Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
  • G01D5/248—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains by varying pulse repetition frequency
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
  • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
  • G01D5/249—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains using pulse code
  • G01D5/2492—Pulse stream
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
  • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
  • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
  • G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
  • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
  • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
  • G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
  • G01D5/34776—Absolute encoders with analogue or digital scales

Definitions

• the invention relates to a measuring element with a track, wherein the track has a material measure. Furthermore, the invention relates to a related measurement method.
• a position in particular an absolute position ei ⁇ ner machine axis, for example in a machine tool, production ⁇ tion machine and / or a robot encoders are used.
• the position that is a measuring element, which element as a linear EIe- or may exist as a rotatory element, the measuring element having one or more tracks having a respective degree ⁇ embodiment in the form of increments of Sensors are scanned to determine the position.
• European Patent EP 0 503 716 B1 discloses an encoder for determining an absolute position, wherein a commercially available absolute track and an incremental track are combined into a single composite track, wherein the measuring graduation is designed in such a way that the individual increments of the material measure are pseudo-neutral. are distributed randomly. The disadvantage is that usually 8 and more sensors are needed to determine the situation. From the publication "The Transformation Measurement Method - A Contribution to the Design of Absolute Measuring Systems", Uwe Kippung, TU Chemnitz, 1997, Dissertation, page 11, a length measuring system from the company RSF-Elektronik from 1992 is known, in which an incremental track and an absolute track can be used to determine a location.
• the object of the present invention is to specify a simple measuring element and a simple measuring method for determining a position, in particular an absolute position.
• a measuring element with a track, wherein the track has a material measure, which is scanned by at least two sensors for determining a position, wherein the material measure is formed such that the sensors as a respective output signal a modulated sinusoidal track signal for determining spend the situation.
• a measuring method with a track, wherein the track has a material measure, which is scanned by at least two sensors for determining a position, wherein the material measure is formed such that from the sensors as a respective output signal a modulated sinusoidal track signal for Determine the situation.
• the modulated sinusoidal track signal is frequency modulated. The situation can then be determined particularly accurately.
• the modulated ⁇ sinusoidal sinusoidal signal is frequency modulated such that with increasing position, the frequency of the track signal increases monotonically or monotonically.
• the location can then particularly a ⁇ be determined once.
• the modulated sinusoidal track signal is amplitude-modulated.
• the position can be determined very precisely in a particularly simple manner.
• the present invention it proves to be advantageous if the transformer ⁇ body is scanned by at least three sensors for determining a position, since then the situation can always be clearly ⁇ be determined. Furthermore, it proves to be advantageous if the measuring ⁇ element is formed in the form of a rotationally symmetric element whose outer contour has a frequency-modulated si ⁇ nusförmige shape. If it is necessary for mechanical constructive reasons during the measurement the scanning head and / or the measuring element in rotation around the Rotati ⁇ onsachse of the sensing element to turn, this has as a result of the special design of the measuring element, no influence on the measurement and thus to the Determination of the situation.
• encoders having the measuring element according to the invention are required.
• a rough position is determined in which in a first step from the track signals from the sensors and determining the location in a second step by means of interpolation using the coarse position.
• the position can be determined in a particularly simple manner.
• FIG. 1 shows a measuring element according to the invention
• FIG. 2 shows a track signal according to the invention
• 3 shows a further frequency-modulated according to the invention
• Track signal, 4 shows another frequency-modulated according to the invention
• Track signal, 5 shows a locus
• FIG. 7 shows an amplitude-modulated track signal
• FIG. 8 shows a further measuring element according to the invention with a scanning head.
• a measuring element 2 according to the invention is shown in the form of a schematic representation.
• the measuring element 2 has a track 3, which has a material measure.
• the material measure consists in the embodiment
• Increments I 1 to I k which are scanned by sensors S 1 to S n for determining a position z.
• Each increment Ii to I k has two regions magnetized in opposite directions (the separation of the individual regions is shown in FIG. 1 by a dashed line).
• the sensors S 1 to S n are arranged on a scanning head 1 and have with respect to a zero point AO of the scanning head, the distances ai to a n .
• the position z indicates the distance from the zero point MO of the measuring element 2 to the zero point AO of the scanning head.
• measurement element 2 is a so-called linear measuring element, that is, the position ei ⁇ ner linear movement is measured.
• the scanning head 1 thereby moves in the direction of the double arrow over the measuring element 2 along in a uniform distance and the position z is measured by at least two sensors (eg, the sensors Sl and S2) formed in the embodiment as Magneti ⁇ cal sensors are scanning the magnetic field generated by the increments I 1 to Ik.
• the sensors Sl and S2 formed in the embodiment as Magneti ⁇ cal sensors are scanning the magnetic field generated by the increments I 1 to Ik.
• the measuring scale of the measuring element of the invention Unlike a commercially available material measure in which all increments in general a constant period length L 1 to L k aufwei ⁇ sen, has the measuring scale of the measuring element of the invention according to Embodiment increments on whose perio den dairyn Li to L k with increasing position z decrease (Alternatively, the measuring standard may also be designed so that the material measure comprises increments whose period lengths Li to L k with increasing position for increasing or their cycle lengths L x and L k simply different values accept) .
• the output signal of the sensor is a frequency-modulated sinusoidal so-called track signal with decreasing period length, ie increasing frequency, the lengths being the period lengths L x to L k .
• FIG. 2 a track signal f (z) generated by the sensor Si as an output signal is shown.
• each of the sensors Si to S n outputs as output a respective modulated sinusoidal track signal f (z) mathematically described by the tracking function f (z), the nth sensor being the signal.
• the track signal f (z) is frequency-modulated.
• An example of the track signal f (z) according to the invention is shown in FIG.
• a first approximate value in the form of a coarse layer for the position z to be determined is first determined by a coarse evaluation from the sensor signals by determining one or more auxiliary quantities. By a subsequent fine evaluation by In ⁇ terpolation the position z is then determined exactly.
• L (z): L k for J ⁇ L ⁇ ⁇ z ⁇ J ⁇ L ⁇ (51010b) with positive, pairwise different period lengths Li, L 2 , ..., L ⁇ , given (see FIG. 3).
• the scanning head 1 according to FIG 1 has at least two Sen ⁇ sors, whose distance a 2 -ai is very small compared to the occurring period lengths, ie
• Possible Solution 2 In the scanning head 1, at least two further sensors are provided whose distance a 4 -a 3 is also very small in comparison to the occurring period lengths and evaluates the quantities corresponding to the first two sensors
• the scanning head 1 according to FIG. 1 has at least one Two sensors whose distance a 2 -ai is not very small compared to the occurring period lengths
• the track signal is given by
• the first sensor supplies the track signal x and the second sensor supplies the track signal y
• ⁇ : (1 + z / c) 2 ⁇ z / L
• ⁇ : [(2 z + L / 4) / c] ⁇ / 2.
• the angle ⁇ can be determined from the measured values x, y up to multiples of 2 ⁇ and thus up to multiples of L, i. It is true that the position can be determined within a period L, not over the period itself. But if one chooses 0 ⁇ c ⁇ , the period can be determined, as will be shown below.
• Equation (52055b) after z i.
• the solution sought is exactly the one for which these values are identical to the actual measured values x, y.
• Solution Option 1 According to the previous exporting ⁇ approximately example.
• Equation (52055b) for all occurring z is less than ⁇ / 2, typically less than ⁇ / 3.
• equation (52270) In contrast to equation (52270), this value is unique, but numerically not so exact, because it comes from the rough evaluation comes. Accordingly, it is here only used the parameter k to determine as in equation (52270) that ⁇ the ⁇ according to equation (52270) according to equation (52275) is most Next Tier ⁇ th, and determines with this k the exact value of ⁇ according to equation (52270).
• Z 0 be the value found by the rough evaluation for the sought-after position z.
• znextx min (Z 0 ) and znextxmax (z 0 ) denote the local minimum and the local one
• ⁇ nex txmax (Z 0 ): m ⁇ + ⁇ / 2, if m is even,
• this method can also be formulated for the measured value y instead of x.
• the track signal f (z) is in this case by
• B (z) B n for (n-1) L ⁇ z ⁇ n L (B ni ⁇ B n2 for nl ⁇ n2) (53020)
• the tracking signal f (z) is made in the ⁇ sem case of a number of successive sine periods of equal period length, but different amplitudes together.
• lower curve the resulting track ⁇ signal f (z) is shown.
• the scanning head 1 has here in the context offindsbei ⁇ game on at least three sensors whose relative position to ⁇ each other
• the coarse position is determined (coarse evaluation). For fine ⁇ evaluation one determines further
• FIG 8 is an example of another possible Ausges ⁇ lay out your measuring element according to the invention 2, of a scanning head 1, which moves in the direction of the double arrow along the measuring element 2 and the measuring standard samples shown.
• the material measure is realized by the 3-dimensional contour of the measuring element.
• the Messele ⁇ ment is implemented here in the form of a rotationally symmetric element, in particular a rack, the outer tooth-shaped contour has a frequency modulated sinusoidal shape ⁇ .
• the scanning head 1 has a permanent magnet and magnetic sensors.
• a frequency-modulated sinusoidal output signal is generated as a track signal. Since the metrical ⁇ African mapping of the contour of the measuring element 1 in the track signal usually has a low-pass characteristic, an amplitude modulation of the contour of the measuring element 2 is additionally performed such that the amplitude of the track signal generated by the respective sensor is constant ,
• the outer contour of the rack has a course in which the tooth heights and depths of the contour are greater, the shorter the respective teeth / tooth gaps are.
• the measuring element 2 and the material measure 3 can also be used as rotatory elements (eg in the form of a round disc ) are present for detecting a rotational movement. In doing so, it is customary, e.g. in an encoder, the scanning head stationary carried out while the dimensional element with the material measure rotates under the scanning head.
• optical sensors and the measuring scale are used in accordance with ⁇ walls to form, for example, optical increments.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)

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• 2004
  • 2004-12-23 DE DE102004062278A patent/DE102004062278A1/de not_active Withdrawn
• 2005
  • 2005-12-16 JP JP2007547470A patent/JP2008525775A/ja not_active Abandoned
  • 2005-12-16 WO PCT/EP2005/056866 patent/WO2006069925A1/de not_active Ceased
• 2007
  • 2007-06-25 US US11/767,845 patent/US20080180093A1/en not_active Abandoned

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