SU1524952A2 - System for controlling technological process - Google Patents

Abstract

The invention relates to automated process control systems (APCS) with the help of control computers and can be used in ACCS of wide-strip hot rolling mills. The purpose of the invention is to increase the reliability of the system. The system is additionally equipped with a dispersion calculation unit and a null organ. These blocks allow you to control the change in the dispersion of the control signal and, by its difference from the preset limit, produce a signal that there is an error in the system. 1 il.

Description

The invention relates to automated process control systems (ASUG1T) with the help of control computers (yBjVi) and can find a change in the APCS of wide-strip hot rolling mills (SHSGP).

The goal of (; bretens is to increase the reliability of the system.

The drawing shows the proposed system. management of the technological process.

The system contains a block of 1 sensors HC, 2, a block of 3 local regulators, a control panel 4, an output converter 5, a block of 6 actuators, a discrete integrator 7 with memory, a block 8 of emergency shutdown, containing element 9 on-delay, element 10 delays for switching off, the circuit NOT 1 1 and the circuit OR 12, the integrator 13, the first null organ 14, the dispersion calculation unit 15 and the second null organ 16, and the output of the sensor block 1

connected to the first inputs of UVLD 2 and bta current 3 local controllers, the second input of UV.M 2 is connected to the first output of the PU, 4 controls, the second and third outputs of which are respectively connected to the first and second inputs of the output converter 5, the fourth output with the first input of the discrete integrator 7, and the first input with the output of the emergency shutdown unit 8, which is the output of the AND circuit PRI 12. The first input of which is connected to the BI I input of the switch-on delay element 9, and the second input to the output of the circuit. NOT 11 whose input is connected to the output element 10 ass Shut-off holders, and the inputs of delay elements 9 and 10 are connected to the first output of U.F.CH 2, the second input of which is connected to the third input of the output converter 5, the fourth input of which is connected to the output of block 3 local regulators, the second output of the HC .M is connected to the input of the 1.3 integrator. the input of which is connected to the input of the first organ 14, the output of which is connected to the third input of the OR circuit 12. The first input of the current source 15

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calculating the variance is connected to the output of the integrator 13, the second input is connected to the second output of the high voltage generator 12, and the output is connected to the input of the second null organ 16, the output of which is connected to the fourth input of the OR circuit 12.

The dispersion calculating unit 15 is used to calculate: 1 the dispersion of the control c1-11 of the ACU 2. The block can be implemented on the basis of the CW 1800 programmable microprocessor and contains boards with which you can perform arithmetic operations, depending on, for example, Language FORTRAN as follows:

DL ENS1ON D, XI, XM, N

((1 / (1)) (X1- ChL) 2),

where X1 X, the current value of the control signal;

X. X is the mean value of the control signal.

BTopoi i well.: 1-organ. 16 serves to record the time at which the output of the unit 15 for calculating the variance exceeds a predetermined value. The value of the reference value is selected from the conditions of this technological process, i.e. it is associated with the INITIAL) variance, for example, the number of BoBi rolls of the SHSHP stand group, selected 1H) |) control total, etc.

Entering the dispersion calculation unit and the second null organ into the system allows to increase the system operation reliability by 11 revealing the reliability of identifying an undetected error in the software, or determining the ACL by determining the instant of which the dispersion of the control signal deviates by an unacceptable value.

The system works in the following way.

The software of the system is being implemented in the UVL.

The mode of operation is set by the operator with the HOMoiuijK) console 4 controls. On the same input source, the rolling data: the band and the band width, the tolerances, the rolling speed, and 1. n. The integration integrator constant 13, then () n the first and second iiyjib-ojiraHOB 14, 16 is also chosen.

After the system has started up, the CCTV 2 calculates for the selected initial data the minimum 1 base conditions of the initial setup, 3, 3 local controllers that are output to the console 4 on the third output of the CCL 2.

In the initial state, at the outputs of interpaPa 13, block 15, the calculation of the variance, the first and second, well, the organs 14 and 16 are zeros. The second output of the UVL 2 is connected via the output converter 5 to the input of the block 6 using the use of these mechanisms. When a strip enters the zone of action of the sensor unit 1, on || 1 meter to the rolling mill of the finishing group

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The SHGSP, the signals from the sensors enter UVM 2 for processing according to predetermined algorithms, as a result of which UVM issues a control signal to the third input of the converter 5, from which, after conversion, the signal goes to the actuator block 6, for example, the cage pressure screws , ruler guides or other mechanisms. At the same time, the control signal is fed to the input of the integrator 13 and the first input of the dispersion calculation unit 15. In normal operation, at the first output of the ACU, a sequence of pulses appears, which are fed to the inputs of delay elements 9 and 10. At the output of the latter, respectively, there will be logical zero and one, which is due to the presence of elements 9 and 10 of the signal from the first output of the high power amplifier at the inlets. At the output of circuit 12 OR, also zero, since all its four inputs have zeroes. During normal (error-free) operation of the ACU, a random signal with a normal valve arrives at the input of the integrator 13 and block 15, as a result of which the output of the integrator 13 is set to a value close to zero or another constant value (determined by the integrators design) the dispersion calculation also establishes a certain constant value, determined by the parameters npoirecca, the construction of the block that implements the npoipaMMbi dispersion calculation. The reference voltages of both null organs 14 and 16 are selected in accordance with the voltages at the outputs of the integrator 13 and block 15 during normal operation of the PC.

With any optic in the system, in particular, undetected errors of the OSS, the normal distribution law of the control signals, 1s to the output of the ACU, may be disturbed, leading to an increase in signal dispersion, i.e., directly at the output of block 15. ( The average value of the monitored signal may remain unchanged, i.e. the signal at the output of the integrator 13 may remain unchanged). As soon as the magnitude of the signal at the output of block 15 exceeds the threshold of operation of the second null organ 16, the output of the latter results in a unit that goes into quarters) input.) For the OR circuit 12, the unit from the output of which goes further to the control panel 4, which disconnects the control channel from the CCL and connects the control channel from the local system. The unit from the output of circuit P, 1P 12 goes to the first input of console 4, connects to the second input of output converter 5 the output of local regulator 3. The control action in control K 3 is calculated based on AND: | formations from sensor unit 1, console settings 4. calculated system and the system, as well as control: 1 signaling signals of UVM, issued at the moment, which is preceded by a failure and

which were stored in the memory of the integrator 7. In accordance with a predetermined algorithm, the regulator unit 3 generates a control signal, which, after being converted in the converter 5, enters the actuators. If an error occurs that does not lead to a change in the dispersion, i.e., the second null-organ 16 triggers, the signal at the output of the integrator 13 is violated, which triggers the first null-organ 14 and further disables the control channel from the ACL.

In the case of the failure of the actual control unit, leading to the cessation of the generation of pulses, at its first output, at the output of element 9, after the delay time has elapsed, a unit appears, which through the OR 12 circuit arrives at the first input of the control panel 4. Element 10 also works, which, when there is no generation from the output of the computer, produces a zero at its output, which after inversion by circuit 11 through circuit 12 also enters the first input of console 4. In both cases, the control channel from UVM is turned off, turns on according to the described algorithm control channel from local control unit 3.

Control from the local regulator unit 3 can be performed both in the case of fault of the CCA and at the initiative of the operator. In the latter case, the operator using the remote control 4 sets the initial set points and turns on the block of local controllers 3. The signals from the sensor block 1 are fed to

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the first input of the block of 3 regulators, which generates the control signals supplied via the converters 5 to the actuators 6.

In the manual control mode, the operator using the remote control 4 supplies to the inputs of the converter 5 control setpoints, which after conversion are transferred to the actuating mechanisms 6.

Thus, the proposed system, in comparison with the known one, allows to increase the reliability of determining the moment of violation of the normal course of the computational process and thereby increase the probability of preventing an accident at the controlled object, i.e., to increase the reliability of the control of the technological process.

The use of this system makes it possible to increase the reliability of the operation of the process control system in the event of failures and failures of the control instrumentation.

Claims (1)

Invention Formula Process control system auth. St. No. 1047565, characterized in that, in order to increase the reliability of the system in operation, it is equipped with a dispersion calculating unit and a second null organ, the first input of the dispersion calculating unit being connected to the integrator output, the second input to the second output of the high-voltage control unit, the output of which connected to the input of the second null organ, the output of which is connected to the fourth input of the OR circuit of the emergency shutdown unit.