DD228994A3 - CIRCUIT FOR CONTROLLING A V / R PAYER IN A SPEED PASSWORD - Google Patents

Abstract

For position control, for example, for the carriage movement of a Knueppelputzschleifmaschine, a circuit for digitally generating a speed setpoint is disclosed. The speed set point has a fixed adjustable path dependent change in accordance with the object and the object of the invention, its size can be changed beginning at an arbitrary place, its amount can be limited by presetting and its reduction always starts at such a distance to a given destination point, that he has a minimum value in the target point. This is achieved by counting path increments in a forward / backward counter depending on the comparison of the counter reading of the forward / backward counter with the specified maximum counter reading and the distance to the changeover location. A programmable divider, which converts the count of the forward / reverse counter to a proportional frequency, is clocked by a generator whose frequency determines the change in the speed reference over the path. The circuit according to the invention can also be used to control other physical quantities. Fig. 1

Description

invention description

Title of the invention:

Circuit for driving a V / R counter in a speed setpoint circuit

Field of use:

The circuit is particularly suitable for the digital generation of a speed setpoint within a freely programmable position control, for example for the carriage movement of a billet grinding machine.

It ¹ "allows a pure hardware solution with little effort, if only a few points are to be approached or only a movement between two boundaries to take place." In addition, it can also be used to control other physical quantities.

Characteristic of the known technical solutions: In order to ensure reciprocal approach of limit points in numerically controlled machines without exceeding them, it is necessary to generate an actuating signal or a reference variable as a function of the distance to the reversing point.

In known hardware solutions, this is done by the gradual reduction of the control signal to wired or free-programmed Vorabsehaltpunkten.

For example, the incremental position indicator IPA 200 (manufacturer VEB Carl Zeiss, Jena) offers the possibility of outputting pre-switch points

A gradual positive and negative acceleration at any point within the given boundary points is not possible

If the control is realized with a computer, the output of a reference variable as in the microcomputer control IR 60/10 (manufacturer Central Institute of Metallurgy Leipzig) can be done by a table assignment of the speed setpoint to the distance from the target point. "The use of a computer is often in simple controls not justified .

From W ₀ Leonhard "counting calculation circuits for control tasks ¹¹ In: Archive for electrical engineering 49. (1964) H. 4, pp. 215-234 it is known, the braking of fast trains by continuously measuring the braking distance to the destination and on the basis of the predetermined Zielgeschv In this case, on pages 216 and 217, examples are disclosed which allow the generation of various functions using counters and adjustable frequency dividers, the result of which is given as Number of pulses per unit of time output.

These solutions allow only the calculation of a reference variable depending on a destination, thus they do not allow the reciprocal approach of boundary points as well as the enlargement or reduction of the velocity solver it at any point after the given function.

Object of the invention:

It is the object of the invention to provide, without the use of a microcomputer and with minimal visual effort, a command variable for driving a V / R counter in a speed setpoint circuit which allows mutual approach of limit points without exceeding it, the speed command also being at any location must be changeable with the same increase over the way »

We have the invention:

The invention has for its object to provide a circuit that controls a V / R counter within a speed setpoint circuit ao, that at the output of the V / R counter a Pührungsgröße arises having a festeinstellbare change over the way, their size can be changed starting from any location, its amount can be limited by default, and its reduction always begins at such a distance from a given reversal point that it has a minimum value in it.

According to the invention the object is achieved by means of a circuit consisting of three V / R counters, of which a V / R counter is connected to a programmable divider, which in turn is connected to a generator, a query logic, two RS-3? Lipflop of which the first one is connected to your V / R counter to be controlled, two comparators, two AND gates, which are followed by an OR element and the V / R counter to be controlled, a second OR element and a second Negator and a switch associated with the programmable divider by connecting the output of the V / R counter to be driven - whose count range is limited in known manner to positive numbers - to the first inputs of the first and second comparators; that the inputs of the OR gate with the stop command and with the output of the second comparator - for the statement: numerical value of the first input i *. Numerical value of the second input - are connected and the negated input of the OR gate is in communication with the output of the first comparator that the output of the OR gate to the input of the second AND gate and with the negated input of the first AND gate is connected, that further the output of the second comparator - for the statement: numerical value of the first input <numerical value of the second input - is connected to the input of the first AND gate, that the circuit input for the specification of

maximum count is connected to the second input of the second comparator in that the outputs of the remaining V / R counter are connected to both the interrogation logic and with the second RS flip-flop in such a way that the highest point of each V / R -Zähler on an input of the R / S flip-flop is connected, the output signal on the one hand, as usual, with the switch and on the other hand with the interrogation logic, and this finally with the second input of the first comparator in conjunction »The target speed is linear Function of the way formed. For this purpose, path increments without counting the sign are counted in the V / R counter to be controlled, specifically when accelerating into the forward counting input and braking up to the counter reading "zero" in the reverse counting input

The programmable divider converts the counter reading into a pulse number per time unit. The frequency of the generator determines the frequency change, which is associated with the change in the count of the to be controlled V / R counter and thus the change of the path.

The distance to Umsteuerpunkt - as a multiple of Weginkremente .- compares the first comparator with the current count = necessary braking distance to Umsteuerpunkt "If the distance is not greater than the required braking distance, the to be controlled V / R counter is counted back by the Weginkremente O

If the output signal of the OR gate does not cause the V / R counter to be counted back, the second comparator triggers the counting up to the predetermined maximum count via the first AND gate. When the preset maximum counter reading is reduced, the second comparator uses the OR element to reverse the count <Since there is a linear relationship between counter reading and speed, the speed setpoint is therefore limited by the second comparator ο '.

In order to enable count-in of path increments in the V / R counter to be triggered after standstill, a minimum pulse frequency is output when the stop command is canceled via the lowest data input of the programmable divider.

With the OR gate, the stop is triggered by the stop command - with the change in the speed setpoint over the path determined by the generator frequency. «

Embodiment:

The invention will be explained in more detail below with reference to an exemplary embodiment. In the accompanying drawings show:

Pig. 1: An advantageous application of the circuit according to the invention for the regulation of the movement of the hydraulically driven carriage of a billet grinding machine,

Fig. 2 u. 3: Diagrams for the forward flow of the speed setpoint for various motion sequences.

The distances to the Umsteuerpunkten are from the up / down counters 1 »2; 1.3, realized by IS 74 193, which are set according to the position of the stick ends determined. After exceeding a Umsteuerpunktes the count zero follows the respective counter 1.2; 1.3 the maximum counter reading, which is counted down with greater than grounding exceedance. The sign change of the highest digit of a counter 1.2 or 1.3 connected with the overshoot point causes the RS flip-flop 1.5 to switch over, and the output signal via switch 1.16 Channel, thereby assigning a sign. The interlocking logic realized by logic gates 1.4 switches the output of those forward / backward counter 1.2; 1 "by 3 whose count smaller? P ~, satisfying this condition when both counters, the reading of the counter is passed to the comparator 12.1, in which the

- 6 -

is counted down by the RS flip-flop 1 "5 certain sign. If the counter is not smaller than Ζ ^η , the number 2 ^ -1 is output to the comparator 1.12, realized by IS 7485.

The incremental movements of the carriage movement are controlled by the OR element 1.1 independently of the direction of movement when the logical conditions of one of the links 1.8; 1.9 in the up / down counter 1 _o 10, realized by IS 74 193, counted. The RS flip-flop 1,11 prevents the counter reading from falling below zero. "The programmable divider 1,14 (IS 7497) clocks a square-wave generator 1" 15 in a known circuit, a change in the rate of increase over the path through a change in frequency requires the generator 1.15, the predetermined maximum speed is to be maintained, even a change in the specification Z ^ _r for the

Max

Comparator 1.13 (IS 7485).

Apart from the stop command, an intervention in the automatic procedure between the Umsteuerpunkten by the brake command is possible. This causes a reduction of the target speed to JW. J and, linked to the query logic, can be used to manually control the carriage movement.

The operation of the circuit will be described in the appendix of the diagrams showing the course of the speed setpoint in different sequences of motion. ·

Fig. 2: Starting from standstill and reversing At point X, the command to stop the cart is canceled. The sign determined by the RS flip-flop 1.5 is positive, the counter 1.2 is counted backwards by the movement direction associated therewith. The output signal increases immediately after + W ^ has been output, with the increase fixed by the frequency of the generator 1.15 to the value determined by the generator frequency and the specification Z "

Max

^{+ W} max ·

At point X "the necessary braking distance begins". The speed specification is reduced with the change determined by the generator frequency over the path to the reversing point X. Here it reaches the value again

Due to the inertia of the car passes over the Umsteuerpunkt X ,, the sign of the Geschwindigkeitsaollwertea changes, the count 1 "2 takes a maximum, and there is a renewed increase in the amount of the setpoint at Umsteuerpunkt X. beginning, about the turning point X, - up to Umsteuerpunkt X .. Here, the count of the counter 1 "2 is zero. The pre-y / backward counter 1.10 is counted back by the Weginkremente until its count at the point X-, with the state of the counted from the reversal point X, - counted counter 1.2 corresponds 1.2 "

Thereafter, the comparator 1.12 releases the count-up of the counter 1.10.

Pig. 3: stop

The output signal has the value + W,.

At point X _r , the command for stopping the car is issued.

Above the lowest data input of the programmable divider 1e14 ', the speed setting decreases immediately by Y / _m -. By means of the links 1.6; 1.3; 1.9, the stop signal causes the countdown 1.10 to be counted down to zero, thus reducing the speed setpoint at point Xj to zero. "

Claims (2)

Inventions ana pr uoh Circuit for Anateuerung of a V / R counter at a rate ssollwertschaltung consisting of three V / R-counters, of which a V / R counter is connected Iler with a programmable T _e, which in turn is connected to a generator, a query logic two RS flip-flops, the first of which is connected to the V / R counter to be driven, two comparators, zv / ei AND gates, which are preceded by an OR gate and the V / R counter to be controlled, a second OR gate and an inverter and a changeover switch, both connected to the programmable divider, characterized in that the output of the to be controlled V / R counter (1 »10) to the first inputs of the first and second comparator (1.12 1.13) that the inputs of the OR gate (1 »6) are connected to the stop command and to the output of the second comparator (1 _O 13) and that the negated input of the OR gate (1.6) is connected to the output of the first comp eichers (1.12) is connected in that the output of the OR gate (1.6) to the input of the second AND gate (1.9) and to the negated input of the first AND gate (1 "3) is connected, that further Output of the second comparator (1o13) with the input of the first AND element (I ₀ S) is connected, that the circuit input (Z ", _,) for Vormax If the maximum counter reading to the second input of the second comparator (1 _O 13) is that the outputs of the two other V / R counters (1 ₀ 2, 1 "3) with both the interrogation logic (1o4) and the second RS-PIipfIoρ (1,5) are connected in such a way that the highest point of each V / R counter (1.2 or 1.3) is connected to an input of the R / S flip-flop (1o5), whose output signal on the one hand in usual way with the switch (1 _O 16) and on the other hand with the interrogation logic (1.4), and this finally with the second input of the first comparator (1.12) is in communication » For this 2 sheets of drawings