DE1473799A1 - Process for digital length measurement and device for carrying out the process - Google Patents

Description

Process on digital length measurement and device for performing the process The automation of length measurement, as required for production monitoring, -control or control is also required for data acquisition for don yereand and other purposes are striven for, can often be achieved by using digital methods.

It is known to use a pulse generator for this purpose is driven by a feeler roller, the Taatrolle ton don su measuring good, meietenz by friction, is rotated.

The difficulty arises with the diode method because the feeler roller the geneuo Linge takes good care of everything from the beginning to the end. To bypass dloxor Difficulty zind elutriohtungen have become known in which the feeler roller on one the material-bearing tape unrolls and the length of the counting of the impulses is two to two Signals is determined. The two signals are generated by a light chain given that interrupted by the beginning and dam end of the lutez bu free gogebon will.

It has become another beXanat facility in which the process vice versa int. There a photocell is moved by a tape along the measuring path. From the tape sine Roche Me # impulse is given via a taztroll, which in turn is between two signals from the Fotselle are counted.

The disadvantage of these procedures is u.s. in that because # by the friction entrainment a slippage arises, which leads to measurement errors and the effort involved in execution of the procedure is great.

Another group of digital length measurement methods is known in with the dam good is pushed against a stop and then the Mossung by sliding sinues stop to the other end or move a light barrier to takes place over the end, the path of the stop or the light barrier until the interruption is measured digitally.

The method only applies to objects at rest, with similar difficulties bela stopping the stop.

The disadvantage of all known methods is that # for reasons of the accuracy for yin length measured but the orOBe of the tolerance of the least stans an impulse has to be generated and this over the full measurement length or at least at least tuber don Me # area. For example aind at 5 s measuring range and 1 at tolerance 5000 Impulse required.

Such a series of impulses can be generated with a Taatrollot but dabol is the accuracy due to the slippage and the elasticity of the transmission medium limited. The measuring speed is restricted by the pulse frequency.

The invention is based on the object of finding a method dam does not have the known equipment and simple devices for various Develop applications.

The invention reads the task in that # at both ends of the MeBstrooke is measured, at one end a coarse measurement duroh a coarse breaker and at the Enderen end of sine peinmeaaung duroh sinon peinrechen takes place. The entire measuring range is divided into coarse intervals and a coarse interval into fine intervals.

Conveniently, a fine interval has the ardue of the tolerans and the coarse interval is greater by one or more powers of ten.

The explanation of the procedure and the description of some examples The illustrations are used for devices for carrying out the method.

Fig. 1 shows a schematic representation of a device according to the Finding the contactless length measurement of a moving 8table. For better Explanations of the procedure are entered in all cases.

Fig. 2 shows a schematic representation of a device according to Finding on periodic width measurement.

Aab. 3 shows a schematic representation of a device according to t Invention for measuring the length of a body between measuring surfaces.

The measuring procedure consists in the fact that from the initial position of a counter from the impulses don Grobrochone are counted in the separate decade of the counter until the urate impulse of the fine rake appears and now the impulses of the fine rake the next impulse of the coarse break appears. Since the pulse train the coarse rake by the abots of the known per se, denoted by coarse interval Pulse generator given plumb and analog in fine rake the pulse sequence through the Abetand the pain interval takes place, the counting is a digital length measurement. The size of the coarse and fine intervals can be selected as desired, with dural optics Lutter can also achieve very high levels of accuracy. The basic position The counter is determined by the arrangement of the coarse and fine rakes; also the counting direction Let the layout of the system be freely designed. All counters become known Devices used.

The procedure is to be explained with the aid of Fig. 1. The Fig. T Seigt a stick 1, deaeen length is to be measured and the otoh in the direction of the arrow Moved via a measuring device, including two measuring rakes. There is one there each Row of pulse generators, which then give an impulse, wonn the end of the don Etnbee just fart about it. The pulse generator, which the abatand ae coarse interval have - in Fig. 1 each 1.0 m - are combined into a coarse screen 2. The pulse generators, which have the distance of a fine interval - in Fig. 1 each 0.1 m - are combined into a fine rake 3. The abatand of the two rakes let tost; However, the measuring length can be measured with the same measuring range can be changed.

The coarse edge is supposed to be overlaid from the rear end Each encoder gives a signal, On is labeled g1, g2 ... g5. Analog should dor fine rake when the front end overflows the signals f0, f1, f2 ... f10 give.

The signals are counted by an up / down counter and d formed with the measurement result.

The mode of operation is as follows: The counter is in the basic position, For example, the arrangement according to Fig. 1 suf 8.0 m Stables since signal g1 appears, the counter is reset to a rough interval, i.e. 1 m. The next signal g2 and all others are followed by further down counting, until the signal fo appears.

Fig. 1 shows the position shortly before this point. The counter iet has been reset to 5.0 m by gl, g2 and g3. Appears in front of the signal g4 the signal fo. This causes a switchover.

The following fine signals f1, f2 ... are applied to the counter and continue it in the corresponding decade, i.e. duroh f1 ton 5.0 to 5.1, through f2 from 5.1 to 5.2. Sikh eo repeats this process for a long time until the next one Coarse signal, i.e. g4, appears.

This means that the count is ended. The counter shows the length L sit a positive folerans to The arrangement according to Fig. 2 serves the periodic Width measurement of a moving bond. The band 4 moves perpendicular to the plane of the drawing. The measuring device 5 oscillates in the direction of the double arrows. It carries the coarse legs 2 and the fine rake 3. Each time the measuring rake moves back and forth, coarse signals are generated l g and @einignal f, which are a digital width measurement according to the invention Procedure permitted. the measurement results can be used to regulate the bandwidth will. A control of the band width or a classification is also possible by arranging meters known to sikh with markings of the desired ones Tolerances or the Ilaseen.

The type of signaling device is arbitrary. For example, light barriers, Infrared barriers, inductive sensors can be used.

The device according to Fig. 3 is used to measure the length of the rod precisely 1 wipe a stop 6 and veines buffer 10. The stop 6 is with its axis 7 slidably mounted in a bearing 8, for example. The movement is hydraulic by means of known hydraulic cylinder 9 causes. The buffer 10 int can be displaced in the housing 11 is arranged and is pressed by means of a buffer spring 12 over the collar 13 to the left.

At the stop 6 there is a coarse height 2, consisting of a sinus comb or a perforated sheet metal or a coarse optical grille, which is flush with the de. tneehlag can shift so that # 14 coarse signals at the fixed light barrier g arise.

On the collar 13 of the buffer 10, a fine rake 3 is attached, the one Structure like the coarse screen 2 can have and interact with each other in the event of a displacement with the fixed light barrier 14 fine signals f are.

To measure the rod 1, this is not shown in a groove, not shown, between the. nzchlag 6 and the buffer 10 placed. The stop 6 with its axis 7 is in the bearing 10 by the hydraulic cylinder 9 lifted the gate in the direction of the arrow and thereby lifts the rod 1 against the buffer 10.

Dlerer moves in walker 11 against the force of the buffer spring 12, which are graduated on the collar 13 of the buffer 10 and on the housing 11.

When the stop 6 and the buffer 10 move, the height also moves 2 and fine rake 3 opposite the fixed light barriers 14 and generate toOurch Coarse signals and fine signals based on the basic principle of the method according to the invention are counted and thereby form the measurement result.

Expectations; 1. Procedure sur digital length measurement in the relative Displacement of the measuring object in relation to the measuring device or parts of the same, measuring impulses through the ends of the measuring path either directly or indirectly via any encoder generated and then counted, characterized in that # those from one end generated pulses come about by a shift by a rough interval, this being a multiple of the shift us a fine interval, de. at the sndersn end leads to a pulse and that by counting the coarse interval pulses in the associated counter decade up to the thawing of the first fine interval pulse and below Subsequent counting of the fine interval pulses in the corresponding counter decade bi The measurement result is found by thawing the next primary interval pulse, where the initial value of the meter is given by the measuring arrangement and the dimensions are.

Claims (1)

2. Torriohtung sur execution of the method naoh claim 1, characterized gekennseichnet because # for the generation of the coarse interval pulses and or the fine interval impulses, which are known per se, are lined up in a row, where the bstend corresponds to the individual encoder de coarse interval 11 or the fine interval and the distance between the belden rwohwn was at least at the moment of the measurement. 3. device to carry out the procedure according to claim 1 thereby marked, d sur generation of the robintorra copule and / or the fine interval impulses Me # calculates and which by alo displacement of a getter au veines stationary encoder the desired impulses erseugt wwrdMtt 4th device after the Claims 2 and 3 characterized by the fact that # the abots of the me # rake directly or indirectly verherber is able to adapt to the measurement length.