SU399625A1 - METHOD OF MANAGING THE PRODUCTIVITY OF A PUMP BATCHER - Google Patents

Description

one

There is a known method for controlling the performance of a metering pump, which provides compensation for the integral value of the dynamic error.

The prelT method differs from the well-known one in that in order to compensate for the dynamic error, the actuator is kept in a predetermined position for a calculated period of time, thereby expanding the range of control of the dosing pump.

FIG. 1, the transient process of the system and the time variation of the integral value of the dynamic error are shown; a transient process in a controlled subtraction, a counter meter, and a change in time of the control signal output; in fig. 2 and 3 shows the block scheme of the device that implements the proposed method.

Let the given value change about «i to P2 (see Fig. 1).

When the deadband exceeds the error signal (U / g), the actuator receives a signal that triggers it at the maximum possible speed in the direction of compensating for the resulting mismatch, which occurs at point C. During the transition process / d, the pump fails to supply the product by the value

the area of the triangle ABC, which is equal to SAIIC - A / g / d. To compensate for this value, the actuator would have to continue its movement in the direction of irreversible direction to the point / (where half of the accumulated accumulation of the squander would be written off, and then reversed and continue its movement until the moment when the mismatch of the current parameter was cleared).

However, if the system operates in an area close to the boundary values, the regulator cannot provide the necessary overshoot value, since it will reach the Kpaihiero level earlier. In this connection, the executive mechanism cannot reach the point / (since earlier, at point D, it reaches the boundary position of Pmax, corresponding to the extreme position of the regulator. To compensate for the error, the actuator must remain in the extreme position for the detrimental and then reversed.

Then the current parameter Pg will vary along the contour of an isosceles trapezoid CDFG, the area of which must be equal to the area of the triangle ABC. The space reached at the Kpainiero position at point D will be copied part of the error, determined by the area of the CDd triangle. Then, the actuator is kept in this position for some time g, during which time at the point E is compensated for the errors determined by the CbEe arcade. For full compensation, the oipibki actuator is kept cn, e at the same time to point F, and the shutter reverses it. Then the square of the four corners of the EFGe will be equal to the four quadrangles CDl: .e and the full name, Therefore, during the time of CCj TeKynuiii iara, the mphter will describe the contours of the trapeippus CDrGs ;;. KdTOpoft corresponds to commercial errors).

Thus, at the moment when the current parameter p. the values of eoV (the extreme position of the regulator, receive a signal, stop the power supply mechanism. OdiovrsMF. But they begin to measure the time interval t until the moment of compensation, and error; delay. , and reverse it.

Onisanny snozd can be implemented) and using the system, consisting of, from unit 1 (see Fig. 2), parameter 2 of parameter 2 (in the case of the next system), comparing devices 3 and 4, adder 5, limit setters positions 6 and 7, command block 8, time interval meter 9, multiplication unit 10, controlled delay delay AND, power amplifier 12, actuator 13, regulator 14, the output element of which acts on control object ii, n of the current feed value sensor Pasos 16.

The device can be made frequency-pulsed on typical logical elements of the automatic automation, papri: .per on the “Spectr. In this case, the values of the parameter n are converted into the corresponding values of the frequency / (see Fig. I), and the calculating and controlling part of the device can be detected: the circuit shown in FIG. 3

This device consists of digital pulorgans 17 and 18, controlled reversible counters 19 and 20, a controlled frequency multiplier 21, a controlled count of one counter 22, a unit 23 of commades, a unit 24, MexaniBivia 25 executive.

When the device is operating on the input of a null null organ 1, signals of a given / s and current fi magnitude 1P s and frequency-frequency clock are continuously received. The signal / s can be received from the digital frequency adjuster or from the sensor of the driving parameter (not shown; s). The signal t comes from a pump drive speed sensor. Well / 1'-org.ns: i realized: are the operations of comparing the input signals, the definition of the value of Af and the sign of the SignAj of the mismatch, the moment of coincidence of the 11-wave-signal of the day) and the sign of none Institut1glegelnoet but zapacheppu onshbki .V; ,,,.

The outputs of the sign of the mismatched SignAf podk. Trans .-) to don1) L1igtelNEgo npfrovoIo. 18. In. 1 signal paths with the sign of alarming of the insensitive zone without signal on the signal SigTLV ;, are connected to the input of the unit 23. Outputs - | -A / and -A / Vel of the signal ; 1, am counter 19. Exit iiiv.A / 11O, hcl10 ju to cn | 1a15; 1 yun1.mu 15nu countercount ;;; 19. About ChS-1 L 1-st survey N unclassified. I11 of the integral dynamic circuit (); (L :, Gz account: chika 19 and counter 22, as well as the input; the block of block 23 and the multiplier 21, connected to

1U 15 in the form of a parallel code is not counted is counter 22 but output A .- ;. The sign 15 (tnch; n A :; is transferred from the output of counter 19, to the input of counter 22 but to the outputs SignA.-, which determine n; 1: p, the number of the counter 22 is written off. When г gpsgs, the value of Az on the output iiivA: The signal is sent to the input of block 23. Counter 22 performs the integral error error and is listed with its double mismatch value 2iAf. The recording of it in counter 22 is tracked at the time iiivAf in the form of a parallel code. 1, is obtained by supplying a pa counting input from a multiplier 2 values

2 | A /

At the moment of snooping the value of 2 .1 / error from the counter 22 on the output of its output, the automatic invA appears. By this signals, the input of the multiplier 21 is closed and the counter 22 is switched from addition to subtraction. Aaaaaver 21 ops1, Svtl yt ugn () is two absolute values | 1s.: 1sin, ras; 1asovann in the form of frequencies 1o-IlP1 L: SNo code. It opens on the signal invA / ;; closed) lv; 1ets by signal.

The inputs of the additional jUKJjpOBoro nullorgan 18 are supplied by the current, its parameter / m and / mgs, / M;: ii, corresponding to 15, 1, and 1 m m:) e1liruyuschem body. The values of / -, ii; and and "1:11 can be in the form of a frequency-pulse code or s in the form of parallel codes - proportional to the frequencies or periods of the current parameter 5 extreme nolo; Ке1П1 х regulating) of a common orb of the axis. . In the null organ

stub / t with ma :: s OR

with output

match signal

compared values -

hivA / v. Controls the pa6oToii bullets organ 18

SignAf sign signal from the zero-body output 17.

The output of the invAfa null organ 18 is fed to the input of the block 23 and to the plus control input of the counter 20, made the half of the latter in the position of summing the input quantity.

Counter 20 performs the functions of measuring the time interval from the moment it arrives at the moment of writing down half of the integral value of the dynamic error to the signal, as well as the controlled delay line of the signal invAf2 to twice the measured time value 2g. This is due to the fact that the counting input of the counter 20, to which the pulses | D / | the absolute value of the current mismatch, is opened by the signal invAfa- In the counter 20, the summation | D / | up to the moment of invN, i.e., write-off of a null error. During this time, the counter 20 accumulates a number characterizing the time interval t, which is required to be measured.

Then, according to the signal, the counter 20 is transferred to the subtraction state, and the current error value | A / | starts calculating

From the number in the counter 20. After writing off this value, the signal inv / V4 appears at its output, since D / does not change in magnitude during the whole measurement time, the time of recording the number in counter 20 and writing it off are equal to each other. The signal at the output of counter 20 is equivalent to the delay of the signal invDf2 by 2m. This signal is fed to the fault input of the counter 20 and to the input of the block 23, having reversed the actuator.

Subject invention

A method for controlling the performance of a metering pump having a linear dependence of capacity on the number of revolutions of the drive, which is established by moving the output element of the actuator, characterized in that, in order to increase the adjustment range in terms of the number of revolutions, the integral value of the dynamic error of the produced working fluid dose is produced. t by holding the actuator in a given position for a calculated period of time.

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