Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
  • G01L3/02—Rotary-transmission dynamometers
  • G01L3/04—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft
  • G01L3/10—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating
  • G01L3/109—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving measuring phase difference of two signals or pulse trains

Definitions

• the invention relates to a sensor arrangement for the combined detection of rotational speed and torque according to the preamble of claim 1.
• sensor arrangements for detecting a rotational speed of a shaft, or more generally a rotating body, such as an engine speed z. B. on a crankshaft, sensor arrangements are known, which have a circumferentially arranged around the rotating body, referred to as a phase track dimensional standard in the form of a series of repetitive, periodic marks and at least one stationary relative to the rotating body arranged, the phase track detecting sensor element.
• the sensor element is sensitive to the markings of the phase trace and generates z. B. at passage of a mark and / or when changing adjacent markers each have a sensor signal, so over a certain angle of rotation, for. B. over a full revolution, a known number or a known sequence of sensor signals is generated, from which by means of an evaluation unit with the aid of a time signal, a speed determined or can be deduced on such.
• the markings of the phase track can be, for example, optical markings, so that the sensor element z. B. can detect light-dark transitions.
• other sensor principles such. B. magnetically or capacitively possible.
• the phase track can directly on the rotating body or on a non-rotatably connected thereto element such. B. arranged a donor wheel.
• Hall elements are preferably used as sensor elements, wherein the markings of the phase track are designed to be magnetic, z. B. as a result of alternately arranged magnetic north and south poles.
• Hall elements When using Hall elements as sensor elements, for example, a differential evaluation can take place, wherein the difference between the signals of two successively arranged in the circumferential direction Hall elements is evaluated.
• Hall ASICs There are also so-called Hall ASICs known per se, which can evaluate a magnetic field direction.
• two-channel differential Hall element arrangements in the form of so-called double differential sensor elements is known, with which in addition to the rotational speed and the direction of rotation can be detected. These consist of a total of three sensor elements, with two sensor elements in each case being connected to antiparallel-connected sensor element bridges. Both sensor element bridges extend parallel to the direction of rotation of the phase track running perpendicular to the axis of rotation in a plan view.
• z. B. by EP 1 861 681 B1 at least on two in the axial direction along a rotation axis at a known distance from each other lying cross-sections of a rotating body known torsional rigidity to arrange a respective phase track circumferentially to a transmitted between the two cross sections of the rotating body torque determine an angle of rotation between the two cross-sections and, based on this, use the torsional stiffness to determine the torque between the two cross-sections.
• the angle of rotation is the twist and the torque is the torsional torque.
• EP 1 861 681 B1 discloses an inclination between the sensor track given by the optimum detection or resolution of the passage of markings on the sensor element and the running direction of the running direction perpendicular to the axis of rotation in the detection of a rotational angle of a rotating body Phase trace to be compensated by using a plurality of mutually parallel arranged phase traces and a matrix-bound evaluation of all Phas traces.
• a sensor arrangement is provided with at least at least two phase traces arranged circumferentially in each case in the axial direction along a rotation axis at a known distance from each other of a rotating body of known torsional rigidity.
• the sensor arrangement has at least one sensor element arranged stationary relative to the rotating body and detecting the respective phase track, on which element the respective phase track passes transversely to the axis of rotation when the body is rotating.
• Each sensor element generates a sensor signal when a marking is passed and / or when alternating adjacent markings of the respective phase track assigned to a sensor element are detected.
• At least two sensor elements assigned to a first phase track are connected to at least one first sensor element bridge for detecting at least the rotational speed of the rotating body.
• This first sensor element bridge extends in a plan view substantially parallel to the phase track and substantially perpendicular to the axis of rotation of the rotating body. At least one sensor element assigned to a second phase track is connected to at least one sensor element assigned to the first phase track to at least one second sensor bridge, which serves to determine a torque transmitted between the two cross sections of the rotating body. The latter is possible by determining an angle of rotation between the two cross-sections by means of the second sensor bridge and closing it with reference to this via the known torsional rigidity of the rotating body to the torque applied between the two cross-sections.
• the second sensor element bridge extends in a plan view transversely to the two phase tracks, for example substantially perpendicular to the two phase tracks and parallel to the axis of rotation of the rotating Body.
• the first sensor element bridge thus extends in the plan view in the direction of the parallel phase traces, more precisely over the first phase trace, whereas the second sensor bridge in the plan view extends transversely, for example at a right angle to the direction of the phase traces, so that the first and the second sensor element bridge include an angle other than an integer multiple of 0 ° and 180 °.
• the first and the second sensor element bridge are perpendicular to each other.
• the first sensor element bridge provided for detecting the rotational speed and the second sensor element bridge provided for detecting the torque are preferably digitally evaluated. Alternatively, an analogous evaluation of one or both sensor element bridges is conceivable.
• the speed detection can also double differential z. B. by parallel arrangement of two sensor element bridges, whereby a direction of rotation detection is possible.
• the phase traces can directly on the rotating body or on each non-rotatable connected thereto elements such. B. a donor wheel, be arranged.
• the markings of the phase traces may, for example, be optical markings, so that the sensor element z. B. can detect light-dark transitions.
• other sensor principles such. B. magnetically or capacitively conceivable.
• the z. B. can be detected with each different sensor elements are conceivable.
• the markings of the phase tracks or at least one phase track may alternatively or additionally be made magnetic, for.
• alternately arranged magnetic north and south poles whereby the possibility of using Hall elements is provided as sensor elements.
• a holistic approach for detecting rotational speed of a rotating body as well as of the torque transmitted via it with a single, in a common housing and / or on a single common chip accommodatable sensor arrangement is also created.
• the sensor arrangement according to the invention over the prior art arise in particular the fact that by combining a detection of speed and torque by means of the two z. B. at a right angle to each other arranged sensor bridges it is possible to integrate both functions particularly space-saving and cost in a housing. Further, it is possible, for example, when using a smart electrical interface, both information, both the information about the speed, as well as that with respect to the torque output via only one signal line, which z. B. cost, material and time savings comes because only one electrical connections must be made. In addition, the sensor arrangement allows z. B. when installed in motor vehicles, the use of torque as a controlled variable, which may account for other, previously necessary sensors.
• the difference between a desired by the driver, z. B. can be used by a motor control unit as a controlled variable, for example, by a pedal position predetermined torque and a torque actually delivered by the engine.
• the sensor element associated with the first phase track, with which the sensor element assigned to the second phase track is connected to the second sensor element bridge is a sensor element of the first sensor element bridge.
• the first and the second sensor element bridge can be arranged in a common housing to form a sensor.
• the first and the second sensor element bridge can be arranged on a common chip to form a very compact sensor chip.
• At least the first and second phase traces may be disposed on two separate donor wheels connected to the rotating body. It is also conceivable that only one phase track is arranged on one encoder wheel, and the other phase senspur is arranged or applied directly on the rotating body. As encoder wheels multipole encoder wheels described above can be used.
• At least the sensor elements of at least one sensor bridge Hall elements, wherein the respective associated phase track comprises magnetic markings, z. B. a sequence of alternating magnetic north and south poles.
• At least the sensor elements of at least one sensor bridge are magnetoresistive elements (eg GMR, giant magnetoresistance or giant magnetoresistor).
• a particularly advantageous embodiment of the sensor arrangement according to the invention comprises at least one further sensor element bridge arranged parallel to the first sensor element bridge, for example comprising a third sensor element assigned to the first phase track and a fourth sensor element also assigned to the first phase track.
• the further sensor element bridge by interconnecting a sensor element of the first sensor element bridge with a third sensor element.
• the further sensor element bridge, together with the first sensor element bridge permits the detection of the direction of rotation of the rotating body in addition to the detection of the rotational speed.
• the first and the further sensor element bridge can form, for example, a differential sensor element arrangement described in the introduction in the form of so-called double-differential sensor elements. Short description of the drawing
• FIG. 1 shows a schematic representation of a sensor arrangement with two phase traces arranged circumferentially spaced around a rotating body in the axial direction of a rotation axis, in a perspective view.
• FIG. 1 shows a schematic representation of a sensor arrangement with two phase traces arranged circumferentially spaced around a rotating body in the axial direction of a rotation axis, in a perspective view.
• Fig. 2 is a schematic representation of a settlement of the two phase traces of the sensor arrangement of Figure 1 in a torque-free state with it schematically illustrated arrangement of a first and second sensor element bridge in a plan view.
• Fig. 3 shows the illustration of Figure 2 in a torque-loaded state.
• FIG. 4 shows diagrams with curves of the signals of the sensor elements of the second sensor element bridge (FIGS. 4a and b), which are shown schematically therein, and of the difference of the signals (FIG. 4c) in an almost torque-free state over an observation period.
• FIG. 5 shows diagrams with progressively illustrated profiles of the signals of the sensor elements of the second sensor element bridge (FIGS. 5a and b) and the difference of the signals (FIG. 5c) in the torque-loaded state over an observation period.
• Fig. 6 is a schematic representation of the structure of a sensor with first and second sensor element bridge according to a first embodiment.
• Fig. 7 is a schematic representation of the structure of a sensor with first and second sensor element bridge according to a second embodiment.
• a sensor arrangement 01 shown completely or partially in its construction in FIGS. 1 to 3 has two phase tracks 04, 05, which are located at two cross-sections 06, which are located at a known distance in the axial direction along a rotational axis 02 of a rotating body 03 , 07 are each arranged circumferentially around the rotating body 03.
• Each of the phase tracks 04, 05 consists of a sequence of periodically alternately arranged markings N, S, for example, periodically alternating magnetic north and south poles.
• the rotating body 03 has a known torsional stiffness, also called torsional rigidity, which results from the product of the polar moment of inertia of the geometry of the rotating body 03 and the shear modulus of the material of the rotating body 03.
• the phase tracks 04, 05 can be arranged, for example, on two encoder wheels representing the two cross sections 06, 07, which are connected to one another, for example, by a suitable shaft or torsion spring with suitable torsional stiffness or torsional stiffness.
• the sensor arrangement 01 has a sensor 08, comprising sensor elements 1 1, 12, 13, 14 (FIGS. 2, 3 and 6) or 15, 16, 17 (FIG. 7) arranged stationary relative to the rotating body 03.
• the sensor elements 1 1, 12, 13, 14 and 15, 16, 17 are sensitive to the marks N, S, or for a change of the markers N, S, so that each sensor element 1 1, 12, 13, 14 or 15, 16, 17 upon passage of a marking N, S and / or when changing adjacent markings N, S of a sensor element 1 1, 12, 13, 14 or 15, 16, 17 respectively associated phase track 04, 05 each one Sensor signal generated.
• the sensor elements 1 1, 12, 13, 14 and 15, 16, 17 are connected in the sensor 08 to two respective sensor element bridges 09, 10 arranged at a preferably right angle to one another.
• the sensor element bridges 09, 10 of the sensor arrangement 01 can basically be arranged in each of an integer multiple of 0 ° and 180 ° different angle to detect speed and torque simultaneously.
• An included angle of 90 ° between the two sensor element bridges 09, 10 is not mandatory.
• first sensor element bridge 09 extends in a plan view (eg, FIGS. 2 and 3) parallel to the two phase tracks 04, 05, parallel to the running direction L of the phase tracks 04, 05, and perpendicular to the axis of rotation 02 of the rotating body 03
• second sensor element bridge 10 extends in plan view, for example, perpendicular to the two phase filters.
• the first sensor element bridge 09 is thus suitable for determining the rotational speed of the rotating body 03, wherein the second sensor element bridge 10 is suitable for determining a torque transmitted between the two cross sections 06, 07 via the rotating body 03, as described below with reference to FIGS. 2 to 5 explained in more detail.
• FIG. 2 shows this schematically a torque-free state in which no torque is transmitted between the cross sections 06, 07 of the rotating body 03
• Fig. 3 is a torque-loaded state in which between the cross sections 06, 07 of the rotating body 03 a maximum torque is transmitted.
• FIGS. 4 and 5 show the curves of the signals GR1, GR2 of the two sensor elements 13, 14 connected to the second sensor bridge 10 via an observation period progressing along the abscissa.
• the signals are proportional to a magnetic field B of, for example, formed as magnetic north and south poles markers N, S, which is why the ordinate is symbolically provided with the symbol B for the magnetic field strength.
• the signals GR1 (FIG. 4a)) and GR2 (FIG. 4b)) of the sensor elements 13, 14 of the second sensor element bridge 10 run as shown in FIG. 4 shown in phase, as well as the markers N, S of the two phase tracks 04, 05 each at the same height to each other, the sensor elements 13, 14 of the second sensor element bridge 10 happen.
• the two signals GR1 (Fig. 5a)) and GR2 (Fig. 5b)) are exactly out of phase, since now the marks N, S of the two phase tracks 04, 05 offset from each other, the sensor elements 13, 14 of the second sensor element bridge 10th happen.
• FIGS. 6 and 7 show two alternative embodiments for the construction of the two sensor element bridges 09, 10 of a sensor 08, for example on a common chip 18.
• the variant shown in FIG. 6 provides for the construction of each of the two sensor element bridges 09, 10 by means of their own sensor elements 1 1, 12 or 13, 14 formed on the chip 18, for example.
• a first, the first phase track 04 associated sensor element 1 1 with a likewise the first phase track 04 associated second sensor element 12 to the first, provided for speed determination and preferably almost parallel to the direction L of the first phase track 04 and the two phase tracks 04, 05 extending Sensor element bridge 09 interconnected.
• a sensor element 14 associated with the second phase track 05 is interconnected with a sensor element 13 which is assigned to the first phase track 04 to the second sensor element bridge 10 which extends perpendicular to the running direction L of the two phase tracks 04, 05 and bridges the two phase tracks 04, 05 Torque determination is provided.
• Fig. 7 comes with only three arranged for example on a common chip 18 sensor elements 15, 16, 17.
• a first, the first phase track 04 associated sensor element 15 with a likewise the first phase track 04 associated second sensor element 16 to the first provided for speed determination and parallel to the direction L of the first phase track 04 and the two phase tracks 04, 05 extending sensor element bridge 09 to interconnect.
• a sensor element 17 assigned to the second phase trace 05 is connected to the first sensor element 15 assigned to the first phase trace 04 and connected to the sensor element 16 to the first sensor element bridge 09 to the second sensor element bridge 10 the first sensor element 15 is both a component of the first sensor element bridge 09 and the second sensor element bridge 10, which preferably extends at a right angle thereto.
• the sensor elements 1 1, 12, 13, 14, or 15, 16, 17 of the two sensor element bridges 09, 10 in a common housing, for example in Form of its own ASIC housing (ASIC) Application Specific Integrated Circuit and / or on a common chip 18 and / or be arranged within a common sensor housing.
• ASIC ASIC
• the two cross sections 06, 07 can also be represented by, for example, arranged on a shaft spaced from each other donor wheels.
• the shaft forms the rotating body 03 with known torsion stiffness.
• the running direction L of the phase tracks 04, 05 then corresponds to the running direction of the encoder wheels.
• Hall elements come as sensor elements in question, wherein the markers N, S of the two phase tracks 04, 05 are then formed as already described as periodically alternately arranged magnetic north and south poles.
• magnetoresistive elements such as GMR elements, conceivable.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)

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• 2009
  • 2009-12-23 DE DE200910055275 patent/DE102009055275A1/de not_active Withdrawn
• 2010
  • 2010-12-07 EP EP10790398A patent/EP2516978A1/de not_active Withdrawn
  • 2010-12-07 CN CN2010800584417A patent/CN102667434A/zh active Pending
  • 2010-12-07 WO PCT/EP2010/069018 patent/WO2011076554A1/de active Application Filing
  • 2010-12-07 US US13/518,728 patent/US8863592B2/en not_active Expired - Fee Related

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