CA1232957A - Rotational sensor - Google Patents
Rotational sensorInfo
- Publication number
- CA1232957A CA1232957A CA000464374A CA464374A CA1232957A CA 1232957 A CA1232957 A CA 1232957A CA 000464374 A CA000464374 A CA 000464374A CA 464374 A CA464374 A CA 464374A CA 1232957 A CA1232957 A CA 1232957A
- Authority
- CA
- Canada
- Prior art keywords
- hall
- angle sensor
- effect
- effect plate
- embedded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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
- G01D5/14—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
- G01D11/00—Component parts of measuring arrangements not specially adapted for a specific variable
- G01D11/24—Housings ; Casings for instruments
- G01D11/245—Housings for sensors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A novel sensor or transducer is provided herein. The sensor is an angle sensor which may be used to achieve spatially correspondent master/slave controls. The sensor includes an inner ring of robust, non-magnetic material within which is fixedly disposed, but preferably is em-bedded, at least one Hall-effect plate ; an outer ring of robust non-magnetic material relatively rotatable with respect to the inner ring, the outer ring having fixed therein, but preferably embedded therein , at least two magnet poles to provide a uniform magnetic field in the inner ring ; and a casing around the outer ring, the casing being formed of a ferromagnetic metal. Electrical connections are provided for the Hall-effect plate for applying a current along the length thereof and for conducting the voltage therefrom which has been produced across the Hall-effect plate. Means are provided for relatively rotating the inner and outer rings. Finally means are provided for reading the voltage which has been produced across the Hall-effect plate. This voltage varies continuously as the sine of the angle of rotation between the inner and outer rings. This sensor thus provides reliable and precise angle sensing.
A novel sensor or transducer is provided herein. The sensor is an angle sensor which may be used to achieve spatially correspondent master/slave controls. The sensor includes an inner ring of robust, non-magnetic material within which is fixedly disposed, but preferably is em-bedded, at least one Hall-effect plate ; an outer ring of robust non-magnetic material relatively rotatable with respect to the inner ring, the outer ring having fixed therein, but preferably embedded therein , at least two magnet poles to provide a uniform magnetic field in the inner ring ; and a casing around the outer ring, the casing being formed of a ferromagnetic metal. Electrical connections are provided for the Hall-effect plate for applying a current along the length thereof and for conducting the voltage therefrom which has been produced across the Hall-effect plate. Means are provided for relatively rotating the inner and outer rings. Finally means are provided for reading the voltage which has been produced across the Hall-effect plate. This voltage varies continuously as the sine of the angle of rotation between the inner and outer rings. This sensor thus provides reliable and precise angle sensing.
Description
32~5~7 This invention relates to an angular position indicator to provide reliable and precisc angle sensing. More particularly, thc sensor of this invention makes usc of the Hall effect.
The l-lall effect is the phenomenon known that if a thin semiconducting plate has a current [I] along its length, then a voltage [E] will be generated across its width in proportion to thc normal component of magnetic flux [B]
through the plate. Consequently, if one or more llall plates are placed in a region of magnetic field, output voltages will be produced which are functions of the flux angle. If a mechanical device is made such that relative rotations between Hall plates and magnetic field is the input angle, then the output voltage or voltages contain angle information.
Numerous devices have been patented to sense angular orientation using the llall effect. lor example, Canadian Patent No. 478,884 issued November 27, 1951, to HANSEN, entitled "Hall Effect Control Initiator" provides an angular position indicator used with galvanometer type electrical instrument.
The patented device employes a tiny plate of material which exhibits the Hall effect, together with a source of current excitation therefor and a magnetic field producing means such as a permanent magnet. The Hall plate and magnet are relatively movable in response to a measuring device rela~ with which the control device is associated, such that at some predetermined measurement value or signal, the Hall plate is cut by the flux of the magnet sufficient~y to produce a control voltage. Because of the orientation of the magnet rela-tive to the Hall plate, hysteresis effects may affect the accuracy of the an-gular measurement.
Canadian Patent No. 486,337, issued September 9, 1952, to, HANSEN, entitled "Hall Effect Telemetering Transmitter" shows a telemetering trans-mitter for a selsyn type system. It uses a plurality of circumferentially positioned Hall effect plates on a structure surrounding a magnet rotated with a mechanically driven indicator arm shaft. A transmitter generator utili~ing ~ . :
.
,~ . , ' :
12 ~ 7 . ~3 95 the Hall e~fect is employed is said tO enable the construction of low-cost reliab1e transmitters which do not re~uirc the use of moving contacts. In this patented device, the permanent magnet was surrounded by the Hall effect cylinder. Because of the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
Canadian Patent 715,732, issued August 10, 1965, to RATAJSKI et al, entitled "ila11 Effect Translating Device" relates to a shaft position trans-lation device. In the patented device position is detected by means of the Hall effect on a semiconductor body. Flux is applied to the semiconductor body from a rotor, which provides angular position to be translated into an electrical signal. In each patented brushless Hall effect potentiometer , a high degree of resolution is said to be obtained. Ilowever, in that patent it was necessary that the magnetic flux always cross the Hall plates at right angles.13ecause of the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
Canadian Patent 740,104 issued August 2, 1966 to Derek A. Rush pro-vided a Hall effect electric position detection device which produce an elec-tric signal in dependence on the position of a member. In the patented device, pieces of a high permeability magn,etic material were arranged so as to form a magnetic circuit cLosed except for at least one gap. Means were provided to produce a variation in the magnetic flux in accordance with a variation of the position of the means. A Hall effect device was disposed in a gap in the circoit so as to be affected by variations in che flux. In operation, a component of the HalL voltage of the Mall effect device was said to be a direct voltage which has a magnitude dependent on the position of the means.
Because of the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement. ~
;~ ; Canadlan Patent 836,179 issued March 3, 1970 to WiLllam B. Walton provldes a displacement sensing transducer utilLzing a Hall generiting device i - 2 -:: . .
~, : : , :: . : ,. . .
,:, : , - , ' : :
- ~3~3S7 as a scnsor. The patcnted dcvicc included a magnctic strip havlng a surfacc~
curved relative to the linc of movement and mounted on one object. Two Hall cffcct sensors were mounted on the other objcct at a position to pass adjacent the magnctic strip upon movement of the objects along the linc of movement and spaced apart from each othcr in a direction substantially parallel to the line of movement with each sensor adapted to produce an output signal varying as a function of the magnctic field respectively applied to each sensor by the magnetic strip. Means were provided which were responsive to the output signals for producing a control output having a magnitude varying as a func-tion of thc output signals. Bccaus~ of the orientation of the magnet relative to the Hall plate, hystcresis effects may affcct the accuracy of the angular measurement.
Canadian Patent 904,423, issued July 4, 1972, to LANG entitled "Electric Pulse Generator" provides a pulse generator useful for measuring Icngth of yarn or thread. In the patented pulse generator, a magnetic system which rotates with the shaft effects a stationarily mounted Hall probe. The Hall probe was positioned adjacent the magnetic system on a fixed plate which preferably had a printed circuit thereon connected to the Hall probe. The end of ~he shaft was magnetized itself or a magnetic member was affixed to the end ol the shaft in the shape of an arc so that the field lines of the magDetic field emerged from the magnetic system approximately coaxially with the shaft. The radially emerging fleld lines of the produced magnetic field ~ vere guided to the Hail generator via ferromagnetic baffle sheets. Becausc of i~ the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
; Canadian Patent 980,450, issued December 23, 1975, to FREEMAN en-citled "Autopilot Employing Improved Hall Effect Direction Sensor" provided a Hall effect device flxed to a first member and a permanent magnet rotatable :: :
~; with a second member providing a D.C. output proportlonal to the sine of the ~232~S~
rclativc angular dcvia~ion bctwecn thc first and second members. The patcnt~d invcntion, I~owcv(!r was dircctcd to thc llall-cffcct dircction sensor in conjunc-tion with spccified elcctronic circuitry. The llall-effcct dcvice was madc responsive to the angular rotation of a separate permanc~nt magnet whose posi-tion in turn was controlled by a magnetic field or other condition to be measured. The rotatable magnet was disposed in the central core and the llall plate was also aligned thereto in the central core. 13ccaus(of the orientation of the magnet relative to the Hall plate, hysteresis cffects may affcct the accuracy of the angular mcasuremcnt.
Canadian Patent No. 1,001,736, issued December 14, 1976, to BABA
et al, entitled "Angular Position Detector Using Magnetic Elements" providcs a shaft position sensor for producing an electrical signal representing an angular position of a rotary shaft. It uses an asymmetrical-shaped or stepped shaft extension, forming a pole piece or magnetic circuit structure. The rotatable pole piece co-operates with fixed permanent magnets and fixed Hall devices. It was thus necessary to provide two magnets with varying flux and two Hall plates. Bccauseof the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
~ Canadian Patent No. 1,046,541, January 9, 1979, MAKABE entitled "Needle Position Detecting Arrangement For Sewing Machine" shows permanent magnets mounted inside a drive pulley for driving the sewing machine main shaft. These magnets co-operate with Hall devices to provide an output pro-portional to needle position. In the patented invention, the magnet and the Hall generator are accommodated between the machine housing and the pulley so that the magnet, during rotation together with the pulley in synchronism with the motion of the needle of the sewing machine, may be detected by the Hall generator in a fixed position, and the position of the needle may be accordingly detected. Bccauscof the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measure-ment.
! - 4 _ :
' :
. ~
~;~32957 ~ ustralian Patent 231,889, or Lawrcnce, C.J. Fricher ct al publishcd February 26, l959, entitled "Improvemellts in transduccrs~, shows an angular position transducer comprising a pair of llall plates sandwiched between two pairs of angularly spaced iron blocks togethcr with a permanent magner. The patented invention provided a transducer comprising in combination an element made of a matcrial having the property of "llall" effect or magneto-resistance when subjected to a changing magnetic field, a magnet, and means responsive an input signal Eor varying the influence of the field of the magnet upon the element. I3eca-lseof the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of thc angular measurement.
The llall-effect sensors of the prior art as described above suffered many deficiencies. The magnetic system could be difficult and expensive to manufacture, since its manufacture could have required many operational steps.
In sensors where the crown magnet and the cup-shaped carrier constituted a relatively large mass, the pulse generator was practically useless with ap-paratus for measuring systems where the rotating parts must have very small moments of inertia. Moreover, in many instances inaccurate measurements resulted because of inaccurate compensation for temperature or acceleration.
~ Moreover, to achieve spatially correspondent master/slave control for robot arm, joint angles in the master and slave arms must be measured precisely. The prior art, including the above described Hall-effect sensors, po~entiometers, and optical sensors was deficient for undersea applications because of si~e, poor environmental isolation, fragility, and course digital output.
Accordingly, it is an object of one broad aspect of this invention to provide a joint anele sensor to implement the spatially correspondent master/
slave design concept.
~ - 5 -:~ : : ~:
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, 3Z~57 An object of another aspect of the present invention is to provide an improved device for translating position into an electrical signal, especially where such position is translated with improved resolution.
~y one broad aspect of this invention, a joint angle sensor is provided for achieving spatially correspondent mater/slave controls com-prising: an inner ring of robust, non-magnetic material within which is fixed-ly disposed, and preferably is embedded, at least one Hall-effect plate; an outer ring of robust non-magnetic material relatively rotatable with respect to the inner ring, the outer ring having fixed therein, but pre-]0 ferably embedded therein, at least two magnet poles to provide a uniform magnetic field in the inner ring; a casing around the outer ring, the casing being formed of a ferromagnetic metal; electrical connections for the Hall-effect plate for applying a current along the length thereof and for conducting voltage therefrom which has been produced across the Hall-effect plates; means for relatively rotating the inner and outer rings;
and means for reading the voltage which has been produced across the Hall-effect plate, that voltage varying as the sine of the angle of rota-tion between the inner and outer rings.
By one embodiment thereof, the inner and outer rings are made of epoxy resin.
By another embodiment thereof the magnet poles comprise two ceramic magnets.
By yet other embodiments thereof, the magnet poles and/or the Hall-effect plate, is embedded in an epoxy resin.
' , - 6 -~3~9S7 sy still another embodiment thereof, the Hall-effect plates are arranged and connected so as to null extraneous electrical effects caused by temperature or pressure.
sy another aspect of this invention, an angle sensor is provided comprising (i) a cap having an annular well extending inwardly from one face thereof and a central well extending inwardly coaxially with respect to the annular well from the other face thereof; ~ii) a pin projecting outwardly from the one face and disposed within the annular well, the pin having a base in the form of a hollow cylinder, the hollow cylinder having fixed therein and preferably having embedded therein, an outer casing of ferromagnetic material adjacent wall of the cylinder, the fixing material being a robust non-magnetic material, e.g. an epoxy resin, t:he magnet poles being adapted to provide a uniform magnetic field within the central well; (iii) means Eor providing relative rotation between the pin (ii) and the cap (i); (iv) at least one Hall-effect plate fixedly disposed, and preferably embedded with the central well, the Hall-effect plate being provided with electrical connections for conducting voltage therefrom which has been produced across the Hall-effect plates; and (v) means for reading the voltage which has been produced across the Hall-effect plate, the voltage varying continuously as the sine of the angle of rotation ZO between the pin (ii) and the cap (i). Preferably the relative rotation~is provided by having the cap fixed and by providing means for rotating the pin.
The embedding material used for the outer casing an'd for the magnetic poles preferably is an epoxy resin. The magnetic poles pre-ferably comprise Lwo spaced apart magnets embedded within the hollow cylin-der In an epoxy resin, most preferably being in the form of two spaced apart ceramic magnets embedded, along with the outer casing, in an epoxy resin within the hollow cylinder.
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1;~32~57 The Hall-effect plates are preferably interconnected Hall-effect plates, embedded within the central core, e.g. by means of an epoxy resin.
Preferably, -the electrical connectors are individually encased within a respective heat-shrink tubing and collectively encased by a common heat-shrink tubing.
In the accornpanying drawings, Figure 1 is a schematic view showing the principles of operation of the angle sensor of a broad embodi~ent of this invention;
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~23~957 Figure 2 is a top plan view of a commercial embodiment oE this invention;
Figure 3 is a section along line III-III of Figure 2;
Figure 4 is an enlarged perspective view of the sensor elements used in the commercial embodiment of Figure 2; and Figure 5 is a circuit diagram of the commercial embodiment shown in Figure 2.
As seen in Figure 1, the angle sensor 10 comprises an outer ring 12 and an inner ring 11, each made of a robust non-magnetic material.
In one example, this is an epoxy resin, but other materials, for example aluminum may be used. Embedded within inner ring 11 are a pair of Hall-effect plates 14. As well known in the art, these Hall-effect plates may be made from any semi-conductor material which has the characteristics of pro-ducing an electric potential along one axis in response to an electrical current and a magnetic field along respective axes normal to that material.
One example of such semi conductor material is a crystal of indium arsenide.
Other examples include bismuth, germanium, or other semi-conductor matexials.
Embedded within the outer ring 12 are one or more permanent mag-nets 13 so arranged that a uniform magnetic field is provided in inner ring 11. The permanent magnets may be formed of any material having a high coercive force, e.g. those known by the trade marks FERRIMAG, CRUCICORE
or ALNICO V, Preferably the magnets are ceramic magnets or other materials, so selected that the magnetic flux is not a function of temperature or ;~ accelsration within operating limits. In order to provide magnetic shield-ing from outside sources, and to complete the magnetic circuit, the sensor or transducer 10 is encased in a ring of ferromagnetic metal 15.
As seen in Figures 2 and 3 the commercial embodiment of the , . ,-' :
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:~Z3~9S7 sensor 10 previously identified as 10 is housed in oval shaped cap 100.
The sensor 110 (see Figure 3) is embedded in a sensor pin 120 which is in the form of a cylindrical projection 121 terminating in a hollow cylinder 122. Within hollow cylinder 122 are sensor ring 115, corresponding to ferromagnetic ring 15 previously described, and magnets 113, corresponding to magnets 13 previously described, each embedded in an epoxy resin 112, corresponding to outer-ring 12 previously described. Sensor pin 120 is disposed in an annular well 123 in cap 100 in such a way that it may be rotated by means (not shown).
The cap 100 is provided with well 111 at the central core therecf, corresponding to inner ring 11 previous]y clescribecl~ w~thill which are fixedly disposed the Hall-effect plates 114, corresponding to the Hall-effect plates 14 previously described. Preferably the Hall-effect plates are fixedly disposed by being embedded in an epoxy resin filling well 11l. Wiring 131, 132, 139 and l40, to be described here-inafter, emerge from the bottom of cap lO0.
The cap 100 is provided with the usual mounting apertures 132.
The structure of the Hall-effect plates 114 is shown in more detail in Figure 4. The Hall-effect plates 114 are each provided with positive terminals 125 and negative terminals 126, the respective wires 127, from the positive terminals of each Hall-effect plate 114 being soldered at 129 to form a common positive wire disposed within a heat-shrink tubing 131, the respective wires 128 from the negatlve terminals 126 of each Hall-effect plate 114 being similarly soldered at 130 to form a common negative wire disposed within a heat-shrink tubing 132. The third terminal 133 from one Hall-effect plate extends as wire 135 which is soldered at 137 to a third j;, 1232~357 terminal within a heat-shrink tubing 139, the third terminal 134 Irom the other 11a11-effect plate extending as wire 136, which is so1dered at 13 at heat-shrink tubing 140.
For proLection thereof, and to provide a rugged structure, wires 127, 128, 129, 130, 135 and 136 and heat-shrink tubings 131, 132, 137 and 140 are all disposed within heat-shrink tubing 141 extending from Ha1i-effect plate 114, the heat-shrink tubing 141 being shown in broken lines for clarity.
As seen in Figure 5, wires 131 and 132 provide excitation to Hall-effect plates 114, while wires 139, 140, transmit the signal from the Hall-effect plates 114.
Thus, as noted above, the sensor of this invention is basèd on the Hall-effect. It consists of two parts: a set of magnets embedded in an outer ring of epoxy, and a set of Hall-effect semi-conductor plates embedded in an inner ring of epoxy. As one or the other ring rotates, a voltage proport1onal to the sine and/or cosine of the angle of rotation is generated. This voltage is produced continuously with infinite resolu-tion, and may be used directly to infer the angle of rotation, or, if ; pulse counting hardware is available, to infer more than one rotation.
- 20 m e inner ring consists of one or more Hall-effect plates embedded in epoxy. If more than one Hall plate is used, (a preferred embodiment) the plates may be arranged and connected ;so as to eliminate (or null) electric ~effects caused by temperature, pressure, etc.
The outer ring consists of one or more magnets embedded in epoxy, placed so as to provide a uniform magnetic field in the inner ring. Since :
~; ~ the magnetic field is constant and there are no ferromagnetic components in the rotating f1eld, no effects due to hysterysis are obsèrved. If the 1 ~
, :
, ~ , ~Z329S7 preferred magnets, ceramic, are used, the magnetic flux is not d function of temperature or acce]eration, wit:hin wide operating limits.
The above-described embodiment of the sensor or transducer of this invention is unique in that it uses the ~iall-effect directly to induce a continuously variable voltage directly from the defining char-acteristics of the iiall-effect, which results in infinitely fine angular resolution. Other liall-effect transducers produce voltage peaks from ridges or teeth cut in a moving part, or measure irregularities in the magnetic field, and therefore provide only crude angular information.
Further, the transducer of this invention is very insensitive to outside influence.
The above-described sensor or transducer of this inventior~
has infinite resolution and is very robust. It has no moving parts other than inner and outer ring relative rotation; it can never wear out; it is virtually insensitive to temperature, opacity of environment, pres-sure, vibration, acceleration, and electromagnetic fields; and it can easily be made insensitive to corrosive environments.
:
~: :, ~ :
The l-lall effect is the phenomenon known that if a thin semiconducting plate has a current [I] along its length, then a voltage [E] will be generated across its width in proportion to thc normal component of magnetic flux [B]
through the plate. Consequently, if one or more llall plates are placed in a region of magnetic field, output voltages will be produced which are functions of the flux angle. If a mechanical device is made such that relative rotations between Hall plates and magnetic field is the input angle, then the output voltage or voltages contain angle information.
Numerous devices have been patented to sense angular orientation using the llall effect. lor example, Canadian Patent No. 478,884 issued November 27, 1951, to HANSEN, entitled "Hall Effect Control Initiator" provides an angular position indicator used with galvanometer type electrical instrument.
The patented device employes a tiny plate of material which exhibits the Hall effect, together with a source of current excitation therefor and a magnetic field producing means such as a permanent magnet. The Hall plate and magnet are relatively movable in response to a measuring device rela~ with which the control device is associated, such that at some predetermined measurement value or signal, the Hall plate is cut by the flux of the magnet sufficient~y to produce a control voltage. Because of the orientation of the magnet rela-tive to the Hall plate, hysteresis effects may affect the accuracy of the an-gular measurement.
Canadian Patent No. 486,337, issued September 9, 1952, to, HANSEN, entitled "Hall Effect Telemetering Transmitter" shows a telemetering trans-mitter for a selsyn type system. It uses a plurality of circumferentially positioned Hall effect plates on a structure surrounding a magnet rotated with a mechanically driven indicator arm shaft. A transmitter generator utili~ing ~ . :
.
,~ . , ' :
12 ~ 7 . ~3 95 the Hall e~fect is employed is said tO enable the construction of low-cost reliab1e transmitters which do not re~uirc the use of moving contacts. In this patented device, the permanent magnet was surrounded by the Hall effect cylinder. Because of the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
Canadian Patent 715,732, issued August 10, 1965, to RATAJSKI et al, entitled "ila11 Effect Translating Device" relates to a shaft position trans-lation device. In the patented device position is detected by means of the Hall effect on a semiconductor body. Flux is applied to the semiconductor body from a rotor, which provides angular position to be translated into an electrical signal. In each patented brushless Hall effect potentiometer , a high degree of resolution is said to be obtained. Ilowever, in that patent it was necessary that the magnetic flux always cross the Hall plates at right angles.13ecause of the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
Canadian Patent 740,104 issued August 2, 1966 to Derek A. Rush pro-vided a Hall effect electric position detection device which produce an elec-tric signal in dependence on the position of a member. In the patented device, pieces of a high permeability magn,etic material were arranged so as to form a magnetic circuit cLosed except for at least one gap. Means were provided to produce a variation in the magnetic flux in accordance with a variation of the position of the means. A Hall effect device was disposed in a gap in the circoit so as to be affected by variations in che flux. In operation, a component of the HalL voltage of the Mall effect device was said to be a direct voltage which has a magnitude dependent on the position of the means.
Because of the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement. ~
;~ ; Canadlan Patent 836,179 issued March 3, 1970 to WiLllam B. Walton provldes a displacement sensing transducer utilLzing a Hall generiting device i - 2 -:: . .
~, : : , :: . : ,. . .
,:, : , - , ' : :
- ~3~3S7 as a scnsor. The patcnted dcvicc included a magnctic strip havlng a surfacc~
curved relative to the linc of movement and mounted on one object. Two Hall cffcct sensors were mounted on the other objcct at a position to pass adjacent the magnctic strip upon movement of the objects along the linc of movement and spaced apart from each othcr in a direction substantially parallel to the line of movement with each sensor adapted to produce an output signal varying as a function of the magnctic field respectively applied to each sensor by the magnetic strip. Means were provided which were responsive to the output signals for producing a control output having a magnitude varying as a func-tion of thc output signals. Bccaus~ of the orientation of the magnet relative to the Hall plate, hystcresis effects may affcct the accuracy of the angular measurement.
Canadian Patent 904,423, issued July 4, 1972, to LANG entitled "Electric Pulse Generator" provides a pulse generator useful for measuring Icngth of yarn or thread. In the patented pulse generator, a magnetic system which rotates with the shaft effects a stationarily mounted Hall probe. The Hall probe was positioned adjacent the magnetic system on a fixed plate which preferably had a printed circuit thereon connected to the Hall probe. The end of ~he shaft was magnetized itself or a magnetic member was affixed to the end ol the shaft in the shape of an arc so that the field lines of the magDetic field emerged from the magnetic system approximately coaxially with the shaft. The radially emerging fleld lines of the produced magnetic field ~ vere guided to the Hail generator via ferromagnetic baffle sheets. Becausc of i~ the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
; Canadian Patent 980,450, issued December 23, 1975, to FREEMAN en-citled "Autopilot Employing Improved Hall Effect Direction Sensor" provided a Hall effect device flxed to a first member and a permanent magnet rotatable :: :
~; with a second member providing a D.C. output proportlonal to the sine of the ~232~S~
rclativc angular dcvia~ion bctwecn thc first and second members. The patcnt~d invcntion, I~owcv(!r was dircctcd to thc llall-cffcct dircction sensor in conjunc-tion with spccified elcctronic circuitry. The llall-effcct dcvice was madc responsive to the angular rotation of a separate permanc~nt magnet whose posi-tion in turn was controlled by a magnetic field or other condition to be measured. The rotatable magnet was disposed in the central core and the llall plate was also aligned thereto in the central core. 13ccaus(of the orientation of the magnet relative to the Hall plate, hysteresis cffects may affcct the accuracy of the angular mcasuremcnt.
Canadian Patent No. 1,001,736, issued December 14, 1976, to BABA
et al, entitled "Angular Position Detector Using Magnetic Elements" providcs a shaft position sensor for producing an electrical signal representing an angular position of a rotary shaft. It uses an asymmetrical-shaped or stepped shaft extension, forming a pole piece or magnetic circuit structure. The rotatable pole piece co-operates with fixed permanent magnets and fixed Hall devices. It was thus necessary to provide two magnets with varying flux and two Hall plates. Bccauseof the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measurement.
~ Canadian Patent No. 1,046,541, January 9, 1979, MAKABE entitled "Needle Position Detecting Arrangement For Sewing Machine" shows permanent magnets mounted inside a drive pulley for driving the sewing machine main shaft. These magnets co-operate with Hall devices to provide an output pro-portional to needle position. In the patented invention, the magnet and the Hall generator are accommodated between the machine housing and the pulley so that the magnet, during rotation together with the pulley in synchronism with the motion of the needle of the sewing machine, may be detected by the Hall generator in a fixed position, and the position of the needle may be accordingly detected. Bccauscof the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of the angular measure-ment.
! - 4 _ :
' :
. ~
~;~32957 ~ ustralian Patent 231,889, or Lawrcnce, C.J. Fricher ct al publishcd February 26, l959, entitled "Improvemellts in transduccrs~, shows an angular position transducer comprising a pair of llall plates sandwiched between two pairs of angularly spaced iron blocks togethcr with a permanent magner. The patented invention provided a transducer comprising in combination an element made of a matcrial having the property of "llall" effect or magneto-resistance when subjected to a changing magnetic field, a magnet, and means responsive an input signal Eor varying the influence of the field of the magnet upon the element. I3eca-lseof the orientation of the magnet relative to the Hall plate, hysteresis effects may affect the accuracy of thc angular measurement.
The llall-effect sensors of the prior art as described above suffered many deficiencies. The magnetic system could be difficult and expensive to manufacture, since its manufacture could have required many operational steps.
In sensors where the crown magnet and the cup-shaped carrier constituted a relatively large mass, the pulse generator was practically useless with ap-paratus for measuring systems where the rotating parts must have very small moments of inertia. Moreover, in many instances inaccurate measurements resulted because of inaccurate compensation for temperature or acceleration.
~ Moreover, to achieve spatially correspondent master/slave control for robot arm, joint angles in the master and slave arms must be measured precisely. The prior art, including the above described Hall-effect sensors, po~entiometers, and optical sensors was deficient for undersea applications because of si~e, poor environmental isolation, fragility, and course digital output.
Accordingly, it is an object of one broad aspect of this invention to provide a joint anele sensor to implement the spatially correspondent master/
slave design concept.
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, 3Z~57 An object of another aspect of the present invention is to provide an improved device for translating position into an electrical signal, especially where such position is translated with improved resolution.
~y one broad aspect of this invention, a joint angle sensor is provided for achieving spatially correspondent mater/slave controls com-prising: an inner ring of robust, non-magnetic material within which is fixed-ly disposed, and preferably is embedded, at least one Hall-effect plate; an outer ring of robust non-magnetic material relatively rotatable with respect to the inner ring, the outer ring having fixed therein, but pre-]0 ferably embedded therein, at least two magnet poles to provide a uniform magnetic field in the inner ring; a casing around the outer ring, the casing being formed of a ferromagnetic metal; electrical connections for the Hall-effect plate for applying a current along the length thereof and for conducting voltage therefrom which has been produced across the Hall-effect plates; means for relatively rotating the inner and outer rings;
and means for reading the voltage which has been produced across the Hall-effect plate, that voltage varying as the sine of the angle of rota-tion between the inner and outer rings.
By one embodiment thereof, the inner and outer rings are made of epoxy resin.
By another embodiment thereof the magnet poles comprise two ceramic magnets.
By yet other embodiments thereof, the magnet poles and/or the Hall-effect plate, is embedded in an epoxy resin.
' , - 6 -~3~9S7 sy still another embodiment thereof, the Hall-effect plates are arranged and connected so as to null extraneous electrical effects caused by temperature or pressure.
sy another aspect of this invention, an angle sensor is provided comprising (i) a cap having an annular well extending inwardly from one face thereof and a central well extending inwardly coaxially with respect to the annular well from the other face thereof; ~ii) a pin projecting outwardly from the one face and disposed within the annular well, the pin having a base in the form of a hollow cylinder, the hollow cylinder having fixed therein and preferably having embedded therein, an outer casing of ferromagnetic material adjacent wall of the cylinder, the fixing material being a robust non-magnetic material, e.g. an epoxy resin, t:he magnet poles being adapted to provide a uniform magnetic field within the central well; (iii) means Eor providing relative rotation between the pin (ii) and the cap (i); (iv) at least one Hall-effect plate fixedly disposed, and preferably embedded with the central well, the Hall-effect plate being provided with electrical connections for conducting voltage therefrom which has been produced across the Hall-effect plates; and (v) means for reading the voltage which has been produced across the Hall-effect plate, the voltage varying continuously as the sine of the angle of rotation ZO between the pin (ii) and the cap (i). Preferably the relative rotation~is provided by having the cap fixed and by providing means for rotating the pin.
The embedding material used for the outer casing an'd for the magnetic poles preferably is an epoxy resin. The magnetic poles pre-ferably comprise Lwo spaced apart magnets embedded within the hollow cylin-der In an epoxy resin, most preferably being in the form of two spaced apart ceramic magnets embedded, along with the outer casing, in an epoxy resin within the hollow cylinder.
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1;~32~57 The Hall-effect plates are preferably interconnected Hall-effect plates, embedded within the central core, e.g. by means of an epoxy resin.
Preferably, -the electrical connectors are individually encased within a respective heat-shrink tubing and collectively encased by a common heat-shrink tubing.
In the accornpanying drawings, Figure 1 is a schematic view showing the principles of operation of the angle sensor of a broad embodi~ent of this invention;
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~23~957 Figure 2 is a top plan view of a commercial embodiment oE this invention;
Figure 3 is a section along line III-III of Figure 2;
Figure 4 is an enlarged perspective view of the sensor elements used in the commercial embodiment of Figure 2; and Figure 5 is a circuit diagram of the commercial embodiment shown in Figure 2.
As seen in Figure 1, the angle sensor 10 comprises an outer ring 12 and an inner ring 11, each made of a robust non-magnetic material.
In one example, this is an epoxy resin, but other materials, for example aluminum may be used. Embedded within inner ring 11 are a pair of Hall-effect plates 14. As well known in the art, these Hall-effect plates may be made from any semi-conductor material which has the characteristics of pro-ducing an electric potential along one axis in response to an electrical current and a magnetic field along respective axes normal to that material.
One example of such semi conductor material is a crystal of indium arsenide.
Other examples include bismuth, germanium, or other semi-conductor matexials.
Embedded within the outer ring 12 are one or more permanent mag-nets 13 so arranged that a uniform magnetic field is provided in inner ring 11. The permanent magnets may be formed of any material having a high coercive force, e.g. those known by the trade marks FERRIMAG, CRUCICORE
or ALNICO V, Preferably the magnets are ceramic magnets or other materials, so selected that the magnetic flux is not a function of temperature or ;~ accelsration within operating limits. In order to provide magnetic shield-ing from outside sources, and to complete the magnetic circuit, the sensor or transducer 10 is encased in a ring of ferromagnetic metal 15.
As seen in Figures 2 and 3 the commercial embodiment of the , . ,-' :
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:~Z3~9S7 sensor 10 previously identified as 10 is housed in oval shaped cap 100.
The sensor 110 (see Figure 3) is embedded in a sensor pin 120 which is in the form of a cylindrical projection 121 terminating in a hollow cylinder 122. Within hollow cylinder 122 are sensor ring 115, corresponding to ferromagnetic ring 15 previously described, and magnets 113, corresponding to magnets 13 previously described, each embedded in an epoxy resin 112, corresponding to outer-ring 12 previously described. Sensor pin 120 is disposed in an annular well 123 in cap 100 in such a way that it may be rotated by means (not shown).
The cap 100 is provided with well 111 at the central core therecf, corresponding to inner ring 11 previous]y clescribecl~ w~thill which are fixedly disposed the Hall-effect plates 114, corresponding to the Hall-effect plates 14 previously described. Preferably the Hall-effect plates are fixedly disposed by being embedded in an epoxy resin filling well 11l. Wiring 131, 132, 139 and l40, to be described here-inafter, emerge from the bottom of cap lO0.
The cap 100 is provided with the usual mounting apertures 132.
The structure of the Hall-effect plates 114 is shown in more detail in Figure 4. The Hall-effect plates 114 are each provided with positive terminals 125 and negative terminals 126, the respective wires 127, from the positive terminals of each Hall-effect plate 114 being soldered at 129 to form a common positive wire disposed within a heat-shrink tubing 131, the respective wires 128 from the negatlve terminals 126 of each Hall-effect plate 114 being similarly soldered at 130 to form a common negative wire disposed within a heat-shrink tubing 132. The third terminal 133 from one Hall-effect plate extends as wire 135 which is soldered at 137 to a third j;, 1232~357 terminal within a heat-shrink tubing 139, the third terminal 134 Irom the other 11a11-effect plate extending as wire 136, which is so1dered at 13 at heat-shrink tubing 140.
For proLection thereof, and to provide a rugged structure, wires 127, 128, 129, 130, 135 and 136 and heat-shrink tubings 131, 132, 137 and 140 are all disposed within heat-shrink tubing 141 extending from Ha1i-effect plate 114, the heat-shrink tubing 141 being shown in broken lines for clarity.
As seen in Figure 5, wires 131 and 132 provide excitation to Hall-effect plates 114, while wires 139, 140, transmit the signal from the Hall-effect plates 114.
Thus, as noted above, the sensor of this invention is basèd on the Hall-effect. It consists of two parts: a set of magnets embedded in an outer ring of epoxy, and a set of Hall-effect semi-conductor plates embedded in an inner ring of epoxy. As one or the other ring rotates, a voltage proport1onal to the sine and/or cosine of the angle of rotation is generated. This voltage is produced continuously with infinite resolu-tion, and may be used directly to infer the angle of rotation, or, if ; pulse counting hardware is available, to infer more than one rotation.
- 20 m e inner ring consists of one or more Hall-effect plates embedded in epoxy. If more than one Hall plate is used, (a preferred embodiment) the plates may be arranged and connected ;so as to eliminate (or null) electric ~effects caused by temperature, pressure, etc.
The outer ring consists of one or more magnets embedded in epoxy, placed so as to provide a uniform magnetic field in the inner ring. Since :
~; ~ the magnetic field is constant and there are no ferromagnetic components in the rotating f1eld, no effects due to hysterysis are obsèrved. If the 1 ~
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, ~ , ~Z329S7 preferred magnets, ceramic, are used, the magnetic flux is not d function of temperature or acce]eration, wit:hin wide operating limits.
The above-described embodiment of the sensor or transducer of this invention is unique in that it uses the ~iall-effect directly to induce a continuously variable voltage directly from the defining char-acteristics of the iiall-effect, which results in infinitely fine angular resolution. Other liall-effect transducers produce voltage peaks from ridges or teeth cut in a moving part, or measure irregularities in the magnetic field, and therefore provide only crude angular information.
Further, the transducer of this invention is very insensitive to outside influence.
The above-described sensor or transducer of this inventior~
has infinite resolution and is very robust. It has no moving parts other than inner and outer ring relative rotation; it can never wear out; it is virtually insensitive to temperature, opacity of environment, pres-sure, vibration, acceleration, and electromagnetic fields; and it can easily be made insensitive to corrosive environments.
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Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An angle sensor for achieving spatially correspondent mas-ter/slave controls, comprising:
(a) an inner ring of robust, non-magnetic material within which is fixedly disposed at least one Hall-effect plate;
(b) an outer ring of robust non-magnetic material relatively rotatable with respect to said inner ring, said outer ring having fixed therein at least two magnet poles to provide a uniform magnetic field in said inner ring;
(c) a casing around said outer ring, said casing being formed of a ferromagnetic metal;
(d) electrical connections for said Hall-effect plate for applying a current along the length thereof and for con-ducting a voltage therefrom which has been produced across the Hall-effect plate;
(e) means for relatively rotating said inner and outer rings;
and (f) means for reading the voltage which has been produced across said Hall-effect plate, said voltage varying con-tinuously as the sine of the angle of rotation between said inner and outer rings.
(a) an inner ring of robust, non-magnetic material within which is fixedly disposed at least one Hall-effect plate;
(b) an outer ring of robust non-magnetic material relatively rotatable with respect to said inner ring, said outer ring having fixed therein at least two magnet poles to provide a uniform magnetic field in said inner ring;
(c) a casing around said outer ring, said casing being formed of a ferromagnetic metal;
(d) electrical connections for said Hall-effect plate for applying a current along the length thereof and for con-ducting a voltage therefrom which has been produced across the Hall-effect plate;
(e) means for relatively rotating said inner and outer rings;
and (f) means for reading the voltage which has been produced across said Hall-effect plate, said voltage varying con-tinuously as the sine of the angle of rotation between said inner and outer rings.
2. The angle sensor of claim 1 wherein said Hall-effect plate is embedded in an epoxy resin.
3. The angle sensor of claim 1 wherein said inner and outer rings are made of epoxy resin.
4. The angle sensor of claim 1 wherein said magnet poles are embedded in an epoxy resin.
5. The angle sensor of claim 1 wherein said Hall-effect plates are arranged and connected so as to null extraneous electrical effects caused by temperature or pressure.
6. An angle sensor comprising:
(i) a cap having an annular well extending inwardly from one face thereof and a central well extending inwardly coaxially with respect to said annular well from the other face thereof;
(ii) a pin projecting outwardly from said one face and disposed within said annular well, said pin having a base in the form of a hollow cylinder, said hollow cylinder having fixed therein an outer casing of ferromagnetic material adjacent the cylinder walls, and at least two magnet poles fixed adjacent said outer casing, said outer casing and said magnet poles being fixed within a robust non-magnetic material, said magnet poles being adapted to provide a uniform magnetic field with said central well;
(iii) means for providing relative rotation between said pin (ii) and said cap (i);
(iv) at least one Hall-effect plate fixedly disposed within said central well, said Hall-effect plate being provided with electrical connections for applying a current along the length thereof, and electrical connections for conducting voltage therefrom which has been produced across the Hall-effect plate;
and (v) means for reading said voltage which has been produced across said Hall-effect plate, said voltage varying continuously as the sine of the angle of rotation between said pin (ii) and said cap (i).
(i) a cap having an annular well extending inwardly from one face thereof and a central well extending inwardly coaxially with respect to said annular well from the other face thereof;
(ii) a pin projecting outwardly from said one face and disposed within said annular well, said pin having a base in the form of a hollow cylinder, said hollow cylinder having fixed therein an outer casing of ferromagnetic material adjacent the cylinder walls, and at least two magnet poles fixed adjacent said outer casing, said outer casing and said magnet poles being fixed within a robust non-magnetic material, said magnet poles being adapted to provide a uniform magnetic field with said central well;
(iii) means for providing relative rotation between said pin (ii) and said cap (i);
(iv) at least one Hall-effect plate fixedly disposed within said central well, said Hall-effect plate being provided with electrical connections for applying a current along the length thereof, and electrical connections for conducting voltage therefrom which has been produced across the Hall-effect plate;
and (v) means for reading said voltage which has been produced across said Hall-effect plate, said voltage varying continuously as the sine of the angle of rotation between said pin (ii) and said cap (i).
7. The angle sensor of claim 6 wherein said cap (i) is fixed in location.
8. The angle sensor of claim 6 wherein said fixing material for said outer casing and said magnetic poles is an epoxy resin within which said outer casing and said magnetic poles are embedded.
9. The angle sensor of claim 6 whexein said magnetic poles comprise two spaced-apart magnets embedded within said hollow cylinder.
10. The angle sensor of claim 6 wherein said magnetic poles comprise two spaced-apart ceramic magnets embedded, along with said outer casing, in an epoxy resin within said hollow cylinder.
11. The angle sensor of claim 6 comprising two interconnected Hall-effect plates.
12. The angle sensor of claim 11 wherein said Hall-effect plates are embedded within said central core.
13. The angle sensor of claim 12 wherein said Hall-effect plates are embedded within said central core in an epoxy resin.
14. The angle sensor of claim 12 wherein said electrical connections are individually encased within a respective heat-shrink tubing and are collectively encased by a common heat-shrink tubing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000464374A CA1232957A (en) | 1984-09-28 | 1984-09-28 | Rotational sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000464374A CA1232957A (en) | 1984-09-28 | 1984-09-28 | Rotational sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1232957A true CA1232957A (en) | 1988-02-16 |
Family
ID=4128810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000464374A Expired CA1232957A (en) | 1984-09-28 | 1984-09-28 | Rotational sensor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1232957A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000029813A1 (en) * | 1998-11-17 | 2000-05-25 | Robert Bosch Gmbh | Measuring device for the contactless measurement of an angle of rotation |
| EP1083407A2 (en) * | 1999-09-09 | 2001-03-14 | Delphi Technologies, Inc. | Analog angle encoder |
| WO2001063212A1 (en) * | 2000-02-24 | 2001-08-30 | Robert Bosch Gmbh | Measuring device for detecting a rotation angle in a contactless manner |
| EP1278044A1 (en) * | 2000-07-12 | 2003-01-22 | Kayaba Industry Co., Ltd. | Angular sensor |
| US6777928B2 (en) | 2002-12-03 | 2004-08-17 | Delphi Technologies, Inc. | Rotary magnetic position sensor having pole differentiated magnets |
| EP1901040A2 (en) * | 2006-09-14 | 2008-03-19 | ZF Friedrichshafen AG | Contactless rotation angle sensor |
| EP3557189A1 (en) * | 2014-09-02 | 2019-10-23 | Infineon Technologies AG | Shaft-integrated angle sensing device |
| DE102016009006B4 (en) | 2015-07-29 | 2024-01-25 | Infineon Technologies Ag | DRIVE TRAIN OF A MOTOR VEHICLE SYSTEM HAVING A SHAFT-INTEGRATED ANGLE SCANNING DEVICE |
-
1984
- 1984-09-28 CA CA000464374A patent/CA1232957A/en not_active Expired
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU756850B2 (en) * | 1998-11-17 | 2003-01-23 | Robert Bosch Gmbh | Measuring device for the contactless measurement of an angle of rotation |
| US6611790B1 (en) | 1998-11-17 | 2003-08-26 | Robert Bosch Gmbh | Measuring device for the contactless measurement of an angle of rotation |
| WO2000029813A1 (en) * | 1998-11-17 | 2000-05-25 | Robert Bosch Gmbh | Measuring device for the contactless measurement of an angle of rotation |
| EP1083407A2 (en) * | 1999-09-09 | 2001-03-14 | Delphi Technologies, Inc. | Analog angle encoder |
| EP1083407A3 (en) * | 1999-09-09 | 2002-07-24 | Delphi Technologies, Inc. | Analog angle encoder |
| US6489761B1 (en) | 1999-09-09 | 2002-12-03 | Delphi Technologies, Inc. | Magnetic arrangement for an analog angle encoder |
| WO2001063212A1 (en) * | 2000-02-24 | 2001-08-30 | Robert Bosch Gmbh | Measuring device for detecting a rotation angle in a contactless manner |
| US7042209B2 (en) | 2000-02-24 | 2006-05-09 | Robert Bosch Gmbh | Measuring device for detecting a rotation angle in a contactless manner |
| EP1278044B1 (en) * | 2000-07-12 | 2011-12-21 | Kayaba Industry Co., Ltd. | Angular sensor |
| EP1278044A1 (en) * | 2000-07-12 | 2003-01-22 | Kayaba Industry Co., Ltd. | Angular sensor |
| US6777928B2 (en) | 2002-12-03 | 2004-08-17 | Delphi Technologies, Inc. | Rotary magnetic position sensor having pole differentiated magnets |
| EP1901040A2 (en) * | 2006-09-14 | 2008-03-19 | ZF Friedrichshafen AG | Contactless rotation angle sensor |
| EP1901040A3 (en) * | 2006-09-14 | 2013-05-22 | ZF Friedrichshafen AG | Contactless rotation angle sensor |
| EP3557189A1 (en) * | 2014-09-02 | 2019-10-23 | Infineon Technologies AG | Shaft-integrated angle sensing device |
| US10704933B2 (en) | 2014-09-02 | 2020-07-07 | Infineon Technologies Ag | Integrated angle sensing device |
| DE102016009006B4 (en) | 2015-07-29 | 2024-01-25 | Infineon Technologies Ag | DRIVE TRAIN OF A MOTOR VEHICLE SYSTEM HAVING A SHAFT-INTEGRATED ANGLE SCANNING DEVICE |
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