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

Definitions

• the invention is based on a device for detecting a rotation angle of a rotatable member according to the preamble of the independent claim.
• a generic arrangement for contactless rotation angle detection of a rotatable element is known.
• the sensor arrangement is constructed from at least two sensor elements and arranged opposite the rotatable element such that the field lines emanating from the rotatable element in each rotational position transverse to the direction of a current in the sensor elements run predetermined sensor structures.
• the directional components of the field lines for determining the rotational position can be evaluated by the phase position between the input and output signals of the respective sensor elements is evaluated.
• As input signals either sinusoidal or rectangular alternating voltages are supplied or DC voltages. It is an object of the present invention to further simplify the device for detecting a rotation angle. This object is solved by the features of the independent claim.
• the inventive device for detecting a rotation angle of a rotatable member has the advantage that due to the relative detection of the rotation angle no internal evaluation units such as microcontroller, etc. for calculating an absolute steering angle directly in Sensor must be spatially integrated. So also a space reduction can be achieved. Corresponding subsequent steps, such as the calibration of the sensor during production at the factory, are eliminated. This brings lower manufacturing and assembly costs. In comparison to sensors with optical measuring elements, the device according to the invention works very robustly, since it no longer loses its precision or function relatively quickly due to possibly penetrating contamination.
• a further sensor for detecting the magnetic field of the magnet is provided, which is arranged spaced relative to the first sensor in such a way that results in a relation to the output signal of the other sensor, a phase-shifted output signal.
• Output signal are forwarded to the evaluation, which reduces the cabling.
• Output signal of a sensor is provided.
• the signal levels of the sensors are selected so that they normally deviate from the voltage levels of the supply voltage or ground. This can be concluded in a particularly simple manner only on the basis of the signal level to a fault in the sensor.
• an error detection unit is particularly expediently provided in the evaluation unit, which detects on the basis of the signal level of at least one of the output signals, whether an error is present in one of the sensors.
• at least one connection element of the sensor has at least one bending region. This is used in particular to compensate for stresses, for example from thermal stress. As a result, the mechanical stability of the arrangement can be further increased.
• connection element of the sensor has at least one further bending region.
• the connection element can be brought into contact with the printed circuit board for electrical contacting, for example by means of soldering, in a manner suitable for this purpose. This makes it easier to manufacture the device while increasing the mechanical strength.
• At least one holding element is provided for receiving mechanical stresses which act on the sensor.
• the holding element is rib-shaped on the housing or on a part connected to the housing. This holding element absorbs mechanical forces acting on the sensor, as a result of which the robustness of the device can be further increased.
• a fixation of the sensor or its connection elements with the housing by melting the retaining ribs, for example by means of heat stiffening or laser action take place, which further increases the strength.
• At least one pocket or recess is provided in the housing for receiving the sensor.
• the sensor is arranged so that it senses a magnetic field of the magnet which is substantially parallel to the axis of rotation of the rotatable member. As a result, the height of the device can be kept low.
• housing at least one fastening means is provided for connecting the circuit board to the housing.
• the fastening means is designed to be thermally deformable for fastening the housing to the printed circuit board, for example by means of Warmverstemmung.
• the attachment process could be done together with the retaining ribs in just one operation.
• at least one rivet connection is provided as a fastening means. This serves in particular for receiving forces acting on the printed circuit board, which are introduced, for example, via the plug.
• the integrated component formed by hub and magnet is produced by molding the magnet with plastic. In this way even more, more complex geometries can be realized in this component in a simple manner.
• the magnet has a substantially L-shaped cross-section.
• the hub can be integrated with great strength with the magnet to an integrated component.
• the hub has at least one driver for transmitting a rotational movement of the rotatable part, preferably a steering column.
• a driver is in the radial direction in the direction of the axis of rotation of the rotatable member extending component or a
• the integrated component could be installed from above or from below without having to adapt the housing to different installation spaces. This increases the flexibility of the arrangement with the same components.
• the hub has at least one preferably oriented perpendicular to the axis of rotation bearing surface for rotatably supporting the hub in the housing.
• the hub is at least on a bearing surface of a low-wear material.
• the bearing surfaces can be chosen independently of the geometry of the magnet so that there is an optimized solution with regard to the interaction with the housing (fits, tolerances, mountability, etc.).
• more complex structures can be realized at the hub.
• the hub is made of the same material as the magnet, preferably made of plastic or a fully magnetizable material. As a result, the production of the component can be further simplified.
• the hub and / or the magnet interacts with a fixing element for fixing to the housing.
• a fixing element for fixing to the housing.
• the fixing element is movable or resilient, preferably as a snap hook, formed and / or connected to the housing or the hub.
• a fixing is in particular a snap hook, which fixes the hub in the axial and radial directions.
• the snap hooks are force-free or stress-free after the assembly process, so that they do not limit the mobility of the hub or the magnet relative to the housing.
• Number of snap hooks is suitably chosen so that the hub is still reliably fixed even in case of failure of a hook, for example, in case of breakage.
• five snap hooks distributed evenly around the circumferential direction of the hub are provided to achieve this functionality.
• the reliability of the device can be further increased.
• a cover for axial fixation of the hub is also superfluous, so that components can be saved.
• FIG. 1 shows a perspective view of a hub with an integrated magnet (without bearing geometry)
• FIG. 2 shows a top view of a multipole magnet
• FIG. 3 shows a perspective view of the arrangement of hub, magnet and sensors
• FIG. 4 shows the time-dependent output signals of the two sensors
• Figure 5 is a perspective view of the device for detecting a
• Figure 6 shows the arrangement according to Figure 5 from below
• Figure 7 is a side perspective view of the hub with integrated
• Figure 8 shows the hub of Figure 7 in plan view
• Figure 9 shows the arrangements according to Figures 7 and 8 in section
• Figure 10 is a perspective view of the device for detecting a rotation angle with inserted hub
• Figure 11 shows the device according to Figure 10 with of opposite
• Figure 12 shows a perspective half-section of the connection of the hub with the housing via fixing elements, Figures 13 to 18 sensor elements, each with differently shaped
• Figure 19 is a perspective view for contacting the
• Figure 20 is a perspective view for fixing the sensor with fixing ribs before reflowing
• Figure 21 is a perspective view of the housing with printed circuit board
• Figure 22 is an overall perspective view of the device for
• FIG. 23 shows output signals of the first and second sensors as well as the output signal resulting from a possible logic operation
• FIG. 24 shows a block diagram of the arrangement for signal processing.
• a magnet 10 is disposed in the upper outer peripheral region and thus form an integrated component 17.
• the magnet 10 is in this case designed as a multipole magnet, as shown in Figure 2, which shows the magnet 10 in plan view is.
• a projection is formed at the lower end of the magnet 10, which extends slightly further in this area in the direction of the axis of rotation 18 of the hub 16 than in its upper region.
• Hub 16 and magnet 10 are engaged, for example, with a steering column or with another part connected to the steering wheel.
• the rotating part in the steering movement for example, the steering column, via a driver 32 with the in the device 8 for
• Rotation angle detection arranged hub 16 connected.
• the hub 16 contains the magnet 10, which is designed as a multipole magnet. This carries distributed over the circumference alternately north poles 12 and south poles 14. During rotation of the steering column, the multi-pole magnet 10 thus rotates at the same angular velocity.
• a sensor 20 at a certain point in the measurable range of the magnetic field, which provides measured values that are dependent on or close to the magnetic field direction at that point.
• a sensor 20 could be used for this purpose, a Hall sensor that outputs a binary signal depending on whether its sensitive area in the majority
• Influence of a north pole 12 or a south pole 14 is located. It is essential that the sensor 20 and the magnet 10 are arranged to be movable relative to each other. Likewise, the sensor could be designed as a reed contact, which changes its output signal as a function of the magnetic field.
• a further sensor 22 is provided which is placed at a defined distance from the first sensor 20 so that a certain offset ⁇ of the two output signals 21, 23 of the two sensors 20, 22 results. Based on the temporal
• Sequence of the signal edges 21, 23 can be closed on whether the steering wheel or the steering column is rotated clockwise or counterclockwise.
• the sensors 20, 22 were arranged radially further outward relative to the magnet 10, so that they detect its magnetic field in radial orientation.
• electronic components are necessary. These are mounted on a printed circuit board 26 and electrically connected. If necessary, additional functions, such as changing the voltage levels, can be implemented there.
• Hub 16 magnet 10, sensors 20, 22 and the printed circuit board 26 are housed in a housing 28, which via an integrated connector 30, the connection to the
• the housing 28 assumes further functions such as, for example, mounting of the hub 16 with magnet 10, axial fixing by means of fixing elements 36 or further fastening functions of the sensors 20, 22 via holding elements 50 to be explained later.
• a core of the inventive device 8 for detecting a rotation angle is the integration of the magnet 10 in the hub 16. This could be achieved, for example, by molding the magnet 10 with plastic.
• the resulting combined component of magnet 10 and hub 16 can be designed so that a wear-free or low-wear mounting of the hub 16 in the housing 28 is achieved.
• the appropriate choice of material of the hub 16 also depends on the material of the housing 28, suitable materials could be, for example, PA12 (polyamide) and PBT (polybutylene terephthalate).
• bearing surfaces 34 which cooperate with corresponding abutment surfaces of the housing 28, regardless of the geometry of the magnet 10 can be chosen so that in terms of interaction with the housing 28 (fits, tolerances, mountability) a optimized solution can be found.
• the bearing to the housing 28 is formed by two mutually perpendicular sectional bearing surfaces 34, whereby the hub 16 is aligned in the axial and radial directions relative to the axis of rotation 18.
• a third bearing surface 34 on the upper edge of the outer circumference of the hub 16 cooperates with the fixing element 36 shown below.
• at least one driver 32 is integrated in the hub 16. In FIGS. 7 and 8, two types of drivers 32 are shown by way of example.
• a radially outwardly oriented recess is provided on the inside of the hub 16 into which a complementary extension of a rotatable part, for example the steering column, can engage.
• a further driver 32 is provided, which has a projection which is oriented from the inside of the hub 16 in the direction of the axis of rotation 18 and cooperates with a corresponding recess in the rotatable part.
• hub 16 and magnet 10 are particularly advantageous because more complex geometries can be realized on the hub 16, such as resilient snap hooks. About such snap hooks, a connection with the housing 28 can be achieved. Alternatively, it would also be possible for the hub 16 to use the same material as for the multipole magnet 10, thereby simplifying the creation of the component.
• hub 16 it could then be produced as a component by means of an injection molding process.
• Another alternative is to design the hub 16 as a symmetrical bearing member with the integrated magnet 10 centered.
• entrainment elements 32 are always required, which are mounted on one side of the hub 16. Is it now necessary for space reasons to install the housing turned 28 because, for example, the plug 30 is oriented in the opposite direction, so it only needs the hub 16 of the
• Device 8 are also installed turned. Thus, without changing the hub 16 or magnet 10, two variants of the same device are available. These possibilities are shown in FIGS. 10 and 11, where both times the hub 16 is oriented in the same way, regardless of the position of the plug 30.
• Another feature of the device 8 is the attachment of the hub 16 with the housing 28, which takes place with the aid of the fixing elements 36. So that the hub 16 with the magnet 10 does not move out of the housing 28 in the axial direction, it must be fixed in the axial direction. For this are the
• Fixing elements 36 are provided, which are preferably designed as snap hooks or clips. It is essential with these fixing elements 36 that on the one hand they permit a movement of the hub 16 about the axis of rotation 18, but prevent an offset in the axial direction with a defined clearance.
• the fixing elements 36 surround the hub 16 in a circular manner. When inserting the hub 16 in the housing 28 counter forces are initially overcome, which occur when bending the fixing elements 36. If the hub 16 has reached its end position, the fixing elements 36 spring back over it, as a result of which the fixing elements 36 are completely free of force or stress. Thus, the hub 16 can rotate without causing the fixing elements 36 undesirable friction.
• the fixing elements 36 are in terms of their
• FIG. 1 An exemplary geometric arrangement of a fixing element 36 with respect to the hub 16 is shown in FIG.
• the fixing element 36 is connected directly or indirectly to the housing 28.
• the hub 16 is inserted for mounting from above into the housing 28 and pushes over the bevel the tip of
• fixing elements 36 with their defined geometry spring-mounted fixing elements 36 could be used.
• the Functions "feather” and “save” can also be distributed to more than one element.
• the fixing elements 36 could not be mounted on the hub 16 nor on the housing 28, but on an additional component which is used for mutual connection of hub 16 and housing 28.
• the fixing elements 36 could also be arranged on the outside of the hub 16 and resiliently engage in corresponding recesses in the housing 28.
• the sensors 20, 22 consist of a housing 40 and a plurality of connecting elements 42, via which the signals of the electronic components arranged in the interior of the housing 40 are brought out.
• the sensors 20, 22 consist of a housing 40 and a plurality of connecting elements 42, via which the signals of the electronic components arranged in the interior of the housing 40 are brought out.
• the connecting elements 42 of the sensors 20, 22 are bent by approximately 90 degrees (reference numeral 43) in order to electrically contact the radially oriented sensor 20, 22 with the printed circuit board 26.
• the sensors 20, 22 are designed as so-called THT components (Through Hole Technology) and used similar to an S MT component (Surface Mounted Technology). This makes it possible to measure the magnetic field of the magnet 10 perpendicular to the orientation of the populated areas of the printed circuit board 26.
• further bending regions 44, 46 of the connection elements 42 are provided.
• a first bending region 44 serves to fix the housing 40 and solder the connection elements 42 to the printed circuit board 26
• connection elements 42 are brought to the circuit board 26 that he wetted as effectively as possible with solder and thereby electrically and mechanically with the circuit board 26 in a Greier Scheme 48
• connection elements 42 can be connected.
• a substantially S-shaped profile of the connection elements 42 thus results.
• the exemplary embodiment according to FIG. 14 only includes a first bending region 44 in order to guide the connecting elements 42 in the contacting regions substantially parallel to the surface of the printed circuit board 26.
• Housing 40 may be omitted if the magnetic field instead of in the radial direction, as described, would now be detected axially.
• the 90 degree bend 43 could also be replaced by a different angle.
• the first flexure 44 could be omitted if required for relevant reasons, such as cost, feasibility, as shown in FIG.
• the second bending region 46 could also be omitted and the contacting with the printed circuit board 26 could be realized other than soldering, for example by a mechanical snap-on connector already mounted on the printed circuit board 26 and in which the connecting elements 42 are inserted. Corresponding embodiments are shown in FIGS. 14 and 16.
• the second bending region 46 could also be omitted, if required because of the soldering process chosen or other reasons, to continue the connection elements 42 to the end in a straight line (FIGS. 14, 16).
• a third bending region 47 could be provided for the outer two connection elements 42 to the distance of the connection elements
• the two outer connection elements 42 are bent outward in a third bending region 47, then run essentially parallel to the surface of the printed circuit board 26 after a 90-degree bend 43, and through the first bending region 44 or U-shaped bend, then run again parallel to the surface of the circuit board until the step-shaped second bending portion 46 aligns the Mixier Schemee 48 in turn parallel to the circuit board 26 in their immediate vicinity for a suitable contact.
• other sensor elements 20, 22 could be bent in this way if they are to be used in the sensor, such as reed contacts / sensors.
• the sensor 20, 22 according to FIG. 14 is arranged in the pocket 41 in the housing 28 and is electrically conductively connected to the printed circuit board 26 by means of the contact regions 48 ( Figures 19, 20).
• rib-shaped holding elements 50 are preferably provided on the housing 28, which are matched to the outer geometries of the connection elements 42.
• forces occur which can act on the connection elements 42 of the sensor 20, 22. In this case, either the solder joint should absorb these forces, which could have a negative effect on their life, unless the forces are absorbed elsewhere.
• the housing 40 of the sensor 20, 22 could be claimed such that the connection elements 42 could take damage in or on the housing 28, for example, tear off. That's why so-called
• Verstemmrippen 50 provided on the housing 48 along the connecting elements 42 as holding elements.
• the connecting elements 42 are first carried out between the ribs 50, whereby they learn a guide and thus a better match between connecting elements 42 and PCB
• the corresponding ribs 50 are shown prior to reflowing.
• the material of the ribs 50 is not melted by hot caulking, but by means of another method, such as by laser action.
• no material could be melted, but the legs are fixed in a different way to the housing 28, for example by adhesive or other mechanical components.
• the fixing function could be realized via an additional component, which is applied to the housing 28.
• the housing 28 with circuit board, 26, but without integrated part 17 is shown.
• the printed circuit board 26 can be fastened to the housing 28 via two pins 51. These pins 51 are part of the housing 28 and thus consist of the same material.
• the circuit board 26 is for attachment pressed into the housing 28 via these pins 51. As a result, the circuit board 26 undergoes the correct positioning.
• the height of the pins 51 is preferably designed so that sufficient material is available to use this additional material by hot caulking for mounting the circuit board 26.
• the corresponding arched shape of the pins after deformation preferably
• Warm caulking is each designated by the reference numeral 52. Furthermore, a rivet connection 53 is provided, which receives in particular on the plug 30 occurring forces and on the circuit board 26 transmitting forces.
• the rivet 53 is preferably made of metal. Furthermore, in this view, the annular bearing surface of the housing 28 for supporting the hub 16 with the lower bearing surfaces 34 can be seen well.
• An offset in the axial direction of the hub 16 is not possible because the bottom of the snap hooks 36 counteracts with the top of the hub 16 an axial offset. It is the recess 32 visible on the inside of the hub 16, which cooperates as a driver 32 with a steering column, not shown.
• a third and fourth sensor could be used to provide their two output signals to a different system, such as a pair of matched voltage levels, the other pair without matching.
• the corresponding bending regions 44, 46, 47 are provided, in particular to compensate for thermal stresses.
• holding elements 50 are provided, the mechanical forces acting on the sensor elements 20, 22 and their Connection elements 42 act, record. These could, as described, be designed as ribs 50.
• the absolute angle can be determined sufficiently accurate and the requesting systems, such as a controller 58, communicated. Furthermore, an algorithm is required, via which the zero position of the steering wheel is to be determined, in order to enable an initialization of the relative detection. This algorithm is also executed in the evaluation unit 60. This algorithm is familiar to the person skilled in the art and will not be considered further below. In the present device 8, therefore, only the output signals of the sensors 20, 22, which are executed as binary signals depending on the type of magnetic field, or the signal 54 linked thereto, are transmitted to the control unit 58. Only then is the absolute position of the steering wheel in a microcontroller 60 determined as an example of an evaluation unit.
• control unit 58 or the microcontroller 60 has a corresponding one
• the absolute steering angle information ascertained in the microcontroller 60 can be forwarded via a bus system 64 to further, unspecified control devices.
• further sensors 66 may be integrated, the values of which are the microcontroller 60 also needed, for example, to calculate appropriate control variables for an electronic stability program in a motor vehicle.
• the control unit 58 is supplied with wheel speed signals from further wheel speed sensors 66, as also shown by way of example in FIG.
• the device 8 for detecting a rotation angle represents a safety-relevant component in the vehicle, which is why the output signals 21, 23 must be checked for correctness.
• 26 electronic components are mounted on the circuit board, which move the binary output signals of the sensors 20, 22 to offset levels. For example, instead of 5V and 0V (as usual pull-up
• the signals are converted to 4.5 V and 0.5 V. If there is a short circuit to the supply voltage or ground in the sensor 20, 22, these quantities are also output by the sensor 20, 22, ie. H. 5 V or 0 V in the mentioned error case.
• the microcontroller 60 From the following system, for example the microcontroller 60, it can be immediately recognized that an error exists in the device 8, since the signal levels differ from the expected signal levels. For this purpose, the microcontroller 60 compares the by the o.g. electronic components changed output signals of the sensors 21, 23 or possibly the associated output signal 54 with corresponding limits and detects in case of exceeding or falling short of an error of a sensor 20, 22. The same could also by a
• Said device for detecting a rotation angle can be used for numerous applications.
• it is suitable for detecting a steering angle.
• the steering angle is already required in a number of vehicle functions, such as electronic stability program, adaptive cruise control, park pilot, driving capability monitoring, active front steering, four-wheel steering, adaptive lighting control or electro-hydraulic steering.
• vehicle functions such as electronic stability program, adaptive cruise control, park pilot, driving capability monitoring, active front steering, four-wheel steering, adaptive lighting control or electro-hydraulic steering.
• the use is not limited to this.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)

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• 2008
  • 2008-10-13 DE DE102008042795A patent/DE102008042795A1/de active Pending
• 2009
  • 2009-10-12 US US12/998,326 patent/US8890515B2/en active Active
  • 2009-10-12 WO PCT/EP2009/063279 patent/WO2010043590A1/de active Application Filing
  • 2009-10-12 EP EP09783953A patent/EP2347221A1/de not_active Withdrawn
  • 2009-10-12 CN CN200980140431.5A patent/CN102177415B/zh active Active

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