SU1481717A1 - Device for functional check of electric drive - Google Patents

Abstract

The invention relates to automation and can be used in process control systems. The purpose of the invention is to increase the completeness of the control. The device contains an actuator 1, shift registers 2, 3, comparators 4, 5, timers 6, 7, subtractors 8, 9, adder-subtractor 10, the element EXCLUSIVE OR 11, trigger 12, elements AND 13-17, element 2И-2ИЛИ 18 , element 4IL-HE19. The device is designed to monitor the correct functioning of the actuator, controlled by the position error signals. The operation of the device is based on the analysis of the magnitude of the error and the rate of change of this value. At the same time, the definition of the beginning and end of the overshoot and the shutdown of the control during the overshoot time are provided, which allows, regardless of the overshoot, to obtain high control accuracy. The device provides control of the speed of testing a large mismatch. And it does not give false information about the malfunction of the inertial drive when the calculated angle value changes abruptly. The device also provides protection for the drive against short-term failures and exit from a fault state, while at the output of the device, undistorted information about the current position mismatch is generated during a fault. 4 il.

Description

I

The invention relates to automation and can be used in systems of automatic control of technological processes.

The purpose of the invention is to increase the completeness of the control,

I

Fig L shows a functional diagram of the device in figure 2 - diagram of the electric drive; FIG. 3 shows the timers; figure 4 - diagram of the drive,

The device contains the electric drive 1, the first and second registers 2 and 3 of the shift, the first and second comparators 4 and 5, the first and second timers 6 and 7, the first and second subtractors 8 and 9, the adder-calculator 10, the element EXCLUSIVE OR 11, trigger 12, first, third., second, fourth and fifth elements. And 13-17, element 2И-2ИЛИ 18, element 4Ш1И-НЕ 19. Device inputs 20-26, device outputs 27 and 28, block inputs and outputs device 29-72.

In the functional diagram, the transmission lines of the code are marked with a /. The functional diagram (Fig. 2) of a possible embodiment of the electric drive 1 contains a code converter - analog 73, amplifier 74, engine 75, gearbox 76, angle converter - code 77. Input 39 receives the control action code converted into an analog signal, which the

controls the motor 75, which rotates the angle-code 77 converter through the reducer 76. On the interrogation signal, input angle 40 generates a code at the output of the angle converter – code 77 that is proportional to the position of the output shaft of the drive. "

The functional diagram (FIG. 3) of the timers 6 and 7 contains an element AND 78, a counter 79 and an element OR 80. Input 43 receives a code written to counter 79. From the output of counter 79 this code goes to the element OR 80, which analyzes the equality O of the contents of the counter 79. If the content is not equal to Oy, then a signal 1 is generated at the output, an opening element AND 78 for passing to the counting input of the counter 79 pulses at the input 44, These pulses reduce the contents of the counter 79. When the contents of the counter 79 are equal to 0, the output the element OR 80 and the timer output 6 and 7 is formed by the signal G, the closure member 78. And will be present before entering a code to the input 43 in such a state timers 6 and 7.

Registers 2 and 3 are shift registers. On the leading edge of the pulses at the input 42, the code from the input 41 is transmitted to the output of the registers and stored in them,

Trigger 12 on signal 1 at syn- t 1 timing input 47 installs

3.1

c in 1 (at the output of the trigger signal 1) when there is a signal at the moment at inputs 45 and 46 of signal 1. Trigger 12 is set to 0 by signal O at input 48 or signal 1 at input 49.

The device works as follows.

1. Device operation with proper drive operation.

1.1. After switching on the device, the clock pulses with a frequency equal to the time resolution of the drive start to enter the input 21 continuously, the duration of the pulses is much shorter than their follow-up period (hereafter, the values associated with the time to these clock cycles will be denoted by i, counting i from 1 to co) to input 20 - the calculated value of the angle of rotation of the drive; to input 25 — the magnitude of the calculated value of the drive speed, represented by the angle of rotation of the drive in a time equal to one pulse of pulses at input 21.

With the arrival of the first clock pulse, the pulse code (pulse duration less than the clock duration at input 21) is received once, input 23 is the maximum duration of the drive transient caused by the disturbance Cfj received at those times i, denoted by j (j takes a value from 1 to p) when an abrupt change occurs at the input 20; at input 24, the magnitude of the maximum duration of the drive overshoot 0: caused by the action.

.The clock pulses are fed to the drive 1, interrogating the transducer 77, the output of the drive is received by the actual position code of the output shaft q, the drive, this code goes to the subtractor 8, the other input receives the value from the input 20 of the device, output 29 subtractor 8, the current position mismatch is generated

BEFORE

Output 30 sets an O signal if &; negative. The code Јj from the input 23 of the device enters the timer 6, thereby forming a signal 1 at its output. This signal is fed to the input 49 of the trigger 12, us-25

817

g

YU

, 15 ; 20

30 35 40

d5 "j 55 17

having turned it into the state O, it goes to the input 69 of element 4ИЛК-НЕ 19, sets the signal O at the output of this element, on which the element 2I-2ILI 18 is open to pass to the output of the error A ;, at the input 65. From the output of the element 2I- 2IL 18 mismatch D; enters the output 28 of the device and the input 39 of the actuator 1, thereby the drive performs the processing of this error.

Figure 4 shows the changes in av; , , BUT; in time t. Point a - the beginning of the operation of the device, at this moment the mismatch L; large and the drive starts to work out this mismatch. The mismatch from the output of element 2I-2ILI 18 also enters the input 41 of register 2, the leading edge of the clock pulse arriving at the synchronization input 42, the register 2 forms at its output and stores this value in time i + 1, i.e. during the i-clock cycle, a b is formed at the register output. This value is fed to the input 41 of register 3, which, similarly to register 2, shifts the mismatch by one cycle, forming a mismatch on its output. Timer 6 counts the time recorded in it, after which (point b in figure 4) the output of the timer is set to signal O. At this point, the drive transition process, caused by an abrupt perturbation at the input, 20, will finish. , (f ,, as shown in figure 4.

1.2, Developing a greater mismatch.

The finder 9 calculates the rate of change of the error provided by the drive

LL; M - &;.,, (2) where L, D;, are the mismatch in the current and previous clock, arriving at inputs 33 and 31, respectively; (is the calculated value of the rate of change of Cf; entering the input 32.

I Output 34 subtractor 9 arrives

code D &; , at exit 35 - the sign of the value of Li; .

514

The comparator 5 generates a signal 1 at the output if the condition analyzed by the drive of a large discrepancy with the guaranteed speed LL of the test is fulfilled:

1L, AZht, | (3)

where &&, is the value arriving at input 50 from the output of subtractors 9;

U & min is the value of the minimum rate of testing, coming from the input 26 of the device. The EXCLUSIVE OR 11 element analyzes the condition for reducing the mismatch resulting from the formula (2) s

sign bd; sign b1,, (4) where sign & & - the sign of the quantity Dj, arriving at the element 11 from the output 35 of the subtractor 9;

sign U1, - mismatch sign L; input to element 11 from output 30 of the subtractor 8. So how &; decreases, condition (4) is fulfilled, i.e. if output 30 of the subtractor is 8-signal 1 (the sign A is equal to +), then output 35 of the subtractor 9 is signal 1 (the sign of U A; equal to -), and vice versa. At the same time, at the output of element 11, a signal O is formed, an opening element AND 13 for passing signal 1 at its input 53 to input 61 of element 16. At the output of element 16, signal 1 is set, since inputs 58 and 59 receive signal O and the signal O is also input to input 60, since the condition / condition analyzed by comparator 4 is not fulfilled.

BUT; & mp (5) where A on - the value is acceptable for the mismatch &, received at the input 22 of the device at which the drive ensures qualitative tracking of the calculated values.

At signal 1 at the output of element I 16, drive 1, registers 2 and 3, and element 2I-2ShSh operate similarly to that described in subsection 1.2.

In this state, the device remains until condition (5) is fulfilled at the moment of time indicated in FIG. 4 through point B, from which the overshoot state begins.

176

1.3. Reconfiguration. Signal 1 from the comparator output

4 is fed to the input 45 of the trigger 12, the input 1 also receives the signal 1 from the output of the timer 7, since its content is equal to the overshoot value 0 :. At the same time, when the next clock enters from the device input 21 to the input 47, the trigger 12 is set to 1. This signal enters the input 53 of the element 14 and the output of the element 14 produces a signal 1, at which elements 19 and 18, drive 1 and registers 2 and 3 work in the same way as described in clause 1.2. The signal 1 from the output of the trigger 12 is fed to the input 64 of the element And 17, to the input 62 it receives a signal O, so the clock pulses fed to the input 63 pass through the element And 17 to the counting input 44 of the timer 7. Thus, the timer begins to count the time overshoot (in FIG. 4, 8 is equal to the time interval Vg). In this case, the drive operation is not monitored. After the passage of time b: at the output of the counter 7, a signal 0m is set, which, at input 48, transfers the trigger to the state O. From this moment on, the device enters the state of the sleepy.

1.4, Tracking.

I

When tracking condition (5) must be fulfilled, the signal O from the output of the trigger 12 is fed to the input 56 of the element 15, which, if there is a signal 1 at the input 57, forms the signal 1 at its output. Then elements 19 and 18, drive 1 and registers 2 and 3 work in the same way as described in clause 1.2. Condition (5) is fulfilled until an abrupt change occurs (f; i.e., to the next, while simultaneously the value,;, S; is received at the input of the device; and the device operates similarly to that described in Section 1.

2. Operation of the device in case of improper operation of the drive.

2.1. Operation in the event of a failure resulting in an abrupt increase in the error U during the tracking state (may occur if the angle converter fails - code 77, unauthorized change to.

input 20 and other cases of failures in the digital part of the device).

In this case, in the trailing state described in subsection 1.4, condition (5) is not fulfilled in the absence of a code at inputs 23 and 24. At the output of the comparator 4, the signal changes to O, thus at all inputs of element 4, OR NOT 19-- signal O, which causes the output of element 4IL-NOT 19 of signal 1 to be output at the device output 27 as a signal Drive malfunction. The subtractor 10 calculates the predicted mismatch value

d, p -, -, + lm-l; -.), (6) where D ;, is the value supplied to the summing inputs 36 and 38 of the adder-subtractor 10 from the output of the register 2; U .g - the value of

input 37 is subtracted from register output 3,

From the output of the adder-subtractor 10 D, p is fed to the input 68 of the element 2K-2ILI 18, which by the signal 1 at the input 67 passes D ;. to the output 28 of the device and to the input 41 of the register 2 and the input 39 of the drive 1. During a failure time, the device calculates D; p and stores these values in registers 2 and 3.

Thus, instead of false D; in this situation, the mismatch A; p is formed, which, under the condition that Cf, slightly varies over time with high accuracy, characterizes the actual mismatch. Consequently, the movement of the drive slightly deviates from 0

If the failure is short-term, then after its termination D; does not exceed u jyjn, condition (5) is fulfilled and the device continues to operate as described in n, l.4.

Thus, in this case, the device provides control of the drive with high accuracy, output to the output 28 of information about the actual error and continued operation of the drive.

2.2 Work at failure during working off of a big mismatch.

2.2.1. The case when when moving the drive mismatch and; not decreasing, but increasing.

This can occur when: the wrong direction of movement due to the failure of the analog part of the drive 1; g when the angle converter fails - code 77 or unauthorized change of Cf; inlet 20, leading to an abrupt increase in D; .

The device will operate as 0, as described in section 1.2, except for the following.

In this case

| L; S b, -. (7) as follows from (2), while

5 sign b D. sign u; (8) and condition (4) is not fulfilled, while at the output of the EXCLUSIVE OR L element, a signal 1 is generated, causing the output of the AND J 3 element to signal O, which does not trigger the AND 16 element. As a result, the element 4IL-NOT 19, element 2K-2ILI 18, electric drive 1 and registers 2 and 3 work as in the case of the failure described

5 in paragraph 2.1.

The drive is controlled in such a way that it moves for a time at a constant speed equal to the speed in the time interval.

0 between (i.2) -MK and (i-l) -MH clock ticks before i-ro clock cycle.

If). varies slightly, the drive control and the formation of b ;. output 28 is produced with high accuracy in the case of a short-term failure, after the termination of a short-term failure and conditions (2) - (4), in which D ;., the values are equal to the current D-, p, the device continues to control driven just as if there was no failure

2e2 „2. The case of no movement of the drive or testing at a speed less than permissible,

5 If the drive is, then

U; -;., JI. ABOUT)

In accordance with formula (2). If the drive moves at a lower than acceptable speed, then

t read by the formula (2) | A & 11 A & mJu

In these cases, the condition

(3), analyzed by comparator 5,

and at its output a signal is generated

e O, which leads to the fact that the output of the element And 13 is also set to the signal O. Next, the device operates as in case 2.2.1.

Thus, an incorrect processing of a large mismatch is detected, when, in particular, the misalignment is reduced due to a corresponding change in the calculated angle value.

Claims (1)

Invention Formula The device for functional control of the electric drive, containing the first comparator, the first and second shift registers, the first and second counters, the first and second elements AND the element 2I-2IL, the input of the decremented first subtractor is the first installation input of the device, the input of the readable device is the information input and the first output is connected to the first input of the first comparator, the second input of which is the second installation input of the device, which is characterized by the fact that, in order to increase the completeness of control s into the device We have the first and second timers, the adder-subtractor, the second comparator, the third to the fifth AND elements, the 4ILI NO element, the EXCLUSIVE OR element, and the trigger, whose sync input, the first input of the fifth AND element, the synchronous inputs of the first timer, the first and the second shift registers are the synchronous input of the device and the output of the device for connecting to the synchronized input of the control object the output of the trigger is connected to the first inputs of the second and fourth elements and the second input of the fifth And element, the output connected to the synchronous input of the second timer, anomalous input of which is purely illustrative and the setting input of the first timer are third and fourth inputs of the mounting device, respectively, the first delay element output is connected to the first input of the reset flip-flop, to the third input of the fifth AND gate, to the second inputs of AND gates from the second d 5 0 5 0 0 e five on the fourth and to the first input of the 4ILI-NOT element, the output of the second delay element is connected to the second reset input of the trigger and to the first input of the trigger installation; the output of the first comparator is connected to the second installation input of the trigger and the third input of the second and fourth elements The second subtractor and the first input of the second comparator are the fifth and sixth installation inputs of the device, respectively; the first output of the first subtractor is connected to the input of the decremented second subtractor and to the first input Om 2I-2ILI, the output of which is the output of the device for connecting to the data input of the control object, information output of the device and connected to the data input of the first shift register, the output connected to the data input of the second shift register, the output of which is connected to the input of the subtractive subtractor The output of which is connected to the second input of element 2I-2IL, the outputs of elements AND from the second to the fourth are connected to the inputs respectively from the second to fourth element 4 OR-NOT, the output of which is a control the output of the device and connected to the third and fourth inputs of the element 2I-2ILI, the output of the first shift register is connected to the input of the second readable subtractor and to the inputs of the first and second components of the totalizer, the first output of the second reader, the second outputs of the first and the second subtractors are connected to the corresponding inputs of the EXCLUSIVE OR element, the output of which and the output of the second comparator are connected to the corresponding inputs of the first And element, the output of the connected fourth input of the fourth element I. FIG. g a 6 6 Fi & W