RU2060502C1 - Method for determining angular and linear velocities by frequency sensors - Google Patents

Abstract

FIELD: automatic control and measurement technology. SUBSTANCE: method involves shaping of pulses followed by passing part of them through moving modulator window, response by frequency sensor, and their counting; frequency sensor functions to shape reference pulses and to count pulses coming from electronic self-excited oscillator feeding the frequency sensor; first pulse is trigger one and corresponds to first pulse enabling pulse counting while last pulse is turnoff one and corresponds to last pulse counting of pulses of electronic self-excited oscillator. Total number of reference pulses is counted and total number of pulses whose frequency equals that of electronic self-excited oscillator between trigger and turnoff pulses is counted continuously. EFFECT: improved accuracy of speed measurement in wide measurement range irrespective of its magnitude. 4 dwg

Description

 The invention relates to the field of automation and measurement technology.

A known method of measuring speed by the number of pulses in one packet of pulses with a linear passage through the window of the modulator [1]
The known method does not provide continuity of measurement due to jumpers between the windows and does not provide accuracy of speed measurement in a wide range of its changes.

A known method of measuring speed by the number of output pulses of the sensor [2]
The disadvantage of this method is that the measurement accuracy increases with increasing speed, and therefore can not be obtained with greater accuracy when measuring low speeds.

 The technical result of the invention increases the accuracy of measuring speed in a wide range of its changes, regardless of its magnitude.

•

A

где f 1/Т частота генератора;
N число выходных импульсов датчика на одно измерение;
A

коэффициент пропорциональ- ности;
m_о общее число реперных импульсов на оборот вала или, например, на 1 мм при линейном перемещении;
m общее число реперных импульсов, соответствующих требуемой точности, задаваемой задатчиком точности.The specified result is achieved by the fact that in the known method for determining the angular and linear velocity by frequency sensors, including the formation of pulses and the subsequent passage of part of them through the window of the movable modulator, perception by the frequency converter and their calculation, the sensor generates reference pulses and counts the oscillations (pulses) of the electronic oscillator feeding the sensor, and the first reference impulse is triggering and corresponds to the first oscillation (impulse), allowing the count of oscillations (impulses ), and the last disconnect corresponds to the last oscillation (impulse), prohibiting the count of oscillations of the electronic self-oscillator, the total number of reference pulses is calculated in accordance with the required measurement accuracy depending on its value, and the total number of oscillations is continuously counted without pauses on the jumper between the slots of the modulator (sensor) (pulses), the frequency of which is equal to the frequency of the electronic oscillator between the start and stop pulses, and the speed is determined by solving the formula in the block brabotki information and the formula is as follows:
n

•

A

where f 1 / T generator frequency;
N is the number of sensor output pulses per measurement;
A

proportionality coefficient;
m _{about the} total number of reference pulses per revolution of the shaft or, for example, 1 mm for linear displacement;
m is the total number of reference pulses corresponding to the required accuracy specified by the accuracy adjuster.

 In FIG. 1 shows a functional diagram; in FIG. 2 time charts; in FIG. 3 and 4, one of the variants of the frequency sensor.

 The device for implementing the method comprises an electronic oscillator 1, an information processing unit 2, a power amplifier 3, a sensor (frequency primary converter) 4, a reference number generator 5 for reference pulses, a counter 6 for the number of packets, and an indication device 7.

и выдает информацию на цифровое табло 7 и в стандартном двоичном коде.The method is as follows. Electrical signals with a frequency f of the high-frequency oscillator 1 are supplied simultaneously to the information processing unit 2 and through the power amplifier 3 to the primary frequency converter 4 (sensor). The sensor 4 generates N oscillations depending on the speed of rotation (movement) in the form of packets that are fed to the second input of the information processing unit 2. At the same time, the sensor 4 generates reference pulses equal to the number of packets, and a signal about the number of packets m is fed to the input of the reference pulse setter 5, and from it to the counter 6 pulses. From the output of the pulse counter 6, signals are given for the beginning of the count and for the prohibition of the count of oscillations of the sensor 4 entering the information processing unit 2. The information processing unit 2 occurs in accordance with the incoming signals from the oscillator 1, the sensor 4 and the counter 6 speed calculation by the formula:
n A

and displays information on a digital display 7 and in a standard binary code.

 At a given rotation (displacement) speed, the number of reference pulses is selected depending on the required accuracy of its measurement, their number increases with decreasing speed.

 To ensure a given accuracy of movement in this range, the number of reference pulses can be entered "manually" or automatically. Thus, the proposed method allows to determine the speed of rotation of the shaft with high accuracy.

 The proposed method is illustrated by a time chart (Fig. 2). The signals from the oscillator 1 (Fig. 2A) are received in the sensor 4 and the information processing unit 2.

 Signals come out from sensor 4 (Fig. 2b and Fig. 2c), i.e., signals come from two rows of sensor slots arranged in a staggered circle, and there can be several (many) rows.

 In FIG. 3 and 4 depict one of the sensor options, explaining the proposed method.

 The sensor can, for example, be mounted on a rotation shaft 8 (Fig. 3), it contains two fixed flanges 9 and 10 with bearings 11. A magnetizing coil (torus) 13 with leads 14 is installed on the flange 9 in the annular groove 12. Between the flanges 9 and 10 a diamagnetic disk (rotor) 15 is installed with slotted slots 16. On the flange 10 at a certain distance from the shaft center around the circumference in the grooves 17 are the cavities of the magnetic film 18 having a rectangular hysteresis loop (PPG), with measuring coils 19 and terminals 20 and with holes 21 for wires.

 The holes are discrete along the length of the plane of the film and the flange along its radius, and through the holes 21 of the film of the flange, coils 19 are stitched with leads 20.

где ψ потокосцепление различной интенсивности при вращении вала. Сигнал от измерительных обмоток будет поступать в блок 2 обработки информации (фиг. 1).High frequency current is supplied from the high-frequency generator through the terminals 14 to the magnetizing coil 13. When current flows through the wires of the coil 13, an alternating magnetic field is formed around it. When the shaft 8 rotates, the rotor 15 rotates, having slotted and shaped slots. The magnetic field of toroid 13 will induce eddy currents (Foucault currents) on disk 6 (rotor). In turn, Foucault currents form their magnetic field. During rotation in the film, a change in the intensity of the magnetic flux will occur. This magnetic flux in the measuring winding 19 will induce an mutual induction EMF:
l

where ψ is the flux linkage of various intensities during rotation of the shaft. The signal from the measuring windings will be supplied to the information processing unit 2 (Fig. 1).

 Bursts (trains) of pulses (Figs. 2b and 2c) are limited, detected (Figs. 2d and 2e), and then differentiate (Figs. 2e, 2g).

 In this case, the first positive starting reference pulse (Fig. 2e) starts the count of pulses from the generator to the information processing unit.

 Pulse counting occurs before the negative disconnecting reference pulse of the last packet of pulses (for example, Fig. 2 master set m6 Fig. 2g.

 In FIG. 2k shows the first positive counting and the last negative counting, which stops the counting of pulses in the information processing unit 2.

 In the information processing unit of the latter, m and f are entered.

 Reference impulses can also be calculated using positive impulses. In this case (for example, m 6), it is necessary that the 7th positive impulse be the disconnecting pulse (Fig. 2k and 2l). Given the shutdown pulse in the setter 5, the number of reference pulses must be set m + 1.

Claims (1)

The method of determining the angular and linear velocity by frequency sensors, including the formation of pulses and the subsequent passage of part of them through the window of the movable modulator, perception by the frequency sensor and their calculation, characterized in that the frequency sensor generates reference pulses and counts the pulses and counts the pulses of the electronic oscillator feeding the frequency a sensor, the first reference impulse being triggering and corresponding to the first impulse, allowing the pulse count, and the last disconnecting and corresponding last pulse, prohibiting the counting of pulses of the electronic self-oscillator, after which the total number of reference pulses is calculated in accordance with the required accuracy of measuring the speed depending on its value and is continuously counted without pauses on the jumper between the slots of the frequency sensor modulator, the total number of pulses whose frequency is equal to the frequency of the electronic the oscillator between the starting and turning off reference impulses, while the speed is calculated in the information processing unit and determined by solving the equation

where f = 1 / T oscillator frequency;
N is the number of output pulses of the frequency sensor per measurement;
A = m / m ₀ coefficient of proportionality;
m _{0 the} total number of reference pulses per revolution of the shaft or, for example, 1 mm for linear movement;
m is the total number of reference pulses corresponding to the required accuracy specified by the accuracy master.

Images