Classifications

• • 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
  • B60R21/013—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 collisions, impending collisions or roll-over
  • B60R21/0132—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 collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value
• • 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
  • B60R21/013—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 collisions, impending collisions or roll-over
  • B60R21/0132—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 collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value
  • B60R21/01332—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 collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value by frequency or waveform analysis
• • 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
  • B60R21/013—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 collisions, impending collisions or roll-over
  • B60R21/0132—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 collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value
  • B60R21/01332—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 collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value by frequency or waveform analysis
  • B60R21/01336—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 collisions, impending collisions or roll-over responsive to vehicle motion parameters, e.g. to vehicle longitudinal or transversal deceleration or speed value by frequency or waveform analysis using filtering
• • 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
  • B60R21/013—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 collisions, impending collisions or roll-over
  • B60R21/0136—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 collisions, impending collisions or roll-over responsive to actual contact with an obstacle, e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
  • G01H1/00—Measuring characteristics of vibrations in solids by using direct conduction to the detector
  • G01H1/12—Measuring characteristics of vibrations in solids by using direct conduction to the detector of longitudinal or not specified vibrations
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
  • G01H11/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P1/00—Details of instruments
  • G01P1/02—Housings
  • G01P1/023—Housings for acceleration measuring devices
• • 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
  • B60R2021/01006—Mounting of electrical components in vehicles
• • 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
  • B60R2021/01122—Prevention of malfunction
  • B60R2021/01184—Fault detection or diagnostic circuits
  • B60R2021/0119—Plausibility check
• • 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
  • B60R21/013—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 collisions, impending collisions or roll-over
  • B60R2021/01302—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 collisions, impending collisions or roll-over monitoring vehicle body vibrations or noise

Definitions

• Vehicle sensor for detecting acceleration and structure-borne noise
• the invention relates to a vehicle sensor for detecting acceleration and structure-borne noise.
• Safety systems in a vehicle require sensors to record the respective driving or accident situation in order to be able to react accordingly. It is known to use transducers as crash sensors to record acceleration and structure-borne noise. A collision with an obstacle or a collision with an obstacle is recognized by evaluating the measured acceleration and the measured structure-borne noise, and appropriate safety measures are initiated by the safety system.
• Previously known vehicle sensors for measuring structure-borne noise are designed to preferably detect transverse structure-borne sound waves. Since a single one of these vehicle sensors cannot determine the direction of propagation of the transverse structure-borne sound wave, several vehicle sensors have to be linked in order to determine the origin of the structure-borne sound wave, and the measured structure-borne noise values have to be evaluated in part with great computational effort.
• a disadvantage of previously known vehicle sensors for detecting acceleration and structure-borne noise has been found to be that their direction of sensitivity for detecting structure-borne noise is often not identical to the direction of sensitivity for detecting acceleration. Therefore, more than two vehicle sensors must often be provided to determine the impact location of the obstacle in order to ensure that the safety system is triggered in accordance with the accident.
• the object of the present invention is therefore to propose a vehicle sensor for detecting an acceleration and structure-borne noise, which is suitable for different purposes.
• An essential idea of the invention is to propose a vehicle sensor that can record both an acceleration and vibration components of a structure-borne sound wave, in particular a longitudinal structure-borne sound wave. Since the direction of vibration of longitudinal structure-borne sound waves lies along the direction of propagation, the origin of the structure-borne sound wave can be determined. Furthermore, the vehicle sensor is designed in such a way that the sensitivity direction for detecting an acceleration and the sensitivity direction for detecting structure-borne noise are oriented differently due to changes in the structure and attachment of the vehicle sensor.
• the invention now relates to a vehicle sensor, the vibrations in
• Transducer signals the at least one transducer being attached to the carrier by means of a connection.
• the connection to Attaching the at least one transducer to the carrier is a non-positive connection that enables vibrations to be recorded.
• the carrier is designed to determine the measurement properties of the vehicle sensor depending on its design. Such a vehicle sensor can be varied in its measurement properties during the manufacturing process or by programming in order to be able to be used variably for different purposes. This means, for example, that large numbers of this vehicle sensor can be produced at low prices.
• the at least one transducer can preferably record the longitudinal structure-borne noise.
• the advantage of the detection and evaluation of longitudinal structure-borne sound waves compared to transverse structure-borne sound waves is that it is possible to determine the origin of the longitudinal structure-borne sound wave and thus the origin of the collision with an obstacle.
• connection for attaching the sensor to the carrier is designed to reduce or prevent the unwanted signals from being picked up by the sensor. Since the longitudinal structure-borne sound waves have lower amplitudes in comparison to the transverse structure-borne sound waves or in comparison to acceleration, it is advantageous to achieve an attenuation of undesired signals already when the connection is made to attach the carrier.
• connection for attachment to the carrier is, for example, an adhesive.
• the carrier is designed to enable detection of the acceleration and / or structure-borne noise depending on its design.
• it enables vibration components of the structure-borne noise, for example the longitudinal structure-borne noise, to be transmitted in a predetermined direction in order to make them available to the measured value pickup to deliver.
• the carrier can include a carrier element, for example for attaching a piezoelectric sensor as a measuring sensor.
• the carrier on the other hand, can also be a construction comprising a plurality of carrier elements, for example if a measuring sensor designed as an ASIC is to be bonded to a first one
• Carrier element is applied, is poured with a molding compound, and is then applied to a circuit board as a second carrier element.
• the carrier is therefore designed to reduce or even prevent the pickup of undesired measuring components by the measuring sensor.
• Both the carrier and the connection for attaching the measurement sensor to the carrier are designed to enable detection of the longitudinal structure-borne noise. Recording the longitudinal structure-borne noise is technically more complex, since the longitudinal structure-borne noise is lower in comparison to the transverse structure-borne noise
• the carrier and the connection for attaching the measurement sensor to the carrier are designed in such a way that the vibration components of a longitudinal structure-borne sound wave are transmitted from a vehicle element to the sensor, while attenuating unwanted signals.
• the carrier is designed, depending on its design, to provide a first sensitivity direction of the at least one measurement sensor Detecting the acceleration and / or determining a second sensitivity direction of the at least one transducer for detecting the structure-borne noise.
• the vehicle sensor can thus be used in areas where, for example, the sensitivity directions for detecting the acceleration and structure-borne noise must be the same, for example for triggering an occupant protection system. It can also be used in areas where different sensitivity directions are required to detect acceleration and structure-borne noise, for example in order to carry out a signal plausibility check for a trigger signal for an occupant protection system.
• the carrier is designed depending on its curvature, a first sensitivity direction of the at least one
• the sensitivity directions can be aligned by a curvature of the carrier such that both the same and different sensitivity directions can be set depending on the location of use and the determination of the vehicle sensor.
• the first sensitivity direction and the second sensitivity direction are preferably almost the same.
• a plane formed, for example, from the vehicle's transverse axis and longitudinal axis can be monitored with regard to acceleration and structure-borne noise, in particular longitudinal structure-borne noise.
• the seismic Mass be glued to the at least one sensor.
• the seismic mass can be formed as part of the sensor, if the sensor is, for example, a micromechanical sensor.
• the at least one measurement sensor can be designed to detect a specific acceleration range.
• a certain acceleration range is specified, which is within +/- 1g and +/- 1000g. If the vehicle sensor is used, for example, in the bumper area of the vehicle, it should detect accelerations in a lower range, which correspond to a collision with a light object, and accelerations in a higher range up to +/- 1000g, which, for example, correspond to a collision with another vehicle.
• the at least one measurement sensor can be designed to enable programming of a specific acceleration range. This enables, for example, a customer-specific setting of a certain acceleration range after the production of the vehicle sensor.
• the at least one measurement sensor can be designed to enable the setting of a specific acceleration range during the manufacturing process of the vehicle sensor.
• a suitable acceleration range can thus be defined during the manufacture of the vehicle sensor by a suitable choice of technology or structure.
• the processing unit can comprise a filter for the selective detection of the acceleration and / or the structure-borne noise.
• a signal is thus made available at the output of the vehicle sensor that the provides desired frequency components of the acceleration and / or structure-borne noise. External signal filtering is no longer necessary and reduces the effort for further evaluation of the signal from the vehicle sensor.
• the filter in the processing unit can be programmable in order to enable a selective detection of the acceleration and / or the structure-borne noise. This enables customer-specific programming of the filter characteristics in order to be able to select the signal components required by the customer for his specific application.
• the filter in the processing unit can be designed such that it can be adjusted during the manufacturing process of the vehicle sensor in order to enable a selective detection of the acceleration and / or structure-borne noise. This allows a selection of the signal components required for a special application to be made already during the manufacture of the vehicle sensor.
• the processing unit is designed to detect high-amplitude transducer signals without overdriving an amplifier circuit arranged in the processing unit.
• the amplifier circuit must be designed in such a way that it is possible to detect and amplify, for example, the transducer signals of the longitudinal structure-borne noise, which have lower amplitudes compared to those of the transverse structure-borne noise, but also measurement value signals of the acceleration or the transverse structure-borne noise can be detected and amplified with higher amplitudes ,
• the at least one measurement sensor can be a piezoelectric sensor, a strain gauge, a micromechanical sensor or a magnetorestrictive sensor.
• a suitable and inexpensive implementation of the vehicle sensor can be made with a suitable choice of the measurement sensor can be achieved.
• a piezoelectric sensor is advantageous, in which the desired different orientation of the sensitivity directions is achieved by a curvature of the carrier.
• the vehicle sensor can be designed as a molded ASIC or as a mechatronic vehicle sensor.
• the carrier can be designed as a lead frame suitable for the molding technique or as a mechatronic carrier suitable for the molding technique.
• the sensor housing can be designed as a molding compound surrounding the carrier.
• the vehicle sensor is preferably attached by pressing or pressing the carrier or the sensor housing inside the vehicle or within a central unit.
• the invention further relates to a device for triggering a safety system in a vehicle with at least one vehicle sensor according to one of the preceding claims and a central unit for evaluating signals from the at least one vehicle sensor.
• a vehicle sensor and an airbag control unit can be used, for example, to trigger the airbag in a vehicle
• Central unit to be arranged in the vehicle.
• An arrangement in which at least two vehicle sensors are mounted inside the vehicle are used, for example, to trigger a pedestrian protection system.
• the invention also relates to a device for use in a diagnostic system of a vehicle with at least one vehicle sensor according to one of the preceding claims and a central unit for evaluating signals of the at least one vehicle sensor.
• An arrangement of this device with a vehicle sensor is possible, for example, in diagnostic or monitoring systems in the vehicle, in which a vibration analysis of certain elements is required.
• this vehicle sensor can also be used in the vehicle's stability and braking systems, in vehicle dynamics controls or in road condition monitoring systems.
• the at least one vehicle sensor is mounted inside the vehicle in such a way as to enable acceleration and structure-borne noise to be detected in a predetermined sensitivity direction.
• the location of the collision can be determined, for example.
• the device monitors when used in diagnostic systems
• Vibration processes in particular variable vibration processes, of certain vehicle elements.
• the device is designed to carry out a signal plausibility check of a signal component of the acceleration with a signal component of the structure-borne noise of the at least one vehicle sensor.
• the signal component of the vehicle sensor that represents the acceleration can be linked to the signal component of the vehicle sensor that represents the structure-borne noise in order to generate a plausibility-activated trigger signal for a safety system, in particular an occupant protection system, in the central unit.
• 1 shows an exemplary embodiment of a device for triggering a security system in a vehicle according to the prior art with a plurality of trigger sensors and a central unit; 2 shows two arrangement examples of acceleration sensors and a central unit of a device for triggering a safety system in a vehicle according to the prior art; 3 shows an arrangement of vehicle sensors according to the invention and a central unit in a vehicle; 4a is a block diagram of the vehicle sensor;
• FIG. 4b shows the filter characteristic of the processing unit of the vehicle sensor
• 5a shows a representation of the vehicle sensor with a piezoelectric sensor without curvature of the carrier
• FIG. 5b shows a representation of the vehicle sensor with a piezoelectric sensor with a curvature of the carrier of 90 °.
• the central unit 2 is arranged centrally in the vehicle, preferably in the central tunnel of the vehicle, and controls it corresponding safety systems such as occupant protection systems or pedestrian protection systems.
• the side sensors 3.1.2 are attached to the side of the vehicle 1 to detect a side crash and have a sensitivity direction in
• these sensors often also include a direction of sensitivity in the direction of the vehicle's longitudinal axis.
• This additional sensitivity direction enables, for example, a plausibility check of a sensor output signal generated by the sensors 3.1.2, in particular in the case of accidents in which the force acting on an accident or collision occurs at an oblique angle to the vehicle's longitudinal or transverse axis.
• the sensors 3.2, 3.3 attached in the front area of the vehicle are used as upfront sensors for detecting a frontal crash in which the force is mainly applied in the direction of the
• Sensitivity direction in the direction of the vehicle's longitudinal axis Either a single sensor 3.3 is centered with respect to the vehicle longitudinal axis or two sensors 3.2 outside the
• the side and upfront sensors are located as close as possible to the outer skin of the vehicle so that collisions with smaller objects can be detected as quickly as possible. Rapid detection of an impact is particularly important in the side area of the vehicle, since here the crumple zone is relatively small and, for example, an occupant protection system should therefore trigger particularly quickly.
• these sensors near the outer skin of the vehicle are particularly susceptible to faults compared to sensors that must be installed inside the vehicle, such as the side sensors. For this reason, structure-borne noise sensors that are not so close are used for crash detection the outer skin of the vehicle because structure-borne sound waves propagate much faster in the vehicle than vibrations caused by changes in acceleration.
• FIG. 2 shows two examples of the arrangement of acceleration sensors 3.4 and a central unit 2 of a device for triggering a safety system in a vehicle 1 according to the prior art.
• an arrangement of two acceleration sensors 3.4 the direction of sensitivity of which is oriented at a certain angle to one another, a plane formed from the vehicle longitudinal axis and the vehicle transverse axis can be monitored with regard to crash-relevant acceleration changes.
• the two arrangements shown in FIG. 2 are preferably used, in which the sensitivity directions are arranged at an angle of 90 ° to one another.
• the direction of sensitivity of the first acceleration sensor is aligned parallel to the longitudinal axis of the vehicle, and the direction of sensitivity of the second acceleration sensor is oriented in the direction of the transverse axis of the vehicle.
• the sensitivity directions of the two acceleration sensors are offset by +/- 45 ° to the longitudinal axis of the vehicle.
• FIG. 3 shows an arrangement of vehicle sensors 4 according to the present claims and a central unit 2 in a vehicle. Since these vehicle sensors 4 also record the structure-borne noise in addition to the acceleration, it is not necessary to attach them close to the outer skin of the vehicle, since the structure-borne sound waves propagate much faster in the vehicle than the vibrations generated by changes in acceleration and a crash can be detected in a time required to trigger the safety system , With the arrangement of two vehicle sensors shown, a plane formed from the vehicle longitudinal axis and vehicle transverse axis can be monitored with regard to structure-borne noise and crash-relevant changes in acceleration.
• a signal plausibility check of the respective sensor output signals of the vehicle sensors 4 by either plausibility checking the sensor output signal of the first vehicle sensor 4 with the sensor output signal of the second vehicle sensor 4 or, for example, the signal component of the vehicle sensor 4 which reproduces the acceleration with the signal component of the same vehicle sensor which reproduces the structure-borne noise 4 is checked for plausibility.
• sensor output signals of further vehicle sensors 4 mounted in the vehicle can be used for signal plausibility checking.
• the vehicle sensor 4 can be attached to different locations in the vehicle, where lower or higher accelerations can be measured depending on the accident situation, depending on the application of the vehicle sensor 4 in its manufacturing process, a certain acceleration range can be specified which is within +/- 1 g and of +/- 1000g. If the vehicle sensor is used, for example, in the area of the bumper of a vehicle, it should detect accelerations in a lower range that occur when a collision with a light object and accelerations in a higher range up to +/- 1000 g, for example in the event of a collision with a other vehicle occur.
• the acceleration range should be selected such that on the one hand the vehicle sensor 4 measures the accelerations required to be able to detect an accident, but on the other hand an overriding of the processing unit for processing the sensor signals is avoided.
• the vehicle sensor can be designed such that customer-specific programming of the acceleration range can be carried out depending on the use of the vehicle sensor.
• the processing unit 4.2 of the vehicle sensor includes one
• Amplifier circuit that amplifies the various signal components that represent the measured acceleration and the measured structure-borne noise.
• the processing unit 4.2 is designed to Detect transducer signals with high amplitude without overdriving the amplifier circuit.
• the amplifier circuit detects and amplifies, for example, transducer signals of the longitudinal structure-borne noise, which have lower amplitudes in comparison to those of the transverse structure-borne noise, but also measurement value signals of the acceleration or the transverse structure-borne noise with higher amplitudes.
• the processing unit 4.2 includes a filter for the selective detection of the acceleration and the structure-borne noise. External signal filtering is then no longer necessary and reduces the effort for further evaluation of the signal from the vehicle sensor.
• the filter in the processing unit 4.2 can be programmable so that the filter characteristics can be customer-specifically programmed and the customer can select the signal components required for his specific application.
• the filter can be configured in the processing unit 4.2 so that it can be set during the manufacturing process of the vehicle sensor. This allows a selection of the signal components required for a special application to be made already during the manufacture of the vehicle sensor.
• the vehicle sensor 4 can not only be used for crash detection.
• Other possible uses are, for example, use in diagnostic or monitoring systems, in which a vibration analysis of certain elements is required, such as. B. a ball or roller bearing monitoring, the use in road condition monitoring systems, in which a vibration analysis of the vibrations occurring in the chassis is carried out, in stability and braking systems in the vehicle or in vehicle dynamics control systems.
• the vehicle sensors monitor movements of a system. The direction of sensitivity of the Acceleration and structure-borne noise are specified by the application and defined by the design of the vehicle sensor in the manufacture of the vehicle sensor.
• the 4a shows a block diagram of the vehicle sensor 4, which comprises a sensor 4.1 for the detection of acceleration and structure-borne noise and a processing unit 4.2 for processing the sensor signals.
• the processing unit 4.2 contains a filter for the selective detection of the acceleration and the structure-borne noise. This provides a sensor output signal 4.5 which provides the desired frequency components of the acceleration and structure-borne noise. Since the longitudinal structure-borne sound waves have lower amplitudes in comparison to the transverse structure-borne sound waves or in comparison with acceleration, a corresponding amplifier circuit is provided which enables processing of the longitudinal structure-borne sound waves.
• the processing unit 4.2 can also include an A / D converter which provides the sensor output signal 4.5 in digital form.
• the sensor output signal 4.5 in analog or digital form is then processed by an evaluation unit 2.1 in the central unit 2 in order to generate a trigger signal for a safety system, for example an occupant protection system.
• FIG. 4b shows a corresponding filter characteristic of the processing unit 4.2 of the vehicle sensor 4 from FIG. 4a, in which the frequency components of the acceleration in the lower frequency range (less than approximately 500 Hz) and the frequency components of structure-borne noise in the upper frequency range (greater than approximately 4 kHz) are detected become.
• the 5a contains a representation of a vehicle sensor 4 with a piezoelectric sensor without curvature of the carrier 4.3.
• the vehicle sensor 4 is mounted on a vehicle element 5, preferably by pressing or pressing the carrier 4.3 inside or in the vicinity of the central unit or in the vicinity of the vehicle outer skin.
• the measuring sensor 4.1 is preferably attached to the carrier 4.3 by a non-positive connection, for example by an adhesive.
• the non-positive connection is designed such that, on the one hand, it enables detection of the acceleration and structure-borne noise, which acts, for example, in the longitudinal direction, and, on the other hand, reduces or prevents the recording of unwanted signals by the measurement sensor.
• a seismic mass 4.4 required for the measurement of accelerations is attached, preferably glued, directly to the measuring sensor 4.1.
• the seismic mass 4.4 can also be integrated in the sensor 4.1. If the measuring sensor 4.1 is, for example, a micromechanical sensor, comb structures are provided for recording accelerations, the displacement of which against one another represents a measure of the acceleration. In this case, the seismic mass 4.4 is a movable comb structure that shifts compared to permanently attached comb structures.
• the longitudinal structure-borne sound waves propagate in the same direction 6.1 as the direction of impact 6.
• the direction of propagation of the transverse structure-borne sound waves 6.2 is perpendicular to the direction of impact 6.
• the longitudinal structure-borne sound waves are transmitted to the transducer 4.1 via the carrier 4.3, the direction of propagation of the longitudinal structure-borne sound waves 6.1.1 transmitted to the carrier 4.3 and the longitudinal structure-borne sound waves 6.1 recorded in the transducer 4.1 .2 runs parallel to the direction of impact and the original direction of propagation of the longitudinal structure-borne sound wave 6.1 transmitted in the vehicle element.
• an acceleration is detected by the sensor 4.1, which is a Direction of propagation 6.3 perpendicular to the direction of propagation of the longitudinal structure-borne sound wave.
• the first sensitivity direction of the measurement sensor 4.1 for detecting the acceleration 6.3 is therefore not identical to the second sensitivity direction of the sensor 4.1 for detecting the longitudinal structure-borne sound waves 6.1.2.
• a deflection of the longitudinal structure-borne sound waves is carried out, as shown in FIG. 5b, by a curvature of the carrier 4.3, so that the transducer 4.1 changes the position in FIG Direction of propagation extending structure-borne sound waves 6.1.2 are supplied, the direction of propagation of the acceleration 6.3 being equal to the direction of propagation of the longitudinal structure-borne sound waves 6.1.
• the curvature of the carrier 4.6 is carried out in such a way that the direction of propagation of the longitudinal structure-borne sound waves 6.1.2 changes by 90 °, but preferably the occurrence of reflection waves is prevented.
• any required sensitivity direction for detecting the acceleration and the longitudinal structure-borne noise by a suitable choice of an angle in the curvature of the carrier 4.6.
• the angle is preferably selected which sets the first and the second sensitivity direction identically.
• the sensor 4.1 is designed, for example, as a flexible piezoelectric layer, it can not only be attached to a straight part of the carrier 4.3, but, as shown in dotted lines, can also extend over the region of curvature of the carrier 4.3. Further embodiments of the measurement sensor 4.1 can be strain gauges, magnetorestrictive sensors or micromechanical sensors.
• the carrier 4.3 is constructed in such a way that on the one hand it enables the acceleration and the structure-borne noise acting in the longitudinal direction to be recorded, and on the other hand it reduces or prevents the transmission of unwanted signals to the sensor 4.1.
• the carrier is preferably designed as a lead frame suitable for the molding technique or as a mechatronic carrier suitable for the molding technique. A molding compound surrounding the carrier serves as the sensor housing.

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• General Physics & Mathematics (AREA)
• Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
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• 2004
  • 2004-10-08 EP EP04789945A patent/EP1678013B1/fr not_active Expired - Lifetime
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  • 2004-10-08 WO PCT/DE2004/002236 patent/WO2005035318A1/fr not_active Ceased
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  • 2004-10-08 US US10/575,200 patent/US8401739B2/en not_active Expired - Fee Related
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