RU150007U1 - LENGTH AND SPEED METER - Google Patents

Abstract

The length and speed meter of the etched rope, containing a drum on which the rope is wound, and an information processing unit, characterized in that a multi-turn absolute angular displacement transducer and a linear displacement transducer are additionally inserted in it, the latter being installed so that the distance between it and the axis of rotation the drum is always constant, and its sensitive element is connected to the rope in the place of its etching from the drum or picking up, while the input shaft of the multi-turn absolute conversion The rotary encoder is mechanically connected to the axis of the drum, and the outputs of the linear displacement transducer and the multi-turn absolute angular displacement transducer are connected to the corresponding inputs of the information processing unit.

Description

The utility model relates to the field of controlling the length and speed of long material wound on a drum. In particular, this is necessary to control the length of the etched rope or cable wound on the winch drum, and to control its etching or picking speed.

Currently, there are several principles for measuring the length and speed of long material, for example, the length is determined using a measuring roller, on which the controlled material is rolled. Another method is based on reading labels applied to the controlled material at a fixed interval. The measurement of speed is nothing more than the calculation of the first time derivative of the change in the length of the etched material.

Known electronic device for measuring the length of the cable and a method for determining the position of the first end of the cable according to patent WO 2009087204, (51) G01B 7/00, G01D 5/14 (43) 07/16/2009, including a controller, measuring device, image recording device, fixed on the free end of the cable, on the protective shell of which, over a fixed distance, ferromagnetic marks are applied, and a reader made in the form of inductors connected to a measuring device.

The disadvantages of the known electronic device for measuring the length of the cable and the method for determining the position of the first end of the cable include:

- the need to create on the controlled material, in this case, on the cable, special marks, which is not always possible;

- the error in measuring the length of the etched end of the cable when changing the distance between the marks in the case of stretching or compression of the cable;

- the use of non-volatile memory in the device, which has a limited number of overwrites. Non-volatile memory is necessary for recording information about the number of read marks at the time of reading the next mark, since in the event of a power failure, controlled information will be lost;

- distortion of information that occurs when the cable length changes during power failure, when the labels are not read and information about the cable length is not recorded.

A known length meter of moving materials according to the patent of the Russian Federation No. 2313064, (51) G01B 7/04, (45) 12/20/2007, containing a drive mechanism for feeding and moving material, measuring drive conveyor and non-drive conveyor. The dimensional drive conveyor that moves the material includes an elastic closed tape, a drive roller, a non-drive roller connected to a primary linear displacement transducer, including a obturator disk and an optocoupler length sensor for moving material. The obturator disk of the primary linear displacement transducer is located on the axis of the non-drive roller. The proposed measuring instrument for the length of moving materials is equipped with a cyclically operating system of dynamic correction of measurement results, which includes a special mark mounted on an elastic tape of the drive conveyor, and an optocoupler mark position of the mark that is fixed relative to the elastic tape and fixes the number of cycles of its rotation.

The disadvantages of the specified measuring length of moving materials include:

- the complexity of the design, which limits the use of the proposed device;

- the use of non-volatile memory in it, the purpose of which and drawbacks in use are indicated in the previous analogue;

- distortion of information that occurs when the length of the material changes during power failure, when information about the length of the material is not read and not written.

The closest device, in terms of features, is (54) "Winch for releasing a portion of an unwound cable of a given length" according to international application (10) WO 2012/084685 A1, (51) G01B 7/02, G01B 7/04, B66D 1 / 46, B66D 3/18, F21V 21/38, (43) 06/28/2012, which is taken as a prototype. This device includes:

- a cable drum designed for winding and unwinding a cable;

- cable cable, one end of which is attached to the cable drum, and the other end is free, on which the actuator is fixed;

- the frame on which the cable drum is installed;

- measuring devices (magnetic sensor, measuring controller and length measuring device) are located on the frame and provide the formation of signals proportional to the length of the unwound part of the cable;

- a data processing device (microprocessor) is designed to control the winding and unwinding of the cable cable according to the signals received from the measuring devices by which information is generated on the length of the etched cable;

- magnetic mark of the initial position of the cable (zero value of the length of the etched cable);

- an electric motor designed to rotate the drum. The winch works as follows. The rotation of the drum 140, on which the cable cable 120 is wound, is carried out by an electric motor 170 by the control signals from the microprocessor 160, the inputs of which, in turn, receive signals from the output of the measuring controller 150. The signal from the magnetic sensor 130, which fixes the initial (zero) state of the cable, and the signal from the length measuring device 155, which controls the angle of rotation of the drum 140. The length of the etched cable is determined by the angle of rotation of the drum relative to the initial state and for mustache rope winding on a drum.

The disadvantages of the known technical solutions adopted for the prototype include:

- the error in measuring the length of the etched cable with multi-row and multi-layer winding of the cable on the drum;

- the use in the winch of a single-turn sensor of the angle of rotation of the drum, which requires the inclusion in the device non-volatile memory necessary to record information about the number of revolutions of the drum and having a limited number of overwrites;

- distortion of information that occurs when the length of the etched cable changes, during power failure, when information about the length of the etched cable is not fixed.

The objective of this utility model is to increase the accuracy of measuring the length of the etched rope and the speed of etching or choosing the rope.

The technical result of the claimed utility model is to increase the accuracy of control of the length of the etched rope and the speed of its etching or selection.

The indicated technical result is achieved in that a linear displacement transducer and a multi-turn absolute angular displacement transducer are additionally introduced into the length and speed meter of the etched rope containing a drum on which the rope is wound and the information processing unit. The case of the linear displacement transducer is installed so that the distance between it and the axis of rotation of the drum is always constant, and its sensitive element is connected to the rope at the place of its etching from the drum or selection. The input shaft of a multi-turn absolute transducer of angular displacements is mechanically connected to the axis of the drum. The output of the linear displacement transducer and the output of the multi-turn absolute angular displacement transducer are connected to the inputs of the information processing unit. The information processing unit in accordance with the output signals of the converters generates the value of the length of the etched rope and the speed of its etching or selection.

Between the essential distinguishing features and the above technical result, there is a causal relationship:

1. An multi-turn absolute angular displacement transducer is additionally introduced into the length and speed meter of the etched rope, in which the angular position of the input shaft, mechanically connected to the axis of the drum, is constantly fixed, which ensures control of the angular position of the drum even when the supply voltage is turned off. This, in turn, allows to increase the accuracy of measuring the length of the etched end of the rope, eliminating malfunctions even with a short-term power outage.

2. A linear displacement transducer has been introduced, which makes it possible to increase the accuracy of measuring the length of the etched end of the rope by measuring rather than calculating the current radius of the winding of the rope, and allowing fixing the beginning and end of the transition from one layer to another when selecting or etching the rope on the drum.

3. The linear displacement transducer is installed so that the distance between it and the axis of rotation of the drum is always constant, and its sensitive element is connected to the rope at the place of its etching or selection from the drum, which makes it possible to measure the radius of winding of the rope on the drum with high accuracy.

4. The output of the linear displacement transducer and the output of the multi-turn absolute angular displacement transducer are connected to the corresponding inputs of the information processing unit, due to which the information on the length and speed of the etched rope is generated by the information processing unit.

Therefore, the combination of the above significant distinguishing features ensures the receipt of the claimed technical result.

The circuit of the meter length and speed of the etched rope is shown in figure 1. Figure 2 - schematically shows the location of the drum with a wound rope and a linear displacement transducer relative to each other, explaining the principle of information processing.

The inventive length and speed meter of the etched rope shown in Fig. 1 includes: a drum 1 on which a rope 2 is wound, a linear displacement transducer 3 (for example, an LIR-DA7 absolute linear photoelectric position sensor manufactured by a special design bureau of measuring systems) , the sensitive element of which controls the distance to the etched or selectable part of the rope, multi-turn absolute transducer of angular displacements 4 (for example, an absolute multi-turn angle sensor AC36 position according to the product catalog of a special design bureau of measuring systems) and an information processing unit 5. The linear displacement transducer housing 3 is installed so that (see FIG. 2) that the distance “A” between it and the axis of rotation of the drum 1 is always constant, and sensitive the element of the linear displacement transducer 3 controls the distance "B" to the rope in the place of its etching from the drum. The input shaft of the multi-turn absolute encoder 4 is connected mechanically to the shaft of the drum 1. The output of the linear converter 3 and the output of the multi-turn absolute encoder 4 are connected to the corresponding inputs of the information processing unit 5. The information processing unit 5 generates the value of the length of the etched rope from the output signals of the converters and the speed of its etching or selection.

The use of a multi-turn absolute transducer of angular displacements and a linear displacement transducer in the meter of length and speed of the etched rope, which controls the current radius of winding on the drum of the etched rope, makes it possible to increase the accuracy of measuring the length and speed of the etched rope.

The meter length and speed of the etched rope works as follows. In the initial state, the rope is wound on the drum 1, and the length of the etched rope in the information processing unit 5 is reset. The current value of the radius of the winding of the rope on the drum 1 is determined by the formula:

A is the distance between the control point of the linear displacement transducer 3 and the axis of rotation of the drum 1, the value of which for a particular design is fixed (see figure 2).

B is the distance between the control point of the linear displacement transducer 3 and the axis of the rope at the point of etching from the drum or selecting (see figure 2).

The length of the completely etched rope is determined by the formula:

r _i is the radius of the winding of the rope of the i-th section of the increment.

Δφ is the interval of increment of the angle of rotation of the drum 1 (the value Δφ is set in radians depending on the specified error in measuring the length of the etched rope), after which the radius r _i of the rope wound on the drum 1 is measured;

- количество измеренных интервалов Δφ приращения при полностью вытравленном канате (φ=φ_max);

- the number of measured intervals Δφ increments with a fully etched rope (φ = φ _max );

i is the index of the increment plot;

r _i is the radius of the winding of the rope of the i-th section of the increment.

The current length of the etched rope is determined by the formula:

- количество вытравленных интервалов приращения Δφ при угле поворота φ=φ_i;

- the number of etched increments of the increment Δφ with a rotation angle φ = φ _i ;

i is the index of the increment section, and with increasing angle (when etching the rope Δφ is positive), the index increases, and with decreasing angle (when choosing the rope Δφ is negative), the index decreases.

The speed of etching or choosing a rope is determined by the formula:

Δt is the time interval for which the rope is etched by the length ΔL = Δφ · r (φ), while the Δφ values for controlling the length or speed of the etched rope can be different.

When measuring speed, two options are possible:

a) for a fixed time interval Δt, ΔL is measured and their ratio is calculated (see formula 3);

b) for a fixed increment ΔL of the etched or selected rope, the time interval Δt is measured and their ratio is calculated (see formula 3).

Since speed is a derivative of a change in length versus time, when measuring speed it is necessary that the interval Δt tend to zero. In real systems, ΔL and Δt cannot be infinitely reduced due to the presence of measurement error. Therefore, when measuring high speeds of etching or choosing a rope, it is advisable to use the first measurement option, and when measuring low speeds - the second option.

As a rule, the winding of the rope on the drum is carried out in layers, while the radius of winding in each layer can be considered constant. When switching from one layer to another, with a high probability, it can be assumed that the winding radius r (φ) changes linearly when the drum 1 is rotated through an angle of 360 °. Using these conditions, the processing of information from transducers 3 and 4 to measure the length and speed of the etched rope is greatly simplified. To do this, it is necessary to calibrate the transition points, according to which, depending on the angle of rotation of the drum 1, the length and speed of the etched rope are determined. In the process, the calibration of transition points can be adjusted. Transitional points or inflection points of the characteristic of the length of the etched rope from the angle of rotation of the drum are the points when the rope is wound from one layer to another. These points are determined using the linear displacement transducer 3 at the moment when its output signal begins to change. Between transition points, there are two types of sections: one type, when the rope is etched or selected from one layer, and the other is the section type, when the rope is etched or selected during the transition from one layer to another. The length of the rope in the area of the first type is determined by the formula:

L _k is the length of the etched rope of the k-th section of the first type;

r _k is the radius of the kth layer of the rope winding on the drum;

φ _t is the value of the current angle of the drum;

φ _k is the value of the initial angle of the k-th plot of the first type.

The length of the rope in the section of the second type is determined by the formula:

L _{k ′} is the length of the etched rope of the k-th section of the second type;

d = (r _k -r _{k + 1} ) is the difference between the radii of the winding of the ropes of adjacent layers, which is determined during calibration or can approximately be taken equal to the diameter of the rope.

Using a linear displacement transducer 3 and a multi-turn absolute angular displacement transducer 4 improves the accuracy of controlling the length of the etched rope and the speed of its etching or selection.

Analysis of similar technical solutions showed that the use of the proposed meter length and speed of the etched rope provides the following advantages compared with known devices:

- allows you to improve the accuracy of measuring the length and speed of the etched rope, especially when monitoring at low speeds;

- allows you to simplify the processing of signals when using calibration transition points.

Claims (1)

The length and speed meter of the etched rope, containing a drum on which the rope is wound, and an information processing unit, characterized in that a multi-turn absolute angular displacement transducer and a linear displacement transducer are additionally inserted in it, the latter being installed so that the distance between it and the axis of rotation the drum is always constant, and its sensitive element is connected to the rope in the place of its etching from the drum or picking up, while the input shaft of the multi-turn absolute conversion The rotary encoder is mechanically connected to the axis of the drum, and the outputs of the linear displacement transducer and the multi-turn absolute angular displacement transducer are connected to the corresponding inputs of the information processing unit.

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