SU1585782A1 - Apparatus for determining parameters of transfer function of linear dynamic object - Google Patents

Abstract

The invention relates to automation and provides for the automatic determination of the time constants of the numerator, denominator and gain of the transfer functions of linear dynamic objects. The aim of the invention is to expand its scope. To achieve the goal, a memory block 8, a differential signal generating unit 9, a synchronizer 3, a recurrence equation solving unit 7, a control signal generating unit 10, a numerator constant time determining unit 11, a display unit 12 are entered into the device. 12 il.

Description

SP DD SP SL

WITH

Yu

3 158

The invention relates to automation, in particular, to the technique of measuring the parameters of the transfer functions of linear dynamic links of automated control systems, and can be used to determine the pair (linear dynamic link emitters widely used in various industries in the field of research and development automation.

The aim of the invention is to expand the scope.

To do this, at regular intervals C c.start time t after applying a test signal to the input of the object under study with the transfer function

(p).

 T-, p + 1

(one)

20

25

thirty

Three values of Ur, Y, Y of the transient characteristic are found, with / 3 T being chosen from the relation, where tnp is the estimated time of the transition process. After that, the difference signals 4U, - Y; -Y1-1, 2 and the auxiliary coefficient 1sd 4U2 // 1y, the time constant of the denominator T () and the gain factor k (y / + koy,) / (k, + 1). Given the step size of discreteness Γ from the relation where 1P 1,2,3, ..., the quantities z {n 3 are sequentially determined by the recurrent formula Z Cu Z n-1, which corresponds to 35 movement along the transition curve with step СР from the moment of time + Moment of the beginning of the transition process at (jk,

tmf 1 and R-L - G-. At each step of the ft ft, a Ug control signal is generated,

proportional to the time interval, S tg + 4 2 -n $, where, 1,2, ... is the incremental step number, and the inequality is checked, where the signal Ug is proportional to the time interval that determines the accuracy of the determination of zfpl. In the case where the previous

40

45

FIG. 1 shows the structural scheme of the device} in FIG. 2 — memory block; in fig. 3 - differential signal generating unit; in fig. 4 is a block for solving recursion equations; in fig. 5 - control signal generating unit; in fig. 6 - input driver; in fig. 7 - time interval meter; in fig. 8 - time relay; in fig. 9 — memory block; in fig. 10 - calculator; in fig. 11 - pilot of the pilot signal; in fig. 12 is a block for determining the time constant of the numerator.

A device for determining the parameters of the transfer function of a linear dynamic object (Fig. 1) contains the object under study 1, the input signal generator 2, the synchronizer 3, the time interval meter 4, the comparator 5, the calculator 6, the recursion equation solving unit 7, block 8 the memory, the differential signal generating unit 9, the control signal generating unit 10, the numerator constant time determination unit 11, the display unit 12.

Memory block 8 (FIG. 2) contains the first to third memory blocks 13 to 15.

The differential signal generating unit 9 (Fig. 3) contains the first and second subtraction units 16 and 17, the key unit 18.

Block 7 of the solution of recurrent equations (Fig. 4) contains a block 19 computed: b: z - r ::: x -v

pitch cp is halved, and the reconstruction process is repeated, starting with, increasing n by one until the inequality 55 is fulfilled and the second switch 24, the first multiplication unit 25, is determined by the value of the memory grid 21-25.

,

with parameter

T. stgJi T,

(2)

The control signal generating unit 10 (Fig. 5) contains a counter 26, a pilot signal forcing 27, a first comparison circuit 28, a circuit AND 29 a second comparison circuit 30.

d

s

0

25

thirty

35

40

45

The theoretical prerequisites for the operation of the device are the episodes resulting from mapping the solutions of the continuous differential equation corresponding to the transfer function (1), observed at discrete instants of time through the drug intervals, to the set of corresponding ones. discrete equations. In this case, for the class of objects under consideration, the connection between the discrete and continuous equations is carried out using the coefficient kj ,.

FIG. 1 shows the structural scheme of the device} in FIG. 2 — memory block; in fig. 3 - differential signal generating unit; in fig. 4 is a block for solving recursion equations; in fig. 5 - control signal generating unit; in fig. 6 - input driver; in fig. 7 - time interval meter; in fig. 8 - time relay; in fig. 9 — memory block; in fig. 10 - calculator; in fig. 11 - pilot of the pilot signal; in fig. 12 is a block for determining the time constant of the numerator.

A device for determining the parameters of the transfer function of a linear dynamic object (Fig. 1) contains the object under study 1, the input signal generator 2, the synchronizer 3, the time interval meter 4, the comparator 5, the calculator 6, the recursion equation solving unit 7, block 8 the memory, the differential signal generating unit 9, the control signal generating unit 10, the numerator constant time determination unit 11, the display unit 12.

Memory block 8 (FIG. 2) contains the first to third memory blocks 13 to 15.

The differential signal generating unit 9 (Fig. 3) contains the first and second subtraction units 16 and 17, the key unit 18.

Block 7 for solving recurrent equations (Fig. 4) contains block 19 for calculating

ki 21-25 of memory, the second switch 24, the first block 25 multiplying.

The control signal generating unit 10 (Fig. 5) contains a counter 26, a pilot signal generator 27, a first comparison circuit 28, an AND circuit 29, a second comparison circuit 30.

The input signal shaper 9 (FIG. 6) contains a stabilized voltage block 31, a first relay 32, a first start button 33, a second reset button 34, a second relay 35, the first is the fourth large-scale blocks 36-39, controlled by the delay unit 40, the third relay 4t, indicator lamp 42.

The time interval meter 4 (Fig. 7) contains the first - the third time relay 43-45, the first frequency counter - the third inverters 46-48, the first - the third coincidence circuit 49-51.

The first, the third time relay 43-45, contains (Fig. 8) transistors 52, 53, a threshold unit 54, a capacitor 55, a controllable terminal 56, a resistor 57.

Memory blocks 13–15 (FIG. 8) contain capacitors 58, 59, resistors 60, 61, fourth relay 62, and DC amplifier 63.

The calculator 6 contains (FIG. 10) the first local control unit 64, the first - the seventh analog-digital converters 65 - 71, the first - the fifth blocks 72 - 76 divisions, the first and second blocks 77 and 78 of the subtraction, block 79

ten

controllable block 40 for cheryk, four scale blocks 36 .- 39 and indicator lamp 42. The first relay 32 has two normally open contacts, the second relay 35 has one normally closed contact, the third relay 41 has two normally open contacts. Button 33 serves to supply a stepped signal to the input of the object under study 1 and has normally open contacts. The button 34 serves to return the devices to their original position and has three contacts — two normally open and one normally closed. Controlled delay unit 40 is a series-connected time relay 43, an inverter 46, 49 matching, the second input of which is connected to the first input of the relay. 43 times. Time relay 43 contains two transistors 52 and 53, to the base of the first of which an input signal is supplied, and its collector 25 is connected via a capacitor 55 to the base of the second transistor, from whose collector an output signal is taken. By selecting the capacitance of the capacitor 55, the required delay is provided.

20

logarithm, the second block IN cleverly-ZO kN. The scaled blocks 36-39 of the representation, the first and second blocks 81 and 82 of the addition, the block 83 of exponentiation.

The pilot signal generator 27 (Fig. 11) comprises a third switch 84, a seventh memory block 85, a third multiplier 86, a third subtraction block 87, a sixth adder block 88.

The constant numerator determining unit 11 (Fig. 12) comprises a third addition unit 89, a second unit, 90 local control, a fourth addition unit 91, a sixth division unit 92, a fourth multiplication unit 93,

In the proposed device for determining the parameters of the transfer function of a linear dynamic object, different blocks of automatic control systems can be used as the object under study 1.

The input signal generator 2 serves to supply a stepped signal to the input of the object under study 1 and to control the process of calculating the coefficients of the transfer function of the objects. Comrade Shaper 2 input signal consists of a block of 31 stabilized voltages, three relays 32,35,41, two buttons and a Reset -34,

They are DC-DC amplifiers. The voltage at the output of scale block 36 is proportional to time. the first fixation of the output signal of the used object 35, the output of the scale unit 37 is proportional to the time 4 between the fixation moments, the output of the scale unit 38 is the pro. proportionally to the value 2, and the output

40 scale block 39 - proportional to the size ..

45

50

55

The synchronizer 3 serves to control the operation of the units of the device and is a ring counter.

The time interval meter 4 is designed to issue control signals at equal intervals of time dC and consists of three identical controllable delay blocks, the structure of which is similar to the controllable delay block 40.

Comparator 5 serves to signal in the case when the signal at its input is close enough or equal to zero, which corresponds to finding the last two of the removed values of the output signal of the object at a steady-state value ..

5782

ten

controllable block 40 for cheryk, four scale blocks 36 .- 39 and indicator lamp 42. The first relay 32 has two normally open contacts, the second relay 35 has one normally closed contact, the third relay 41 has two normally open contacts. Button 33 serves to supply a stepped signal to the input of the object under study 1 and has normally open contacts. The button 34 serves to return the devices to their original position and has three contacts — two normally open and one normally closed. Controlled delay unit 40 is a series-connected time relay 43, an inverter 46, 49 matching, the second input of which is connected to the first input of the relay. 43 times. Time relay 43 contains two transistors 52 and 53, to the base of the first of which an input signal is supplied, and its collector 25 is connected via a capacitor 55 to the base of the second transistor, from whose collector an output signal is taken. By selecting the capacitance of the capacitor 55, the required delay is provided.

20

ZO Prince. The scale blocks 36-39 are DC-DC amplifiers. The voltage at the output of scale block 36 is proportional to time. the first fixation of the output signal of the used object 35, the output of the scale unit 37 is proportional to the time 4 between the fixation moments, the output of the scale unit 38 is the pro. proportionally to the value 2, and the output

40 scale block 39 - proportional to the size ..

five

0

five

The synchronizer 3 serves to control the operation of the units of the device and is a ring counter.

The time interval meter 4 is designed to issue control signals at equal intervals of time dC and consists of three identical controllable delay blocks, the structure of which is similar to the controllable delay block 40.

Comparator 5 serves to signal in the case when the signal at its input is close enough or equal to zero, which corresponds to finding the last two of the removed values of the output signal of the object at a steady-state value ..

The memory block 8 serves to store, through time points, the values of the transition process of the object under study 1. The memory block 8 consists of three identical memory blocks 13-15, constructed on the basis of a DC amplifier.

The differential signal generating unit 9 consists of two subtracting units 16 and 17 and a key unit 18. Blocks 16 and 17 subtract serve to form differential signals () and (J and are integral operational amplifiers, and key block 18 consists of three contactless relays, in which the first control input is connected to the fourth input of block 18.

The calculator 6 consists of seven analog-digital converters 65-71, a local control unit 64, five division blocks 72-76, two subtractors 77 and 78, a logarithm block 79, a multiplication unit 80, two addition blocks 81 and 82, a block 83 exponentiation. The local control unit 64 serves to control the operation of all the arithmetic units of the calculator 6 and is a ring counter, and the arithmetic units 72-83 are universal type blocks, in which the result is recorded and stored in the output register after the execution of the operation.

The recurrence equation solving unit 7 consists of a square root calculating unit 19, two switches 20 and 24, three memories 21-23 and a multiplication unit 25.

The control signal generation unit 10 contains a counter 26, a pilot signal driver 27, two comparison circuits 28 and 30, AND 29 circuit. Counter 26 is designed to count the number of pulses arriving at its first input from the first output of synchronizer 3 and fixing this number in the form of a binary code. The pilot signal generator 27 consists of a switch 84, an addition unit 89, a memory unit 85, a multiplication unit 86, a subtraction unit 87, a division unit 88. All arithmetic units are universal type units.

1 Block i 1 of determining the time constant of the numerator consists of a block 90

o

five

0

five

0

five

0

five

0

five

local control, block 91, block 92 del-eni, block 93 multiplication. All blocks are similar to device blocks for defining the ois parameter.

The display unit 12 consists of a triggering decade system, a decoder and a scoreboard.

A device for determining the parameters of the transfer function of a linear dynamic object works as follows.

Knowing about the duration of the transition process of the object under study 1, using the scale unit 36 sets the time t of the first fixation of the values of the transition process, and using the scale unit 37 sets the duration of the time interval t. The value of r1c is chosen from the condition that the measured values do not fall on the steady-state value of the transition process, where the operation of the device is impossible. Using scale unit 38, the value 2 is set, with the help of scale unit 39, the value of the signal IL, which determines the maximum allowable calculation error.

When the button 33 is closed, the start in the imaging device 2 of the input signal triggers the relay 32 and closes its open contacts, the button 33 is blocked. When the second normally open contact is closed, the signal from the first output of the imaging unit 2 of the input signal is fed abruptly to the input of the object under study 1. At the same time, the signal at the output of the object under study 1 is a transient which enters the first inputs of the 13-15 memory blocks. At the second output of the input signal generator 2, after the time scale 36 is set, the time to from the output of the controllable delay unit 40 is given to the signal fed to the first input of the meter 4 time intervals, from where it is fed to the first time relay 43-45 inputs. When a signal is applied to the base of the transistor 52, it opens, the capacitors 55 are connected in parallel to the emitter-base transition of the transistor 53. The transistor 53 is locked and in the closed state until the capacitors 55 are discharged through the resistor 57. When it terminates process times

9

a row of capacitors 55, the base current of the transistor 53 reappears, the latter opens, and there will be no output signal. Thus, the time delay depends on the time constant. The number of capacitors 55 connected to the circuit is determined by the number of triggered keys 56. The delay of the signals by the meter 4 time intervals is equal to LS,, Back-H, respectively. As signals arrive at the second inputs of the memory blocks 13-15, the relay 62 triggers and the corresponding values of the transient process are memorized.

The difference between the last two memorized values from the output of the subtractor 17 of the subtraction unit is fed to the input of the comparator 5. In the case that the duration of the interval of the time interval r) (correctly selected, i.e., the recorded values of the transient process did not fall into the steady state, the output signal the comparator 5, the relay 41 closes its normally open contacts. The indicator lamp 42 lights up and a control signal is generated at the sixth output of the driver 2 of the input signal, which, acting on the fourth input of the 18 keys, leads to attaining the keys, after which the memorized values of the transient process are fed to the inputs of the calculator 6. Then, using the same control signal, the parameters K and T of the transfer function are calculated.

After the end of the process, the local control unit 64 generates a signal arriving at the first input of the synchronizer 3, and starts its Synchronizer 3, alternately issuing signals to the control inputs, blocks 21,25,23,89,85,84, organizes the process calculating magnitude values

- t-, l

  with a 4-fn resolution and

15

comparison of the magnitude of the control signal Ug t + / jC-n (f with zero and U value. The calculation process will continue until the control signal Ug becomes less than zero and the condition is not met, in this case o is halved, and the number The calculation steps, recorded by counter 26j, are reset, and the calculation is repeated first, until the inequality is fulfilled.

to

15

de e

o-ro - 40 45

25

50

j 585782 10

f

the value of the numerator time determination unit 11 calculates the value of T, which, together with K and T, is displayed on the display of the display unit 30.

If the duration of the time interval f is chosen incorrectly, the signal at the first input of the imaging device 2 of the input signal does not appear and the relay 41 does not close its normally open contacts, the indicator lamp 42 does not light up and the control signal to the inputs of the blocks 12-15 does not arrives. In this case, it is necessary to reduce the value 41 at the output of the scale unit 37 and repeat the experiment from the beginning. A restart is possible only after object 1 has returned to its original state. To do this, press button 34. Reset the input signal generator 2, then the signal from the control winding of relay 32 is removed, it opens its normally open contacts and disconnects the signal from the input of the object under study 1. At the same time, a signal is sent to the seventh input signal 2 of the input signal and transmitted to the zero. input inputs of all digital blocks of the device.

The advantage of the proposed device lies in the possibility of determining the parameters of the numerator of the transfer function of the object, which significantly expands its field of application by making it possible to study a wide class of integro-differentiating links. In this case, it is sufficient to obtain only three values of the transition characteristic of the test; object on any of its parts, which greatly simplifies the identification procedure.

Claims (1)

Claims. A device for determining the parameters of the transfer function of a linear dynamic object, comprising an input driver, the first signal output of which is connected. with the input of the object under study, and the first command output with the first command input of the time interval meter, as well as the comparator and calculator, from. characterized in that, in order to expand the field of application of the device, a memory block, a differential signal generation unit, a synchronizer, a recursion equation solving unit, thirty 35 the control signal generating unit, the numerator constant time determining unit and the display unit, the first - fifth command inputs of the calculator are connected respectively to the first - fifth command outputs of the input fipper, the first command output to the first command input of the synchronizer, the second command - | Q whose input is connected to the sixth command input of the transmitter, the first to the third command outputs are connected respectively to the first - third codification, the first command input to the fourth command input block and solve recurrence equations whose command input is connected to the first command output of the control signal generation unit, the second command output of which is connected to the third synchronizer command input and the second command input of the constant time numerator, signal output which is connected to the first signal input of the display unit, the first and second signal inputs Mandatory inputs of the recursion decision block of which are connected to the seventh and the vertical equations, a quarter to the sixth command outputs correspond to the first to third commanding inputs of the shaping unit: the control signal. the fourth signal outputs of the calculator, the first - the third signal inputs of which are connected respectively to the first - third signal and outputs the fourth signal outputs of the calculator, the first - the third signal inputs of which are connected respectively to the first - third signal and outputs The first and second signal inputs of the KOTO-JQ differential alarm generation unit, the first command input — with the fourth command input of the recurrence equation solving unit; The command line input is connected to the first command output of the control signal generation unit, the second command output of which is connected with the third command input of the synchronizer and the second command input of the numerator constant time unit, the signal output of which is connected to the first signal input of the display unit, the first and second signals The main inputs of which are connected to the seventh and eighth signal outputs of the calculator, the first - the third signal inputs of which are connected respectively to the first - third signal outputs and outputs differential signal conditioning unit connected to the first and second signal outputs of the calculator, the fourth and fifth command inputs to the seventh and eighth command outputs of the synchronizer, the eighth command output -25 with the sixth command input of the calculator and the fourth command input of the recurrent level unit, third and fourth signal inputs - with the third and fourth signal outputs 30 nen respectively with the first - third command outputs of the time interval meter, the second command input of which is connected to the second command input of the calculator divisor, the sixth command 35 input is connected with the seventh command output of the input signal generator, the sixth command output of which is connected to the command input of the differential signal generating unit. calculator, nine-command input — with the first command input of the recurrence equation solving unit, the first and second signal inputs of which are connected to the fifth and sixth signal outputs of the calculator, the signal output — with the first signal input of the numerator constant time block, the second and third signal inputs of which are connected to the first and second signal inputs of the in40 block The fourth signal output of which is connected to the command input of the input signal generator through a comparator, the first is the third signal inputs — respectively, the first or third signal outputs of the memory unit, the first signal input is connected to the output of the object, and the third command inputs are connected. 3 Figm 6 1585782 G 2 J 5 7 / O1 / USC / W GB Phg / g 5 YU / O1 / USCgl / JXULUu 27 28 g /. J J 6 "7 I five -lf Fg / g7 F 49 JP 50 11