RU2478186C1 - Electro-optical pendulum level sensor - Google Patents

Abstract

FIELD: physics.SUBSTANCE: level sensor has a pendulum, a light emitter, a line of light detectors and a housing. This scheme includes a slit diaphragm, a switch, a comparator, a reference voltage source, a unit for calculating the number of the middle illuminated light detector, a unit for calculating linear and angular displacement of the pendulum. The light emitter and the slit diaphragm are located on the pendulum and the line of light detectors is located on the housing symmetrically about the pendulum at a certain distance. Outputs of the light detectors are connected to inputs of the switch, the output of which is connected to the first input of the comparator. The second input of the comparator is connected to the output of the reference voltage source and the output of the comparator is connected through the unit for calculating the number of the middle illuminated light detector to the input of the unit for calculating linear and angular displacement of the pendulum. The slit diaphragm forms a narrow radiation beam which illuminates a limited number of light detectors. Signals from the outputs of all light detectors are compared with the reference voltage, as a result of which the index numbers of the illuminated light detectors are determined. The index number of the middle illuminated light detector is then determined.EFFECT: high accuracy and resolution when measuring the angle of deviation of a pendulum owing to narrowing of the radiation beam by the slit diaphragm and use of a device for processing the signal from the light detectors.2 dwg

Description

The invention relates to devices for measuring the deviation of an object in a vertical plane and can be used to control and straighten the position of the railway track.

Known pendulum level sensor ELT-133.00 firm "Plasser & Thuerer" (Austria) [Raspopov V.Ya., Ivanov Yu.V., Zotov S.A. Sensors of the level of control systems for straightening railway machines // Sensors and systems - 1999. - No. 4. - S.40-43]. It contains a massive pendulum, a casing in the lower part of which there is a bath, the profile of which repeats the profile of the lower part of the pendulum along its radius. There is damping fluid in the bath. The pendulum is suspended in the housing using an axis rigidly connected to the pendulum and two ball-bearing supports. The axis of rotation of the pendulum is associated with the axis of rotation of the potentiometric angle sensor.

The vibration of the pendulum is transmitted to the axis of rotation of the potentiometer using pulleys and flexible transmission (steel cable, cord, gear belt). The main disadvantage of this method of signal pickup is the presence of a static sensor error due to the friction moment in a mechanical transmission. In addition, there is wear on the potentiometer both during operation and during transportation of the sensor.

Thus, the disadvantages of the device include the presence of a significant static error due to the moment of friction in a mechanical transmission, which limits the possibility of its use.

The prototype is a device for controlling movements, made in accordance with the patent of the Russian Federation No. 2150086. It has two blocks of sensors located perpendicular to each other, each block is made in the form of a pendulum, at the end of which there is a light emitter, and on the scale there are a number of light detectors located symmetrically with respect to the pendulum at a certain distance.

The disadvantage of this device is that the light emitter due to beam divergence illuminates several light detectors at once, which reduces the resolution and accuracy of determining the angle of deviation of the pendulum.

The technical task of the invention is to improve the accuracy and resolution when measuring the angle of deviation of the pendulum due to the narrowing of the radiation beam using a slit diaphragm and the use of a signal processing device for light detectors.

The stated technical problem in the present invention is solved in that the optoelectronic pendulum level sensor comprises a pendulum, a light emitter, a slit diaphragm, a number of light detectors, a housing, a switch, a comparison device, a reference voltage source, a unit for calculating the number of the middle of the illuminated light receivers, a linear calculation unit and angular displacement of the pendulum, moreover, the light emitter and the slit diaphragm are located on the pendulum, and a number of light detectors on the body are symmetrical with respect to the pendulum for some distance, the outputs of the light detectors are connected to the inputs of the switch, the output of which is connected to the first input of the comparison device, the second input of the comparison device is connected to the output of the reference voltage source, the output of the comparison device through the unit number calculation of the middle of the illuminated light receivers is connected to the input of the linear and angular displacement calculator of the pendulum .

The essence of the invention lies in the fact that the slit diaphragm forms a narrow beam of radiation that illuminates a limited number of light detectors. The signals from the outputs of all the light detectors are compared with the reference voltage, as a result of which the serial numbers of the illuminated light receivers are determined. Then, the serial number of the average of the illuminated light receivers is calculated. Thus, knowing the sizes of the light detectors and the distance between them, it is possible to determine the linear and angular movement of the pendulum with high accuracy and resolution.

The invention is illustrated by drawings. Figure 1 shows a structural diagram of an optoelectronic pendulum level sensor. Figure 2 shows the signal generated at the outputs of the light receivers.

The proposed optoelectronic pendulum level sensor comprises a pendulum 1, a light emitter 2, a slit diaphragm 3, a row of light detectors 4, a housing 5, a switch 6, a comparison device 7, a reference voltage source 8, a unit for calculating the number of the middle of the illuminated light receivers 9, and a linear calculation unit and angular displacement of the pendulum 10, and the light emitter 2 and the slotted diaphragm 3 are located on the pendulum 1, and a number of light detectors 4 on the body are symmetrical with respect to the pendulum 1 at a certain distance, the outputs of the light detectors 4 are connected connected to the inputs of the switch 6, and its output is connected to the first input of the comparison device 7, the second input of which is connected to the output of the reference voltage source 8, the output of the comparison device 7 through the unit for calculating the number of the middle of the illuminated light receivers 9 is connected to the input of the unit for calculating linear and angular displacement pendulum 10.

The operation of the device is as follows. When the pendulum 1 deviates from its initial position relative to the housing 5, the light beam from the light emitter 2, formed by the slit diaphragm 3, is shifted relative to a number of light detectors 4, illuminating several of them. As a result, the signals shown in Fig. 2 are generated at the outputs of the light receivers, which are fed to the inputs of the switch 6. In the comparison device 7, the signals from the output of each light receiver are compared with the reference voltage generated by the reference voltage source 8. As a result, the numbers of the light receivers i and i + are determined m, the output signal of which is equal to the reference voltage. Moreover, the number of illuminated light detectors m is a constant value for this design and is mainly determined by the width of the slit of the diaphragm. Next, in block 9, the number of the middle of the illuminated light receivers is determined

.

.

The linear displacement of the pendulum is determined in block 10 by the formula

Δl = Δj (d + c),

where Δj is the increment value of the number of the illuminated light receiver;

d is the width of the light receiver;

C is the distance between adjacent light receivers.

The angular displacement of the pendulum is determined by the formula

,

,

where R is the distance from the suspension axis of the pendulum to the light receiver.

The use of such a signal processing algorithm can increase the resolution of determining the pendulum displacement to d + c, despite the fact that several light detectors are simultaneously illuminated. Blocks for calculating the number of the middle of the illuminated light receivers 9 and calculating the linear and angular displacement of the pendulum 10 can be implemented as a programmable microprocessor device.

Thus, the set of features of the proposed device, the implementation of which can be performed in accordance with figure 1, can improve the accuracy and resolution when measuring the angle of deviation of the pendulum due to the narrowing of the radiation beam using a slit diaphragm and the use of signal processing of light detectors.

Claims (1)

An optical-electronic pendulum level sensor containing a pendulum, a light emitter, a number of light detectors, a housing, characterized in that a slit diaphragm, a switch, a comparison device, a reference voltage source, a unit for calculating the number of the middle of the illuminated light receivers and a linear and angular displacements of the pendulum, with the light emitter and the slit diaphragm located on the pendulum, and a number of light detectors on the body symmetrically with respect to the pendulum at a certain distance, outputs with the wind receivers are connected to the inputs of the switch, and its output is connected to the first input of the comparison device, the second input of which is connected to the output of the reference voltage source, the output of the comparison device through the unit for calculating the number of the middle of the illuminated light receivers is connected to the input of the unit for calculating the linear and angular displacements of the pendulum.

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