JPS5885107A - Method of measuring length of movable object in noncontact manner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses sensors arranged with a predetermined distance from each other, and determines the number of sensors covered by the object when the tip of the object reaches the start sensor. The present invention relates to a method of measuring the length L of a movable object without contact, in which an approximate value LO of the length of the object is obtained by determining .

Such a method is described, for example, in GB-PS 1, 542.286. In this patent specification, it is provided to pass through a second group of senna whose spacing is a fraction of the above-mentioned length unit in order to determine the residual length L-LO of the object. Methods for determining the length of pre-pulled fibers are known since a large number of sensors are required to determine the length with sufficient accuracy.

In this case, a first elapsed time required for one end of the fiber to pass between two detectors arranged at a known distance from each other is measured. From this time value, the speed of the fiber is then determined by dividing the interval by the first elapsed time. From the second elapsed time required for both ends of the fiber to pass one detector, the length of the fiber is determined by multiplying the velocity by the second elapsed time. This method also has particular drawbacks, since changes in fiber velocity can greatly affect the measurements.

The invention is therefore based on the task of improving the above-mentioned prior art methods in such a way that the measuring accuracy is increased and the number of sensors required is reduced. Furthermore, the influence of the change in velocity of the object on the length measurement accuracy should be minimized as much as possible.

These problems are solved according to the present invention in order to obtain one residual length L1=L-LO... First, when the tip (11) of the object (1) reaches the start sensor (2) and in the direction of movement. Measure the time T1 that elapses between the arrival of the rear end (12) of the object (1) to the sensor (4) which is still covered by the object (1) at the rear, and then... ,
When the rear end (12) of the object (1) reaches this sensor (4) and a reference sensor that is arranged in the moving direction of the object past the start sensor (2) and has a constant distance L2 from the start sensor. (7) Object (1) + 7) Tip (II)
The time T2 that elapses between reaching the time of LO is measured, and the residual length L1 is determined by the relational expression LO, and the residual length L1 thus obtained is added to the approximate value LO. The problem is solved by a method of measuring the length of a movable object without contact.

Other advantages and detailed descriptions of the invention will now be described with reference to the following embodiments and with reference to the accompanying drawings.

The object is indicated by 1 in FIG. 1, and its length is to be determined. An example of this is a binding object or a tube moving over a roll (the roll is not shown for clarity).

The object has a leading end 11 and a trailing end 12, and sensors 2 to 7
It moves in the direction of the arrow shown at 13 on the top. It is advantageous to use a beam box, which is known per se, as a sensor. Each light box has a light source and a photocell. The object 1 acts as a reflector, so that whenever the object passes through the ray box, the rays reach the photocell.

Sensors 2 to 7 are connected via conductors 21 to 26 to an electronic control receiver including a computer 141. The length of the object determined within this device is displayed on the display device 15.

In FIG. 1, it can be seen that the tip 11 of the object 1 has just reached the sensor 2, which is used as a start sensor. Sensors 3 and 4 transmit respective signals via conductors 22 and 23 to device 14, thereby indicating the presence of object 1 on the sensor. The device is therefore able to determine an approximate length LO.

In order to obtain the remaining length L1=L-LO, we calculate the time T1 that elapses between the time when the leading end 11 of the object 1 reaches the start sensor 2 and the time when the rear end I2 of the object 1 reaches the sensor 4. Measure (Figure 2). This measurement is possible, for example, by starting a counter (not shown) contained in the device 14 when the start sensor 2 confirms the arrival of the object 1. The counter then stops again at the moment when the sensor 4 detects the rear end of the object (ie at the moment when the corresponding photocell no longer receives any light).

■ L1=VXTI (1) can be found from. Here, V represents the speed of the object.

Now, for example, with a second counter (also not shown), on the arrival of the rear end 12 of the object 1 to the sensor 4 (starting of the second counter) and the tip of the object l to the reference sensor 7. When the time T2 that has elapsed between reaching 11 (second counter stops) is measured (FIG. 3), the speed is determined as 2 from the relationship (2). Here, L2 represents the distance between the start sensor and the reference sensor.

By substituting equation 2 into equation 1 and solving this equation for Ll, the residual length L1 can be found.

TI+T2 The solution to this equation is obtained, for example, by the computer shown at 141 in FIG.

Although the invention has been described above with particular reference to embodiments relating to measuring the length of tubes, the invention can also be used with other objects such as, for example, sheets or rods.

[Brief explanation of the drawing]

FIG. 1 shows the object to be measured at the starting position for the measurement, FIG. 2 shows the position of the object in the first time measurement, and FIG. 3 shows the position of the object in the second time measurement. 1...Target 2...Start sensor 3
~6...Sensor 7...Reference sensor 11.
... (object) leading edge 12... (object) trailing end procedural amendment 1. Display of the case Patent Application No. 478966 of 1982 2, Name of the invention Method for measuring the length of a movable object without contact 3, Person making the amendment Relationship with the case Patent applicant address 4, Agent 5, Amendment The [Claims] and [Detailed Description of the Invention] columns (1) [Claims] of the subject specification are amended as follows. 1. By using sensors arranged with a predetermined distance from each other and determining the number of sensors that are blocked by the object when the tip of the object reaches the start sensor, This is a method of non-contact measuring the length L of a movable object where an approximate value LO of the sameness L is found. (2) When the tip (11) of the object (1) reaches the sensor (4) which is still not shielded by the object (1) at the rear in the moving direction, the rear end of the object (1) (12) Measure the time T1 that elapses between the arrival of the object (12) and...Next, the rear end of the object (1) to this sensor (4) (
12) and after the start sensor (2), a certain amount 14 is disposed in the moving direction of the object.
Reference sensor (7) with Is 2, to object (1
), the time T2 that has elapsed between reaching the tip (11) of the A method for measuring the length of a movable object without contact, the method comprising: adding the residual length L1 determined by the method to an approximate value LO. 2. Method according to claim 1, characterized in that a light box is used as the sensor (2 to 7). ” (2) On page 6, line 12 of the Letter of Specification, “I instruct you to do something.” is amended as follows. "Instructs what to do (i.e., the sensor is shielded by the object 1)." -L

Claims (1)

[Claims] 1. Using sensors arranged at a predetermined distance from each other, the number of sensors covered by the object is determined when the tip of the object reaches the start sensor. This is a method of measuring the length L of a movable object without contact, whereby an approximate value LO of the length of the object is obtained, and in order to obtain -residual length L1=L-LO, ...When the tip (11) of the object (1) reaches the start sensor (2) and the object reaches the sensor (4) which is still covered by the object (1) at the rear in the moving direction Measure the time T1 that elapses between the time when the rear end (12) of object (1) reaches this sensor (4), and then the time when the rear end (12) of object (1) reaches this sensor (4). and the time when the tip (11) of the object (1) reaches the reference sensor (7) which is arranged in the moving direction of the object past the start sensor (2) and has a constant interval L2 from the start sensor. A movable object characterized in that the time T2 that elapses in . A method to measure the length of without contact. 2. Method according to claim 1, characterized in that a light box is used as the sensor (2 to 7).