SU1500999A1 - Apparatus for automatic control of the mass of a dose - Google Patents

Abstract

The invention relates to the discrete automatic control of the mass of the dose and can be used to regulate the process of batch dosing in the food, chemical and other industries. The purpose of the invention is to improve the accuracy of regulation. To do this, in the device for automatic control of the mass of the dose containing the dispenser 1, the display unit 2, the control unit 3, the setting device 4, the computing unit 5, the memory unit 6 and the control unit 7, in block 5, the arithmetic average value of the mass deviation is estimated. the product being metered, as well as the dynamics of the change in the average mass of the dose from sample to sample, which allows to predict and compensate for deviations in subsequent samples. 1 hp f-ly, 2 ill.

Description

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The invention relates to a discrete automatic control of the mass of the dose and can be used to regulate the process of batching dosage in food, chemical and other industries,.

The purpose of the invention is to improve the accuracy of regulation.

Figure 1 shows the block diagram of the described device; Fig, 2 is a functional diagram of the computing unit.

The device contains a dispenser 1, an indication unit 2, a control unit 3, a setting unit 4, a computing unit 5, a memory unit 6 and a control unit 7, the outputs 8, 9 of the unit 3 being connected to the unit 2 and the inputs 10, L of the computing unit 5, The output 13 of block 3 is connected to the input J2, the outputs 14, 15 of block 6 are connected to the inputs of setpoint 4, the outputs 16-20 of block 6 are connected to the inputs of block 5, three outputs of which are connected to the inputs 21-23 of block 6 connected by inputs 24- 27 to the console outputs 7.

Block 3 contains a weighing device that determines the mass of doses at the outlet of the dispenser 1. In this case, the measurement results are fed to the inputs of the computing unit 5 and block 2 as signals of underweight () and overweight f (+). In addition, in block 3, the magnitude of the deviation from the dose of masses is determined, which is also entered in block 5 o

The regulation of the dosage process is based on the calculation of the estimate, the conditional expected value of the Task 4, which provides form-40ni /, (t + it) for a given f (t),

Metering of the metering correction controller 1 along 4 t is a discrete step during

increased the mass or decrease in the mass of the control signal before the supply of n, a compensation with a duration proportional to the deviation of the mass of the dose from the nominal value of the input signal.

Extension block 5 contains 45 volumes of the dispenser. Estimate t calculated element OR 28, counter 29, sum- (, ak the sum of the estimate m ((t) and ocentor 30-33, divisor 34, multipliers "and the th mass caused by the change

35, 36 and the element ЫЕ 37. In block 5, the bulk density for time dt. Ec-v

the average arithmetic mean is estimated.

..., mjj mass doses per

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..., mjj 50 times, t, then, as is well known and mathematical statistics, the best

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The mean value of the deviation of the mass of the dosed product S from the Nominal value, and also the dynamics of the change in the average mass of the dose from sample to sample, which allows to predict and compensate for this deviation in the subsequent choice of KG Block 6 is a device i Ct, t + At and prior the value of this

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As an estimate, he suggests, with the difference between the estimate of ft j. (average S mass over time

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the values of the tuning coefficients, I, T and the sample size p entered from the console 7, the results of intermediate calculations performed by block 5, the input of the specified information in blocks 4 and 5. The console 7 provides for the input of the numerical values of the above parameters 0 ditch in memory cells of block 6 with corresponding addresses, for example, in binary code.

In the synthesis of block 5, it is assumed that the current value of the mass 5 of the dose in the batch dosing process is random. The determining factor in the change in dose mass at a constant volume of the dispenser is product heterogeneity and, to some extent, the error of the actuators, therefore, the change in dose mass (t) at the dispenser output for a given volume is the sum of two random processes over time (t ) / f, (t) - «- jr (t), where (t) is a slowly varying component due to a change in the average bulk density of the product;

if (t) is a rapidly changing component due to instantaneous fluctuations of bulk density.

Regulation of the dosage process is based on the calculation of the estimate, the conditional expectation of

0ni /, (t + it) for a given f (t),

.li t, t

..., mjj mass doses per

50 time, t, then, as is known from mathematical statistics, the best.

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Ct, t + At and prior value of this

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As an estimate, he suggests, with the difference between the estimate of ft j. (average S mass over time

the storage of operational information

, - (S,., AM,.,).

Further, as an estimate choose dM - S +; -L S .., where k is the current sample number from n follower

doses. The choice of n is determined by obtaining a reliable estimate, as well as possible delays in the control system. The values of the coefficients of g. , Vb.- determined by the quality of the product and the nature of its changes. If the quality of the product varies, only slightly over a certain time interval, the value of Q is close to 1. With significant changes in the quality of the product, in order to prevent the regulation process from swaying

29 of the block 5. From the output of the dispenser 1, the sitacles corresponding to the mass values of the doses are fed to the input of the block 3, and from the outputs 8, 9 the signals go to the inputs of the block 2 and the element 28 of the block 28 of the block 5. These signals correspond to the results of measuring the mass of the doses in the form of underweight signals f (-) or overweight B () “From the output of the OR 28 element, the signal is fed to the input of counter 29, which, regardless of the sign (polarity) of the signal, counts (sums) the number of doses, 15–15 silently through the weight measurement the unit of the control unit 3, equal to the volume of the analyzed sample of the signal largest sample size from the counter

the value of the coefficient must be fed to the inputs of the adder 30 and but should be reduced. The coefficient coefficient 20 of the divider 34 AND is determined by the correlation of the process (t): with an increase in the correlation coefficient ((t), j (t + + 4t)). The value is chosen closer to 1. The value of the coefficients 1.1 and 25 ° C, in which the sum is applied. Signals about the magnitude of the deviation of the dose mass from the nominal value come from the output 13 of block 3 to the input of the adder

the same depends on the type and quality of the product, the design features of the feeders of the dispenser. When simulating a control process on a computer, for example, JQ has determined the best

92 and 0.2. After determining the value of D M, for which it is necessary to change the mass of the dose of the product, with the help of assigning them or subtracting them depending on the value of the sign bit. The number of cycles of summation is equal to the volume of the sample analyzed. A signal from the output of the adder 30 is fed to the input of the divider 34, in which the arithmetic average of the deviation of the mass of the dose Sj from the nominal value of this sample is calculated. The information about the value of S comes on

 with

ka 4 and inputs from the console 7, the multiplier 35 inputs, the adder 31, and

also recorded in block 6. The record in block 6 is the clocking signal for the call from block 6 to the multiplier (where K is the coefficient

p food, determined by the time of operation of the actuator and the corresponding change in the volume of the dispenser, and the density of the material) calculates the product T –dM, which determines the time of work

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35 value of the coefficient I. The result of the calculation of the product. from multiplier 35 enters adder 32. At the same time, the output of block 6 and input into adder 33 is made

the actuator of the dispenser 1, the values In and., obtained by

until a desired change in dose volume is achieved. The direction of change in the volume of the dispenser in this case is determined by the sign 4MX

the results of the analysis of the previous sample, as well as the entry into the counter 29 of the value of the sample size to prepare it for the analysis of the next sample

The device operates as follows: The sum S -it is calculated in adder 33.

2 M

at once.

The values of the coefficients -I ,, and the sample size and, determined depending on the material properties and parameters of the actuator of the dispenser 1, are entered as corresponding signals from the console 7 in block 6, and the value of the sample volume is recorded in the counter

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29 of the block 5. From the output of the dispenser 1, the sitacles corresponding to the mass values of the doses are fed to the input of the block 3, and from the outputs 8, 9 the signals go to the inputs of the block 2 and the element 28 of the block 28 of the block 5. These signals correspond to the results of measuring the mass of the doses in the form of underweight signals f (-) or overweight B () “From the output of the OR 28 element, the signal is fed to the input of counter 29, which, regardless of the sign (polarity) of the signal, counts (sums) the number of doses, 15–15 silently through the weight measurement the unit of the control unit 3, equal to the volume of the analyzed sample of the signal largest sample size from the counter

29 is fed to the inputs of the adder 30 and 20 of the divider 34, 25 0, in which the sum29 is fed to the inputs of the adder 30 and the divider 34 0, in which the sum is applied. Signals about the magnitude of the deviation of the mass of the dose from the nominal

or subtract them depending on the value of the sign bit. The number of cycles of summation is equal to the volume of the sample analyzed. A signal from the output of the adder 30 is fed to the input of the divider 34, in which the arithmetic average of the deviation of the mass of the dose Sj from the nominal value of this sample is calculated. The information about the value of S comes on

inputs of multiplier 35, adder 31, and

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35 value of the coefficient I. The result of the calculation of the product. from multiplier 35 enters adder 32. At the same time, the output of block 6 and input into adder 33 is made

the results of the analysis of the previous sample, as well as the entry into the counter 29 of the value of the sample size to prepare it for the analysis of the next sample

+ DMK, which flows through the element IE 37 to the input of the adder 31, where the difference (8k, + dM) is calculated. The result of the calculation is fed to its input of the multiplier 36 ° At the same time, from the output of the adder 31 to the input of block 6 pos; the clock signal goes out, making the output from block 6 and writing to the multiplier 36 the value of the coefficient K.

The value of 5c- () calculated in multiplier 36 is fed to adder 32, where it is added to the result of multiplication in multiplier 35. The result of calculating Mts from the output of adder 32 is entered into block 6. The signal jMc is clocking to output from block 6 of coefficient values, converting weight - duration and DMC, From the output of block 6, 4M signals ({enter the inputs of the setting device 4, the outputs of which form control signals Up (+) or Up (-) to effect the correction of the dispenser 1 towards the increase or decrease in the dose proportional to the input signal Am. Duration of control signal depends on the values of Tij and D M, and determines the time of operation of the dispenser mechanism performer Nogo 1, and hence the amount of change in volume or mass of the measured dose.

Claims (2)

1. A device for automatic control of the mass of the dose, containing a dispenser connected by two inputs to the corresponding outputs of the setter, and an output to the input of the control unit, the first and second outputs of which are connected to the corresponding inputs of the computing unit, so that that, in order to increase the accuracy of the fireworm, a control panel and a memory unit were inserted into it, connecting the first and second outputs with the corresponding inputs of the setter, the first, second, third and fourth inputs - with the corresponding outputs of the pool It is the control, fifth, sixth and seventh WMOs dami - respectively with the first, second and third outputs of the computing unit, and the third, fourth, fifth, sixth and seventh outputs - with the corresponding inputs of the computing unit connected by the eighth input to the third output of the control unit. 2. A device according to claim 1, characterized in that the calculator of your block contains four adders, a counter, two multipliers, 51, a divider, an element NOT and an OR element connected to the information input of a counter connected to the first output of the first input of the divider, and the second output - To the first input of the first adder, connected by an output to a single input, a divider, the output of which is connected to the first input of the second cyMJS-ia-torus and the first input of the first multiplier, connect the output to the first input of the third adder, the second input of which with the output of the second multiplier connected by the first input to the output of the second adder, the second input of which is connected to the output of the NOT element connected by the input to the output of the fourth adder, the first and second inputs of the OR element, the initial installation of the counter second input of the first multiplier, the first and the second inputs of the fourth adder, the second input of the second multiplier and the second input of the first adder are respectively the first to the eighth inputs of the block, and the output of the second adder, the output of the third adder and the divider output Are the first, second and third outputs of the unit respectively. F. 2