JP2019536991A - Method for determining absolute position, electric motor, and operating device for friction clutch - Google Patents

Abstract

A method for determining an absolute position by a magnetic sensor device having a GMR sensor and a magnetic field generating magnet movable relative to each other, wherein the GMR sensor and the magnetic field generating magnet are first moved in a first movement direction. Movement relative to each other, and then relative to each other in a second direction of movement opposite to this first direction of movement, thereby allocating positions that cannot be initially allocated due to hysteresis A method and an electric motor, comprising: a stator, a rotor, and a magnetic sensor device having a GMR sensor and a magnetic field generating magnet, wherein the GMR sensor is coupled to the stator and the magnetic field generating magnet is coupled to the rotor. An electric motor that is coupled and whose absolute angular position of the rotor can be determined by a method as described above, and at least as described above. One of has an electric motor, the operation device for a friction clutch.

Description

  The present invention relates to a method for determining an absolute position by a magnetic sensor device having a GMR sensor and a magnetic field generating magnet (Gebermagnet) movable relative to each other. Further, the present invention is an electric motor, comprising a stator, a rotor, a magnetic sensor device having a GMR sensor and a magnetic field generating magnet, wherein the GMR sensor is coupled to the stator, and the magnetic field generating magnet is The invention relates to an electric motor coupled to a rotor. Furthermore, the invention relates to an operating device for a friction clutch.

  From DE 10 2016 221 1802.1, four signal states are provided for one revolution of the magnetic element, which are provided with magnetic elements and are arranged spirally along or about the axis of rotation. It is known to determine the rotational speed of a component that rotates about an axis of rotation by means of at least one multi-turn sensor operating according to the GMR principle with an electrical conductor. In order to detect the rotation speed, the resistance of the conductor is detected via the rotation angle, and the rotation speed is determined based on the signal state. The two signal states are indistinguishable via the pivot angle, and one distinguishable switching state is detected between the two indistinguishable states. Based on two multi-turn sensors that rotate relative to each other about a rotation axis by a rotation angle not equal to zero, the assignment of the angular position of the rotating component in the indistinguishable signal state of one multi-turn sensor to the other Of the multi-turn sensor of the present invention by detecting a distinguishable signal state.

  From German Patent Application No. 10 102 162 21 173.1, two distinguishable magnetic elements are provided, which are arranged along or about the axis of rotation and spirally about the axis of rotation, with respect to one revolution of the magnetic element. It is known to determine the rotational speed and angular position of a component rotating about an axis of rotation by means of at least one multi-turn sensor working according to the GMR principle with an electrical conductor having a half-bridge signal. In order to detect the rotation speed, the resistance of the conductor is detected via the rotation angle, and the rotation speed is obtained based on the half bridge signal. A magnetic sensor working according to the AMR principle determines the angular position of the component in each of two semicircles, and a multi-turn sensor determines where in the semicircle the angular position is determined.

  The object of the invention is to improve the method described at the outset. It is a further object of the invention to improve the electric motor described at the outset. It is a further object of the invention to improve the operating device described at the outset.

  This object is achieved by a method having the features of claim 1.

  The method according to the invention can be used to determine absolute angles. The GMR sensor and the field generating magnet may be rotatable relative to each other. The GMR sensor and the magnetic field generating magnet can first be rotated relative to each other in a first rotational direction, and then relative to each other in a second rotational direction opposite to the first rotational direction. Can be rotated. The GMR sensor can be used to count the number of rotations. GMR sensors are sometimes referred to as multi-turn sensors.

  The method according to the invention can be used to determine the absolute stroke amount. The GMR sensor and the field generating magnet may be movable relative to each other along the stroke axis. The GMR sensor and the field-generating magnet can first be rotated relative to each other in a first direction of movement along the stroke axis, and then in a second direction opposite the first direction of movement along the stroke axis. They can be rotated relative to each other in two directions of movement. The stroke axis may be linear.

  The GMR sensor is a sensor based on a giant magnetoresistance effect. The GMR sensor can have a spiral. This spiral may have a plurality of spiral arms. The spirals can be arranged in a diamond. The GMR sensor can have a GMR stack. A GMR sensor can have a reference layer and a sensor layer. The magnetization state of this sensor layer may be changeable. The GMR sensor can have a domain wall generator. This domain wall generator can be located at the end of the spiral. The domain wall generator may be able to generate a 180 ° region. This region may be injectable into the helix and / or may be removable again. The magnetization state of the spiral arm may be changeable under the influence of the movement of the magnetic field. The magnetization state of the spiral arm may be changeable by moving the magnetic field and the spiral relative to each other. The rotational speed may be magnetically storable. Movement may be detectable without a voltage supply. Movements may be memorable without a voltage supply. The electrical resistance of the helix can be related to the magnetization state.

  When the magnetic field generating magnet and the GMR sensor rotate relative to each other, a rotating magnetic field can be applied to the GMR sensor. A GMR sensor can have four signal states per revolution. GMR sensors may have hysteresis. Due to this hysteresis, the signal state of the GMR sensor becomes partially indistinguishable.

  The GMR sensor and the magnetic field generating magnet can be moved relative to each other by a predetermined stroke amount / angle in consideration of the motion resolution of the GMR sensor, particularly the angular resolution. GMR sensors can have 90 ° angular resolution. The GMR sensor and the magnetic field generating magnet can be rotated relative to each other by about ± 45 ° starting from a rotational position that cannot be initially assigned.

  The GMR sensor can be connected to a half bridge circuit. In each case, three distinct signal levels may be output. A High level, a Middle level, and a Low level may be output, respectively. The signal states of the GMR sensors may be distinguishable by a combination of different half bridge signal states.

  Furthermore, the object of the invention is solved by an electric motor having the features of claim 5.

  The electric motor may be controllable by an electric control device. This electrical control device may be a control device. The electrical control device may be a local control device. The electrical control device can have a computing device. The electronic control device can have a storage device. The electrical control device can have at least one electrical signal input. The electrical control device can have at least one electrical signal output. The electrical control device can be structurally and / or functionally signal-guided to at least one further electrical control device. For this signal-guide connection, a bus system, for example a CAN bus, can be used.

  The electric motor can have a housing. The stator can be fixedly arranged on the housing. The rotor can be rotatably mounted in the housing. The magnetic field generating magnet can be mounted on the rotor side. The GMR sensor can be mounted on the stator. The magnetic field generating magnet and the GMR sensor can define a measurement gap for non-contact counting of the number of revolutions to determine the absolute angle.

  An electric motor can be used as an actuation drive. Electric motors can be used for use in motor vehicles. The electric motor is used to operate an automated transmission, electronic accelerator pedal, valve adjuster, window adjuster, seat adjuster, sliding roof adjuster, mirror adjuster and / or air flap adjuster. Can be.

  The object of the invention is further achieved by an operating device having the features of claim 6.

  The operating device may be a hydrostatic operating device. The operating device can have at least one master cylinder, at least one slave cylinder, and at least one hydraulic section formed between the at least one master cylinder and the at least one slave cylinder. . At least one electric motor can be used to power at least one master cylinder. At least one slave cylinder can be assigned to a friction clutch.

  The friction clutch may be a single clutch or a dual clutch. Friction clutches can be used for placement in the power train of a motor vehicle. The power train may have a prime mover. The prime mover may be an internal combustion engine. The power train can have a friction clutch. The power train can have a transmission. This transmission may be a manual transmission. The power train can have at least one drivable vehicle wheel. A friction clutch can be used to locate between the prime mover and the transmission.

  In summary, and in other words, it turns out that the invention makes it possible, in particular, for the rotational speed to be determined without angle information by means of GMR multi-turns. The output (half bridge signal) of the magneto-resistive multi-turn sensor has three statuses (High, Middle, and Low). Depending on the position of the magnet, the four possible "combinations" during one revolution are identifiable, but the inherent hysteresis of the sensor makes the status non-unique. If this is tolerated by the system, it will deviate from the hysteresis region, so that the magnet can be turned slightly, for example ± 45 °, or equipped with a magnet, in order to determine the exact number of revolutions (eg, １ ／ revolution). Move the piston somewhat.

  According to the present invention, an absolute angle can be specified in addition to the rotation speed count. Additional angle sensors can be omitted. Assembly time is reduced. Measurement accuracy is improved.

  Hereinafter, a plurality of embodiments of the present invention will be described in detail with reference to the drawings. From this description, additional features and advantages will be apparent. The specific features of these embodiments can form the general features of the present invention. Features of these embodiments that are linked to other features may also form individual features of the invention.

FIG. 3 shows a diagram with the signal course of a GMR sensor in a half-bridge while the magnetic field is rotating. FIG. 4 is an enlarged enlarged view of the signal course of the GMR sensor in the half bridge during the rotation of the magnetic field. FIG. 3 shows a diagram with the signal course of a GMR sensor in a half-bridge when the magnetic field rotates clockwise and counterclockwise and the corresponding signal pattern with hysteresis.

FIG. 1 shows a diagram 100 with the signal courses 102, 104 of a GMR sensor in a half-bridge while the magnetic field is rotating. In this diagram, x ₁ axis, Yes and rotation angle plotted on x ₂ axis and x ₃ axes, voltage on the y-axis are plotted. The signals 102 and 104 can take three different signal levels, High, Middle and Low, respectively. During one revolution corresponding to 360 °, four essentially distinct signal level combinations 106, 108, 110, 112 of the signals 102, 104 occur. The signal level combination 106 is the signal 102High / the signal 104High. The signal level combination 108 is the signal 102 Middle / the signal 104 High. The signal level combination 110 is the signal 102Low / the signal 104High. The signal level combination 112 is signal 102 Middle / signal 104 Middle.

  FIG. 2 shows an excerpted enlarged view 200 of the signal paths 202, 204, such as the signal paths 102, 104 shown in FIG. 1, of a GMR sensor in a half-bridge while the magnetic field is rotating. It can be seen in detail that the signal level combination 208 of the signal 202Middle / the signal 204High exists for a short time even at the start of the signal level combination 212 of the signal 202Middle / the signal 204Middle due to the hysteresis. This makes it impossible to initially assign a rotational position. Nevertheless, to assign a rotational position, the magnetic field is rotated in the opposite direction by about 45 ° until the rotational position can be assigned, deviating from the hysteresis area 214.

  FIG. 3 shows a diagram 300 with the signal course 302 of the GMR sensor in a half-bridge when the magnetic field rotates clockwise and counterclockwise, and the corresponding signal pattern with hysteresis. Is shown.

In this diagram, the rotation angles over 1.5 rotations corresponding to 540 ° are plotted on the x-axis x ₁ , x ₂ , x ₃ , and the voltage is plotted on the y-axis. The x ₁ axis, sinusoidal signal curve 302 resulting from the signal pattern of the GMR sensor is shown. The x ₂ axis, the signal pattern of the first half-bridge are plotted. The signal level of the first half bridge may have a low level 304, a middle level 306, and a high level 308. The x ₃ axis, the signal pattern of the second half bridge are plotted. The signal level of the second half bridge may have a low level 310, a middle level 312, and a high level 314.

  When the magnetic field rotates clockwise, a GMR sensor signal pattern having a first signal level 316 results. If the magnetic field rotates counterclockwise, a GMR sensor signal pattern having a second signal level 318 will result. If the direction of rotation changes, a hysteresis region 320 occurs.

100 diagram 102 signal, signal progression 104 signal, signal progression 106 signal level combination 108 signal level combination 110 signal level combination 112 signal level combination 200 excerpt enlarged view 202 signal, signal progression 204 signal, signal progression 208 signal level combination 212 signal level Combination 214 Hysteresis area 300 Diagram 302 Signal progression 304 Low level 306 Middle level 308 High level 310 Low level 312 Middle level 314 High level 316 First signal level 318 Second signal level 320 Hysteresis area

Claims (6)

In a method for determining an absolute position by a magnetic sensor device having a GMR sensor and a magnetic field generating magnet movable relative to each other,
The GMR sensor and the magnetic field generating magnet are first moved relative to each other in a first direction of movement, and then moved relative to each other in a second direction of movement opposite to the first direction of movement. And thereby assigning locations that cannot be initially assigned due to hysteresis.   The method according to claim 1, wherein the GMR sensor and the magnetic field generating magnet are moved relative to each other by a predetermined stroke amount / angle in consideration of a motion resolution of the GMR sensor.   The GMR sensor has an angular resolution of 90 °, and rotates the GMR sensor and the magnetic field generating magnet relative to each other by about ± 45 ° starting from an angular position that cannot be assigned first. The method according to at least one of the preceding claims, characterized in that the method is characterized in that   The GMR sensor is connected to a half-bridge circuit and is capable of outputting three distinct signal levels (304, 306, 308, 310, 312, 314), respectively. The method of at least one of the preceding claims. An electric motor, comprising: a stator, a rotor, a magnetic sensor device having a GMR sensor and a magnetic field generating magnet, wherein the GMR sensor is coupled to the stator, and the magnetic field generating magnet is connected to the rotor. In the electric motor being coupled
An electric motor characterized in that the absolute angular position of the rotor can be determined by the method according to at least one of claims 1 to 4.   An operating device for a friction clutch, comprising at least one electric motor according to claim 5.

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