SU851108A1 - Batch-weighing scale feeder control device - Google Patents

Description

(54) CONTROL DEVICE FOR A WEIGHT PORTIONAL DISPENSER

This invention relates to weighing technology, in particular, to weight-measuring devices. A device for controlling a weight batch metering device is known, which comprises a sensor. and the weight sensor of the portion, and the block for determining the moment of optimal transition to the filling mode l 3. This device does not provide the required accuracy, since the algorithm of its operation does not eliminate the fluctuations in the dosing process caused by the varying productivity of the user. . The closest in technical essence to the present invention is a control device for a feeder of a weighted batch doser containing a selso-sensor, the rotor of which is connected to the axis of the arrow of the dial indicator, shapers of pointed and reference pulses, unit generator and output node t2. The disadvantage of the device lies in the fact that the signal of pre-emption includes a component caused by the presence of an oscillatory process of the weighing system, which entails an error in the value of the input pre-emption and, accordingly, the dosing accuracy. The purpose of the invention is to improve the accuracy of dosing. The goal is achieved by introducing an intermediate portion setter, two time selectors, a trigger and a shutter open and close signal conditioners, the intermediate portion setting unit being connected to the input of the first time selector, which connects the output of a sharp pulse pulse former to one of the open gate signaling input , another vh6d of which is connected with the driver of the reference pulses, and the output - with the first input of the output node, wherein

the unit of the intermediate portion is connected to one trigger input, and the unit master is connected to another trigger input, the output of which is connected to the input of the second time selector connecting the driver of acute pulses to one of the gate closure signal generator, the other input of which is connected to the portion master, and the output - with the second input of the output node.

The drawing shows a block diagram of the device.

The device contains a pointer indicator of the dispenser I associated with the rosin of the sensor 2, the shaper 3 sharpened pulses, the shaper 4 of the control signal, the first time selector 5, the intermediate portion setters 6, the second temporary selector 7, the trigger 8 of the difference between the set and intermediate portions, the setpoint 9 portions, control signal generator 10, output node 11 and reference pulse generator 12

The device works in the following way.

Before the start of dosing, the unit 9 sets the required value of the portion, and the unit 6 sets the intermediate value of the portion equal to, for example, half of the required value. Unit 9 generates rectangular voltage pulses of length t 2 proportional to the required portion value, and unit 6 generates square, voltage pulses of duration -t proportional to some part of the required value, for example, half. The sensor 6 can change the duration of the generated pulses within from O to t2, this changes the speed at which the shutter opens, and hence the performance of the feeder. at the beginning of the dosing cycle and shutter speed at the end of the dosing cycle.

The frequency and phase rectangular pulses fopmipye W x setting elements 6 and 9 are determined by a frequency and phase reference pulse shaper 12. When dosing the angular position of the arrow indicator dial dispenser 1 is converted selsinomdatchikom 2 phase shift between the reference voltage on its three-phase winding and the control voltage on single phase winding. The shaper of 3 pointed impulses forms a sequence of pulses with a frequency equal to the frequency of melting of the sensor 2 and a phase proportional to the mass of material in the receiving tank of the dispenser 1.

The sharp-ended impulses of the imaging unit 3 and the rectangular impulses of the setter 6 arrive at the corresponding inputs of the time selector 5, the output of which produces pulses whose phase shift is proportional to the mass of the material in the receiving tank of the dispenser 1 in the dosing cycle interval from zero to t The output of the selector 5 is associated with one from the inputs of the former 4. To the other input of the former 4, support pointed pointed start-impulses are received from the former 12. From the output of the former 4, voltage impulses gf of a coral form are removed constant duration from zero to t., the width of which increases in proportion to an increase in weight of the material in the receptacle, i.e. the control process is carried out with positive feedback. When the current mass value is equal to the intermediate value set by the setting device 6, the driver 4 switches to the static state of equilibrium and at its output the pulse voltage becomes equal to zero.

Claims (2)

Square pulses with a duration of ta I formed by the setting device 9 serve to control the trigger 8 and the driver 10. For control, only the falling edge of the negative differential pulse of the setting device 9 is used. Trigger 8 is triggered by the falling edge of the negative differential of the setting pulse 6. At the output of the trigger 8, square impulses whose duration is equal to the difference -bj-i .. These impulses are sent to one of the inputs of the time selector 7, to the other input of which the pointed impulses are fed from paddle 3. Thus, at the output of the selector 7, pulses are formed, the phase shift of which is protonated. the mass of material in the receiving tank of the metering unit in the dosing cycle from -t pulses are starting for the former 10, to the other entrance of which stop pulses are supplied from the setting unit 9. The former 10 forms a sequence of rectangular pulses whose width decreases in proportion to the mass of the mat Rial in the receiving tank in the dosing cycle interval from -fc to -bа. those. the control process is carried out with negative feedback. If the current value of the mass of the material in the receiving tank is equal to the required value specified by the unit 9, the driver 10 switches to the static state of stable equilibrium and at its output the pulse voltage becomes equal to zero. The control outputs of the driver 4 for opening the gate and the driver 10 for closing the gate are delivered to the inputs of the output node, where after logical addition and integration they are fed to the input of a PD controller (not shown) that is part of node 11. The executive mechanism of the controller moves I regulate the body of the feeder in accordance with the control law formed in the device. In this case, the cessation of the supply of material to the receiving tank is carried out by 6 anticipation, depending on the material loading rate at the end of the dosing cycle. The magnitude of the preprocessing time is determined by the dynamics of the dosing process and the settings of the PD-controller. The operation of the entire device is synchronized by the shaper of 12 reference pulses, producing sharp-pointed pulses with a frequency of the supply voltage of the Rsysing-sensor 2 The control signals generated in the device determine aperiodic nature transient dosing, which improves the dynamic quality of the automatic cyclic dosing control, thereby increasing the accuracy to system development and reliability. The loading of the receiving container of the dispenser starts with increasing speed due to the formation of positive feedback in the control system, as a result of which sharp dynamic shocks of the material being metered in the receiving container are eliminated, which significantly improves the dynamics of the dosing process and eliminates oscillation. In the middle of the dosing process, the shutter opens completely and the loading speed has a maximum value, decreasing towards the end of the process, due to the formation of negative feedback in the control system. The command for stopping the dosing is given with an advance depending on the speed of loading and therefore the dosing error of the mass of material in free fall is reduced to the minimum value. The invention The control unit of the weighing batch weighing batcher, containing a selsyn sensor, the rotor of which is connected to the axis of the dial gauge pointer, forms: pointed and supporting pulses, a portion setter and an output node, characterized in that an intermediate portion setter, two time selectors, a trigger and a signal generator for opening and closing the shutter are introduced, and the intermediate portion setter is connected to the input of the first time selector connecting the output of the needle pulse shaper with one of the signal inputs of the gate opening, the other input of which is coupled to the reference generator. pulses, and the output - with the first input of the output Node while setting. The intermediate portion is connected to one trigger trigger, and the portion control is connected to the other trigger input, the output of which is connected to the input of the second temporarily selector connecting the shaper pulse generator with one of the inputs of the shutter edge signal generator, the other input of which is connected to the portion set, the exit is with the second entrance of the exit evil. Sources of information that are considered in the examination 1. Copyright. USSR certificate 403963, | КЛ. From 13/24,. . 2. USSR author's certificate G 01 (; 13/28, 1976 602789, class, rototype). H eleven 12 w ten "