DE3219452C2 - Dynamics control arrangement for a distance measuring device - Google Patents

Abstract

In a measuring device for determining the distance of a target object from the travel time of a measuring light pulse that is emitted to the target object, reflected there and received by the measuring device, it is necessary to achieve a high level of measurement accuracy, the intensity of the measuring light pulse to the distance and reflectivity of the target object as well to adapt the transparency of the medium lying between the target object and the measuring device, which is done by optical attenuation of the measuring light pulse initially generated with the highest possible intensity. According to the invention, this optical attenuation in distance measuring devices which have a light path switch (10) in order to feed a light pulse generated by the transmitter (1) either into a transmission measuring light path (15) or into a reference light path (11) is achieved by the The times at which the transmitter (1) emits a light pulse in each case are controlled as a function of the movement of the light path switch (10) so that only a desired part of the amount of light emitted by the transmitter (1) in a light pulse to the receiver (23 ) arrives.

Description

of the light paths at the moment a light pulse passes through the separating point Arrangement is that of dealing with your within can carry out a continuous damping further limits. There are difficulties here allerr'.r.igs Then, if the light pulse has a spatial dispersion, then the temporal one Center of gravity of the transmitted part of a light pulse against the temporal center of gravity of the undivided light pulse Depending on the selected degree of attenuation In different Catfish can be shifted, which is immediate affects the running measurement to be carried out to determine the distance.

b) This last-mentioned problem can be solved by one for the measuring light path and / or for the · Refer £ riz !! ch * "'e ° several functions» to each other provides parallel flushing sections, which then turn into a single one in the further course Measurement or reference light path are brought together and each of which has a damping device with a fixed damping factor, which differs from the damping factors In den different sections. Thus, a desired damping can be achieved in that the entire light impulse with the help of the light path switch in each of those Elnspelsungsabschnitttt is steered. In the one this damping 'respective filter or the like is arranged. The attenuation can only be applied to this catfish change gradually, but this does not lead to any particular problems, since at least the photoelectric Receiver can always process a certain amplitude range and the damping factors the different damping devices can be coordinated so that the The product of the smaller damping factor and the dynamics of the receiver is slightly larger than the next larger damping factor, so that a slightly overlapping connection of the individual damping areas results in a complete damping area. 1st about it In addition, the transmitter power can also be changed, so the dynamic factor available as a result also included in this product so that there are correspondingly larger differences between the damping factors of the individual filters and, with the same total attenuation range, results in a smaller number of filters. In those cases where this is the structure of the light pulses allowed, can, according to the invention, also here additionally with partial coverage of the light paths be worked, whereby the number of functionally parallel light path sections and thus can also reduce the required damping devices.

c) A particularly preferred and advantageous variant combines parts of variants a) and b) in the manner; that a plurality of flushing sections parallel to one another are not required for the respective light path and yet it is not necessary to work with a partial overlap of the light paths. This happens because the permanent periodic movement of the light path switch in the light path in which the light pulses are to be attenuated continuously brings attenuating elements, for example filters with different attenuation factors, and the light pulses are generated in such a way that they are at the time on the light path. Changeover switch, in which the desired damping element is offered to you.
In addition, one can also work with a plate covering of light paths. If this is not the case, then only a gradual change in the damping factors is also possible. For the reasons already mentioned under b), however, this does not give rise to any particular difficulties.

With all three variants it is in principle possible to use the Attenuation of the measuring light pulses either before they are sent to or after they return from the target object perform. The latter case is preferred, because here the target object or his surroundings! Environmental light In the same catfish as the measuring light is attenuated and thus errors caused by different Environmental light occur in the Avalanche Dlode, can be eliminated, and at the same time the signal / noise ratio is significantly improved. To achieve this attenuation on the receiving side, it is only necessary to use the light path switch and the receiving light path to coordinate their structural design so that not only that Transmission light but also the reception light impinges on the light path switch and from this to the Recipient is forwarded to the world.

A rotating switch provided according to the invention to implement variant c) as a light path switch Disc preferably has a plurality of openings on the one hand, which rectilinear the light coming from the transmitter and let through as measuring light without partial overlap, and with the same radial distance from the Axis of rotation, a multitude of mirrors, each of which is suitable for receiving the light coming from the transmitter divert the reference light path. On the other hand, the disc has a different radial distance from the Axis of rotation another multitude of openings that are located move through the path of the measuring light coming back from the target object and the various Contain filters providing attenuation values. They are both the openings that let the transmitted light through as well as the mirrors and those that let the reference light through Openings in each case combined into groups of the same size, with In one group of the receiving light openings All the different attenuation values that are present are always represented. Each group of Send light openings and each group of mirrors is a group of receiving light openings in the way assigned that a measuring light pulse exiting through a certain transmission light opening on its return of the target object passes through a certain receiving light opening, or that when it arrives one of A specific mirror reflected reference light pulse at the receiver there at the same time through a Ambient light which has passed through a certain receiving light opening. This allows on the one hand through the selection of the "correct" transmission light opening for a measuring light pulse already determines the desired attenuation and on the other hand through the "correct" selection of the mirror for the associated reference light pulse for it care must be taken that the light conditions at the receiver for both pulses are as similar as possible to one another, with It is assumed that an attenuation device arranged in the reference light path produces an invariable Damping element and a controllable optional

See attenuator includes the amplitude of the reference light pulse Is matched as closely as possible to that of the measuring light pulse arriving at the receiver.

Arrange the above-mentioned groups of transmission light openings and mirroring and / or associated reception openings on the pane so alternately that in the receiving light openings the different filters, which in the same catfish in each group, are present are. Also have the same order in each group, after the correct damping has been found by experimental measurements to, it can be obtained several individual measured values for both the measuring light moving tent and the reference light moving tent, from which then to achieve a single, particularly accurate measured distance value before or after the subtraction of mean values are formed, operate the whole arrangement strictly periodically so that with exactly the same tent spacing A measuring light pulse and a reference light pulse are always alternately received at the receiver will.

The analog circuits that process these impulses have, like all analog circuits, the property that the size of the error you have impressed on the measurement signal to be processed depends on the time interval depends between two successive signal processing operations of the same type. Due to the pearlescence the control is now achieved according to the invention that these errors with the same size In the Run-time values of both the measuring light pulses and the associated reference light pulses come in and become thus emphasize in the subsequent difference formation.

In addition, there is one in the tent measuring device For the distance measuring device in question, it is generally a base sign! Use attached to the various points is used and therefore unmistakable catfish on practically all lines as, even if there is a very small, periodically fluctuating interference signal.

If the arrangement is not operated with a bellow Perlodidity. but with a repetition frequency that is an integral multiple of the frequency of the base signal is, the interference voltages caused by the cell signal also go into the analog signals with the same amplitude and therefore fall out again in the subsequent difference formations, and the timing process is simplified.

Is a sufficiently high signal for the tent base If a frequency, for example 15 MHz, is selected, the periodic operation described above can be easily performed perform under the condition that the light impulses enter the openings of the rotating disk should pass through full overlap with the preceding and following ray paths.

A problem arises when such a distance measuring device is supplied with power from a battery from the fact that the various voltages required in the device are generated with the aid of a chopper must, whose edges when they start or end with the generation of a running time measurement Signal coincide, making an exact measurement impossible.

In order to avoid this source of error, it is advantageous to control the time of the trigger generator so that the Light pulses not only to the correct tent points for the desired attenuation on the light path switch but also in such a way that the start and end of the signal running time measurements also fall within time periods.

in which no disturbances caused by chopper edges occur.

If you want the distance measuring device to achieve a particularly high measurement accuracy in the above described catfish periodically and synchronously with the Operate a time base signal, this condition can no longer be realized. In this case it is according to the invention intended. In the tent dreams, in the beginning or At the end of a run-time measurement fall to blank the chopper, d. H. to suppress its vibrations for a short time and instead feed the power supply from a buffer capacitor. Since it is also with long distances just about tent rooms in the order of magnitude from 60 to 70 ns. Is this without major technical effort possible.

The invention is described below with reference to exemplary embodiments described with reference to the drawing; in this shows

Flg. 1 is a schematic block diagram of a distance measuring device in which, according to the invention the dynamics control with the help of an and reception light paths arranged optical switching and attenuation unit is feasible,

Flg. 2 shows the schematic representation of a first embodiment for an optical switching and switching device Damping unit according to Flg. I,

Flg. 3 shows a second, particularly preferred embodiment for an optical switching and damping unit according to Fig. 1 and

FIG. 4 shows a front view of the damping disk shown in section in FIG. 3.

As shown in Fig. 1, has a after The distance measuring device operating on the principle of light impulse measuring is a transmitter 1, for example a laser transmitting diode and a transmitting diode with this Energy-supplying sound arrangement can comprise, which essentially consists of a "slowly" chargeable Energy storage in the form of a capacity and a controllable electronic switch that is used to quickly generate the energy accumulated in the energy storage device via the transmitter diode Discharge laser light pulse.

This switch is controlled by a Trigger generator 3, the output signal of which is also used at the same time as the start or as a preparation signal for the start is used for the respective signal treadmill measurement. There is a delay element between the trigger generator 3 and the transmitter 1 2 switched, which on the one hand ensures that, for example, even when measuring a very short Remove the stop signal for the treadmill measurement a sufficiently large time interval from the start signal so that these two signals from one and the same timing channel easily follow one another can be processed, and on the other hand causes the signal transit time measurement before the point in time and so that trouble-free starts, in which the transmitter responds to the trigger signal with the generation of a reacts very quickly and comparatively large current surge through the transmitter diode, with very strong interfering signals which would make it extraordinarily difficult to concurrently or briefly after the light pulse generation by the transmitter 1 emitted start signal for the Slgnai transit time measurement to be recorded precisely in terms of time.

The light impulses generated by the transmitter 1 are over a transmitter light path 7 of an optical switching and damping unit 8 supplied, the z. B. a mechanical one contains movable light path switch 10, the ic

laughing at his position one out of the transmitter light path 7 exiting light pulse either in a transmission measuring light path 15 or an internal reference lamp 11 steers.

The from l.lchiwegumschalter 10 in his Mcßllchtsiellung Feeded into Scnde-Mcßllchlweg 15 Light pulses are transmitted to a transmission optics 16, which is shown in simplified form as a single lens and which sends light pulses to the target object whose distance is to be measured.

The part of everyone reflected by the target object Light pulse is from the In Flg. 1 also schematically Receiving optics 18 shown as a single lens via a receiving measuring light path 19, one in the optical Switching and damping unit 8 contained, changeable optical damper 20 and a receiving light path 21, 22 is fed to a receiver 23 which, for example, has a photodiode with a converter with a downstream amplifier and signal generation circuit which serves to transmit a signal generated by it when receiving a light pulse a line 24 to a tent measuring device 25 as a stop signal to the from this tent measuring device to end the signal running time measurement carried out for the respective light pulse. This signal transit time measurement was previously, as mentioned above, correlated with the trigger signal emitted by the trigger generator 3 has been started, which can be fed to the tenting device 25 via the oil line 27.

In the event that the output signals of the trigger generator 3 are to be synchronized with a tent base signal generated in the tent measuring device 25, a line 29 is provided through which the corresponding signals from the tent measuring device 25 to the trigger generator 3 can be transferred.

The time measurement results obtained by the tent measuring device 25 are via the lines 28 of a central process control, computing and evaluation unit 30 supplied, on the one hand from these Laufzelt measured values the corrected measured distance values are determined and brings it to the display and which, on the other hand, controls the functional processes in the entire measuring device. This sequence control, computing and evaluation device 30 can preferably comprise a microprocessor.

The from the light path switch 10 in its reference light position Light pulses fed into the reference light path 11 pass through an optionally controllable one optical damper 33 and are at a branch point 35 in the part leading to the receiver 23 so 22 of the received light path. The reference light pulses running on this path from the transmitter 1 to the receiver 23 are subject to sender with regard to the trigger signal and recipient until the generation of the Stop signals for the tent measuring device 25 are the same Delay or signal processing tents like the Measuring light pulses, of which they are essentially only in terms of the length of the between the light path switch 10 and the branching parts 35 differentiate the light path passing through. Because the length this reference light path 11 and thus also for his The time required to run through is known very precisely, can be carried out with the help of the signal run-out measurement Reference light path those mentioned above, also for the Signal-moving-tent measurements over the measuring section are effective Delay and signal processing tents eliminated by forming the difference between the respective measured values will.

A signal exchange between the optical switching and damping unit 8 and the sequence control, Computing and evaluation device 30 takes place via line 39, which is multi-core or bidirectional may be, so that for example via line 40 the information relating to the current position of the light path switch 10 to the sequence control, computing and evaluation circuit 30 and transmitted via the Lines 41 and 42 adapted to the respective operating state command signals from the sequence control, Computing and evaluation equipment 30 can be delivered to the optical attenuator 20 and 33, respectively.

According to the invention, the light path switch! 0 can either be used directly to switch the To change the intensity of the light pulses generated by the transmitter 1 and emerging from the transmitter light path 7, before they reach the transmission optics 16 or are fed into the Rcfcrcnzüchf.veg ü, or he can in extremely advantageous catfish with the Dynamlksteuerurig serving optical damper 20 to achieve a particularly simple, optimally operable and combined very quickly to extremely exact measurement results leading dynamics control arrangement will}.

The direct intensity control with the aid of the light path switch 10 is now illustrated in FIG. 2 illustrated Ausführungsbelsplels explained. In Flg. 2, the light path switch 10 is controlled by an oscillating mirror 45 formed, which is shown between a measuring light position 46 and a dashed line Reference light position 47 can be moved back and forth periodically is what is to be indicated by the curved arrow 48. The angular distance between the two mentioned positions Is In FI g. 2 of clarity depicted for the sake of greatly exaggerated. In fact, the two positions can be much closer to each other, so that the switching process can be carried out very quickly. The souring of the oscillating mirror 45 is done by a control unit 49, as shown by the arrow 50 is indicated. The measuring light position 46 and the reference light position 47 of the oscillating mirror 45 are distinguished by the fact that in them an imxlmaler Share of the light energy emerging from the transmitter Lichtwfcg 7 when a light pulse is emitted into the associated transmission measuring light path 15 or reference light path 11 is fed in. About this maximum smile to ensure despite the permanent periodic movement of the oscillating mirror 45, the times In each of which the trigger generator 3 emits a trigger signal with the movement of the oscillating mirror 45 must be corrected precisely in terms of time so that those exiting from the transmitter 1 responding with a delay Light impulses strike the oscillating mirror 45 at the right moment. If you move the tent points in at which the trigger signals are generated, towards these optimal points in time, the oscillating mirror 45 steers Always only a part of the amount of light of a light pulse in the emitted from the transmitter light path 7 relevant light path 15 or 11. Thus, the amplitude of the Change the light impulses that are controlled within wide limits. For this purpose it is advantageous if the Control unit 49 the current position of the oscillating mirror 45 related information on the line 40 and the receiver 23 information about the instantaneous amplitude of the corresponding signals the line 43 to the sequence control, computing and evaluation unit, which then via the line 51

13 14 I.

a corresponding maximum time transmitter power must be used on the trigger generator 3, the '§,

Shifting the trigger signals causing control trigger generator 3 is timed so that by f |

can forward signals. the light path switch 10 the entire in one light

In this case, it is then possible to apply the amount of light contained in the variable impulse into the inlet opening of the

The availability of the optical path located in the reference light path 11 is guided. In

see damper 33 to waive and here a filter with all other cases is however required for the

Provide a fixed attenuation ratio that the Inten optical signal attenuation of the trigger generator 3 in time

The reference light pulses are reduced to such an extent that it is controlled in such a way that the light emitted by the transmitter 1

the oscillating mirror 45 only within the range of the receiver pulse at a time on the Lichi path switch

ger 23 processable dynamic range encounter an adjustment io 10, in which this such a position

the reference light intensity assumes that only a desired part of the light intensity

must be carried out. pulse contained in the amount of light contained in the onward

The optical attenuator 20 can then, if not only the light path, while the rest at the entrance window Gie the intensity of the reference light pulses, but also that of the light path deflected past and somewhere in the measuring device

the measuring light pulses with the help of the oscillating mirror 45 15 is absorbed. JL

can be omitted. To achieve this on a momentary partial coverage of the; ν

With a good signal / noise ratio, however, it is advantageous to use optical signals based on light paths

sticky, not the dynamics control of the measuring device fungus can be the transit time of a light pulse ^

emitted, but the distance measuring device reflecting from the target object only then in meaningful, -

th light pulses to steam, as 20 full catfish pass through it at the same time, if it is ensured. that ; _:

also the ambient brightness and through it the light pulse from a quasi point-shaped light:

conditional noise is reduced. This source of need is emitted, or that in the case of a flat light

of the reflected light impulses does not find different surface areas one after the other with the help of the opti- quelle ' ^Vr

See the 20 attenuator instead, which lights up in the process of doing your light with different

Signal moving tent measurements above the reference light path 25 angles, for example in a subsequent light guide

11 also serves to feed the fiber from the receiving optics 18. If this condition is not met, i

at these times received and on the receiver 23 an optical attenuation by partial overlap to ^: ι

Successful ambient light to the same extent that the temporal focus of the forward->

vaporize, as is the case with the respective associated signal th light pulse depending on the selected <

Tent measurement takes place over the measuring light path. 30 damping, d. H. Depending on the extent of the When using a periodically moving respective partial overlap, a time shift Oscillating mirror 45 as a light path switch 10. The experience for measuring light pulse and reference light pulse

for example with a frequency of 5 kHz to 10 kHz can be different and thus with the subtract:

works, the ends of In the F1 g. 1 and 2 do not emphasize the signal running tents, which means that \

Sende-Meßllchtweg 15 or the reference light path 11 35 can result in considerable measurement errors.

forming optical fibers are arranged so that the above condition cannot be met, so are

Measuring light position 46 or the reference light position 47 according to the invention when using a swing

not with the reversal points of the oscillating mirror or a rotating prism as a light path

coincides. This enables the measuring switch for the measuring or reference light to be attenuated.

The frequency and the repetition frequency of the reference light impulses each have a plurality of functionally parallel pulses

pulse, since with each full oscillation of the spIe light paths are provided, each of which has a different,

gels 45 both the measuring light position 46 and the reference invariable attenuation value yeast and it will ever

spotlight position 47 is run through twice. according to the requirements of the trigger generator in

Instead of the oscillating mirror 45 shown in Fig. 2, depending on the movement or current position

According to the invention, in order to achieve a higher light level of the light path switch 10, it can be time-controlled in this way.

Pulse repetition frequency uses a mirror prism that the oscillating mirror 45 or the rotating mirror

be that uniformly around a prism on the plane of the drawing the incident light pulse completely In the

vertical axis rotates. From the controller 49 feeds the correct light path, where the light pulse then

must then only be subjected to the desired damping for an approximate constancy, without

Angular velocity provided and a passage 50 thereby a temporary shift in the center of gravity occurs

of each mirror surface through a certain angle- With such an arrangement it is then different than with

The signal that characterizes the position is generated and the partial overlap is not continuous, but only

Line 40 to the process control. Calculation and a step change in the damping value Evaluation element 30 can be passed on. possible. But since the sensitivity of the avalanche The light paths 7, 11, 15, 19 and 21 are in the Flg. 1 55 photodiode of the receiver 23 by changing the

and 2 shown exclusively as optical fibers, whereby the supply voltage can be influenced (attenuation value

in front of or behind the end faces of these optical fibers, for example 1: 5.5) and the one contained in the receiver 23

to be provided condenser or imaging lenses of the tene. downstream of the avalanche photodlode

Are omitted for the sake of simplicity. According to the invention amplifier, for example, a dynamic range of 1: 6.6 If the optical fibers can at least partially also have 6ö, a dynamic results for the channel

by other known light guide and imaging media of approx. I: 36. so that the individual attenuation levels In

such as B. mirrors, lenses, etc. are replaced. the parallel light paths are each increased by a factor

With the previous Schilderen); of the action worlds differ between 1:30 and 1:35

one of an oscillating mirror 43 or a rotleren- can. This leads to the fact that, for example, with

the mirror prism formed light path switch 10 65 six parallel light paths and the dynamics of the

it was assumed that only in cases where the amplifier has a total dynamic range of more than I: 10 "

In which can be reached because of very great distance and / or very,

low reflectivity de3 target object the In the event that the output power of the transmitter

15 16

can still be changed in a ratio of 1: 5, the run increases to pass through there as a delayed interference light pulse

Channel dynamics to 1: 180. This results in a signal shift triggered by the actual measuring light pulse.

to disturb the corresponding enlargement of the factor between the work processes in such a way that incorrect measurements

individual attenuation levels. gen comes or a flawless time interval measurement

In Figs. 3 and 4 a further embodiment 5 is made completely impossible. This is done by the In

an optical switch according to the invention and the openings 62 to 65 attached, inclined

Damping unit 8 shown, in which a rotating damping filter prevents. Throw these openings Disk 55 is used, which is particularly advantageous, namely for sending out measuring shots

both the one behind the transmitter light path 7 is used, if very large distances are not required.

located light path switch 10 as well as the 10 are to be measured, d. H. so if the danger

between the receiving measuring light path 19 and that there is that the interference pulse just described without

Reception light path 21 arranged, changeable opti- further measures to disrupt the measurement

see damper 20 in a single component has sufficient amplitude with one another. In these cases, In

united. where the light emitted by the transmitter 1 anyway

How to get the F i g. 3 removes. In which the rotating 15 has to be damped, it does not pose any problems. Disk 55 In one of the line III-III from FIG. 4, the transmitter light already follows before it emerges from the

The section is shown, the disc 55 but a measuring device around the iahenden by the discussion

Shaft 56 driven by a motor 57 in such a way that it dampens the damping filters by a factor of 1:10,

rotates steadily in the direction of arrow R. Then comes the from the optical receiving equipment

The approximate constancy of the angular velocity 20 lines reflected the light component back to the transmission optics 16

this rotation can either be returned by one at the motor 57, so it passes through when projecting onto the

known control circuit located or through the end face of the optical fiber 7 in its light path

central sequence control, computing and evaluation located attenuation filter a first time, where he

Unit 30 are monitored and ensured, which, as with the reflection at the front end of the light guide

then with the motor 57 via the line 58 corresponding to fiber 7 and when you step through the

exchanges relevant information and command signals. Attenuation filters weakened in a ratio of 1:10

The rotating disk 55 is arranged in such a way that it becomes so that, in total, there is attenuation by an outermost circumferential area in the ray factor of 10 ~ ³ . The interference path of the light weakened in this way intervenes, which in this case is no longer able to emerge from the transmitter light path 7 shown here as a Llchtlett- llchtlimpuls and from the receiver 23 a disruption of the signal processing of the one in Flg. 3 only to be effected symbolically by means of its central axis of the previous measuring light pulse. The inclined position of the damping filters in the openings weK,; r is guided by the indicated lens 59 with reduced divergence. 62 to 65 is prevented from being on the surface of the

In this outermost area, the disk 55 has filters reflected light components reaching the transmission optics 16.

alternating groups of openings 60 to 35 gene and thus themselves can become interfering signals.

65 and mirror 70 to 75. The first two openings The two holes SO and 61, each facing the outside

60 and 61 of each group are to be used as the circumference of measuring shots for distant target objects.

direction of the disc 55 elongated holes formed. If stands are used, they do not show any

the trigger generator 3 is controlled in such a way that it opens under attenuation filters, since the large distance

Taking into account the corresponding delays 40 the above-described formation of interfering reflections

the transmitter 1 for emitting a light pulse does not play any role. The elongated formation of this

then caused when one of these openings 60, 61 allows both openings 60 and 61, moreover, the

located in the beam path behind the transmitter-Llchtweg 7, measurement shots for these large distances so early

so this light pulse gets completely undamped over the to generate that despite the great distance the am

Sende-Messllchtweg 45 shown as a free beam path target object reflected light pulses on the

15 to the transmission optics 16 and from there to the Zlelge optical damper 20 forming part of the rotating

object. The other openings 62 to 65 contain disk 55 and in particular on the receiver 23 for right

jewells a damping filter that a comparatively ten tent arrive, as explained in more detail below

low damping factor of 1: 10, for example.

supplies and the optical axis of the beam path 15 is below 50. Each group of holes 60 to 65 follows in the outer

cuts at an angle other than 90 °. ren 3erelch of the rotating disk 55 an equally large

These attenuation filters have the following purpose: In the group of mirrors 70 to 75, which, as can be seen in particular cases in which the distance measuring device in FIG Your reflective surface at Target object is to be appropriate that a retro 55 traversing the beam path 15 at an angle reflector, it can be at an unfavorable position of 45 ° to the optical axis of this beam path. Retroreflector happen that that part of a If the trigger generator 3 is controlled so that he Light pulse that causes the receiving optics 18 and Insbe transmitter 1 to do so. At a point in time, a special light on the end face of the optical fiber 21 to emit the pulse in which one of the mirrors 70 to the part of the receiver which leads to the branch point 35 60 75 In the just described and In FI g. 3 forms for the SpIefangsllchtweges, is reflected, is located on the position shown in retrogel 71, then this is reflector goes back to the transmission optics 16 and deflected by light pulse on the mirror by 90 ° and by a this is focused on the front end of the optical fiber, lens 77 on the front end of an In Flg. 3 the front || which forms the transmitter light path 7. Without the attenuation filters 65 provided in the section of the reference light path 11 forming light openings 62 to 65, the filter fiber 32 is focused, would be the part reflected again on this end face

of the light pulse with a sufficiently large amplitude The reference light pulse generated in this way occurs at the other

Over the entire measuring light path to the receiver 23 end of the optical fiber 32, a lens 78

Converted into a parallel bundle of light and passes through a controllable optical damper 33, which is formed here by a Graukell disc 80, which is used to achieve a desired damping value with the help a stepping motor 81 about its axis 82 in both directions can be adjusted, as indicated by the double arrow S. Behind the changeable optical attenuator 33 passes through the reference light pulse a damping filter 83, which has a fixed predetermined damping ratio, to then at the branch point 35 with the help of a partially transparent mirror 85 via an interference filter or in the center frequency Tunable interference filter 87 In the part 22 of the received light path leading to the receiver 23 to be coupled. For this purpose, the parallel light bundle is applied to the The end of the optical fiber forming this part of the receiving light path is focused.

The optical pimp 33 can also be formed by a PLZT or a PLIOZT disc.

In a radially welter inner area has the rotating disk 55 has successive groups of openings 90 to 95, each of these groups six openings, d. H. comprises as many openings as the groups of openings or mirrors described above 55 have openings or mirrors in the outer edge region of the disk.

The openings 90 to 95 located further inside are arranged so that, when the disk 55 is rotated, they run through the receiving measuring light path 19 leading from the receiving optics 18 to part 21 of the receiving light path at a point, i, at which the cross section of the beam path 19 m'X security is smaller than the diameter of the openings 90 Ls 95. A lens 96 is arranged behind the rotating disk 55 in the direction of light-pulse travel, which lens focuses the light onto the front end of an optical fiber 21 forming the input part of the receiving light path. The measuring light emerging at the other end of this optical fiber 21 is converted by a further lens 97 in the same way into a parallel light bundle, as was described above for the reference light and the lens 78.

The measuring light then passes straight through the inclined, partially transparent mirror 85, i. H. with a very little attenuation and reaches the lens 86 via the interference filter 87, from which it is applied to the end face the optical fiber is focused, which forms the part 22 of the receiving light path leading to the receiver 23.

Each of the openings 90 allows undamped passage of the received light while in the openings 91 to 95 filters with different attenuation ratios are attached. It is essential that from group to group all holes 91, all holes 92, all holes 93, all holes 94 and all holes 95, respectively have a filter with the same attenuation value.

When using this rotating disk, the measuring light passes through the dynamic control on the Receiver side is attenuated, only a single light path from the Sende-Messllchtweg 15 via the transmission optics 16, the target object, the receiving optics 18, the receiving measuring light path 19 and the front part 21 of the Receiving light path 21, 22 to the branching point 35 and from there welter to the receiver 23. Yet is not used with a plate cover for damping of light paths worked at the moment of the passage of the respective light pulse.

Instead, the trigger generator 3 is sometimes like this controlled so that it causes the transmitter 1 to emit measuring light pulses precisely at such a point in time, in which not only one of the openings 60 to 65 letting the transmitter light through is fully covered in the beam path of the Sende-Messllchtweges 15 but also one of the openings 90 to 95 fully covering in the beam path of the Receipt-Meßllchtweges 19 is. This full coverage is practical for short and medium distances given at the same time, since the disc 55 be * one preferred speed of approx. 130 rev / s practically not moved further in the time required by the measuring light to traverse these short and medium distances. Only for long and very long ■ distances (up to 10 km) the rotation of the S: hot 55 plays a role in relation to the running tent of the measuring light impulses e:; ne role.

! 5 This is also one of the reasons why the: for the Emission of the measuring light pulses for large and very large distances openings used (> 0 and 61 of each group in the circumferential direction of the disk 55 are designed so that one with a Reservation of approx. 3.1 ° emitted light rays this Openings can pass through unhindered. Through is it is possible to deliver the measuring light pulse so early in each case that it will be released when returning from the target object the corresponding opening 90 or 91 straight: meets in its fully covering position.

The different attenuations required for dynamic control are achieved in this embodiment generated by the fact that the rotational movement the disk forming the light path switch 10: i 5 permanent in one and the same light path filters with different Apply dampening factors and that the trigger generator 3 in dependence on the Movement of the disc 55 is controlled so that it triggers the transmitter to tent points that ensure that the subsequently emitted measuring light pulse -nell its Returning from the target object, just the filter delivering the currently desired damping factor in one which finds holes 90 to 95. Damfc the measuring light pulse Step through the rotating disk 55 to the respective tent point on the transmitter side as well can. There is a number of openings 60 to 65 provided, which corresponds to the number of the different Openings delivering attenuation corresponds to 90 to 95 per group on the receiver side.

In an arrangement in which, as in Fit; 3 shown. Transmitting measuring light path 15 and receiving measuring light path 19 with respect to the center of rotation pi. nktes the Disk 55 are exactly diametrically opposite, are due the above-mentioned "simultaneity", with which one of the transmission light openings 60 to 65 and the associated one of the receiving light openings 90 to 95 achieve full coverage with the associated radiation sources, in each case the center of a transmitting light opening 60, 61, 62, 63, 64, 65 and the center of the associated receiving light opening 90, 91, 92, 93, 94, 95 arranged on a common disk diameter, as shown in FIG. 4th for one of the openings 62 and the associated opening 92 is indicated by a dash-dotted line 101. The radially directly inside the silk opening 62 received light opening! »2 not this transmitting light opening but the one diametrically opposite Associated with mirror 72.

The other mirrors 70, 71 and 73 to 75 of each group are each diametrically opposite! The corresponding receiving light opening 90, 91 and 93 to 95 are assigned, each of these receiving light openings containing a filter with the same attenuation factor as the correspondingly numbered receiving light opening

19 20

assigned to an opposite transmitting light opening ± 1 mm at distances of up to 10 km)

is. can be.

The sense of this arrangement is also the reference light. Assuming that the receiver 23 of the impulses at very specific points in time, the amplifiers connected downstream of the receiving photodiode signals the movement or the current position of the rotles between 175 mV and 1150 mV depend with a sufficient inner washer 55 to trigger. A basic arity and a further processing feeding principle of the device according to the invention consists, which corresponds to a dynamic range of approx - should be subtracted from each other by changing the supply voltage by only one value, which can be changed by a factor of 1: 5.5, the result is a dynamic range of approx. This includes not only a very 1: 36.3 and a corresponding attenuation must be used to adapt the light intensity of the reference light pulses as bright as possible to the corresponding measurement light pulses, selected measurement light pulses to achieve a long range, to ensure that something is done with the aid of the controllable optical attenuator 33 is the incoming signals In at the receiver 23, but also an adaptation of the respective brightness range that can be processed by this. This background brightness. For this purpose, the attenuation takes place on the one hand through the measurement path reference light pulses are not triggered if any and the reflectivity of the target object is one of the mirrors 70 to 75 in the exit beam path of the (external attenuation) and on the other hand to compensate for the transmitter light path 7; rather the possible differences in this case is always -Me derje- 20 used in the Größennige the mirror 70 to 75, the counter on the order of 1: 1 to * 10: 10 ¹⁰ Hegen can, through the opposite side of the disc 55 a Err ^ fangsilcht- inventive time control of the trigger gene opening is assigned, which contains the same filter as rators 3, depending on the movement of the disc, that receiving light opening through which the associated 55 (internal attenuation), and possibly with the help of measuring light pulse passes. This ensures a change in the power output by the transmitter 1 that the receiver 23 when receiving the reference (additional channel attenuation).

renzlichtimpulses the same environmental brightness "sees" and If the transmitter power cannot be changed, it works

so that it has the same temporary response behavior as the measuring device for finding the right interior damping

when receiving the associated measuring light pulse. fung from a very great distance of the

Similar to the one described above, the target object is also not 30 and a high level of external attenuation dynamic control working with partial overlaps, and sends a first measuring light pulse as an experiment in which the light pulses in different, functionally through one of the openings 60 with a large mutually parallel but with different attenuation distances corresponding lead, so that the filter equipped light paths are directed. Is also reflected light pulse due to the no attenuation here with the aid of the disk 55 only one associated opening 90 which brings about gradual changes comes back. Included . -ung of the attenuation possible, which, however, as already explained above, is the receiving photodiode to maximum sensitivity, Because of the In any case available- kelt switched.

The dynamics of the receiver 23 are not special. The receiver 23 includes catfish known per se

Offers difficulties. a comparator that monitors whether that is to be amplified

To determine the current position of the disk 55 40 output signal of the receiving photodiode or one of your

and thus the driving timing for the trigger m .hgeschalteten resonant circuit, the upper limit of

Being able to choose generator 3 correctly indicates the disk exceeds 1150 mV. If this is not the case, then means

55 radially still welter inside a multitude of holes 98 this that actually a very distant and / or

on, of which in each case one of a radial ray associated poorly reflecting target object is appropriate

net is on which the center of one of the openings 90 to 95 was 45 and that the correct internal attenuation value,

and the openings 60 to 65 or the mirrors 70 to 75 namely 1: 1 has already been found.

lies. These holes 98 are used to give the comparator an overload signal with the aid of the In

Flg. 3, from a light source 99 and a light source, well the 1150 mV have been exceeded, so is

Dlfferentlal-Photodlodc 100 formed light barrier by the central process control, computing and

Via the line 40, the respective position of the rotating evaluation unit 30 on the one hand and on this catfish

Disc 55 identifying signals to the central tent measured value obtained because it was

Sequence control, arithmetic and evaluation unit 30 has a measurement error that is too large, and

which then in turn control the trigger generator 3, on the other hand, the sensitivity of the received photo

Via the line 51 shown in Fig. I temporarily correct diode reduced in the ratio of 1: 5.5. This is how it is done

drives. 55 quick, that ready? through the next, through the broadcast

As shown in FIG. 4, one of the holes 98 can have an opening 60 passing through a measuring light path 15 a

have a different distance from the axis of rotation 56 than the measuring pulse which can then be emitted

other holes 98 and through a separate one, not shown again through the associated one, no damping caused

set light barrier can be scanned, through which at the end opening 91 / reaches the receiver 23,

every revolution of the disk 55 a clear position. Μ If the override comparator responds again, see above

signal for the sequence control, arithmetic and output, this measured value is also discarded, the receiving milk

werteelnhelt 30 is generated. kelt the receiving photodiode back to the high. Who"

Should now be switched with a device constructed according to the invention and the next measuring light pulse

The initially completely unknown distance measuring device sends the measuring device through one of the openings 61

Distance of a target object with unknown 65 leaves and back through the associated opening 91

Reflexion power must first be determined, in which there is a filter with a damping factor

the correct attenuation of 1:30 is found by the measuring device itself. This is in the event that the

so that exact measurement results (accuracy of the preceding measurement light pulse the threshold value of

1150 mV was only slightly exceeded, ensures that the amplifier contained in the receiver 23 now not too small, d. H. under the lower one A signal that falls within the desired working range is received instead of a signal falling to the limit of 175 mV.

If the override comparator responds with this third attempt,> o will be the next Measuring light pulse emitted again through one of the openings 61 and received the associated opening 91, however, the sensitivity of the receiving photodiode is again reduced in a ratio of 1:: 5.5.

If this also leads to an overload of the receiver amplifier, the sensitivity of the receiving photodiode is increased again and the next measuring light pulse is emitted through one of the openings 62, which, as described in detail above, use an inclined filter with an attenuation factor to suppress interfering light reflections! : !!) contains. This attenuation of the transmitted measurement signal is therefore easily justifiable, because the previous measurement tests have shown that an attenuation of 1:30 is not sufficient to report an overload of the receiver amplifier. The n; deflected light pulse then passes through the opening 92 belonging to the opening 62 to the receiver 23, in which a filter with an attenuation factor of 1: !! 00 is arranged, so that this light pulse has a total internal attenuation of 1: 1000. This attenuation value is selected so that it is slightly smaller than the product of the attenuation value of the preceding receiving light opening, in this case the receiving light opening 91, and the dynamic value of the receiver 23. The same applies to the attenuation values in the following receiving light openings 93 to 95, which jwells a filter with an attenuation factor of 1: 3 · 10 ^! , 1: ΙΟ ¹ or 1: 3 · 10 ', which in connection with the attenuation filters contained in the associated transmission openings 63, 64 and 65, total internal attenuation factors of 1: 3 · 10 * 1: 10' or 1: 3 · 10 ⁷ results, so that, taking into account the dynamic range of the receiver 23, an overall dynamic range of more than 1:10 'can be achieved.

Does the override comparator also speak at that emitted through the transmitting light opening 62 and received by the associated receiving light opening 92 Measuring light pulse on. in this way the sensitivity of the receiving phoid diode can initially be reduced and overall, the procedure described above using increasingly higher levels of Danish: .pfungs levels in the subsequent openings 93 to 515 are continued, so until finally the overload comparator no longer responds and the correct damping value has been found.

If the transmitter power can also be changed, for example in a ratio of 1: 5, then every time the over-control comparator responds with a damping provided through one of the openings 90 to 95 and with the receiving diode switched to minimum sensitivity, before the sensitivity is increased and the use d «:> next stronger damping filter in one of the openings 91 to 95, first a further measurement attempt was made with reduced transmitter power. Since an overall dynamic range of 1: 180 can be achieved by switching the receiver and the transmitter, filters with correspondingly more differing attenuation values can be provided in the window 55 in the openings 91 to 95 and thus an even larger overall dynamic range a! are covered. at With a constant overall dynamic range, the Number of openings having different attenuation filters, d. H. the number of openings per group and a correspondingly higher number of measuring and reference light pulses per revolution of the Disc 55 are delivered.

In addition to the circuits already mentioned, an amplitude amplification and rectification circuit is provided in the receiver 23, to which the amplified output signal of the received photo code is connected Resonant circuit is supplied. If the correct attenuation has been found for the measuring light pulse, then this is done The DC voltage signal emitted by this rectifier is held in a sample-and-hold circuit until it is passed through an analog / digital converter In a digital numerical value has been implemented that then again the central sequence control, computing and AüSWcriCCiniieit 30 Supplied iiiiu u'üii stored

According to a particularly preferred method, the attenuation found is now always used to determine a particularly exact measured distance value alternatively a measuring light pulse and a reference light pulse are generated and, in addition, between two successive light pulse measurements a moose measurement is made in the tent measuring device 25.

As already mentioned above, the reference light pulses are deflected via that of the mirrors 70 to 75 to which that of the openings 90 to 95 is assigned Is, which has an attenuation filter with the same attenuation factor that is also used in the measurement light-moving-tent measurement, so that the environmental brightness at the measuring light pulses and the reference light pulses is attenuated in the same Welse.

To adjust the amplitude of the reference errors! pulse to the amplitude of the measuring light pulses are how already mentioned. A solid one in Referencellchlweg 11 Attenuation filter 83 with a constant attenuation factor and an optical attenuator 33 with a variable Damping factor arranged.

As already mentioned, the internal attenuation for the measuring light pulses must be within a very high range can be changed, since the external attenuation can change in a correspondingly large range. The desired goal is always the ratio of the smallest to keep the maximum light intensity incident on the receiving photodiode in the dynamic range of 1: 36 that can be processed by the receiver 23, and possibly to multiply this by the ratio (1: 5) that can be achieved by switching the transmitter power; this is achieved by the fact that at large External attenuation a correspondingly small internal attenuation and possibly a high transmitter power and conversely, if the external damping is small, a correspondingly large internal damping and possibly one small transmitter power is selected.

For this reason, the change in the amplitude of the measuring light pulses arriving at the receiving photodiode can be at most in a range of 1: 36 or I: 180 and the controllable optical attenuator 33 built into the reference light path only needs to be able to attenuate the reference light pulses in this ratio , while the remaining range of 1: 3-I0 ⁷ can be done by the fixed damping filter 83 and the inclined, partially transparent mirror 85. If one assumes, for example, that the inclined mirror, which for as little dampening as possible

Measurement of the measuring light required If 99% of the impinging reception measuring light path is not disturbed. For large and very straight lines, the light passes through and only deflects 1%. H. So for dps reference light an attenuation factor of the dung Sendellchtöffnungen 60 and 61 of erfordervon 1: 100 provides, the Dämpfungsfllter 83 must possess from about 3 · 10 ^-5 a Liehe zeltliche derivative also in compliance with the attenuation factor. 5 above condition must be carried out.

In the remaining range of 1:36 or 1: 180, the controllable optical damper 33 is bllden-

Adaptation of the amplitudes of the reference light pulses to the gray wedge disk 80 or a corresponding one the external measuring light pulses by also noting the one from the PLZT or PLMNZT disk, above mentioned rectifier when receiving a reference that it is advantageous to use your attenuation range with renzllchtlimpulses emitted DC voltage signal In io, for example, 1: 72 or 1: 360 twice as large as the the sample-ard-hold circuit temporarily stored by the receiver 23, possibly together with and digitized and the digital value obtained in this way with the transmitter 1 specified dynamic range of 1: 36 to choose the previously obtained digital value of the associated or 1: 180. This can be preventative Measuring light pulse is compared. Does the deviation take into account the fact that the performance of the larger than a specified tolerance range, then with 15 transmitting diode In general, In the course of the tent on the ■;

corresponding command half supplied via line 41 decreases. Except for a corresponding shortening ;;

Signals the stepping motor 81 adjusted so that the graying of the maximum measurable distance has this world ■ '■; {

wedge disk 80 the next reference light pulse In the no adverse consequences if you go through the above * r

correct catfish weakens. Measure In reference light path ii for a corresponding <·. ■ ·.

Are in this catfish both for the Meßllchtlmpulse 20 appropriate compensation. -L

as well as for the reference light pulses the correct] i

Attenuation values found, the above-mentioned B Series of measuring light and reference light moving tent measurements. 4 sheets of drawings

gene and elk processes take place and it can be from the

The individual measured values obtained in this way mean values formed 25;

from which the searched distance measurement value can then be calculated.

It is of particular importance that the entire Reception channel and in particular also the tent measuring j

circuit 25 are operated strictly periodically so that 30;!

the measurement accuracy to the values given above;, j

can be brought. A particular advantage of the newly ^-:;

described embodiment of the Llchtwegumschat- 0

ters 10 is that the rotating disk 55 has an f j

such strictly periodic operation of the receiving channel 35 Jj

and the downstream tent measuring device actually: j

Hch made possible after once the correct damping = j

is found. The disk 55 possesses, as one can in particular

special the F1 g. 4 takes, three groups each of ■;

Transmission light openings 60 to 65 and mirrors 70 to 75 40 Y

and the associated receiving light openings 90 to 95. Cj

This means that with every rotation of the disk in exactly Γ;

three measuring light pulses and in between; ',

see nested three reference light pulses emitted ij

and the associated signal tents measured 45; -

can be. The time interval between the '* <

Send time and the reception point of a measuring ΐί

light pulse from the distance of the target object ^:

depending, but this can be done with a corresponding ■ - :.

Timing of the activation of the trigger generator 50 'yyyy

tors 3 can be easily compensated. To this - "ij

Purpose is determined by the central process control, computing 0

and evaluation unit 30 with a not yet strict ά

Have periodicity to the further measuring processes -; |

the first measurement attempt the approximate distance of the 55 jgj

Target object, which because of the aperiodicity of the measurement processes still with a comparison to the target Accuracy of ± 1 mm subject to considerable errors can be. Yet this determination of distance is sufficiently accurate to then determine the 60 did to be able to calculate the necessary lead time of the further measurement and reference shots. There how already mentioned, for short and medium distances the Running time of the measuring light pulse In comparison to the speed of rotation of the disk 55, no role plays a role, becomes 65 by the time limit just mentioned, the condition of full coverage of the transmission and reception light openings with the transmission / measurement light path or the

Claims (27)

Patent claims: 1. Dynamic control arrangement for a distance measuring device based on the principle of Laufzeltmes- s Solution of a measuring light pulse from a transmitter controlled by a trigger generator generated, sent via a transmission optics to the target object, reflected by this and by the measuring device is received by means of receiving optics and directed to an electro-optical receiver, which in In response to this, an electrical signal is generated to terminate the transit time measurement, with the from The light path leading to the transmitter optics has a branch point at which the transmitter incoming light can be fed into a device-internal reference light path traveling directly to the receiver, dadtt'ch marked that on the Branch piece a light path switch (IG) is arranged, through which a light pulse generated by the transmitter (1) at each measuring thrust the transmission measuring light path (15) and at the transmission optics (16) Each reference shot can be approached to the reference light path (11) and that the Trlggf r generator (3) occurs the measuring shots and / or the reference shots can be time-controlled in such a way that in each case a predeterminable Part of the amount of light emitted by the transmitter (1) in a light pulse reaches the receiver (23). 2. Arrangement according to claim 1, characterized in that the light path converter (10) is movable Is. 3. Arrangement according to claim 2, characterized in that the light path switch (10) performs a periodic movement. 4. Arrangement according to claim 2 or 3, characterized in that the trigger generator (3) tentatively is controllable so that by the corresponding effective position of the light path switch (10) to Achieving the desired attenuation is a predeterminable part of that contained in the respective light pulse Amount of light In a single continuing section (IS or 32) of the measuring light path (15, 19) or the reference light path (11) can be fed in. 5. Arrangement according to claim 2 or 3, characterized in that the trigger generator (3) in time so controllable. that effective through the appropriate becoming position of the light path switch (10) to achieve the desired attenuation the entire in the amount of light contained in the respective light pulse in a selected one of several functionally parallel sections of the measuring light path or of the reference light path can be fed in, each of these sections having a damping element with a shows another damping factor. 6. Arrangement according to claim 2 or 3, characterized in that the trigger generator (3) in time is controllable so that by the corresponding effective position of the light path switch (10) the total amount of light contained in the respective light pulse in a single further Section (15 or 32) of the measuring light path (15, 19) or of the reference light path (11) can be fed in and that in the measuring light path (15, 19) or the reference light path (11) depending on the momentary Position the Llchwegumschalters (10) a different damping filter with a damping factor Can be brought to the desired size. 7. Arrangement according to one of claims 3 to 5, characterized in that the light path switch (10) is a periodically oscillating mirror (45) is provided, the measuring light position (46) and the reference light position (47) being selected so that they do not coincide with the reversal points of the mirror (45). 8. Arrangement according to one of claims 3 to 5, characterized in that as a light path switch (10) a rotating prism with reflective side surfaces is provided, the axis of rotation of which is perpendicular to the optical axes of the light paths ending at the prism. 9. Arrangement according to one of claims 3 to 6, characterized in that as a light path switch (10) a constantly rotating disk (55) is provided, the axis of rotation (56) of which is parallel to the optical axes of the one that ends at the disk (55) Light paths (7, 15, 19, 21) and the in your den at least one area covering the light path (7) coming from the transmitter (i) in a straight line transmitting opening (60 to 65) and at least one of the transmitter light at a predetermined angle deflecting mirror (70 to 75), and that the Sende-Meßllchtweg Π 5) to receive the straight light transmitted through the disc (55) and the reference light path (11) for receiving the deflected light are arranged. 10. The arrangement according to claim 9, characterized in that the disc (55) has a plurality of openings (60 to 65) which allow the transmission of light to pass through has several mirrors (70 to 75) deflecting the transmitter light, that all openings (60 to 65) and mirrors (70 to 75) are at the same distance from the axis of rotation (56) of the disk (5S) and that in at least one (62 to 65) of the openings (60 to 65) a filter that attenuates the transmitter light is arranged. 11. Arrangement according to claim 9 or 10, characterized in that the disc (55) has an area which leads from the receiving optics (18) to the photoelectric receiver (23) Receiving measuring light path (19) covered and that in this area a large number of the received light through openings (90 to 95) is provided. which all have the same distance from the axis of rotation (56) of the disc (55), and that at least in some (91 to 95) of these openings (90 to 95) a filter that attenuates the reception light is arranged in each case. where the damping factors of different filters partially differentiate from each other. 12. The arrangement according to claim 11, characterized in that in each case η of the openings (90 to 95) of the disc (55) which allow the receiving light to pass through are combined to form a group which includes an opening (90) which allows the receiving light to pass through unattenuated and n- \ openings ( 91 to 95), in each of which a filter with a different attenuation factor is arranged, and that in each group the attenuation-free opening (90) and the openings (91 to 95) with the filters with different attenuation factors are arranged in the same order. 13. The arrangement according to claim 12, characterized in that the damping factors of the In Corresponding openings (90 to 95) of different groups arranged filters one another are equal and that the damping factors of Filters belonging to a group differ from each other by a factor that is smaller than that Ratio of the largest to the smallest of the photoelectric receiver (23) and the one following it Canal processable. Signal amplitude is. 14. The arrangement according to claim 12, characterized in that the damping factors of the in Corresponding openings (90 to 95) of different groups arranged filters one another are the same and that the damping factors of the to Filters belonging to a group differ from each other by a factor that is smaller than that Product of the ratio of the largest to the smallest of the photoelectric receiver (23) and that of him downstream channel processable signal amplitude and from the ratio of the largest to the smallest from the transmitter (1) is deliverable power. 15. Arrangement according to one of claims 11 to 14, characterized in that the openings (60 to 6S) of the disk (55) which allow the transmitter to pass through are combined to form groups comprising η openings, between which groups of mirrors which deflect the transmitter light are located, comprising η mirrors (70 to 75), that each the groups of openings (60 to 65) comprises at least one opening (60, 61) which is extended in the circumferential direction and in which no filter is arranged, and that in de.i the remaining openings (62 to 65) at an angle different from 90 ° at an angle to the optical axis (ISa) are arranged attenuation filters, which all have the same attenuation factor. 16. Arrangement according to one of claims 10 to 15, characterized in that always one that Transmitter light-transmitting opening (60 to 65) or a mirror that deflects the transmitter light (70 to 75) and an opening (90 to 95) transmitting the received light with their centers on one common radial beam emanating from the axis of rotation (56) of the disk (55) are, and that the disc (55) has at least one hole (98) which is a different distance from the Has axis of rotation (56) than the openings (60 to 65 and 90 to 95) and the mirrors (70 to 7S) and through which a light barrier (99, 100) can be released once with each rotation of the disc (55), their signal to determine the current position of the disk (55) unc * to monitor your rotational speed serves. 17. The arrangement according to claim 16, characterized in that at a predetermined angular distance in front of each of the center of two openings or an opening and a mirror with each other connecting radial rays a hole (98) releasing the light barrier is provided and that the when passing through these holes (98) through the light barrier (99, 100) signals emitted for preparation serve to carry a light pulse. 18. Arrangement according to one of claims 9 to 17, characterized in that in the receiving light path (19, 21) between the rotating disk (55) and the photoelectric receiver (23) a tellransparent mirror (85) at an angle to the optical axis of the Reception light is arranged through which the received light passes straight and through the the light coming from the reference light path (11) can be deflected and into the light leading to the receiver (23) Part (21) of the Hrnpfangsllchtweges (19, 21) can be coupled together 19. Arrangement according to one of the preceding claims, characterized in that in the reference light path (11) in series one behind the other an attenuator (83) with a fixed attenuation factor and a controllable attenuator (33) is arranged with a variable attenuation factor are. 20. The arrangement according to claim 19, characterized in that the ratio of maximum to the minimum damping factor of the controllable attenuator (33) at least equal to that Product of a numerical value that takes into account the age-related decline in transmitter power and the ratio of the maximum to the minimum signal amplitude obtained from the photoelectric Receiver (23) and its downstream channel can still be processed. 21. The arrangement according to claim 19, characterized in that the ratio v ~ m maximum to the minimum damping factor of the controllable attenuator (33) at least equal to that Product of a numerical value that takes into account the age-related decline in performance, the ratio of the maximum to the minimum signal amplitude received by the photoelectric receiver (23) and still process its downstream channel; can be, and the ratio of the maximum is the minimum power that can be delivered by the transmitter (1). 22. Arrangement according to one of claims 19 to 21, characterized in that the controllable Attenuator (33) is a gray-tipped disk (80) which can be rotated by a stepping motor (81). 23. Arrangement according to one of claims 9 to 21, characterized in that the controllable attenuator (33) is a PLZT or a PLWNZT cup is. 24. Arrangement according to one of claims 19 to zi, characterized in that the control signal for the controllable attenuator (33) can be obtained by comparing the amplified and rectified Slgr> alamplitudes that the photoreceiver (23) when receiving a measuring light pulse on the one hand and when receiving a reference light pulse on the other hand emits. 25. Arrangement according to one of the preceding claims with one for generating the various Chopper used for the required voltages, characterized in that the trigger generator (3) Depending on the chopper vibrations, it can be controlled that the start and end of the signal run-time measurements fall in tent rooms in which there are no disturbances caused by the chopper flanks appear. 26. Arrangement according to one of claims 1 to 25 with a chopper serving to generate the various required voltages, characterized in that a circuit arrangement for suppressing the vibrations of the chopper can fall in the periods of time in the beginning and end of a Slgnai Laufzeltmess , and one In these tent dreams the. ^r ".romversorgung the device the acquiring buffer capacitor are provided. 27. Arrangement according to one of the preceding claims, characterized in that for optimization of the signal / noise ratio Center frequency tunable interference filter (87) In a parallel light path in front of the receiver (23) arranged 1st. The invention relates to a dynamics control arrangement for a distance measuring device based on the principle of measuring a measuring light pulse according to the The preamble of claim 1. Such a distance measuring device is, for example, in DE-OS? l 03 567 described. There the branching point is static, i.e. each light pulse emitted by the transmitter is split into two parts, one of which is emitted as a measuring light pulse to the target object and the other as a reference light pulse is fed directly to the control, with the latter for starting and the first as a reference light pulse is used to stop the treadmill measurement. The problem of adapting the intensity of the emitted measuring light pulse to the reflectivity and distance of the target object and the intensity of the reference light pulse to that of the reflected measuring light pulse is solved with the help of damping devices that are switched into the light path between the receiving optics and the detector device or into the reference light path and can in principle be of any type. The adjustments just mentioned are necessary because the intensity of the received measuring light pulse can fluctuate within wide limits due to the causes mentioned as well as the influences of the respective light permeability of the medium lying between the measuring device and the target object. Since the receiver of the detector device has a low dynamic range compared to this amplitude range of the reflected light pulse. Is it necessary to achieve a high measurement accuracy to weaken the intensity of the light impulses emitted by the transmitter, which is selected for a large measurement range, if very small distances and / or the distances of very well reflecting target objects are to be measured. Since, moreover, the response behavior of the receiver can change as a function of the intensity of the light pulse incident on the photodetector. Is it necessary to achieve the most similar processing possible of the measuring light pulse and the reference light pulse that the latter has approximately the same amplitude as the light pulse reflected from the target object? In the case of very distant and / or poorly reflecting target objects, it is therefore necessary to reduce the amplitude of the reference light pulse accordingly. Known damping devices such as iris diaphragms or retractable filters are suitable for this either comparatively large and unresponsive and therefore unsuitable for high measuring frequencies, or expensive and not readily usable. In contrast, the invention is based on the object of providing a distance measuring device of the initially mentioned mentioned type so that the required attenuation of the light pulse intensities in a simple, inexpensive and reliable type can be done at high speed. At a. Distance measuring device of the aforementioned It is kind of like in DE-OS 32 19 423 based on a patent application filed at the same time described, also possible, the transit time measurement not with a reference light pulse branched off from the measuring light pulse but to start by the electrical control pulse emitted by the trigger generator causes the transmitter to emit a light pulse, so that strictly speaking there are no light pulses but a signal run-out measurement is carried out, whereby the signal is initially in electrical form, then occurs as a light pulse and then again as an electrical signal. The influence of doing this during the two "Electrical" phases occurring signal delays and their fluctuation and drift phenomena the measurement result is eliminated by the fact that immediately before and / or after the measurement light pulse, the target object is globally regulated, a reference light pulse is directed into the device-internal reference light path, the signal transit time measurement described above is also carried out. In this case it is temporal Length of the "optical" phase known exactly, so that the signal delays in the two "electrical" Phases determined and because of the shortness of the time in which the measuring shot and reference shot follow one another, with the signal delays of the "electrical" phases that occurred during the measuring thrust equated or can be eliminated by subtracting the measured values obtained in this way. For the required feeding of the light pulse emitted by the transmitter once into the measuring light path and a ^ j in the reference light path is a light path switch provided, which moves and at the same time corresponding measuring light positions (feeding in the light pulse In the measuring light path) and reference light positions (feeding the light pulse into the reference light path) passes through. This optical path switch, which is required anyway, can now also used according to claim I to solve the problem on which the invention is based will. In the context of the concept according to the invention, namely the times at which the light pulses hit to control the movable light path switch so that due to the current position of the light path switch the desired damping is achieved, there are the following three preferred variants: a) In the output area of the light path switch, which is controlled by a periodically oscillating mirror, a with an approximately constant angular velocity rotating mirror prism or one with approximately constant Rotating angular velocity, deflecting mirror and light passage openings Disc can be formed, there is only a single continuing Einspelsungsabschnltt of the measuring light path and / or a single further feed section of the reference flight path. To the Achieving, for example, 50% attenuation, it is ensured that a light pulse is too hits the mirror, the mirror prism or the rotating disk at such a point in time that due to the current position of the light path switch, only half of that in the Light pulse contained amount of light in the entrance window of the further light path falls while the other half runs past it and / or is absorbed. To achieve a lower or greater attenuation, there will be correspondingly different points of impact for the light pulse on the light path switch selected to reduce the amount of light falling into the further light path to zoom in or out. The advantage of such a variable part coverage