JPH02268210A - Method for measuring width and length of slab - Google Patents

Abstract

PURPOSE:To perform highly accurate measurement by obtaining the slant angle of a slab being conveyed, and correcting and operating the measured values of the apparent width and length of the slab. CONSTITUTION:Range finders M1 and M2 measure the distances to the side surfaces of the front end and the rear end of a slab S, and the apparent width of the slab is obtained. Tip detecting parts PH4 detect the front end of the slab S in conveyance. The range finder M1 measures the distance to the rear end. Thus, the apparent length of the slab S is obtained. Then, the specified position of the front end of the slab S is detected based on the output of a rotary encoder 13. A slant angle is operated based on the measured values by the range fingers M2 and M3 at this time and the measured values of the range finders M2 and M3 at the time point when the slab S is moved by a specified distance. The apparent width and the length of the slab are corrected and operated based on said slant angle. Thus, the measurement whose measuring accuracy is very high can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for measuring the width and length of slabs transferred on a conveying line.

[Prior art and problems to be solved by the invention] Conventionally, as a method of measuring the length of a slab, for example, a light source irradiates the object to be measured and the reflected light is received to measure the distance from the light source. A method using a distance meter that detects the position of a light spot is being used.

However, this method has a problem in that if the slab is moved obliquely to the transport direction, measurement errors occur and accurate measurements cannot be made.

The present invention was made to solve this problem, and an object of the present invention is to provide a method for measuring the width and length of a slab that does not cause errors even if the slab moves skewed.

[Means for Solving the Problems] A slab width measuring method according to the present invention measures the distances from both sides of the slab being transferred to the side surface near the tip and the side surface near the rear end of the slab, and calculates these distances. and the distance from the vicinity of the tip of the slab to the vicinity of the rear end of the slab, and the step of determining the inclination angle of the slab based on the distance from both sides of the slab to the side surface near the tip or the side surface near the rear end of the slab. and a step of determining the slab width based on the inclination angle of the slab and the apparent slab width.

Further, in the slab length measurement method according to the present invention, distances from both sides of the slab to be transferred to a side surface near the tip of the slab and a side surface near the rear end are each determined as n1, and these distances and the tip of the slab are A process of determining the inclination angle of the slab based on the distance from the vicinity to the vicinity of the rear end, a process of determining the apparent length of the slab by measuring the length between the front end and the rear end of the slab, and determining the slab length from the inclination angle and the apparent slab length.

[Function] In this invention, the inclination angle of the slab to be transferred is determined, and the slab width and length are determined based on this inclination angle and the apparent slab width and length.

[Embodiment] FIG. 1(A) is an explanatory plan view of an apparatus and related equipment for carrying out a method according to an embodiment of the present invention, and FIG. 1(B) is an explanatory side view thereof. In the figure, (Ml) is a distance meter that measures the distance from the reference position (10) to the rear end of the slab S. (M2) and (M3) are distance meters, respectively.
The distances from the reference positions (11) and (12) to the side surfaces of the slab S are respectively measured. (PH1) to (PH4) are tip detectors, consisting of a pair of emitter and receiver,
Detect the tip of the slab S. (13) is a rotary encoder which is attached to a roller and measures the transport distance of the slab S by detecting the rotation of the roller.

FIG. 2 shows the measurement principle of the distance meter (Ml). The range finder (Ml) has a light source (21) on the light emitting side, and a lens (22) and an image sensor (23) on the light receiving side. The light from the light source (21) is reflected at the rear end of the slab S and passes through the lens (22) to the image sensor (23).
), and the distance to the rear end of the slab (30) is determined from the scanning angle θ of the image sensor (23) and the height H from the light source (21). Here, the distance is distance - H・tan
It is determined by θ. This rangefinder (Ml) has its light receiving window (2
4) From the relationship 6, the 13 constant range is the distance Ml as shown in the figure. The configurations of the rangefinders (M2) and (M3) are basically the same as the rangefinder (Ml).

FIG. 3 is a block diagram showing the measurement circuit of the above device. In the figure, (30) is an arithmetic circuit, each distance meter (Ml) (M2) (M3), tip detector (PH1)
~ (PH4) and the output of the rotary encoder (13) are input, respectively, and the width and length of the slab S are determined by performing predetermined calculations to be described later.

Next, a method for determining the width and length of the slab S in the above-mentioned apparatus will be explained.

FIG. 4 is a diagram explaining the basic measurement method, and shows a state in which the slab S is moving parallel to the transport direction. The slab width is the output L2 of the distance meter (M2) (M3). L
Obtained by 3.

WO-Lw-(L2 + L3)
-= (1) Note that Lv is distance meter (M2) (M3)
is the distance between the reference positions (11) and (12).

The slab length is determined as follows. When the tip of the slab S passes, for example, a tip detector (PH4), the detection signal is input to the calculation circuit (30), and at that timing, the distance data L1 of the distance meter (Ml) is read into the calculation circuit (30). and the preset distance meter (Ml)
The slab length LO is obtained by subtracting the distance data Ll from the distance (Lh4) between the front end detector (PH4) 1 and the tip detector (PH4) 1.

Lo -Lh4-LL -(2
) The above explanation is an example in which the slab S moves parallel to the transport direction, but it does not actually move like that, so Lo and WO are the apparent slab lengths here. and width.

Next, a description will be given of measurement when the slab S is moved obliquely at an angle θ.

FIG. 5 is an explanatory diagram when measuring the slab width and length when the slab S moves diagonally.

First, a method for determining the inclination angle θ of the slab S will be explained. A predetermined position near the tip of the slab S is detected by the output of the rotary encoder (13), and the output of the distance meter 0'12) (M3) at that position is read. The measurement data at this time are assumed to be L2f' and L3f. After that, the output of the rotary encoder (13) is read and each distance meter (M2) (M
Read the output of 3). The data at this time is 1.2b
, L3b. Using these data, θ is determined by the following equation.

V l −(L2f' −L3f”I /2y 2−
(L2b -L3b) /2i9 -jan-'1(
yl-y2)/21 After determining the inclination angle θ in this way, each apparent value determined by equations (1) and (2) can be calculated by correcting the above actual measured values using the following equations. , determine the slab width W and length taking into account the inclination angle θ.

W-Wo cosθ L -L o cosθ In the above example, width -2000go+, length -9
With a 100me slab, at θ-31, the following?
#1 A constant result has been obtained.

Without skew correction Width with skew correction (Iam) 2003.5 2000.8
Length (Iam) 9118.6 9108.
1. In the above embodiment, an image sensor is used as the distance meter, but it goes without saying that a conventional distance meter may also be used. In addition, the tip detector (PH1) ~ (
PH4) may be appropriately selected and used depending on the length of the slab.

[Effects of the Invention] As described above, according to the present invention, the angle of the transferred slab is measured and the measured values of its width and length are corrected, so that the 1llJ constant accuracy is extremely high. It has become.

[Brief explanation of drawings]

1A and 1B are plan and side views of an apparatus for carrying out a method according to an embodiment of the present invention and related equipment, FIG. 2 is an explanatory view of a distance meter, and FIG. FIG. 4 is a block diagram of the measuring circuit. FIG. 4 is an explanatory diagram of the basic operation when the slabs are being transported in parallel, and FIG. 5 is an explanatory diagram when the slabs are being transported diagonally. In the figure, (Ml), (M2), and (M3) are distance meters.

Claims (2)

[Claims] (1) Measure the distance from both sides of the slab to be transferred to the side surface near the tip and the side surface near the rear end of the slab, respectively,
a step of determining the inclination angle of the slab based on these distances and a distance from the vicinity of the tip of the slab to the vicinity of the rear end; A method for measuring slab width, comprising the steps of determining an apparent slab width based on a distance, and determining a slab width based on an inclination angle of the slab and the apparent slab width. (2) Measure the distances from both sides of the slab to be transferred to the side surface near the tip and the side surface near the rear end of the slab, respectively,
The step of determining the inclination angle of the slab based on these distances and the distance from the vicinity of the tip to the vicinity of the rear end of the slab, and measuring the length between the tip and rear end of the slab, and determining the apparent slab. A method for measuring slab length, comprising the steps of: determining the length; and determining the slab length from the inclination angle of the slab and the apparent slab length.