Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/14—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
  • B60R21/015—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
  • B60R21/01512—Passenger detection systems
  • B60R21/01516—Passenger detection systems using force or pressure sensing means
• • 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
  • G01G—WEIGHING
  • G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
  • G01G19/40—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight
  • G01G19/413—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means
  • G01G19/414—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means using electronic computing means only
  • G01G19/4142—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups with provisions for indicating, recording, or computing price or other quantities dependent on the weight using electromechanical or electronic computing means using electronic computing means only for controlling activation of safety devices, e.g. airbag systems

Definitions

• the invention is based on a connecting element according to the type of the independent claim.
• a generic connecting element in which the relative movement between a magnet system and a magnetic sensor system is used for force measurement.
• the magnet system is preferably a permanent magnet, a Hall sensor element being used as the magnetic sensor system, which can be arranged symmetrically or centered relative to the permanent magnet.
• the connecting element according to the invention with the features of the independent claim has the advantage that the magnet system is now arranged relative to the magnetic sensor system in such a way that a component of the magnetic field is linearized perpendicular to the relative movement between the magnetic system and the magnetic sensor system. This improves the measurement of the magnetic field and thus the force measurement. This achieves an optimized symmetry and strength of the magnetic field with minimal installation space. In particular, this results in an increased magnetic stroke per relative movement. This causes a greater change in the magnetic field as a function of the location. The consequence of this is that a linear magnification increases over the measuring range with reduced mechanical deflection Output signal in magnetic field sensors is achieved. This improves, for example, the insensitivity to disturbing influences like lateral forces and moments.
• the decisive factor is the relative movement between the magnet system and the magnetic field sensor system. It is irrelevant whether the magnet system or the magnetic field sensor is stationary or whether the magnet system or the magnetic field sensor is moving or if both, i.e. move the magnet system and the magnetic field sensor system. Generally, the magnetic field of the magnet is measured here. By changing or designing the far field, the shape and strength or extension of the near field is also optimized, and thus an improvement in the sensor signal is achieved.
• the femfield is set or optimized by the size, the geometry and the position of the magnets relative to one another.
• the magnet or sensor position is interchangeable and arranged along a bending beam.
• the aim is to achieve a maximum relative stroke between the magnet and sensor with minimal influence of lateral forces and moments.
• At least one pole transition that is to say the region between the north and south poles of a magnet of the magnet system, has a recess relative to the magnetic field sensor system.
• This recess can be, for example, a notch, a gap, a slot or some other type of depression on the pole transition. This recess is small in size compared to the geometrical
• the magnetic field generated in this way has an increased field strength around the edges of the recess or a symmetrical field is generated by the shape of the recess. It is thereby achieved that the component of the field perpendicular to the deflection direction has an improved linearity It is also advantageous that at least two pole shoes, preferably a single magnet system, are provided on the magnet system, which produce a stronger magnetic field, since the magnetic field facing away from the magnetic sensor system is now also deflected by the pole shoes to the measuring location between the pole shoes.
• the shape of the pole pieces defines, among other things, the symmetry and shape of the magnetic field on
• the surface of the magnet system is shaped in such a way that the surface approaches the magnetic sensor system. This will optimize
• Shaping of the magnetic field achieved By shaping the surface of the magnet accordingly, the shape and strength of the magnetic field at the measuring location are optimized for the measuring signal and an insensitivity to shear forces and moments is increased
• Such a multi-magnet system allows the magnetic field shape and strength to be set, for example by the distance and the position of the magnets from one another. The location-dependent change in magnetic field can be measured between and to the side of the magnets.
• measurements can be carried out in the area of maximum magnetic field gradients and at a location of minimal interference.
• unequal magnetic poles can also face each other. This allows a targeted magnetic field gradient to be set, e.g. to obtain a preferred direction with increased sensitivity.
• a pole transition of a magnet is opposed by a pole of another magnet. This creates a defined asymmetrical field, which enables a multi-divided measuring range.
• an increased resolution can be achieved in a desired measuring range and a reduced one
• a preferred direction of the measuring range can also be set.
• the shape and strength of the magnetic field can be set to the size of the magnetic poles involved and their distance from one another.
• FIG. 2 single-magnet systems with a specially shaped surface
• FIG. 3 exemplary embodiments for multi-magnet systems, the same poles being opposed to one another, FIG. 4 the connecting element,
• FIG. 5 shows another multi-magnet system
• Figure 6 further multi-magnet systems.
• a connecting element which is used instead of a bolt or a screw for fastening a vehicle seat and at the same time measures the force that is exerted on the seat, is connected to a control unit for actuating personal protection means in order to prevent the triggering, for example of an airbag , when a seat is vacant
• the connecting element it is also possible to characterize an object that is located on the vehicle seat more precisely, namely via the load distribution. It has proven to be advantageous for the connecting element to use the relative movement between a magnet system and a magnetic field sensor, preferably a Hall sensor, for measuring the force in the connecting element.
• FIG. 4 explains how the arrangement of the magnetic field sensor system and the magnetic field system is arranged in a connecting element and the force is measured.
• Connecting element 41 is permanently installed on a holder 40 which is mounted on the chassis of the vehicle. At the other end, connecting element 41 is connected to the seat, which is indicated here by receptacle 43. The connecting element 41 therefore receives the weight 42 exerted on the seat via the receptacle 43. The weight 42 is transmitted through the sleeve 44 into the body of the connecting element
• Air gaps 47 are provided here as overload protection.
• the seat force sensor thus consists of an inner bending element and an outer sleeve which is welded tightly and firmly at one end. This welding therefore takes place with the holder 40.
• This assembly is the active element of the sensor. Within the sensor, the shift is caused by the action of a force
• the signal from the Hall sensor 46 is to be fed to a housing attached to the circumference of the bolt, where the signal processing takes place on a printed circuit board.
• the processed signal is then fed to a connector interface, at which the signal is fed to the control unit for controlling personal protection devices in the vehicle via mating connector and wiring harness. Since the force is converted into a linear displacement and the Hall sensor 46 converts this displacement into a signal, any movement or displacement of the Hall sensor 46 or its holding device due to external forces must be avoided, since this would lead to a misinterpretation or measurement.
• FIG. 1 shows single-magnet systems which are designed according to the invention.
• FIG. 1 a shows a magnet 11 with a recess 10 in relation to the magnetic field sensor system Hall, the deflection of the magnetic field sensor system Hall taking place in the transverse direction, as indicated here.
• the magnet 11 generates a magnetic field 13 facing the magnetic field sensor system Hall and one of the magnetic field sensor system Magnetic field facing away 12.
• the depression is small in relation to the dimension compared to the geometric size of the magnet 11.
• the magnetic field generated in this way has an increased field strength around the edges of the depression.
• FIG. 1b shows a variant, in which case a notch that tapers to a point is provided.
• the magnet 15 in turn has a magnetic field 17 facing the magnetic field sensor system Hall and a facing magnetic field 14, the notch 16 generating a symmetrical magnetic field.
• Figure lc describes an alternative.
• the magnet 101 is framed by pole shoes 18 and 19.
• the pole shoes cause a stronger magnetic field to be generated for the magnetic field sensor system Hall. This is caused by the fact that the rear magnetic field is deflected by the pole shoes to the measuring location between the pole shoes.
• the shape of the pole pieces defines, among other things, the symmetry and shape of the magnetic field at the measuring point, which lies between the pole pieces. All three examples, A, B and C lead to an improved linearity of the magnetic field perpendicular to the deflection direction.
• FIG. 2 shows four exemplary embodiments of how the shape of the magnet is designed such that the surface of the magnet runs towards the magnetic field sensor system Hall.
• the south pole of the magnet 200 is shaped so as to taper towards the magnetic field sensor system Hall.
• the magnetic field 202 or 203 is accordingly optimized.
• FIG. 2b shows an alternative.
• the south pole 204 is now rounded off to form the Hall magnetic field sensor system. This also optimizes the magnetic field 201, 205 accordingly.
• FIG. 2c shows a further alternative. Now the north and south poles with their pole transition face the Hall magnetic field sensor system.
• the facing side is also rounded here, which shows the contour 207.
• the magnetic field 209 is thus optimized accordingly.
• the rear magnetic field 206 is irrelevant here.
• FIG. 3 shows three examples of multi-magnet systems, the Hall magnetic field sensor system being located in the area between the two magnets.
• FIG. 3a shows a two-magnet system in which the poles of the two magnets 300 and 301 face each other, namely the same poles.
• the magnetic field of the two poles 300, 301 is shaped accordingly by the magnetic field lines 303, 304, 305 and
• the magnetic field sensor system Hall can be moved here in the measuring direction, that is to say transversely, which is indicated by the arrow 302.
• the Hall magnetic field sensor system is arranged off-center from the field.
• measurements can be carried out in the area of maximum magnetic field gradients and at one location ⁇ nimal interference.
• Figure 3b shows a variant.
• the Hall magnetic field sensor system is now not directly between the two magnets 300 and 301, but somewhat outside.
• Such a multi-magnet system allows the magnetic field shape and strength to be set, for example, by distance and position from one another.
• the location-dependent change in the magnetic field can be measured between, as in FIG. 3a and also in FIG. 3c, and to the side of the magnet.
• Figure 3c shows a variant.
• the two magnets 307 and 308 are arranged with respect to each other with respect to the south pole.
• the north poles are located behind each.
• the magnetic field is then formed accordingly, as here by the magnetic field lines 309, 310, 311 and 312.
• the measuring direction is indicated here in the vertical direction 313.
• FIG. 5 shows a two-magnet system in which the two magnets 50 and 51 face each other in their different poles. As a result, the magnetic field 52 and 53 is formed, the magnetic field sensor system Hall lying outside the area between the
• FIG. 6a shows a multi-magnet system with a magnet 60, at the pole transition of which a magnet 61 is arranged opposite.
• the magnetic field sensor system Hall which in turn deflects horizontally here, is arranged between the two magnets 60 and 61.
• the resulting magnetic field is indicated by the field lines 62, 63, 66 and 65.
• an increased resolution can be achieved in a desired measuring range and a reduced resolution outside this desired measuring range.
• a preferred direction of the measuring range can also be set.
• a very large magnetic field gradient is present in the transition area NS 60, or vice versa. The closer the Hall sensor comes to the N pole, the more homogeneous the field becomes, ie the Hall sensor shows maximum sensitivity. This gives a preferred direction with increased sensitivity, for example in one measuring direction.
• FIG. 6b shows an alternative, now with a symmetrical field 68, since the upper magnet 69 is now composed of three poles, namely a south pole in the middle and two north poles each outside.
• the lower magnet 61 is arranged with its south pole opposite the south pole of the magnet 69.
• the south pole of the lower magnet 61 is somewhat larger than the upper south pole of the magnet 69.
• the magnetic field 68 thus created between the two magnets 69 and 61 is due to the
• the shape and strength of the magnetic field can be set by the size and width of the magnetic poles involved and their distance from one another.
• Single or multiple magnet systems with a magnetic field sensor system or a magnetic sensor-magnet arrangement are provided, which are adjusted or calibrated separately.
• the distance between the magnet and sensor is set and fixed at the optimum distance by separate mounting.
• the calibrated system is then guided and fixed laterally through the sleeve and the bending element.
• the magnets are thus firmly connected to the sleeve and the sensor is firmly connected to the bending element.
• the reverse arrangement with a magnet in the bending element and the sensor in the sleeve is also possible.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Mathematical Physics (AREA)
• Theoretical Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)
• Measuring Magnetic Variables (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=34895118

Family Applications (1)

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Citations (1)

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• 2004
  • 2004-03-10 DE DE102004011591A patent/DE102004011591A1/de not_active Withdrawn
• 2005
  • 2005-01-10 CN CN200580007783.5A patent/CN1930459A/zh active Pending
  • 2005-01-10 WO PCT/EP2005/050080 patent/WO2005088267A1/de active Application Filing
  • 2005-01-10 EP EP05701473A patent/EP1738146A1/de not_active Withdrawn
  • 2005-01-10 US US10/592,609 patent/US7777482B2/en not_active Expired - Fee Related
  • 2005-01-10 JP JP2005518699A patent/JP2006514750A/ja active Pending

Patent Citations (1)

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