DE2032031C - Arrangement for the automatic rotation of a movable element in the tangential direction of the path to be traveled - Google Patents

Description

3 4

speed from the path angle traveled as well as from a speed component r _x , ν _υ into a digital setpoint value

Program can be adjusted to specific angles. (Memory! ») For the path angle and thus the rotational

According to the invention, this object is achieved as follows for the element 1,

solved that the speed components by means of the analog quantities v _z and v _u (for example

an analog-digital converter and one of these 5 DC voltages) of the path control 60

influenced counting device in an equivalent by means of modulators 10, II by against each other

Numerical value are implemented, the sine oscillations F _Mx , F. \ h one, offset by 90 ° on a digital control

tion of a stepping motor rotating the element sinusoidal generator 13 amplitude modulated and in alternation

acts. seisspannungen F _x , F _u implemented, which in a summing

The advantages achieved with the invention consist of circuit 12 added, so that the result is, in particular, that the entire informational alternating voltage Fr results, the amplitude processing of which is no longer electromechanically equal to the geometric sum of the two amounts, as was previously the case. This results in a higher accuracy of F _x and F _y is and their phase compared to and greater reliability. A connection of the fundamental _oscillation F Mx (0 °) of the generator 13 is equal to the tool and control electronics via the error-prone 15 the path angle. The fundamental component Fu _x feedback lines is not applicable. Since no moving zero components (angle sensors) are used to control the resulting oscillation Fr , point detectors 14, 15, which also show any wear at zero crossing, are not required. The invention enables the oscillations F _Ä , Fw to output a digital signal a with one and the same system, not just an auto and b. Both signals α, h control a gate 16 matic tangential control according to c ". 'N Geschwindig- ao, the pulses P _{2 of} a square-wave generator 17 blocks components, but it can also be external or let through. When the gate 16 is open, discrete path angles can be specified , the pulses P ₁ beispiels- to a counter 18. the pulses P _1, by the program or by hand. So far, the square wave generator 17 was also control the generator 13 for this purpose two separate systems are required. at which the rectangular pulses P _t in sinusoidal

Appropriate further developments of the invention as implements alternating voltages,

subject matter can be found in the subclaims. Between the frequency P _{1 of} the square wave generator

The invention is based on an i; i of drawing 17 and the modulation frequencies of the Sinusgene-

schematically illustrated embodiment in more detail rators 13 there is a fixed frequency ratio. It

explained. It shows must be equal to the number of steps (384) of element 1

F i g. 1 be a principle circuit of the invention over one revolution. When rotating the

A moderate arrangement, element 1 by 360 °, the square wave generator 17

Fig. 2 is a signal diagram of the analog-digital input as many pulses P, in the counter 18, as

Original setter, steps (384) over one revolution at the step

F i g. 3 another signal diagram of the analog motor 2 is possible. The frequency ratios

Digital converter, 35 must remain constant, otherwise computational

F i g. 4 shows a detailed circuit of the inventive errors (incorrect path angles!). In practice

according to the arrangement. are therefore not two generators 13, 17 available,

In Fig. 1 is a rotatable drawing tool 1 but from the rectangle generator 17 are also

indicated, which an engraving stylus, a cutting- the modulation frequencies F _Uz , F \ i _v derived, like

knife or a rotary prism of a light signal head 40 is detailed below. The relationship

can be. As a drive element for the rotation (through between frequency P ₁ and modulation frequency F _Mx

Double arrow indicated) a stepper motor 2 is 1: 384. This ratio is digitally enforced,

turns, which is controlled by the digital signals of a step- The gate 16 is depending on the size

motor control 3 is applied. The control 3 Ben Fm ₁ and Fr controlled, and in the counter 18

and a forward-reverse counter 4 obtained Im- 45 are thereby more or less Iirpulse P ₂ einge-

pulse Psm of e ^; An electronic right-angle chip count. The reading of the counter 18 corresponds to the number

voltage generator 5. The numerical value B of the counter 4 of the recorded pulses P ₁ and thus also the

is available as an absolute actual value at a comparator 6, path angle.

which a further numerical value A occurs as an absolute When driving around curved curves

Setpoint is supplied, which changes v _x and v _v ^{continuously via a selection switch} o.

ter 7 either from a memory 8 for angle of rotation in the signal diagram according to FIG. 2 are

from the program (e.g. punched tape 61) or play specified how the measured sinusoidal voltages

from a memory 9 for path angles from the counterparts F _x , F ₁₁ , Fr for the four different quadrants

velocity components v _x and v _y comes, which run. In the first quadrant, v is _x and _{v is} respectively

from a known path control 60 with .55 positive, in the second quadrant v _{x is} negative and »·"

two actuators (indicated by the outputs X _s positive, in the third quadrant v _x and v _{v are} negative

K for element 1) for the method of element 1 and in the fourth quadrant v _{x is} positive and ij,

are taken in an AM 'plane. The save negative. The vibrations obey the laws

9 and 9 thus contain the rotation angle setpoints, where F _x = F _x cos Ω t and F = F „sinüf.

which the stepper motor 2 adjusts. 60 χ χ ν

Due to the stepper motor 2, the addition of the two vectors results in ρ - corresponding to the number of steps over one revolution. ρ α. ρ
and determined by the transmission ratio ^z "'
between stepper motor 2 and element 1 a certain The pulse α is the output signal of the zero-crossing number of angular steps over one revolution 65 gear detector 15 (Fig. 1) for the frequency F _Mx , (for example 3 £ 4). . and the pulse b is the output signal of the zero-The conversion of the analog, the path control passage detector 14 (Fig. 1) for the resulting 60 taken for the element 1 speed frequency Fr.

The pulse sequence α is the reference! Pulse sequence, v _y amplitude-modulated oscillations. The one that is fixed in the phase (0 °). Alternating voltages are available via two summing resistors

Is the resulting frequency / "" by zero, stände27, though out 28 to the input of Summiervcr- and from negative to postitive area stärkers 29th to the output occurs Fr then the signal b corresponding to the 5 amount is L. of the trajectory vector, while the phase resulting frequency Fr goes through zero from the positive angle of the oscillation Fr compared to F _x or Fm _x into the negative range, then the signal b is equal to the angle of the trajectory velocity vector, corresponding to 0 (vertical arrow). This phase angle is now measured digitally,

The ratio of v _z and v "and its sign gives by at zero crossing of the counter 18 F _Ux that is different vibrations resulting _t0 is released, the pulses P ₁ counts. In Nullgen Fr and from the resulting impulses passage of Fr of the counter 18 is inhibited. The follow α and b, which control the gate 16 (Fig. 1). The content of the counter corresponds to the phase angle. The phase shift from b to α includes direct The measurement of the zero crossings of Fr and Fm _x bar the path angle or, in other words, it is done by two zero detectors 14, 15. Angle of the sum vector from v _x and t> _y . 15 The zero detector 14 can be a Schmitt trigger or

If the pulse sequence α goes from L to 0, it will also be an operational amplifier. Input 30 counting started (gate 16 open). If then the is controlled by Fr , the second input 31 pulse train b from L to 0, the count is set to zero. If input 30 is positive, then stopped (gate 16 closed). the output potential becomes correspondingly negative, and

The count area is dashed in quadrants _ao vice versa. The zero detector 15 is designed in this way, indicated. that with a positive control of the input 32

In the signal diagram according to FIG. 3, the output potential is also positive again, the second quadrant with the signals a, b and others becomes positive, and with a negative control the signals are displayed. The relationship of the pulse train P _t output potential negative. The zero detector 14 is inverted and the signal sequence α is fixed. _{The input signal is derived} from the signal α is aS, while the zero-scaled signal a 'is derived. Inside the detector 15 not inverted.

Signal α are 192 pulses P _t . From the Signa! b A square wave generator 17 is a single-phase

a signal b ' is also derived. A signal c is derived from the signal pulse sequence P _t out (frequency about 30 kHz), which len a ', b' , by means of which the binary counter 18 controls a binary counter 18 via a gate. 7or 16 (F i g.!) Is influenced. Disappears e _s Da? Gate 16 is indirectly controlled by the DigiUs! S! ^o na! en signal c, a signal d is formed, which controls the memory zero detectors 14, 15, rather 9 to take over the numerical value of the counter The zero detectors 14, 15 are two memory

18 (Fig. 1) opens. The measurement is thus ended, elements 33, 34 connected downstream, which are used for stepping down and the stepping motor 2 moves after the end of counting to the angle given by the signals α, b in signals α ', b' (FIG. 3 \. A new counting can begin ₃₅ since the modulation frequency Fmx does not occur in every period when the signals a 'and fc' are counted accordingly

It is therefore a sampling process covering the entire system, then counting again and so on, in which the measured value (target value) is formed again and again for a short time, followed by a pause in measurement ₄₀ a gate 35 is performed, the gate 16 and a mono-followed again a measurement value formation and so on. The step-stable multivibrator 36 controls. The gate 16 controls motor continuously follows the setpoint values formed in this way. the binary counter 18, which is followed by a memory 9

In FIG. 4 it is assumed that one is not switched.

Continuous path control with the analogue shown below. Gate 16 is opened when the modulation

DC values ± v _x and ± v _{y are} present. There can be 45 vibrations Fu _x coming from the positive through the setpoint values of the speeds, but zero is also possible. At the zero detector 15, the signals are the actual values, if tachometers are present (tachometer from L to 0, and the signal a 'of the storage element voltages). They are analog voltages, the 34 of which goes from 0 to L. At this point in time the "height is proportional to the magnitude of the speed signal b 'of the memory element 33 is already L (see diagrams, the direction of the speeds being 50 grams according to FIG. 2), so that at the output of the is expressed by the sign (direction of travel gate 35 a signal c corresponding to L occurs, whereby the tool I according to FIG. 1). the gate 16 released wildly. So get the

The constant variables control amplifiers 21, 22 for pulses P _{1 of} the square-wave generator 17 in the counter 18. Level adjustment or filtering. The outputs V _x , Now, coming from the positive, the only

v _v are connected to modulators 10, 11, which can be the passage of the resulting frequency Fr, then multipliers (an element that forms the signal b and the signal b ' from the zero product of two input variables). A factor detector 14 and storage element 33 corresponding to 0 is the constant value V ₁ or r 1 and the other (FIG. 3), whereby the gate 35 and also the gate 16 factor is an alternating voltage Fm _x or Fuy are blocked so that the counter 18 is no longer (modulation frequency). Both modiation voltages count.

genes are the same in amplitude, but phase by 90 °. This means that the angle in the counter 18 is in digital

shifted, corresponding to the vector angle van V _x form, and this is taken over by the memory 9, and r ". The modulation voltages go to the takeover, as well as the signal c of the gate modulators 10, 11 via selective alternating current 35 goes from L to 0, whereby the monostable 23, 34 with band passes 25, 26, because the connected 65 multivibrator 36 an impulse d for the purpose of taking over voltages offered have a rectangular shape. of the path angle in the memory 9. The multi

At the dt η outputs F _x , Fy of the modulators 10, U vibrator 36 automatically returns to its starting position and the changing direct voltages v _{x come} back. The counter 18 is reset via a

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'■ 7 8

Reset input 46, always when the change «to» rotation of the program «or vice versa.

Signal a 'of the memory element 34 on the next over the selection formed as OR slaves

from the positive zero crossing of the modulus switches 7 go to the comparator 6 either directly

lation oscillation Fm _x (time / 'in Fi g. 3) from the program value or the tangential control value

L goes to 0. S the memory 9. The comparator 6 compares the target

In the period I ₁ (Fig. 3) is measured, in value of the angle for the tool 1 (word A) with

The counter 18, the actual value angular position of the tool (word B) is reset during the period t _t.

and in the period / _a a measurement takes place again etc. The word B are the output signals of a forward

At the end of the perioder, the memory9 contains the down counter4, the. so the angular position of the

from the velocity components v _x , \ _v io of the tool.

Derived setpoint value of the angle is available from stepper motor 2 in FIG. 4 only

which the stepper motor 2 can be adjusted immediately bt- four windings indicated, which via amplifier

starts. 52 by signals from a four-digit shift register 53

According to a further embodiment, the setpoint can be activated. The control is such that

also from a program (for example hole 15 only one winding is energized at a time.

strip 61 in Fig. 1) can be specified. The shift register 53 receives incremental pulses Ps μ

digital signals derived from this program, which are generated for motor 2 via a square-wave generator 5.

the angle of rotation;) represent, are sent to the inputs 1 ', With each clock pulse, the motor 2 makes a

2 ', 4', 8 ', 10', 20 ', 40', 80 '. The numbers are the step. The clock pulses of the generator 5 are also

Values of the signals that a decimal dual ao fed to the up / down counter 4, the

Converter 47 and two logic elements 48, 49 thus every single step of the motor 2 - namely

head for. Linking forwards and backwards is included in the converter 47. Register 53

members 50 connected downstream, which work together from one and the counter 4 so work synchronously.

Gate 51 can be controlled. The outputs of the control Should the system take its basic position, so

logic elements 50 and the outputs of the memory 9 »5 is a signal corresponding to L at the input G

are based on the layout consisting of OR levels. The counter 4 is thereby set to zero,

selector switch 7. and motor 2 rotates until the factory

The logic elements 50 are set by a tool 1 in a zero position (corresponds to the angular position

ar. Output of gate 51 occurring command »turn 0 °; photoelectric scanning on the tool)

hung from the program «(signal corresponding to L) is free, which is digital by a signal N corresponding to L

given what a tool rotation means. is reported back. The generator 5 is thus

So there are two operating modes that can be set. locked via the gate 43, and the motor 2 remains

The tool 1 can either be stopped by specifying one.

digital value are rotated by the program, if there is now an absolute setpoint at the comparator 6, which results in a fixed setting angle, or 35 (word A) is applied , which means that the angle of rotation 1 is automatically specified based on the angular position 0 ° of the movement is, the motor 2 starts running, speaking of the travel path of the tool 1 in which each step is counted by the counter 4, whereby the A'-K level. The actual value position is represented, which is compared with the setpoint value via the VerSoli from the program (8). As already mentioned above, the generator 5 runs for as long as the output signal of the indicates a program value to the inputs Γ, 2 ', 4' ... comparator 6 on the line 54, which via a specified, for example in values of OR stage 45 is connected to the generator 5, 1 to 95. The OR stage 49 with eight inputs corresponding to L is. The signal corresponding to L occurs (represented by the dashed line with eight as long as A 4 = B. If A = B, then there are also intersections) determines whether a signal corresponds to the output signal of the comparator 6 corresponding to 0, corresponding to L is present at the inputs and outputs the generator 5 is stopped and thus a signal L is then also sent to the gate 51. At the output of the motor 2.

Gate 48 occurs with entered values from 1 to 95. A new angular position can always give a signal corresponding to 0 from tool 1, which can be reached at the negated input of gate 51 by turning it to the right or left. At the output of this 50, the system works as a tangential control, so gate 51 occurs with a signal corresponding to L , the rotation of the tool takes place during its intervention through which the AND stages 50 are opened, whereby a continuous sequence of the so that the to the Inputs 1 ', 2', 4! ... pending rotary movement must be guaranteed. As a result of the information from the program (8) via the selection comparator 6 and the logic circuit 39, 40, the switch 7 is passed to the comparator 6. Even if the direction of rotation of the stepper motor 2 is determined in such a way that the tool 1 is moved, the program has priority from the starting position to the new position of the information, since the signal ent tool 1 always results in the smaller rotation path corresponding to 0 of the gate 48 the Gate 16 is locked and is placed. This also ensures that the signals P _t and c on the counter 18 we rotary drive continuously over the 360 ^c / 0 ° -SlelIung j are inoperative. ⁶ O runs away.

Should an automatic setting of the angle of rotation be used to determine the direction of rotation of the tool 1

take place (tangential control), then the difference between new and everything becomes a higher one

Value as 96 vmgegelicn (l> e.g. 98). This setpoint is used. If the new value is greater than

The program value is determined by the gate 48, the old value, so the direction of rotation is positive, and

and at its Auspanp a signal occurs corresponding to /. 65 vice versa. Assume that the tool

on, whereby the 1 «n 16 is released and the gate 51 is in the fourth quadrant and it should be in the first

is blocked. The output signal of the Lores48 quadrant, the direction must be positive,

bcwiil.l thus switching from »Tnngc-ntialslctic- although the difference is negative, since over the 360" / O ⁰ -

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Place the way must be taken. The criterion for this is that the difference between age and the new angular position is 180 °.

If the amount is <180 °, then the direction of rotation is of the tool according to the sign of the difference; if the amount is 180 °, the direction of rotation is dos tool opposite to the sign the difference.

The comparator 6 thus forms signals A> B and (A - B) <half (192) of the steps per revolution from which it is to be decided in which direction the motor 2 is to run. The decision is formed with the link 39. A memory element 40 is set by this, by means of which it is recorded whether it is to run forwards or backwards. Correspondingly, the counter 4 and the register 53 are driven by the output signals of the memory element 40.

As indicated above, when a signal corresponding to L is applied to input G (basic position of the system), tool 1 is to be brought into its zero position (angular position 0 °). Gate 43 outputs a signal corresponding to L as long as the "zero mark" (signal G) is not yet present (a signal corresponding to 0 is then present at input N). The signal corresponding to L of gate 43 causes generator 5 to be enabled and pulses Ps μ to reach register 53 and counter 4. Once the tool 1 has reached its zero position, the signal at the output of the gate 43 is correspondingly 0 and the generator 5 is blocked. The gate 44 clears the counter 30, namely once when the basic position is to be assumed, and secondly whenever the tool 1 runs over its zero mark.

Two frequencies are used to convert the analog quantities v _x , v "into digital setpoints for the stepper motor control. Once the frequency P _{1 of} the generator ί7, which is the Zämcffrefrequenz for the counter 18, and also the modulation frequency Γ for the analog quantities v _x , v _y . Counter frequency and modulation frequency have a certain fixed relationship. Since in the present case 384 units are assumed for one revolution of the tool 1 and one revolution of the tool 1 corresponds to one period of the modulation frequency Fm , the counter frequency must be exactly 38 * 4 times the modulation frequency. To use two generators, as shown in FIG. I is indicated

ίο results in difficulties because of the required Fre quenzstabilitüt. The ratio is now enforced because the modulation frequency Fm is derived from the square-wave frequency P ₁ . For this purpose, the square wave generator 17 is followed by a frequency converter 56, which has a ratio of 1: 191. This is followed by a further frequency converter 58, which can be designed as a two-stage number and is set in a ratio of 1: 2. .At its outputs 70, 71 two face each other

ao square-wave pulse phase-shifted by 90 °

follow with the frequency 1: 384. The one for you Modulation of the analog constant quantities necessary!

The phase shift takes place digitally.

The divider 56 can be a dual counter

»5 which counts to 192. The number 192 is 2 * + 2 ⁷ (64 (-128)

If the corresponding signals (Z.) turn off

went 72, 73 of the coaster 56, then dei Coasters 56 deleted via lines 74, 75

and at the exit of gate 57 a signal occurs

speaking L , which acts as an input signal on the counter 47 ·.

The two square-wave pulses, shifted by 90 °, follow the reducer 47 and go to the identical active bandpass filters 23/25 and 24/26, at their outputs

Sinusoidal alternating voltages Fn _1x , Fm » occur, the frequency of which is reduced to the frequency P _{1 of} the rectangular voltage unj of the generator 17 in the ratio 1: 384, as is also the case in the diagram according to FIG. 3, and the amplitudes of which are exactly gHch.

1 sheet of drawings

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Claims (9)

1 2 a logic circuit (39, 40) the stepper motor claims: control (3) controls such that the tool (1) from the initial position to the new 1. Arrangement for the automatic rotation of a position covers the smaller rotary path
movable element in the tangential direction 5 of the train to be driven, whereby by means of two controlled actuators a relative movement of Element and path plane takes place and the rotation
of the element by means of a third actuator The invention relates to an arrangement of the first-mentioned actuators derived from the analog for the automatic rotation of a movable EIe speed component of the element (tool, scanner or the like) in which the catch is influenced marked direction of the path to be driven, whereby by means of net that the speed components ( v _x , two controlled actuators a relative movement Vy) by means of an analog-digital converter (10 15 of the element and path level and the rotation up to 15) and one This counting of the element is influenced by a third actuator device (16 to 18) into an equivalent, which is converted from the control loops of the two numbers, the analog Ge control (3 to 6 ) one of the element (1) rotating speed components of the element influences stepping motor (2 ) acts. ao will. 2. Arrangement according to claim 1, characterized in that the analogue constant values ( \ _x , called, for example, numerically Yy) by means of modulators (10, 11) in alternating-controlled drawing systems are used. There are sizes (F ₁ , F _u ) with a 90 ° phase shift around different drawing tools, such as are set, which are added geometrically by means of a summing device 35 cutting knife for cutting plastic films, (12), and that by means of how they are used during manufacture The phase angle of the templates can be used by semiconductor masks of a circuit (14, 15). Furthermore, engraving stylus, with the resulting alternating size (Fr) compared to which any geometries in coated foils, reference white size (F _x or F _Mx ) can be digitally re-engraved. Finally, it is used for numeric sets. 30 controlled drawing systems also a light drawing head 3. Arrangement according to claim 1 and 2, characterized in that a light beam of a certain shape is characterized in that by de - circuit (14, 15) generated (magazine "Werkstatt und Betrieb", 101, at zero crossing of the reference variable (F _Mz ) 1968, 10, pp. 597 to 602). the counting device (18) for counting a pulse from the tool by means of a numerical one sequence (Pi) is enabled and, when the path control crosses any curve, any changing variable (Fr) that results is blocked. drive, it is necessary because: tool in the tan- 4. Arrangement according to claim 1 to 3, thereby rotating the gential direction. When using a cutting knife marked that from the counting pulse sequence (P _z ) , the cutting edge must point in the tangential with rectangular shape by means of reduction gauges (46, 47), and with an engraving stylus and active band passes (23 to 26) the 90 ° 4 »Whose cutting edge is always perpendicular to the tangent of the phase-shifted alternating modulation variables to be driven curve. With a light signal (Fiuz, F ₁ Uy) are derived. head must be the line of symmetry of the rectangular 5. Arrangement according to claim 1 to 4, characterized in that the light spot is aligned in the tangential direction, that on the stepping motor (2), otherwise the light spot on the via a selector switch (7) optionally from the 45 photosensitive material (film) generated line speed components (V _x , Vy) derived thickness depends on the angle at which the drawing is carried out or the number given by a program (8), ie the line thickness is not constant. values (A) act. So there is a requirement that the angle of rotation 6. Arrangement according to claim 1 to 5, characterized in that the tool is always the same as the path angle.
characterized that the equivalent numerical value 50 is already a tangential control with equal to the absolute setpoint of the angular position of the work current drive and sine-cosine potentiometers as tool (I). Angle encoder has been proposed (German patent 7. Arrangement according to claim 1 to 6, characterized in registration P 17 63 910.0). The tools are characterized by the fact that the engraving stylus and the cutting knife are used for setting the tool (1) and a digital setpoint value 55 The drive system and the sine-cosine-potentio-actual value comparison element (6) with an actual value counter meters take up a lot of space in the .Light sign head,! he (4) is provided, which the stepper motor (2) would also have to count from the light sign head or the controlling pulses (Psm) . other tools feedback signals to the control 8. Arrangement according to claim 1 to 7, characterized in that electronics are given, which is generally characterized in that the reference point (zero mark) 60 relatively long lines that connect the tool and control for the quasi-absolute setting of the angle electronics takes place. Here, the position of the tool (I) whose 0 ° position is, scattered interference voltages can occur which result in errors from which a signal (N) is derived, which is based on the object of the invention, an actual value counter (4) and the To create the tangential control, which has a lower stepping motor (2) controlling pulses (Psm), a technical effort than the one proposed and which works. in which sensitive feedback signals are avoided 9. Arrangement according to claim 1 to 8, characterized. It should also be possible that the element characterized in that the comparison element (6) with (tool or the like) both automatically in Abhandln-