RU2148293C1 - Oscillating movement electric drive - Google Patents

Abstract

FIELD: electrical engineering, in particular, electric drives, which actuating body performs oscillating and reciprocal movements, for example, for mechanical testing of cables for multiple bends, arranging long articles, while their are turned over coils, reels, and so on. SUBSTANCE: Goal of invention is achieved by introduced position detector which is mounted on rotor of electric motor. Reverse pulse counter, amplitude setter, central processing unit and pulse generator are introduced into frequency converter. EFFECT: increased functional capabilities and increased precision of operations due to stabilization of oscillation amplitude because of feedback circuit for rotor position and regulation of oscillation frequency of shaft of actuating motor. 2 dwg

Description

 The invention relates to the field of electrical engineering, in particular to special electric drives, where the executive body performs oscillatory and reciprocating movements, and can be used for mechanical testing of cable products for repeated bending, in devices for laying long products when winding them on coils, reels, etc. .P.

 Known electric oscillatory motion drive / 1 /, containing a two-phase electric motor, the field winding of which is connected to an alternating current source, a frequency converter, the outputs of which are designed to connect to the phases of an alternating current source, respectively, an inverter, the output of which is connected to the terminals of the motor control winding, a functional digital-to-analog converter , an amplifier with an adjustable gain, a frequency difference converter into a code, the first and second inputs of which unified respectively with said first and second inputs of the frequency converter, the outputs of which are connected respectively to the remaining inputs of the frequency difference to the code converter and the first and second inputs of the amplifier with adjustable amplification factor.

 However, in this device there is no feedback on the position of the rotor, which does not allow maintaining the amplitude of oscillations in case of unstable load on the motor shaft during rotation in different directions.

 A device for testing flexible cable products for multiple rewindings / 2 /, comprising a control unit, a drive, two removable reels for winding and winding a cable product, a signal conditioner, a reversible pulse counter, a single vibrator, a digital storage and sampling device, a digital-to-analog converter, a position controller , comparison device, rectifier, comparator, amplitude regulator, master oscillator and switch.

 However, although position feedback has been introduced in this device, this does not allow stabilizing the amplitude of the oscillations, since during neutral stabilization, only the difference between the positive (in the forward direction) and negative (in the opposite direction) amplitudes is stabilized, but not the oscillation amplitude itself.

 The closest analogue is a device for controlling a two-phase asynchronous motor in the mode of oscillatory motion / 3 /, containing a frequency converter connected by an input to an alternating current source (mains) and an excitation winding, and an output to a control winding. The frequency converter contains a phase detector, the first and second frequency dividers and a voltage-frequency converter connected to the inputs of the frequency dividers, an input to the output of a phase detector, the inputs of which are connected to an AC source and the output of the first frequency divider, and the output of the second frequency divider is connected to control input of the inverter.

 The disadvantages of this device are the inability to maintain the amplitude of the oscillations of the rotor, the lack of regulation of the amplitude of the oscillations.

 The present invention is aimed at expanding operational capabilities and improving the accuracy in the operation of the electric drive of periodic motion by maintaining a given amplitude of oscillation.

 This is achieved by the fact that a position sensor, a signal shaper, a reversible pulse counter (RSI), an amplitude adjuster, an arithmetic logic unit (ALU) are additionally introduced into the frequency converter.

In FIG. 1 presents a block diagram of the proposed device, in FIG. 2 is a graph of the dependence of the value of the amplitude of the oscillations of the shaft χ _m on the oscillation frequency Ω _o .
The device comprises an induction motor 1 with an excitation winding 2 connected to an AC source 10, and a control winding 3 connected to a frequency converter 4 containing a phase detector 5, the first input of which is connected to the excitation winding 2, the second input to the output of the first frequency divider 6, connected by the input to the input of the second frequency divider 7 and the output of the voltage converter 8 — the frequency connected by the input to the output of the phase detector 5. The inverter 9 is connected by the input to the output of the second frequency divider 7, and the output the house to the control winding 3. An additional position sensor 11 is installed on the motor rotor, and a signal conditioner 12 is connected to the frequency converter, connected by an input to the output of the position sensor 11, an output to the counting input of the RSI 13, and the control output to the control input of the RSI 13 and ALU 15. ALU 15 is connected by inputs to the output of the RSI 13 and the setpoint amplitude 14, and the output to the input of the frequency divider 6 with an adjustable division ratio.

 The device operates as follows.

Different-frequency powering of windings 2 and 3 from the network and the frequency converter causes the oscillatory mode of operation of the electric motor 1. The frequency of the motor shaft oscillations Ω _o is equal to the difference in the frequencies of the voltages supplying the motor windings
Ω _o = 2π (f _c -f _y ) (1)
where f _with - the frequency of the supply voltage;
f _y - the frequency of the voltage of the control winding is determined by the formula
f _y = f _c n ₁ / n ₂ , (2)
where n ₁ is an adjustable division ratio;
n ₂ is a constant division coefficient.

, где величина ξ - частота вращения двигателя, а

Эти импульсы поступают в АЛУ 15 и являются сигналом к вычислению значения поправки частоты колебаний. Реверсивный счетчик импульсов 13 ведет непрерывный счет импульсов и формирует на выходе параллельный двоичный код, соответствующий амплитуде колебаний.Management is carried out by changing the coefficient n ₁
n ₁ = (1-Ω _o / 2πf _c ) • n ₂ (3)
In the process of oscillations, from the position sensor 11 located on the shaft of the actuating engine, the pulse signals are supplied to the signal shaper 12, generating signals for the counter 13, as well as pulses at the moments of changing the direction of rotation of the motor shaft

where ξ is the engine speed, and

These pulses arrive at ALU 15 and are a signal for calculating the correction value of the oscillation frequency. The reversible pulse counter 13 maintains a continuous pulse count and generates a parallel binary code corresponding to the amplitude of the oscillations at the output.

, (5)
где χ - амплитуда колебаний;
F_m - амплитуда электромагнитного усилия;
ε - внешнее демпфирование;
ρ_o - позиционное нагрузочное усилие;
T_o - относительная постоянная времени.The amplitude of the steady-state oscillations of the motor shaft depends on the oscillation frequency according to the law / 4 /

, (5)
where χ is the amplitude of the oscillations;
F _m - the amplitude of the electromagnetic force;
ε is the external damping;
ρ _o - positional load force;
T _o is the relative time constant.

где Δχ = χ_з-χ_д - сигнал рассогласования амплитуды колебаний.In the absence of external damping and positional loading force ε = ρ _o = 0, the law takes the form / 4 /
χ = F _m / Ω $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ T $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ (6)
Thus, the amplitude of the oscillations is inversely proportional to the second power of the oscillation frequency. This characteristic has the form shown in Fig. 2. Based on the values of the given χ _s and current χ _d vibration amplitude, ALU 15 regulates the closed-loop electric drive of periodic movement, by introducing an adjustment of the oscillation frequency ΔΩ = Ω _d -Ω _s , twice per period. For this, the value of the division coefficient n _{1 is} determined by the formula

where Δχ = χ _s -χ _d is the signal of the mismatch of the oscillation amplitude.

 As a result, the blood pressure transmits the rotational-vibrational movement to the actuator within the specified range of movement, maintaining a constant amplitude of the oscillations.

 Thus, the proposed device allows stabilization of the amplitude of the oscillations due to the introduction of feedback on the position of the rotor by adjusting the frequency of oscillations of the shaft of the Executive motor. The negative nature of position feedback determines the desire of the system to reduce the mismatch between the given and the current amplitude, thereby stabilizing the amplitude when it changes, caused, for example, by a change in load or other disturbances. This allows you to fine-tune and ensure the specified angle of rotation of the ABP, and hence the bending angle of the cable product in bending test installations, as well as providing the specified width for laying long products when winding them on coils, reels, etc.

 In addition, the inventive device allows you to expand the operational capabilities of the device, with great accuracy and in a wide range to adjust the angle of bending of the cable product, which will bring the test conditions closer to the operating conditions, thereby increasing the reliability of the test, and, in addition, makes the stacker of long products universal, since it becomes possible to form any standard sizes of technological bobbins of fastening cable threads. There is the possibility of implementing an electric drive based on microcontrollers, which allows you to organize software control in industrial networks.

 List of sources of information.

 1. AC N 2028026. Electric drive oscillatory motion. / Aristov A.V., Timofeev A.A., Shumar S.V.

 2. AC N 1779949. Electric drive of oscillatory motion. / S.A. Tkalich, V.D. Shiyanov, L.A. Bakhmutova.

 3. AC N 1453577. A device for controlling a two-phase asynchronous motor in the mode of oscillatory motion. / A.V. Aristov, S.A. Tkalich, V.D. Shiyanov.

 4. Lukovnikov V.I. Electric oscillatory motion. M .: Energoatomizdat, 1984

Claims (1)

 A periodic motion electric drive comprising a two-phase asynchronous motor with an excitation winding connected to an AC source and a control winding connected to a frequency converter, including an inverter, a phase detector, first and second frequency dividers, and a voltage-frequency converter connected to the output with inputs frequency dividers, the input - with the output of a phase detector, the inputs of which are connected to an AC source and the output of the first frequency divider, and the output of the second divider is hour It is connected to the control input of the inverter, characterized in that an additional position sensor is installed on the motor rotor, and a reversible pulse counter, an amplitude adjuster, an arithmetic-logic device, and a signal shaper generating a signal for the counter and generating pulses at the moment of change are introduced into the frequency converter direction of rotation of the motor shaft, connected by an input to the output of the position sensor, by the output to the counting input of a reversible pulse counter, controlling the output to the control input to a reversible pulse counter and an arithmetic-logic device, which, based on a given and current value of the amplitude of the oscillations, corrects the oscillation frequency twice per period, for which it determines the pressure coefficient of the first frequency divider, the arithmetic-logic device is connected by inputs to the output of the reversible pulse counter and the amplitude adjuster, and the output to the input of the installation of the division ratio of the first frequency divider.

Images