SU1008625A1 - Batch-type scale control device - Google Patents

Abstract

: A WEIGHT PORTIONAL BATTERY CONTROL DEVICE containing a weight sensor connected to the inputs of two sharpened pulse formers, the outputs of which are connected to one input of the comparison elements, the other inputs are connected to the outputs of the square pulse shaper connected to the power source, dose trigger, the inputs of which are connected to the outputs of the comparison elements, and the outputs - to the indicator of the current weight and to the converter of the sequence of rectangular pulses in a digital code, the calculator The weights are connected via the first digital-to-analog converter to one input of the adder, to the other input of which the portion master is connected, and to the output is a comparator connected to the output of the second digital-analog converter and to the input of the control unit, characterized in that increase the accuracy of dosing by predicting the nature of the device’s behavior over the entire weight gain interval; the sequentially connected control driver, the calculator for estimating measurement error the basic coordinate. and the evaluator. phase co-ordinators, a priori values of the phase co-ordinates and predicted increments of the phase co-ordinators, calculators of additional mass addition speeds and predicted speeds of increments of the phase co-ordinates, the output of the square-wave sequence converter in the digital code is connected to the input of the control actions generator of the calculator of the phase co-ordinator. with the input of the second (L of the digital-to-analog converter, with the calculator of the rate of weight gain and with the photo the world’s a priori phase coordinate value, the output of which is connected to the phase coordinate estimator calculator, the phase coordinate measurement error estimator calculator, and the attachment rate calculator to surges, whose output and input 00 of the predicted increment speed calculator of the phase coordinate are: related to others inputs are calculated, the bodies estimate the errors in measuring the phase coordinate, and inputs the numerator of the predicted rate of increment of the phase coordinate and the former a priori value of f the coordinates of the base card are connected sshyhodom shaper prog noziruemogo phase coordinate increments having an input coupled to an output of one of the needle pulse generators.

Description

The invention relates to weighing equipment, in particular, to dosing devices for bulk materials, for example, when preparing concretes and other mixtures at concrete mixing plants of the construction industry.

A device for controlling a weight portioning dispenser is known, which contains a selsing sensor, the rotor of which is connected to the arrow of the dial indicator of the dispenser, the batcher of the portion and the control unit G.

In this device, a predetermined dose of a component is weighed in two steps; to the coarse weight threshold and from the coarse weight threshold to the exact weight, and the weight from the coarse weight threshold is produced in multiple portions. Two-step dosing in most cases does not provide the required accuracy, lengthens the dosing cycle time, causes increased equipment wear and, which also has a significant negative effect on the psychology of the staff.

. Closest to the proposed technical entity is a device for controlling weight portions of the dispenser that contains a weight sensor connected to the inputs of two formers of pointed pulses, the outputs of which are connected to one input of the comparison elements, the other inputs of which are connected to the outputs of the rectangular ICT formers connected; to a power source, a dose trigger, whose inputs are connected to the outputs of the comparison elements, and the outputs to the current weight indicator and to a converter of a sequence of rectangular pulses into a digital code, a weight gain rate calculator connected via the first digital-analogue converter to a single input adder: to which another input is connected to the portion master., and to the output - a comparator connected to the output of the second digital-to-analog converter and to the input of the control unit G2.

In the prototype, the most reliable values of the statistics of the load weight are determined by the values of the random signal at times, corresponding to the extremums of the speed of a non-stationary random process. The disadvantage of the device will be at a low density in the receiving points of the static characteristic, which are separated from each other by a half period of the oscillatory component of the signal. Extrapolation of the signal between points leads to durine. Unpredictable errors due to the random nature of the filtered signal. Another drawback is found when the output of the sensor does not contain a regular oscillatory disturbance. It is not possible to detect extreme process speeds by differentiating the sensor signal.

The purpose of the invention is to improve the dosing accuracy by predicting the nature of the behavior of the device over the entire weight gain interval.

The goal is achieved by the fact that the weight portion batch dispenser contains a weight sensor connected to the inputs of two sharpened pulse drivers, the outputs of which are connected to one input of the comparison elements, the other inputs of which are connected to the outputs of the square forming driver connected to the power source, a dose trigger, the inputs of which are connected to the outputs of the reference elements, and the outputs to the indicator of the current weight and to the converter of the sequence of rectangular impulses in the digital code, the weight gain rate calculator connected via the first digital-to-analog converter to one input of the adder, to the other input of which the portion master is connected, and to the output — a comparator connected to the output of the second digital-analog converter and to the input of the control unit are entered sequentially the connected driver of the control action, the evaluator of the estimation of the error of measuring the phase coordinate and the evaluator of the estimate of the phase coordinate, the formers of the a priori value of the phase coordinate and Phased phase ratio increment, calculator of the additional mass addition speed and predicted phase coordinate increment speed, the output of the square pulse sequence into digital code converter is connected to the input of the control generator, the output of the phase coordinate estimator calculator is connected to the input of the second digital-analog converter, with the calculator of the weight gain rate and the shaper of the a priori value of the phase coordinate, the output of which is connected to the subtracted The Phase Coordinate Estimator, the calculator of the measurement error of the phase coordinate and the calculator of the additional mass addition rate, the output of which and the output of the predicted velocity increment of the phase coordinate calculator are associated with other inputs of the calculator of the phase coordinate measurement error estimate and the inputs of the predicted phase increment calculator input the coordinates and the former of the phase coordinate a priori are connected to the output of the generator of the predicted increment of the phase coordinate Ata whose input is connected to. the output of one of the formers of pointed impulses. FIG. 1 shows a device, a block diagram; FIG. 2 is a graph depicting the change in the state of the dozer. During dynamical weighing. The device includes a dispenser 1, the arrow axis of which is associated with the generator of the selsyn-sensor 2, the source of the rotary feed, the shaper 4 of the pointed and the shaper of 5 square-wave pulses, shaper pulse shaper and shaper pulse shaper 7, connected via comparison elements 8 and 9 with dose trigger 10, current mass indicator 11, direct-pulse-sequence converter 12 to digital code associated with the output flip-flop 10, block 13 for detecting a trend of a non-stationary random signal, calculator 14 speeds, digital-analogue converters (D / A) 15 and 16, adder 17 sensor 18 servings, comparator 19 voltage, control unit 20 and dose setting indicator 21. The trend detection unit 13 contains a control driver 22, a phase coordinate measurement error estimator 23 (optimal nonlinear filter), a phase coordinate estimator 24, a phase coordinate generator 25, a priori phase coordinate value generator, 26 predicted phase coordinate increment generator, speed calculator 27 the addition of additional masses and the calculator 28 of the predicted rate of increment of the phase coordinate. The device works as follows. The angular position of the arrow of the dose indicator 1 is converted by the selsyn sensor 2, excited from the source 3 of the reference power supply into a voltage, the phase of which is proportional to the angle of the dose indicator arrow. (D Selsyn works MME polyphase induction phase shifter. Shaper 4 vatolnost ostrokonechn1h of successive pulses with a phase shift defined by the RNase-phase winding voltage relsina sensor 2 relative to the phase (reference power source 3. The shaper 6 forms a sequence of needle pulses, having a phase of the voltage source of the reference power supply. The synchronization between the formers 4 and 6, the formers 5 and 7, emit rectangular blocking pulses in mass and support, respectively, which are They are compared with elements 8 and 9. Comparison of elements 8 and 9 are given to the dose trigger 10, which forms a sequence of square impulses with a duration proportional to the current value of the dispenser coordinate {position 1b of the indicator hand of the dispenser). Indicator 11 of the current mass values and into the converter 12 pulses in a digital binary-decimal code. In block 13, the trend coordinate code Z (t) of the non-stationary random Signal x (t) is detected using the signals optimal RMS estimates of the phase coordinates of a dynamic object t (meter) with discreteness, for example, 20 ms (FIG. 2). The phase coordinates of a weighted batch doser, representing a non-stationary vibrational weakly damped link, are estimated under incomplete information conditions and an arbitrary form of transient perturbations using nonlinear filtering of signals. The estimate m of the phase coordinate Z is formed by the calculator 24 according to the algorithm: m2. (K) Z (K) -mp (K), cj where Z (K) is the a priori value of the phase coordinate; mg (K) is an estimate of the measurement error of 2 phase coordinates; To index, indicates discrete points in time. The signals of the Z (K + 1) coordinate are removed from the output of the element 25, which forms the a priori value of the phase coordinates in accordance with the algorithm z (K + 1) m (K) + A2 (+), where AZ (K + 1) is the predicted increment of the phase coordinates removed from the output of imager 26. Thus, in the described algorithms, open-type strategies are used (the sight method), which involves the introduction of elements of anticipating the behavior of system 1 in the entire range of motion. The use of such (algorithms, dictated by the very essence of the problem under consideration, which has no solution without predicting the further course of the process based on

the measurement carried out in the previous step.

Optimal in the mean-square estimate of the error in measuring the phase coordinate of those is taken from the output of the calculator 23, which is a non-linear digital filter.

Acceleration G and control action are determined by the ratio d2x

Yi mi; G dUr - 9.

J y

f jji "IT

aQX, where g is the acceleration of the force of solid; td is the constant component of the reduced mass of the system Er, the construction coefficients. The coordinates of the trend Z and the rate of addition of additional masses up to; the component V being detected can only be measured with interference Su: Z + Vg 7 V t where V. V (Z) (l- f-) H is the maximum value of the heights of free fall; VP - free fall initial speed; Zfn - weighed maximum weight. Interference in trend measurements is given by a differentiated two-dimensional vector process with components (Ej, 2) that allow for V 2 2. Interference with velocity measurements Sv is a broadband random process, approximated by white noise, v Rib where y (i 1,2,3 ) - independent random processes of the type of white noise M.0,, 0 (1 # 5),) (it) -c / HP M - operator of mathematical expectation; Stt; - Kronecker symbol; 1 / T is the integration constant of B. B2, R is the time functions independent of the phase codes. Included in the equations for the elements of the error covariance matrix

The filtering j, j-, 2, J2.2 coefficients, L take into account the effect of the members rejected during linearization.

The solution of systems of differential equations is made by one of the numerical methods that allow the use of a computational device (linear digital filter), whose operation is described by a linear difference equation of the form

N

M

.-Цъ.

p-center "Ip-.

i n-i

-1 where Xj, у „- input and output signals; . a, C - coefficients. Thus, to calculate the output signal values (estimates of the measurement error of the phase coordinate), it is sufficient to use arithmetic operations — multiplication, addition, and subtraction, implemented using a device containing reception registers, memory registers, adders, and shift registers. Registers can be registered, for example, on K155TM2 type triggers. adders - on integrated circuits of type K155IMZ and K155LP5. Information is read out by a command from block 4. A computational algorithm for optimally estimating the trend coordinates can also be implemented on microprocessor sets, supplemented by a permanent storage device for storing the filter program and its coefficients, a random access memory for storing the values of input and output signals and intermediate variables . For the purpose of controlling the batching, information about the mass and speed of the process, obtained in a digital code from the outputs of the trend detection unit 13 and speed calculator 14, is restored to the DAC 15 and 16. The voltage from the DAC 16 in the form of a stepwise extrapolated signal is fed to the adder 17, the last also associated with an 18 portion setting unit. As a result, an analog control signal is output from the output of the adder 17, corrected according to the dynamics of the process (speed) and the height of the freely falling column of the dosing component (due to delay in the system). The adder is implemented on conventional operational amplifiers, the setpoint device is a resistor connected in a potentiometer circuit to a DC power source. The outputs of the D / A converter 15 and the adder 17 are compared in levels of c. the voltage comparator 19 and, if they coincide, the comparator forces the control unit 20 to terminate the dosing process. The setting of the desired dose value is monitored by the instrument indicator 21. Thus, the device provides one-stage single weighing by processing the non-stationary output signal of the meter according to the following algorithm: -Our-digital conversion of the resigning sensor signal; - formation of precisely measured control action; - optimal in rms-estimation of the phase coordinates of the object, adequate to the trend coordinates, methods of nonlinear filtering with a given density of the trend in conditions of incomplete information and an arbitrary form of transitional disturbances; - restoring mass and velocity estimates for control and dynamic correction for dosing rate and lateness. The use of the proposed device for controlling the weight portion of the HbiM dispenser allows weighing a predetermined portion of a component with an accuracy that exceeds the required GOST standard and shortens the time of weighing. In addition, the device allows one-stage dynamic weighing and is cases when the output signal of the object has an arbitrary form of transient disturbances. The Sanam expands the functionality of the device to a class of non-stationary random signals with irregular disturbances. Laboratory tests of the device showed that the error in weighing the required dose of a component is less than 1% with a dosing cycle of 6-12 seconds (depending on the type of component).

Claims (1)

:: WEIGHT PORTION DOSER CONTROL DEVICE containing a weight sensor connected to the inputs of two sharp-pulse generators, the outputs of which are connected to one input of the comparison elements, the other inputs are connected to the outputs of the rectangular pulse shapers connected to the power supply, dose trigger, the inputs of which connected to the outputs of the comparison elements, and the outputs to the current weight indicator and to the converter of the sequence of rectangular pulses into a “digital code, dial speed calculator, in ca connected through the first digital-to-analog converter to one input of the adder, to the other input of which a portion controller is connected, and to the output - a comparator connected to the output of the second digital-to-analog converter and to the input of the control unit, characterized in that, in order to increase accuracy dosing by predicting the behavior of the device over the entire interval of weight gain, series-connected driver of the control action, a calculator for estimating the error of measurement of the phase coordinate are introduced into it inati and computer evaluation. phase coordinates, shapers of the a priori value of the phase order and of the predicted increment of the phase coordinate, calculators of the rate of addition of additional masses and the predicted rate of increment of the phase coordinate, the output of the converter of the sequence of rectangular pulses in a digital code connected to the input of the driver of the control action, the output of the phase estimator - coordinates. connected to the input of the second digital-to-analog converter, with a weight gain calculator and with a phase coordinate aprior, the output of which is connected to a phase coordinate estimation calculator, a phase coordinate measurement error estimator, and an additional mass addition rate calculator, the output of which and the predicted increment rate calculator input. phase coordinates are connected to other inputs of the phase error measurement estimator coordinates, and the inputs of the calculator of the predicted velocity increment of the phase coordinate and the shaper of the a priori value of the phase coordinate Nena c ^ vyhodomformirovatelya predictable phase increment coordinates whose input is connected to the output of one of the needle pulse generators.