DE1234065B - Method and device for following a curve with the aid of a beam guided along a small search circle along the curve - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

G06k

German class: 42 m 6 - 9/16

Number: 1234 065

File number: G 33991IX c / 42 m6

Filing date: January 11, 1962

Opened on: February 9, 1967

The invention relates to a method and a device for following a curve with the help of a beam guided along the curve on a small search circle, in which the when exceeded of the curve line derived by the beam intersection point impulses with the point in time the exceeding of the given instantaneous value of the deflection voltages of the search circuit generator in relation are set and in which from this relationship the displacement path of the search circle center determining values can be determined.

Devices for following curves which use an optical search circle which is automatically guided around the edge of any curve are known. The track of the search circle is relatively narrow compared to the curve followed, and the speed at which the circle is traversed is relatively high compared to the speed at which the circle moves along the unknown curve. Two intersections with the unknown curve are ideally combined when passing through the circle in order to generate an alternating voltage through a suitable filter. A function of this alternating voltage is then compared by a phase detector with the sine waves that generate the search circle, so that x and y speed components arise, through which the center of the search circle is moved in the direction in which the error between the search circle and the unknown curve and the DC voltages previously set determine the speed of the search circle moving along the curve.

Method and device for descendants of a curve with the help of a on a small search circle along the curve guided beam

Applicant:

General Electric Company, Schenectady, N.Y. (V. St. A.)

Representative:

Dr.-Ing. W. Reichel, patent attorney, Frankfurt / M., Parkstr. 13th

Named as inventor:

Leonard Gladstone Abraham Jr., BaUston Lake, N.Y. (V. St. A.)

Claimed priority:

V. St. v. America January 12, 1961 (82 211)

Can follow curves, run across the spaces in characters and unknown Follow curves either stepwise or continuously.

In the method of the type described at the outset, the intersection pulses are used according to the invention to sample that instantaneous value of the voltage of the search circle generator which determines the displacement path of the search circle center.
direction depends on the AC voltage signal that is applied to In one embodiment of the invention

the two points of intersection of the circle with the curve, the speed with which the curve is traced, and of the maintenance of the circle shape, by utilizing a single point of intersection. For the desired phase comparison in the known search circle curve with the unknown phase detector, at least a few rounds of the curve are required when moving the known search circle. So if the rotation along the unknown curve is increased considerably, frequency is 450 kHz, every time the search circle intersects the curve, a vector is generated along the curve that becomes a stored one satisfactory error voltage is generated. This vector is added, which reproduces the previous Ko-speed but cannot be increased indefinitely by 45 ordinates of the unknown curve. Only at will without reducing the accuracy of the intersection points of the circle with the direction selected for the follower. Curve, the coordinates Ax and Ay of the search

An object of the invention is a method according to which the circle is scanned and then to the previously stored one unknown curve is added faster than before to the next coordinates so that the center point is can be driven, as well as a device for 50 of the search circle in the direction of the intersection Implementation of this procedure. emotional. The search circle can move around a route

Furthermore, the device should move intersecting with the radius of the search circle.

709 508/148

is equivalent when the movement is triggered in the direction indicated by the amplifier 14 only to a holding member 16, intersection point. The speed of the beam applied to the scanner 15 scanning pulses A and B will lead along the unknown. The holding element 16 stores the signals from one and the angular frequency of the beam on the search circle which are transmitted from the curve, which is then only a function of the search circle radius amplifier 14. 5 Sampling time to the next. So if the with a device in which the size of the search scanner 15, the output signal of the amplifier 14 circle is the same as in the above-described input for a short period of time to the holding member 16 direction and the beam passes an angular frequency of, the value is this signal has a stop of 450 kHz, a tracking speed of member 16 can be stored up to the point in time at which approximately 450 m / sec can be achieved. The expression io the output signal of the amplifier 14 again - "curve" means either a line of lines which is scanned in, whereupon the holding element 16 receives and stores a new comparison with the diameter of the narrow search circle output signal of the amplifier 14, or the outline of a larger figure . chert. The signal emitted by the holding element 16

The invention is explained in more detail with the help of figures χ or the speed of the deflection span

explained. It shows 15 voltage χ in the x direction and is used in an integrator 17

F i g. 1 is a block diagram of an exemplary embodiment. The integrator 17 is thus from the lead of the invention, output signal of the holding member 16 actuated, integrated

F i g. 2 the search circuit, which in one execution constantly determines the output voltage χ and leads the

Example of the invention is used, integrated value of the adding circuit 9 as an additional

F i g. 3 is a circuit diagram to explain setup ao borrowed size,

functions for sampling, pulse storage and integration The channel via which an integrated signal is dem

grate, which in the embodiment of FIG. 1 y-deflection amplifier 8 is fed to the for

are used, and the ^ deflection is practically identical. The initial

F i g. 4 shows a circuit diagram of a blocking oscillator as well as signal r · cos Φ of the generator 13

25, whose input and output circuit amplifies an isolating amplifier 18 which has a Jy-Ab '

the embodiment of Fig. 1. Button 19 controls a holding member 20 in the

In the embodiment according to FIG. 1, pulses are supplied at an instant in which the curve to be traced on a transparent pulses A and B control the scanner 19. The body 1 is recorded, onto which a light beam 2 output signal y of the holding element 20 falls from an integrator 21 generated by a cathode ray tube 3 and then focussed in the adding system and by a lens system 4. The circuit 11 added to the y-deflection signal,
The function of integrating a lens system 6 onto a photomultiplier 5 channels, as described above, is to focus the light generated by the generator 13. The optical system generates a light search circle on the curve to be followed along the track to the curve 35 to be followed on the body 1. The adding circuits 9 and 11 add and excite the photomultiplier 5, the output of which the output signal stored for the center of the search circle changes sharply when the light track intersects the coordinates x, y vectorially to the radius of the search curve. Of course, a circle can also be used.

TV camera tube, e.g. an orthicon, vidicon. 2,

or iconoscope tube, a light trail at the un- 4 ° whose center is O , at points R and 5 in a

known curve. The reflective hatched area MN can also enter or exit this area

controlled light can be used. crosses the borders at points R, S, T and U.

The cathode ray supplying the light beam of a tape M, which is narrower than the diameter

tube 3 according to FIG. 1 works with two deflection- the search circle is,

strengthen 7 and 8 together, of which the first the 45 The crossing of the beam 2 shown on the body 1 in the horizontal direction and the second in a curve with the search circle is deflected from the photomultiplier vertical direction. The deflection amplifier 7 compartments 5 perceived. Its output signal contains its input signals from an adder, a proportional addition of the Δ and Δ y coordinates of the voltage source and the deflection amplifier 8 from a 5 ° circle to the entire x ~ and y-deflection voltage in adder circuit 11 and a potentiometer 12. The instant when the circle and curve of the potentiometer tap can cut into the middle position, for example. In order for the output signals of the generator to be set so that the light beam 2 initially scans approximately 13 in the desired manner, which falls in the center of the body 1. Photomultiplier 5 with an amplifier and

The ray of light! is then controlled so that it connects 55 amplitude limiter 22, which executes a circular movement, that is, an output signal of the photomultiplier 5 describes a rectangular search circle with a small diameter Ir , makes it shaped. The rectangular pulses are then their coordinate voltages Δ χ and Δ y from a generator 13 and adding circuits 9 and 11 in the input part of a trigger circuit 23.

are fed. The generator 13 expediently contains a rectangular, moderately an oscillator, one of which has a positive output pulse from the previously set output signal r-sin Φ of the adder circuit 9 and its duration as a function of the differentiated output signal r · cos Φ , generated for the first output signal. You can expediently output signal phase-shifted by 90 °, the adding a monostable multivibrator, in particular a circuit 11 is fed. The voltage r · sin Φ 65 contain Schmitt trigger. This positive pulse is also fed in an integrating channel via a separator to an arm of a three-pole switch 24 and amplifier 14 to an x-output designed as a "gate" to a double scaler 25, the blanker 15 of which is fed to the output signal of the past terminal another arm of the switch

24 is connected. The switch 24 optionally sends the signal from the trigger circuit 23, the double scaler 25 or a quadruple reducer 27 passed through to a blocking oscillator 26. Is to the input terminal of the blocking oscillator 26 is connected to a third arm of the switch 24, the in its first position the output terminal of the trigger circuit 23, in its second position the Output terminal of the two coaster 25 and in its third position the output terminal of the four coaster 27 connects. In the third position of the switch 24, the double coaster 25 controls the quadruple coaster 27, each of which expediently contain a bistable multivibrator, which emits an output pulse after every second input pulse. Thus can be selected from Intersections of the search circle with the curve recorded on the body an input signal are generated at the blocking oscillator 26. Optionally, only at every second or fourth intersection an input signal for the blocking oscillator can be generated.

According to one feature of the invention, the blocking oscillator 26, the dual coaster 25 and speak the quadruple scaler 27 only responds to positive pulse edges. The blocking transducer 26 consequently only works when the photomultiplier 5 has a transition of the light beam 2 from a relatively transparent to an opaque area on the body 1. If the diameter of the search circle is smaller than the width of the curve to be scanned or the extended curve Area is, an output pulse is then for the intersection of circle and curve from the blocking oscillator 26 generated when the circle enters the opaque area of the curve.

As can still be seen, the light beam following the curve then moves out of the position of the previous search circle in the direction of this intersection along the curve. With descendants the curve becomes the search circle counterclockwise around the intersected curve or figure moved around; in addition to this movement comes the turning movement on the search circle itself against the Clockwise added.

In certain cases, when the diameter of the search circle is larger than the line to be traced, you want to z. B. can neglect certain curve interfaces. On a road map you want to z. For example, neglect another unknown curve that the first one crosses at a motorway junction. If then the search circle diameter is larger than the motorway junction and the two- and four-way coasters are switched on, all cross lines or roads are neglected, so that one follows a single curve, although it is crossed by others. If the diameter of the search circle is larger than the width of the curve to be followed, the double coaster forms an aid to ensure the movement of the search circle along the curve in a predetermined direction. In this context, reference is made to FIG. 2, in which the search circle moves along the curve from O to a point P. Because of the double reducer 25, the blocking oscillator can only respond to the transition from light to dark at the S or U interface. When moving the search circle in the direction from O to P , the interface U can be switched off from light to dark with the aid of the two-step reducer 25, while at the interface 5 it is scanned and the signal is fed to the blocking oscillator 26.
The preferred device will now be explained, which ensures that the search circle consistently follows the curve. The blocking oscillator 26 contains a differentiating circuit which responds to the positive input pulses, and a device which, with the use of the input pulse, generates a sharp output pulse which is fed to an amplifier 28. The blocking oscillator 26 has a recovery time which can be set in advance and which slightly exceeds the period of time during which the search circle from the desired interface S to the undesired interface U is traversed. This recovery time can be set as a function of the angular velocity Φ on the search circle in such a way that the blocking oscillator 26 does not recover after a pulse has been emitted during a period of time which is slightly greater than the time required to traverse an angle of 180 °. The blocking oscillator 26 itself can thus be adjusted in such a way that the search circle consistently follows the curve in one direction. The amplifier 28 controlled by the output pulse of the blocking oscillator 26 generates positive and negative pulses A and B and feeds them to the scanners 15 and 19, from which the signals emitted by the search circle generator 13 are scanned or be allowed through.

As soon as interfaces are scanned from light to dark

the blocking oscillator 26 delivers sharp pulses which are broken down into simultaneous positive and negative pulses with the aid of the amplifier; these allow small sections of the sine or cosine oscillation emitted by the search circle generator 13 to pass through to the holding element 16 and 20, respectively. This then stores the sampled voltage up to the next intersection and feeds it to the integrator 17 or 21. In the adding circuits 9 and 11, to which the deflection signals for the search circle and the integrated deflection signals are fed, the deflection voltages x + Ax and y + Ay arise, from which the search circle is guided along the curve to be followed.

With the help of the holding elements 16 and 20, from which the incoming pulses are stored, the integrator 17 or 21 can be supplied with a relatively constant input voltage so that the movement of the search circle along the curve becomes uniform and, for certain purposes, the x or y Component appears to be flawless. The holding members 16 and 20 can also be omitted; however, the movement of the search circle and the output variables χ and y then change discontinuously by discrete individual values at each intersection. If analog output signals that change by discrete individual values are desired, this mode of operation can be used e.g. B. exploit for electronic calculating machines. Depending on the structure of the device according to the invention, a gray or black curve can also be traced on a white background.

The amplifier 14 contains an arithmetic amplifier 14 a, which is preferably designed as a direct current amplifier with a high gain and strong negative feedback. The computing amplifier 14 a, whose input variable is sin Φ, controls a cathode

stronger stage 14 &, whose output resistance is fed to the control of the as a bridge circuit of diodes on terminals A and B for the duration of the positive and negative key pulse and whose built-in zfx scanner 15 is low. The bridge duration is usually very short, the voltage sin Φ circuit scanner has an input terminal 29 and the capacitor 37 and in this an output terminal 30, between the diodes 31-32 5 stores. After the scanning process, the remains off and 33-34 are switched off. Two diodes 31-32 are sampled voltage values of sin Φ in the capacitor so that their cathodes are stored with the input 37, because both diodes 32 and 34 are blocked and output terminals are connected, while at and the input 39 of the amplifier 40 very much other two, 33-34, the anodes with the one is high resistance.

input and output terminals are connected. The computational amplifier 40 is a difference Clamps of bridge 35 and 36, each with a stronger DC amplifier at the junction of two diodes arranged high gain, the one input 39 for positive are also located at the tap of a span and an input 41 for negative signals voltage divider. and is designed so that the signal at the output

One end of the voltage associated with terminal 35 of the amplifier in phase with the positive one-way divider is due to a relatively high output signal and a negative voltage to the negative input signal. The opposite end is 180 ° out of phase. A feedback from this voltage divider provides the control or key circuit 43 ensures a high input input, which is also denoted by A according to this applied resistance and a slight drift of the arithmetic key pulse A. ao stronger when the circuit 43 between output

One end of the voltage 42 and input 41 assigned to the terminal 36 is connected, but the voltage divider is at a relatively high input 39 a higher input resistance on positive Tension. The opposite end faces.

This voltage divider represents the other key input. An arithmetic amplifier 44, which receives its input signal

gang, which is labeled B accordingly. A 25 received from the amplifier 40, supplies an output signal circuit with a large time constant, which contains the parallel with correct phase, which is a measure for the x-compo circuit of a capacitor 37 and a high nente of the speed ώ of the movement of the search resistor 38, is between the starting circle along the curve to be followed. terminal 30 of the bridge and ground and the output of amplifier 40 is also

provides an input signal to an integrator 17 only positive 30, e.g. B. a Miller integrator, Input signals responsive terminal 39 of a supplied, the output of which is connected to the resistor 45 Computing amplifier 40 is connected to the very high input of the adder 9. impedance. The integrator 17 serves to successively

The bridge circuit of the Δ x sampler 15 switches sampled values of sin Φ to integrate and the signal from the course of the output voltage sin Φ of the integral for addition with sin Φ itself, which is fed via amplifier 14 sampled instantaneous values to the resistor 46, the adding input output terminal 30 of the bridge in the presence of direction 9. A third resistor 47 is applied between ground and the output ends of the resistors at terminals A and B, respectively, of appropriate positive and negative duty cycle. The capacitor stands 45 and 46 as well as the terminal χ + A χ connected 37 charges to the respective sampled value to 40 tet in order to complete the adder circuit. The signal sin Φ through the resistor 46 at the next sampling time therefore essentially retains this charge value until halfway. a small search circle coordinate voltage to the

In the absence of a tactile pulse at the terminal χ + A χ, while the output signal of the men A and B ensure the negative and positive integrator 17 via the resistor 45 the mean voltages, which via the voltage divider the 45 point of the search circuit on the traced Terminals 35 and 36 are supplied that all curve leads and further serves to completely block the search circuit bridge diodes, because then after each scanning operation of the scanner 15 in the each diode is biased with a high voltage in the reverse direction resulting from the scanning operation . In the presence of a comparative move along the curve. The time constant positive voltage from amplifier 28 (in 50 or the effective gain of integrator 17 is Fig. 1), which is fed to terminals A and B , adjusted so that the search circuit during each so that terminal A is positive and the terminal B sampling period is negative by as much as its radius, however, the diodes 31 and 33 may shift face value.

conduct and limit the potential of the terminals 35 F i g. 4 shows a schematic circuit diagram of the

or 36 such that the terminal 35 is non-positive 55 blocking oscillator 26 of FIG. 1 together with one and the terminal 36 not more negative than the output-related circuit. The anode of the input voltage sin Φ of the low-resistance cathode tube 48 is parallel to the anode circuit of the blocking amplifier 14 b . The resistance of the vibrator tube 59 so that a positive input voltage divider is applied between terminals 35, 36 and the pulse from switch 24 (FIG. 1) which is greater than the resistor 60 terminal 49 which is the input bias voltage source correct polarity between the terminals 35,36 and the respective seated in order to trigger a positive output pulse at the upper key input A or B. The diodes 32 and 34 supply the end of the output winding 50. A similarly current to the output terminal 30 like input pulse to terminal 49 from either direction of opposite polarity generates a feedback oscillation across the anode because diode 32 does not allow terminal 30 to 65 winding 51 and grid winding 52 which are more negative than the voltage becomes sin Φ , and the diode feedback transformer of the blocking oscillator does not allow the terminal 30 to be more positive than that. Such an oscillation immediately loads a voltage sin Φ becomes. Therefore, during the capacitors 53 on and switches the blocking

vibrator in the usual way by a bias. A positive output pulse goes through the diode 54 and controls the power amplifier 28 through, so that this simultaneously generates a positive and a negative sampling pulse A and B with high power at its output in order to control the samplers 16 and 19 through. The time constant of the grid capacitor 53 in the blocking oscillator and the associated resistors 54, 55 and 56 of the lattice circle can be selected so that the blocking oscillator responds, for example, during at least 180 ° of the rotation of beam 2 on the search circle and not to input pulses at the terminal, to avoid ambiguous To disable intersections along a curve that is narrower than the diameter of the search circle.

Claims (14)

Patent claims: 1. Procedure for following a curve with the aid of a beam guided along the curve on a small search circle, in which the intersection pulses derived from the beam when the curve is crossed are related to the instantaneous value of the deflection voltages of the search circle generator at the point in time when they are exceeded This relationship determines the values determining the displacement path of the search circle center, characterized in that the intersection pulses are used to sample the instantaneous value (sin Φ, cos Φ) of the voltage of the search circle generator which defines the displacement path (Δ y, Δ y) of the search circle center. 2. The method according to claim 1, characterized in that those intersection pulses are suppressed before scanning, which increases after differentiation into the negative Have pulse edges. 3. The method according to claim 1 or 2, characterized in that those intersection pulses are suppressed, their time interval from the previous intersection pulse less than that required to run through an angular distance of 180 ° on the search circle Time is. 4. The method according to claims 1 to 3, characterized in that every second intersection pulse is automatically suppressed. 5. The method according to claims 1 to 3, characterized in that every fourth intersection pulse is automatically suppressed. 6. The method according to claims 1 to 5, characterized in that the scanned Instantaneous value of the voltage of the search circuit generator is stored until the the next intersection pulse triggers the scanning. 7. The method according to claim 6, characterized in that the scanned and stored Voltage value of the search circuit generator before the addition with the one coordinate of the center of the search circle is integrated over time. 8. Apparatus for carrying out the method according to claim 1 with a cathode ray tube and associated deflection circuits for deflecting the cathode ray to be tracked to the curve in an x and y direction, a search circle generator for generating sine and cosine voltages, which to form a search circle the x- and y-deflection voltages are superimposed, a photoelectric converter which generates intersection pulses when the curve to be traced is intersected by the search circle, and a circuit for supplying correction variables moving the center of the search circle along the curve to be traced to the deflection circuits of the cathode ray tube, characterized in that parallel to a line that runs from the search circuit generator (13) directly to an adder circuit (9, 11) connected upstream of the respective beam deflection amplifier (7, 8), a scanner (15, 19) designed as a "gate" is located whose key input (A, B) at which the intersection impulses delivering n device (5, 22, 23, 26, 28) is connected. 9. Apparatus according to claim 8, characterized in that between the photomultiplier (5) and the scanner (15, 19) a trigger circuit (23) is connected, which has a differentiating Includes input circuit. 10. Apparatus according to claim 9, characterized in that between the trigger circuit (23) and the scanner (15, 19) has a blocking oscillator (26), the blocking duration of which is after the last Input pulse corresponds to at least half a revolution of the beam on the search circle. 11. The device according to claim 10, characterized in that the output pulses of the Blocking oscillator (26) are needle pulses. 12. Device according to claims 8 to 11, characterized in that between the Photomultiplier (5) and the scanner (15, 19) one or more multiple coasters (27, 25) lie. 13. Device according to claims 8 to 12, characterized in that immediately on Key input of the scanner (15, 19) a device (28) is connected, which from each intersection pulse two identical pulse pulses, but of opposite polarity generated. 14. The device according to claim 8, characterized in that between the output of the Sampler (15, 19) and the adding circuit (9, 11) a sampled instantaneous value to for scanning the next storage element (16, 20) and, if necessary, an integrator (17, 21) are switched on in series. Considered publications:
French patent specification No. 1185152. 1 sheet of drawings 709 508/148 1.67 ι Bundesdruckerei Berlin