DE2029834C - Photoelectric measuring device for determining adjustment movements of a movable object in relation to a fixed reference system - Google Patents

Description

2 02S 834

> If one adjusts movements of a solid body, the corresponding supplies of the two sputea

4lsFunMon of forces acting on Om Study time by a quarter of this period against each otherecr

i% n will, for example, shifted by aerodynamic force. . ...

It can be advantageous to use the reference position of this For an important user

i object not through, mechanical connections, 5 finding carries the FesÖröiper, whose mogl ^ e ««

"but through a magnetic suspension you have three degrees of freedom, three pesti

, iR_ ^ Jh _n «>. ~ "Λγ-_ -_i_it t Γ * · , ____ *. j; _: ..... η _π mruxr imn Hn »I en!

probes have three degrees of freedom fixed by a magnetic suspension,

gain. Means for the realization of a solrange, each one of three M ^

Chen magnetic suspension and, for example, measuring devices and, uod those of

in the French patent specification 1104494 from the Sen facilities carried out "elektris

in the French patent specification 1104494 from sen facilities erfcaliene »elektnscnen _- ^ - ti. May 195 * and in the additional patents a70314 and to are combined to obtain other signals, 72054 of April 21, 1955 and June 7, 1957 be which represent the parameters that the augeo- ι

wrote. It is also known that it is possible to designate or emen the position of the object in view Magnetic suspension devices corresponding to the position correction mechanism,

is used for signals that control the displacement cbend of the other signals mentioned. ;

of an object compared to a fixed position. 15 Details about the invention emerge from

tion measure, so auzubüden that the object automatically the following description in connection with mn table returned to this position wildly. the drawing, in which various rounds

The examples on which the present invention is based are shown. In detail shows The task is, in a technically advanced figure, a purely block diagram showing the main

Compared to known devices, a one-way structure of a built according to the invention inside ^

to create direction that makes it possible to present the size of the direction, ■ ■ · a

Adjustment of an object both with regard to FIG. 2 is a preferred embodiment of the

Rotary movement as well as a rectilinear device with an optical fixed marking that gen movement. Each fixed part is supported by the object and its adjustments marking three coordinates, two of which are to be measured,

Represent translations and the third a rotation F i g. ^ Another possible embodiment

represents. As can be seen from the following explanations of an optical fixed marking, it is also possible, with the aid of FIG. 4, to create a diagram that shows the path, * ^ε Jj * ""

of three fixed marks and three corresponding rend the distraction from the electronic image of the photoelectronic devices the dimensions of three 30 optical fixed marking opposite the central one Translation coordinates and is traversed by three Rotationswin- opening of the disc, which this not to receive, which receives the various possible electronic images, and also the adjustments of an object that shows six draws of freedom that take place between the adjustments has to fully define spaces in the space. of this image exist, depending on whether the 1 Jrestmar-

In the following it is assumed that the observation is in its rest position, which is also the reference point Misalignments - translations and rotations are called, or -ie by translation unu / functions - relatively small amplitudes after both sides or by rotation with respect to this reference position ten from a reference position in which it is adjusted, .11 · oi

three right-angled axes connected to the object. 5 shows an overall graphical representation with three fixed axes in space together with ₄ ° rather the change in the deflection currents than ™ ηκηοη fall, which is plotted against the time associated with the measuring device, which are the ^oils " ^KS P" ^ie "° These three last-mentioned axes and 7 run through, and the corresponding analysis plays one of two, which is shown below as sights of the output current, ^ which is referred to by aer roiuachse, the role of a main axis of the electron multiplier tube 4 {V 1 g 1 ) & ψ ™ device and is hereinafter referred to as "axis Z" 45 when the ν. η of these tubes received optiscne, while the other two axes as the image of the fixed marking in its reference position , oaev "axis A-" and "axis Y < . In a .yerscho- opposite this reference position.

The task set is according to the invention with benen position. Part of the F1 g. 2i a · * »J" ™ · a photoelectric measuring device of the initially named Ve ™ na> r ^^ Bra mentioned Art solved in that the deflection 50 th can una the adjusting elements of this book to determine the facility from two of these fixed markings that are perpendicular to each other, There is deflection units with separate, opposite- F i g. 6 a schematic diagram of a simple analog

phase-shifted signals delivering the computer based on the curves of the h 1 g.ο distraction signals are connected. allows to characterize the values of this adjustment

To maintain the deflection device with the two large sicrants,

steering units is expediently used so that the F i g. 7 is a perspective view; one to

Electron beam creates a closed curve in the form of the invention on a movable object of a rectangle, in particular a square, which has six degrees of freedom and, ηώ: threeiF «J-writes .fixed devices which generate orthogonal magnetic fields, each of which is assigned 60 regions in space, ^the lines of these coils being perpendicular to one another during each of the four quarters and forming the axis of a scanning period successively through one, each of these ^ n> n Bnnhung current is fed which is assigned according to a linear time according to the invention for determining the adjustment function from a minimum value to a maximum. ._....,. _{hiKrh Hp} .. _en value grows, then constantly at the maximum value 65 From F1 g. 1 is em object 1 he ^^ ¹ ^ '. ^^ ,. remains, then measured according to the same linear radio position. et ^{and no} ™ ^al ^ 2 · finally remains at the minimum value. In the rest position of the object I _1, a main axis is

2029I & 34

that of this object, an optical system 3 (symbolically represented by a lens) and a photoelectron multiplier tube 4 is common.

The object 1 has an optical fixed marking 2 on an exactly flat surface which, when the object is in the "rest position" is perpendicular to the axis .Z and thus also to the plane of the drawing, an optical fixed marking 2, the appearance of which, viewed in the direction Z, is shown in FIG . 2 is shown. This fixed marking has two axes X _x and V ₁ which run perpendicular to one another and which coincide in the rest position of the object 1 with two fixed axes X and Y which also run perpendicular to one another and whose plane is directed perpendicular to the Z direction. One can assume, for example, that the X axis runs perpendicular to the plane of the drawing and the} 'axis runs in the plane of the drawing, as shown in FIG. 1 is shown.

F i g. 2 shows a preferred embodiment of the fixed marking 2, which consists of two black squares and two white squares which alternate in the circumferential direction and are separated from one another by the axes X _x and Y _x.

F i g. 3 shows a modified form of the fixed marking carried by the object 1, which here consists of two consists of narrow black and mutually perpendicular stripes on a white background. The fixed marker could also consist of two perpendicular to each other on a black background running white stripes.

In the device according to FIG. 1, the optical image of the fixed marking 2 is imaged by the optical system 3 on the photocathode of the photoelectron multiplier tube 4. As has already been mentioned, suitable electronic optics form an electronic image on a conductive disk contained in the multiplier tube 4 as a representation of this optical image. This disk carries a small, preferably centrally arranged opening. Under the action of the control currents which flow through the deflection coils 6 and 7, which are inductively coupled to the tube 4 and which are periodically supplied by a control signal generator 5, the entirety of the electron beams which generate the electronic image in the multiplier tube is alternately in the direction X and in deflected in the Y direction. There is therefore a shift in the electronic image with respect to the pane. Consequently, at the cockroach's mouth, the transitions from a "white" zone to a "black" zone of the image result in a sudden change in the current received by the AoS input electrode 13 of the multiplier tube 4, and these transitions take place in time transmissions which, on the one hand, are caused by the Distraction, on the other hand caused by the displacement of the object 1 from its rest position, if such a displacement exists,

The comparison computer 8 receives, on the one hand, the

electrical voltages that .at the terminals of the Impedance 14 can be generated by the currents emanating from, the electrode 13, and on the other hand Via the connection 9 comparison signals which are supplied directly by the control signal generator 5 or from it

ίο be derived. These comparison signals have the Property that they occur at fixed time intervals during each deflection period. In return in addition to the comparison signals, the signals emanating from the output electrode 13 appear at times which corresponds to the displacement of the electronic image and consequently to the displacement of the optical image of the fixed marking 2 and the object 1 are variable. The resulting Comparison signalsc appear at the output

ao gangways 10, 11 and 12 of the comparison computer 8 and are - if necessary after a suitable deformation - given to a working group. In Fig. 4, X _n and Y ₀ denote the right-angled axes of the fixed directions which

as run parallel to the axes X and Y and are linked to the electronic image of the fixed marking, which is depicted on the disk, the central opening of which is at point O, the center of the square P ₀ . P _? , P ₁ , P ₉ is located. The axes X ₀ and Y ₀ intersect

the one at point C ₀ , which - when the fixed marking is in the reference position - moves at constant speed on the circumference of the square.

If, on the other hand, the fixed marking from the reference

position is shifted, the point C ₀ moves to C ₁ , and the axes X _n and Y ₀ shift to X ₁ 'X _x and Y ₁ ¹ Y ₁ - The adjustment is due to the right-angled coordinate values χ and y of C ₁ opposite the axes X ₀ and Y ₀ and through the win-

kel / 4, marked between X _x X ₁ and X ₀ . The centers of the sides of the square P ₀ , P _? , P., P ₆ , in the middle of which the opening of the disk is located at point O, _{are denoted by P 1} , P ₃ , P. and P ₇ . With T is the period of a complete reading

kung around the square and with i ₀ the moment in which, in the absence of an adjustment of the fixed marking, the point C ₀ passes the point P _n. If one assumes as "black" those squares that are on the one hand between JL and F ₁ oad

if, on the other hand, between X ₁ ' and F / beMden, and the other two squares are assumed to be "white", there is a transition of opening 0 from a white zone to a black zone (or vice versa):

at the moment fj = ^ + (βτί ^, ϊπΙ *,) νοΐ white narih Sdrasttz;

37 *
hn moment t, = J ₀ + (fiif € “in P ₅ ) from Schwarz to Weffi;

at the moment C ₅ = * <, + - (for C ^ in P ₈ J from white to black;

in the case of tL = t ₀ ^ {for C ,, in P ₁ ) from black to white.

T 2O2S834 U
7 8

This means that the output electrode 13, _

of the photoelectron multiplier tube 4 (Fl g. 1) ge _t '- ^ 4. ± _ (* -L ¹ Z. I + tgi4,),

delivered electricity in the mentioned moments of 8 \ I I.

a constant maximum value / _{0 changes} to a minimum value or vice versa. S, T / - xtgi4, + y \

Now, when the solid marking by the GroE ^l i "* 7 * ΓI j + ^A 11 · .y. Ben x, y, A ₁ , as defined above, a * J \)

has experienced certain adulteration, one gets through

the easy calculation that the corresponding over- where I half the side length of the above mentioned takes place at the following times: io th square.

On the other hand, from FIG. 4 also shows that T IyIgA. - χ \ at the fixed points in time / ₀ , f ₂ , f ₄ and ί _β , in

f / = fj + - I + tg / 4j J, where C ₀ , the center of the non-obscured image,

⁸ V '' _{passes through points P 0} , P ₂ , P ₄ and P ₆ , the open

T i xXe.A + y \ ^{15 now} S ^ each in a white, black, white

f _s ' = r, - \ —I —-— <Mg / 4,], or black area. So you can

8 \ I I. to write:

8 ^X ""'12)

So if you have electrical voltages V ₀ , V _b , F i g. 1 run through. As can be seen, this V change _c and V _d with amplitudes etiialten can, which corresponds ₃₅ currents during a quarter period linearly from a speaking proportional sizes (1 + a), (1 + b), the maximum negative starch - I _b up to an equal (1 + c) and (1 + d) are, it will be possible from maximum positive strength + I _b . Then they change the solution of the obtained from an analog computer in the opposite direction, and the time intervals, where system (2) receives the quantities x, y and XgA ₁ TM . rend which these changes occur, depending-Man are immediately sees the way that _4O wefls by Viertdperioden separated from each other in

which the current maintains a constant strength

XgA ₁ = (fl * - 6) / 2 / (3) (the horizontal sections of the curve). The curve

56 is a quarter period from the curve

and that the four values a, b, c, d are not shifted independently 5 a. The control currents, as they are represented by each other, but with each other the relationship _K curves 5 a and 5 b , can have by means of: * known devices are obtained that are not

fall under the present invention.

{a + 6) = (c + d) . (4) Curve 5 ο shows the current / that is supplied by the photo

Electron multiplier tube 4 (Fig. 1) obtained

Is prior to the description of a simple analog ₅ "when the hard mark and its optical image computer, the ac determining the distance y, and% A _x in the reference position (rest position) are, from the bets of the electrical voltages V _4n V _1n if x = y = tgA _t = O. The current of ^ o Vd proportional to (1 + α), (1 + b), (1 + c), pipes thus changes between a minimum O (1 + if) allowed, is first shown how to get this and a Maximum / ₀ with half the deflection voltages can be obtained. ^ ₅ period T / 2.

Fig. S shows various curves as functions. Curve 5a * shows the change in curve Sc,

the time t, which occurs when a, b, c and d are changed as a result of an adjustment of electrical quantities which are not more or less equal to zero during operation of a long picture. In the fig. 1 occur, at the moment the transitions from black occur over a deflection period T. ^ to white or from white to black no more

The time scale selected in Fig. 5 has its za the times f ,, t _t , I ₅ , L ₃ , but to the time origin at the time ^, the points defined above i, \ i _s ', / ₅ ', t, ' which has become opposite to the fore. The period T is subdivided into eight identical points in time by (aTVS), {bT / S), {cTß) sections, and the division points are shifted or (oT / 8). Here one has t _v I _x , ig, I ₄ , ig, l ^, t ,. The final point is _Ss simplification wQIkSrSch assumed that a, b, c, the time mark I ₉ . Curves 5e and Sb show that and d are all positive, but this is in no way a function of time as the tax changes - a necessary requirement. The quantities α, b, c atoms which the vertical deflection coil 6 and the and d can assume any wager, advance horizontal deflection coil 7 according to the device provided that equation (4) remains satisfied.

209686/408

In order from the sequence of Si shown in FIG. 5 When the voltages V _a, K _6. V _e and V _d with signals corresponding to the values (1 + α), (1 + b), (1 + c), the values (l-fä) can be taken from proportional voltages. K. (l + q). the procedure is as follows: · V (I + b) One generates four electrical calibration voltages with the ^K o I ¹ + ^c h period T in the control signal generator 5 of the circuit 5 ° "^ ¹ according to FIG K ₀ (II-ti), curve Se. These voltages are over ... ... "., Three quarters of the period Γ equal to zero and take, where K _{0 is} a constant voltage, during the period 774 usually the value one io is used to derive the values of (xlt), (y //), ig A _x . In Fig. 5, only that of these voltages is drawn,,,, Curve Sd of a For this purpose, three of these voltages are applied proportionally to the signal (1 + a) . The other values are calibrated because of the above equation ren calibration voltages, which are not shown here, ( ⁴ ) are not independent] three corresponding ones have the same waveform as the curve Se, but i _{S are} inputs of the analog arithmetic shown in FIG r this curve by a quarter of the circuit. This circuit is in the comparison period T, by a half period T 2 and by three computers 8 of FIG. 1 included. A quarter of the period T is shifted accordingly. One shifts to this same circuit. constant voltage with the magnitude (- K ₀ ).

It can be seen that a logic circuit - ao In F i g. 6, the switching means designated S

For example, a circular addition stage contained in the comparison computer 8 and those designated by M

■ AND circuit - on whose inputs the stages of multiplication by circuits. The in F i g. 6 dar-

5t and Se shown signals are given, the circuit shown also has a polarity

Via the connection 9 from the control signal generator 5 reversing stage INV . The circuit of FIG. 6

(Pig. 1) are obtained, at its output a Si a _S J ^ert ' ^based on the voltages K ", K ₆ , V _d and

gnal delivers the waveform of curve 5 / with (. ^v oh ^d) e values (* //), (y / i) and tg ^ ,, which are sought

a constant amplitude A ₀ and a duration, or rather electrical voltages, which the

(f / - / _H ) has. The time integration of the output last-mentioned quantity with the same coefficient

signals of the AND gate supply dnc voltage pensions k proportionally said. These last mentioned

with the quantity K ", which is proportional (1 -f a) , the 30 voltages are applied to terminals 61, 62 and 63

stored and at the end of each period T obtained while the voltages K ₀ , K ₆ , V _d (K ₀ )

by an impulse of short duration (also from the »n the terminal correspondingly designated in Fig. 6

Encoder 5 derived) is reset to zero. The ^{men ele} g g ^l. Waveform is shown by the curve 5g, and of ^course, other Analogrechen-

Its maximum amplitude is used during most of the 35 circuits, which are the same

the period T held in memory. Results based on three different

It is easy to see that an amplitude ^{span of the} sizes K 1, K ₆ , K _f , V _{d is provided} .

voltage V _a proportional (1 f d) by similar means.

Can be maintained by applying a calibration voltage to the above devices

same waveform again curve 5 e is used, the 40 detection of displacements of a solid

however, wrote the value one between the times r _e , which has six degrees of freedom, for example

and t _H occupies. an aerodynamic model known by

In contrast, a slightly different means in magnetic suspension must be used in a Procedures are used to keep the tensions K ₆ sochskanal; of a model whose

and V _r to get the proportional (1 + b) and 45 position to be measured electrically to the

(1 { c) are to be checked, ie during the times (r ₄ - ί, Ο and control of a correction device, with

(/ _e i _s ') occur. If the curves Sd and which the ^ model are kept in a reference position

If you compare 5 g with each other, you can see that each of the .den should and at the same time by measuring the

Voltages K ₆ and V _c through the use of one provided by this latter device _F , ^ circuit "Exclusive-OR" will get 50 values to capture the forces acting on this model

f | to which the signal 5 <f and one of the calibration voltages under the effect of a given flowing current

S? act gea with a wave mes corresponding to the curve Se.

§§ be entered shape, but the amplitude in Fig. 7 is shown the model 71, the ^ä "Section One in the voltage between the K _6, not shown here by Male! Inside the Man-Zeitpuakten tj and _t i or For the voltage V _c between 55 and 72 of an experiment & anak ηώ the axis X _n meshes the times / _s and ^ occurs. There is therefore gnetically suspended. The mode 71 can combine a large number of different logical switching stages in the direction of three fixed circles, which are the same results Gefern can, and perpendicular to each other geo- U. length voltages V "F _6, V _e and V ₄ aas a signal bit axis X _n, Y _n and Z ₀ run, the SD, the Pig. S and EScnspannungeü as Se, in &"normally m emem Ptmktnn inside this Mopassender, the RuhesteSüng the model of phase. One can defls cut. Ia, for example, this" aND NICHTc circuits the axes Y _n and length by the Use of funds a. Due to the time points of the three fixed rules 73, 74 and 75, the derivatives of the AMsu rs Sa and 56 are easily attached to the surface of the model Tt, "old" graze or wetaehr aas this lead- "5 ßfc fixed marking 73 is the axis Y _n assigned, ttmgen with changed sign. It is therefore that forms your line of sight, and the fixed markings appear, they are attached to the Stcoersignali9. * CT 5 (Fig. 1) zn? 4 and 75 are the axes Z _n am! (- - Z ₀ ) with eia- ■ - * ■ - · * - other opposite directions / ugconlnrt that

also form their lines of sight. Each of these mentioned Line of sight is a unit consisting of a lens and an optical electron multiplier (81, '82), (83, 84) or (85, 86) assigned. Each of these units is equipped with deflectors, comparison stages, and calculators, such as organs 5, 6, 7, 8 in F i g. 1, connected.

In the rest position 71, the planes of the fixed markings 73, 74, 75 (or rather the planes tangential thereto if the model surface is curved) are exactly perpendicular to the axes Y ₉ , Z ₀ . (Z ₀ ). The angular deviations of the model 71 from its rest position are assumed to be small, so that the cosine of this angle remains in the vicinity of one during operation, and the displaced position of the fixed markings 73, 74, 75 can be equated with those positions that result from a corresponding translation (je, Y ₁ ), x _t y ,, x, V ₈ ) can be obtained in the aforementioned planes of rest and by corresponding rotations through the angles A _x , A ₂ , A ₃ in the same planes.

If the model now moves out of its rest position, computation organs which correspond to the organs shown in FIG. 6 and are assigned to the axes Y ₀ , Z ₀ (- Z ₀ ), supply corresponding values for the quantities (x, y,), (x _t yj, (x, y,) and A ₁ , A ₁ and A _3. By means of a known computing device which is not part of the invention, it is possible, from the above-mentioned values, which by the way are not independent of one another, derive the values of any six parameters which, in the form of electrical signals, express the displacement of the model 71 with respect to its rest position which cause the model to be magnetically suspended, in the form of coils that are normally inserted into the jacket 72.

The advantages of a system according to the invention will be even better understood when one considers draws that it has no mechanical commutator at all !, which is especially true for the deflection devices acting on the electron beam of the photomultiplier tube Meaning is. It can therefore easily be a deflection at relatively high frequencies, for example at Realize 500 Hz. Incidentally, the deflection frequency is only determined by the inherent capacitance of the deflection coils 5.6 in FIG. 1 limited.

Further advantages of the invention are that the system in the, for example, from FIG. 7 can be seen Application form no electrical interaction between the devices for the magnetic Suspension and the measuring devices and that it is no longer necessary to make corrections the functions for the shape or volume of the 'solid body to provide its adjustment

ao or behavioral characteristics in a flowing stream one wants to study.

A system according to the invention also has the advantage in the same field of application that it does not have any elements that would match the free

The space between the shell 72 and the object 71 (Fig. 7).

Finally, it must also be mentioned that the deflection organs that act on the electron beam are a or multiple multiplier tubes acting could also cause a circular deflection, though one in. the present description stcta has assumed that the deflecting organs are influenced so that they cause a deflection accordingly create a square (or a rectangle). Such a deflection, however, would require devices that are less simple in structure than those described above in order to generate suitable output currents to achieve these tubes. For this reason, a square deflection is also preferred Solution has been chosen.

For this purpose 2 sheets of drawings

Claims (3)

Λ 2 029 §34 During the Einpchtmg sr eäienfaUs . i '·. Claims; Wise Vomclitimgejiwei ^ nde ^ inn the op
\: ' . . ^ nes or several of these FesrmarJaerungen on the t ^: LFptoelrtiaseheMeßeiniMnting zurBestim- Fbiokatnode a suitable photoelectron measurement of the understanding movements of a with at least S multiple tube. These pipes "eist" at least one of two connections to each other vedac- fötoelectric device in order to opti-; Fending axes and areas differently see Bfld an efc * tronic B ^ to file down, the ^ brightness-exhibiting fixed margin «is formed on an electrically conductive screen« », the« flat, movable object has an opening opposite one through which a narrower fixed one Reference system, consisting of a number of photographic markings corresponding to the elementary electron beam that can pass through, which forms part of the entire beam, which, on electrical to shape. The intensity of this elementary beam multiple tubes, in which a disk net a depends on the electron flow that falls on the disk certain opening tin passage of a part 15 at the location of the opening, and consequently that of the electron beam is provided, iemer with brightness of the optical image in that point, upstream optics as well as nacngeschalretem whose electronic Bfld is formed at this point. Amplifier and a section of the photoelectron multiplier tube that influences the electron beam above the disc and that is connected to a periodically transmitted electric current, amplified in the amplifying signal generator, is picked up on the steering device and one of the deflection signals - an output electrode of this tube controlled evaluation device, there and forms at the terminals of an electrical circuit, characterized in that the deflection electrode connected to an electrical Sikungseinrichtung from two perpendicular signals, the size of which consists of the strength of this current acting on deflection units, which are connected to. separated, mutually phase-shifted Si The shape of the electronic image is gnale delivering outputs of the deflection mer is determined in a known manner by the signal transmitter are connected. Completion of electron beams with the help of suitable 2. Device according to claim I, thereby applied magnetic fields of a lateral deflection indicates that the object is subjected to three fixed marks 30, with the effect that at this carries and that three correspondingly assigned opening the cross section of the entirety of the Elekfotoelek Irish multiplier tubes provided electron beam can be detected. are that with a common revaluation device with which the above-mentioned .direction are connected. the most important principles are 3. Device according to claim 2, characterized in the French patent 1 501 457 that the common evaluation input from ? 2. November 1966. In this device with a device for Posirionskor- directions carries the object whose adjustment movement correction is connected to the object. gen one wants to study, festival marks that out alternating black and white sections 40 exist, and the deflection of electron beams is effected by alternately and periodically subjecting these rays to two deflections, the after The invention relates to a photoelectric measuring device at right angles to each other and parallel to the plane direction for determining adjustment movements of the fixed marking running directions in a one with at least one two planes at right angles to each other, which are themselves exactly perpendicular to the mid-point running axes and areas of different direction of the entirety of the rays in their Licher brightness having fixed marking runs in the rest position. Within the sampling period the moving object seen in relation to one is the time interval, measured in relation to one another fixed reference system, consisting of a fixed point in time of this period between markings corresponding to the number of photoelectric, 50 points in time at which sudden changes occur Conversion of the optical image into an elec- tration of the size of the signal that is generated in the niche information serving multiplier tubes, in with the output electrode of the photoelectron verdenes a disk with a certain opening multiple tube connected working group receiver a measure of the displacement of the electron beam is provided for the passage of part of the electron beam is, furthermore with upstream optics as well as 55 see image and consequently the shift of the opti downstream amplifier and one the Eltk- see image compared to a fixed reference frequency electron flow in front of the disc influencing, with the two aforementioned deflectors Distances assigned to a periodically operating deflection signal generator accordingly result in a bound deflection device as well as one from the display of the translation adjustments of this image steering signal generator controlled evaluation device. 60 opposite the fixed position; Shifts The device according to the invention used measured in two at right angles to each other in a known manner one or more optical figurative directions, for example horizontally and vertically rcn, the luminous and dark parts, for example, and both of them perpendicular to a horizontal bed have white and black parts and those on the direction of pull, which is the main thing of the system Surface of the solid are attached, the 65 forms the arrangement. This ge to the state of the art One wants to measure displacements. This figure-listening system allows Transla to be measured the following with the name »fixed marking«, that is, linear displacements of the object designated. tes, but not from rotational movements of the object.