Dr. Johannes Heidenhain Gmbh

Johannes Heidenhain Gmbh

Other

Alfons Spies

Wolfgang Holzapfel

Alfons Ernst

Erich Strasser

Johann Mitterreiter

Kurt Feichtinger

Hermann Meyer

Steffen Bielski

Andreas Schroter

Gerald Metz

Arnold Teimel

Harald Bernard

Josef Muller

A multi-turn rotary encoder that includes a first code carrier connected with an input shaft, a scanning device that scans the first code carrier and generates an absolute position of the input shaft within one revolution, and a digital code word is present at an output of the scanning device and a second code carrier for measuring the number of revolutions of the input shaft. A reduction gear is arranged between and coupled to the first and second code carriers. The second code carrier includes a magnetic body with at least one north and south pole and a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with the magnetic body. An evaluation circuit integrated into the substrate, wherein scanning signals, which are phase-shifted with respect to each other, from the sensor elements are supplied, and that the evaluation circuit combines the scanning signals in such a way that a second digital code word is present serially or in parallel at an output of the evaluation circuit. A combination logical device, which is supplied with the first and second digital code words and which forms a resultant multi-digit code word therefrom.

Multiturn rotary encoder with multiple code carriers coupled by a reduction gear

A position measuring system that includes a scale graduation and a scanning element, wherein the scanning element moves relative to the scale graduation along a measurement direction so as to generate position-dependent, intensity-modulated output signals. The scanning element includes a dynamic characteristic, which has saturation areas adjoining both sides of an at least partially approximately linear operating area, in which no significantly changed output signal results any more, even when the input signal changes. The scanning gap (d) between the scale graduation and the scanning element is selected in such a way that as the scanning element moves over its entire measurement range a modulation between maximum input signals, which are located in the saturation areas of the dynamic characteristic, takes place. In order to eliminate the distortions of the output signals which usually occur in this modulation area it is furthermore provided to perform signal filtering in order to remove, in particular, the third harmonic from the output signal.

Position measuring system

An arrangement as well as a method for the automatic correction of error-containing scanning signals, which contain defined deviations from the ideal signal shape, of incremental position measuring devices is disclosed, wherein an ideal signal shape is presupposed by a downstream arranged evaluation unit. In this case the scanning signals are supplied to a processor unit, and correcting values are determined by means of a correction algorithm which are converted in turn into appropriate control signals. The analog scanning signals as well as the control signals are supplied to a correction unit, which contains several adjustment possibilities for correcting the error-containing scanning signals by the control signals acting on them. The processor unit as well as the correction unit are arranged in such a way that scanning signals, which have already passed through the correction unit, are present at the input side of the processor unit.

Arrangement and method for the automatic correction of error-containing

A position measuring device having a magnetic graduation scanned by a scanner unit which contains magnetic field sensitive elements as sensors. A high frequency alternating auxiliary field is generated to magnetically bias the magnetic field sensitive elements.

Magnetic measuring system having a particularly oriented auxiliary field

In a magnetic position measuring device for determining the relative position of two objects which can be moved with respect to each other, a magnetic graduation is scanned by at least two Hall elements for the generation of position-dependent output signals. The Hall elements respectively have at least one supply voltage and one measuring voltage connector. Furthermore, at least one switching unit is provided, which periodically interchanges the supply voltage and the measuring voltage connectors of each Hall element with each other. The periodic interchange of the supply voltage and measuring voltage connectors of the various Hall elements with each other is furthermore synchronized by means of at least one synchronization unit.

Magnetic position measuring device using Hall elements as sensors and

A measurement representation with magnetic elements disposed in the measuring direction, comprising fitted-together base bodies, wherein all magnetic elements of each base body are magnetized with the same orientation in one single common direction, and that the fitted-together measurement representation has alternatingly a magnetic element of a base body and of a further base body, wherein the magnetic field of the magnetic elements of the one base body is oriented opposite the magnet field of the magnetic elements of the other base body in the fitted state.

Two piece measurement representation with magnetic elements magnetized

A position measuring device having a sensor, the output signal Sd of which is a function of the distance between a graduation and a scanning unit. To render the distance-dependent signal independent of temperature changes, the sensor consists of a potentiometer circuit with an active branch and a complementary branch. Magneto-resistive elements which scan the graduation are disposed in the active branch. Resistive elements are disposed in the complementary branch which have the same temperature behavior as the magneto-resistive elements of the active branch, but are substantially insensitive to magnetic fields. The voltage across the active branch is taken as the distance-dependent measuring signal Sd and is used to control the amplitude of the position-dependent scanning signals generated by scanning the graduation.

Position measuring device having a sensor for sensing the distance

A magnetic measuring system having a scale and a scanning unit, the scanning unit having a plurality of magneto-resistive elements which are disposed at an angle .beta. with respect to the measuring direction. The scanning unit generates an auxiliary magnetic field which acts perpendicularly to the measuring direction so as to magnetically bias the magneto-resistive elements.

Position measuring device employing primary and auxiliary magnetic fields

A position measuring instrument for measuring the relative position of two objects movable relative to one another. The position measuring instrument comprises a periodic measurement scale division having a period t and a scanner unit, wherein the scanner unit and the periodic measurement scale division move relative to one another in a measuring direction. In addition, the scanner unit comprises four groups (A-D) each comprising at least four magnetoresistive elements (A.sub.n -D.sub.n) (n=1, 2, 3, 4, . . .), which are interconnected in the form of a series-parallel circuit to form a half bridge circuit having an upper branch and a lower branch. The upper branch comprises a magnetoresistive element from each group (A-D) and the lower branch comprises a corresponding magnetoresistive element from each group (A-D). Furthermore, the magnetoresistive elements of the upper branch are offset from the corresponding magnetoresistive elements of the lower branch by t/2. The position measurement instrument further comprises an evaluation device to form position measurement values from position-dependent output signals generated by the magnetoresistive elements in response to relative movement between the periodic measurement scale division and the scanner unit.

Position measuring instrument

A phase grating is provided in this length or angle measuring apparatus, which operates by interference. A beam striking the phase grating from a laser is diffracted into .+-.1st order beams at the phase grating. The diffracted .+-.1st order beams are reflected at retroreflecting elements and, diffracted once again at the phase grating, and made to interfere in pairs. The modulations in intensity of the two-beam interferences are converted by detectors into electrical signals that are phase-displaced from one another. The diffraction grating is configured such that at least one partial beam cluster of the zero order of diffraction is involved in the formation of at least one of the two-beam interferences.

Position measuring apparatus utilizing two-beam interferences to create

The angular graduation of a graduated disk is scanned in a measuring device by a scanning unit by the movement of light beams in two angular graduation areas located diametrically opposite each other. To compensate for wobble errors caused by the wobbling of the graduated disk, the light beam emanating from a light source impinges on the graduated disk at a point outside of the angular graduation and, following reflection and deflection by a triple prism, impinges parallel to itself in the form of a light beam on an impact point in a first the graduation area. The light beam is split into two diffraction beams by the graduation, and meet, after having passed through a deflection prism, at a meeting point in a second angular graduation area. Since the impact point and the meeting point are always located on the same radius, the wobbling of the disk does not have a disadvantageous effect on the accuracy of measurement.

Photoelectric device for position measuring

A position measuring arrangement is disclosed which comprises a three-grid measuring system. A first grid is illuminated under an angle .alpha.. Two partial beams result from diffraction on the first grid. the two partial beams impinge on a second grid, which may be the scale of the position-measuring arrangement. Diffraction of the partial-beams on the second grid result in four partial-beams of which the two partial-beams lying closest to the grid normal impinge upon a third grid. The third grid again diffracts the partial-beams and brings them into interference. The partial-beams which are intensity-modulated by interference by the third grid impinge upon photodetectors, by which they are transformed into phase-shifted electric signals and fed to and evaluated arrangement.

Photoelectric position-measuring arrangement having a plurality of

A measuring system is disclosed which is integrated into a feed arrangement in such a way that the structural size of the feed arrangement is not increased significantly. In the disclosed embodiments, the feed arrangement includes a compressed air cylinder which includes a hollow profile and a piston movable within a cylinder defined by the profile. In one embodiment, a measuring scale is positioned within a groove formed within the hollow profile and this measuring scale defines a magnetic measuring graduation which is scanned by a scanning unit accommodated in the piston of the air cylinder.

Device for measuring feed movement

In a photoelectric measuring device for measuring the position of two objects which can be rotated relative to each other, a grid located on a graduation support, which is connected with one of the objects, is scanned by a scanning device connected with the other object. To eliminate the eccentricity between the grid and the rotational axis of the graduation support, the light beam emitted by a light source is split in a first graduation area of the grid into two first order diffraction beams, at two diffraction angles. After two-fold deviation by two parallel mirrors, the first order diffraction beams are again joined, in a second graduation area of the grid that lies diametrically opposite the first graduation area. The first order diffraction beams join at the same diffraction angles at which they were emitted from the first graduation area of the grid. Consequently, the beams at the second graduation area are parallel to themselves as they were emitted at the first graduation area.

Photoelectric angle measuring device

A magnetic measuring instrument for measuring the relative position of two objects includes a scanning unit which incorporates a magnet positioned to scan a measuring division. The measuring division is provided with alternately magnetically conducting and magnetically non-conducting zones. Measuring signals of high signal quality are generated because the induction generated by the magnet in the measuring division runs only in planes perpendicular to the longitudinal extent of the measuring division (the measuring direction x). Magnetic field sensitive sensor elements in the air gap between the magnet and the measuring division scan the air gap induction to generate position dependent measuring signals.

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Seebruck, Germany

Alfons Spies