected by them are reflected by top and reverse reflecting mirrors O1 ad O2 and photographed by a telecamera D. When the object body is moved as shown by an arrow, a stripe pattern formed by the slit corresponding to recessed parts 1-3 are detected on the object body. For the purpose, the speed of scanning is varied to obtain calculation precision corresponding to required precision, thereby increasing the processing speed of weight decision making.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a weight determination method for measuring the weight of articles such as vegetables and fruits in a non-contact manner without using a weight sensor.

(Prior art and its problems) The weight of an article is generally detected by a weight sensor. However, when trying to measure the weight of frozen vegetables or the like having an uneven surface, there is a desire to measure the weight in a non-contact manner without using a weight sensor.

Until now, no weight determination method has been developed that can effectively meet such demands.

(Object of the Invention) The object of the present invention is to project a slit pattern from above and diagonally below the object to be measured while moving the object, and to determine the degree of curvature of the object to be measured by the slit. An object of the present invention is to provide a weight determination method that calculates the height of a slit position of an object and continuously measures the weight of the object based on the calculated height.

(M essential points of the invention) The weight determination method of the present invention includes, while moving the object to be measured,
The slit pattern is projected diagonally above and below the object to be measured, and the projected surface is photographed with a television camera through reflectors placed above and below the object. Calculate the height of each slit position of the object.

The method is characterized in that the volume of the object to be measured is determined based on this, and the volume is multiplied by the apparent specific gravity to measure the weight of the object to be measured.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) and 1(b) are explanatory diagrams illustrating the principle of the weight determination method according to the present invention. As shown in FIG. 1(a), a television camera D is installed above the object Q placed on the mounting plate DE''2. Also, by setting the slit pattern projection axis α of the slit s projected by the projector P at the angle between the optical axis Z of the television camera and θ,
When the slit pattern is projected onto the object to be measured Q, the slit position appears shifted by d when viewed from the television camera D side. By examining the deviation d of this slit (striped pattern), the thickness (height) h of the object to be measured Q can be obtained using the following equation.

h=d@tan(w/2-θ)・・・・・・・・・(1
) From this, as shown in FIG. 1(b), from the deviations d1 to d4 of each slit projected onto the object to be measured Q, the portion where each slit is projected onto the mounting table DE (hereinafter referred to as slit position) ) is determined by the height h of the object to be measured. By integrating the volumes of the small prisms found from these heights, the approximate pseudo volume of the object to be measured is obtained, and by multiplying this by the apparent specific gravity of the object to be measured, it is possible to use a weight sensor. It is possible to measure the weight of the object to be measured. However, this measurement method cannot accurately measure the volume of the lower half of the object to be measured, and there is no other way than to measure the weight by assuming that the volume of the lower half is the same as the volume of the upper half. Therefore, in the present invention, a slit pattern is projected on the upper and lower surfaces of the object to be measured, the object to be measured is divided into upper and lower halves, the weights of each are measured, and the weights are added up.

FIG. 2 is a schematic block diagram showing an apparatus for determining the weight of an object to be measured according to the present invention.

Although not shown in the figure, slit projectors c, c2 for the upper surface and for the lower surface are respectively arranged diagonally above and diagonally below the object to be measured Q placed on a moving belt conveyor. The slit light projected onto the object to be measured from the slit projectors for the upper and lower surfaces is reflected by the upper surface reflecting mirror O1 and the lower surface reflecting mirror 02, and is photographed by the television camera D. In addition, slit projector C for upper and lower surfaces
Slit pattern projection axes α1 and α of 1 and C2, respectively
2 is the optical axis Z perpendicular to the horizontal plane H2 that divides the object to be measured Q into two.
They intersect at one point T above. Further, it is assumed that the object to be measured Q is moved in the direction of the arrow by a belt conveyor (not shown).

The image taken by the television camera D is taken into the monitor television E and the A/D converter F.
converts the captured image into, for example, an 8-bit 256×256 pixel image, and stores this in the image memory G. The image memory G is connected to the image memory G via the pass line N.
Floppy disk H1 main memory I, printer J, CR
It is connected to the CPU together with hardware such as TK and keyboard L. The CPU performs the process described in the flowchart of FIG. 4 to determine the weight of the object to be measured.

FIG. 3 is a detailed explanatory diagram of the present invention. In this embodiment, one slit is projected onto the object to be measured from diagonally above and below, and the object is moved in the direction of the arrow. Therefore, for example, on the upper part of the object to be measured, a striped pattern in which the slits are shifted according to the unevenness of the object to be measured can be detected, as shown by ■, ■, and ■ in the figure. For this reason, by changing the scanning speed of the slit, as shown in Fig. 1(b),
Compared to the case of projecting a horizontal striped slit pattern, calculation accuracy corresponding to the required accuracy can be obtained, and the processing speed of weight determination can be improved.

FIG. 4 is a flowchart illustrating the processing means of the present invention. Next, this flowchart will be explained.

(1) An image taken by a television camera that captures the slit pattern projected onto the object to be measured is a pixel (pixel) image.
Since we only know the thickness in +) units, it is necessary to calibrate the units in advance to determine the size in real space. In step A1, a process is performed to determine how much the pixel value in the image corresponds to in units of cm. To do this, for example, take a picture of a white piece of paper with a diameter of Acm using a TV camera, capture the image, find out how much the Acm image is in terms of pixel values, and calculate the number of pixels equivalent to BemI from this. . This result is used to convert the object to be measured into cm" units, which will be explained in step A5. (
(2) Next, move the object to be measured (Step A2) Data on the deviation (stripe pattern) of the slit projection plane of the lower surface of the object to be measured. (3) Based on this data, use equation (1) to calculate the height from the height point T of the slit position on the upper and lower surfaces to the upper surface or lower gable surface.Step A4) Step A M + A4 until the object to be measured leaves the slit projection plane.
Repeat the process (step A5). (4) The slit projection plane on the object to be measured is photographed by a television camera, and a pixel-by-pixel image is obtained. The volumes of the upper and lower parts of the object to be measured are determined as the sum of the heights of each pixel position (step A6). That is, the volume is determined by the integral value of each pixel width.

(5) Since the volume obtained from the image is in pixel units, it is converted into Cm units in real space (Step A7)
. For this, the calibration value obtained in step A1 is used, and for example, the volume in pixels obtained in step A6 is
Divide by the number of pixels equivalent to 512 cm', and then divide this by 5
Determine the volume in cm ml by multiplying by 12.

(6) Add the volumes of the object to be measured obtained from the slit patterns on the upper and lower surfaces to determine the total volume (step As).

(7) Multiply the total volume by the apparent specific gravity of the object to be measured to convert it into weight (step A9).

(8) Output the obtained weight value to a CRT, printer, etc. (step A+o).

(9) Check whether there is a next process for the object to be measured. Step A+1). If there is a next process, repeat steps A2 to AIO.

(Effects of the Invention) As explained below, according to the present invention, since the slit pattern is projected diagonally above and diagonally below the object to be measured, the volume of the object to be measured can be accurately measured. Since the degree of curvature of the slit on the object to be measured is continuously detected while moving the object, the weight of the object to be measured can be determined continuously without contact without using a weight sensor. .

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are explanatory diagrams of the basic principle of the present invention,
FIG. 2 is a schematic block diagram of an apparatus for carrying out the present invention, FIG. 3 is a detailed explanatory diagram of the present invention, and FIG. 4 is a flowchart for explaining the present invention. Q: Object to be measured, C: Slit projector, D: Television camera, E: Monitor TV, F: A /D converter, G...
...Image memory, H...Floppy disk, ■...Main memory, J...Printer, K...CRT, L... ··keyboard,
M...CPU, N...Passline Patent applicant: Ishida Koki Seisakusho Co., Ltd.
Person Patent Attorney Minoru Tsuji Figure 3 Movement Figure 4 Start Correct Al No, sf,, A2 ES Tepa Ichiya Buki Self-Round, A3 Slit Height Han A4 No 74,5 JLI Car γFS Pot Total A, < 戟Honesty used 1,1zA7-, Breath, A-Also Rizutonomatern

Claims (1)

[Claims] While moving the object to be measured, a slit pattern is projected from diagonally above and below the object to be measured, and the projection plane is continuously photographed by a television camera through reflecting mirrors placed above and below the object to be measured; The height of each slit position of the object to be measured is calculated from the image taken from the television camera, the volume of the object to be measured is determined based on this, and the volume is multiplied by the apparent specific gravity to determine the height of the object to be measured. A weight determination method characterized by measuring the weight of.