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
  • B60R21/015—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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
  • B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
  • B60N2/002—Seats provided with an occupancy detection means mounted therein or thereon
  • B60N2/0021—Seats provided with an occupancy detection means mounted therein or thereon characterised by the type of sensor or measurement
  • B60N2/0024—Seats provided with an occupancy detection means mounted therein or thereon characterised by the type of sensor or measurement for identifying, categorising or investigation of the occupant or object on the seat
  • B60N2/0025—Seats provided with an occupancy detection means mounted therein or thereon characterised by the type of sensor or measurement for identifying, categorising or investigation of the occupant or object on the seat by using weight measurement
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
  • B60N2210/00—Sensor types, e.g. for passenger detection systems or for controlling seats
  • B60N2210/40—Force or pressure sensors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
  • B60N2220/00—Computerised treatment of data for controlling of seats
  • B60N2220/10—Computerised treatment of data for controlling of seats using a database
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
  • B60N2230/00—Communication or electronic aspects
  • B60N2230/30—Signal processing of sensor data

Definitions

• the invention relates to a method for evaluating a seat profile according to the type of the independent claim.
• the patent claim has the advantage that the influence of dynamic processes such as cornering, the boarding behavior on an incline and rapid movements of an object on a vehicle seat are used to evaluate a seat profile that is recorded with the sensor matrix.
• This is an inexpensive, no-hardware solution to make better statements to be able to do via the seat profile and thus to enable better reactions from restraint systems or other systems to which this data is made available.
• the continuous changes in the sensors are used as the changes in the seat profile. It is particularly advantageous if the sensor values are compared with at least one threshold value in order to detect changes in the sensors.
• Changes in the center of gravity are monitored by a change in position of the at least one center of gravity.
• the center of gravity is calculated in the usual way, as is known from physics.
• the dynamic factor is determined from a weighted sum of the changes in the sensors of the sensor matrix and the changes in position of the at least one center of gravity. These two characteristics are thus taken into account in order to possibly compensate for the influence of one characteristic by the other characteristic.
• the Weighting factors are already known and have been developed from experimental studies.
• the method according to the invention has a holding function in order to make it possible to detect short-term high dynamic factors by setting a decay function.
• an apparatus for carrying out the method according to the invention which has a sensor matrix in a seat mat of a vehicle seat, an analog-digital converter for digitizing the sensor values, a memory for temporarily storing data and a processor for calculating the dynamic factor.
• FIG. 1 shows a block diagram of the device according to the invention
• FIG. 2 shows a block diagram of a control device for a sensor matrix
• FIG. 3 shows the evaluation of the change in the center of gravity
• FIG. 4 shows the applications of the holding function
• FIG. 5 shows a flow diagram of the method according to the invention.
• a sensor matrix in a seat mat in a vehicle seat is a means of making an occupant classification.
• Occupant classification is based either on the seat profile and / or a weight estimate. Both the seat profile size and structures resulting from the seat profile can be evaluated for the seat profile. These structures include the
• the occupant classification is necessary in order to selectively control restraint systems such as a multi-stage airbag, so that optimal protection is provided for the occupant and injuries caused by the restraint system are minimized.
• a multi-stage airbag allows the restraining force with which the airbag is inflated to be switched in stages. This enables the airbag to be adjusted depending on the weight of the person. Dynamic effects such as fast cornering, boarding behavior on mountains or other inclines or inclines as well as rapid movements of a person on the vehicle seat lead to short-term changes in the seat profile when the seat profile is recorded continuously, which are not necessarily useful for adjusting the restraint system, since such seat profiles isolated give a false impression of the object on the vehicle seat.
• the seat profile is usually with a
• the quality parameter is compared with a predefined threshold value in order to decide whether the given seat profile can be used or not.
• this quality parameter is evaluated here with a dynamic factor in order to also include the dynamic processes in the evaluation of the seat profile.
• the dynamic factor is calculated on the one hand based on the seat profile and / or at least one center of gravity. Changes in the sensors of the sensor matrix are continuously monitored for the seat profile. At the center of gravity, changes in position of the at least one center of gravity are monitored continuously. By forming a weighted sum from the changes in the
• the dynamic factor is determined by sensors and the changes in position of the at least one center of gravity, the weighting factors having previously been determined experimentally. By using a holding function, short-term, high dynamic factors can be detected.
• FIG. 1 the device according to the invention is shown as a block diagram.
• a sensor matrix 1 is connected to a control unit 2 for the sensor matrix 1 via a data input / output. Via a second data input
• control device 2 for the sensor matrix 1 is connected to a control device 3 for a restraint system 4.
• the control unit 3 for the restraint system 4 is connected to the restraint system 4 via a second data input / output. The connections can also be made here
• Bus lines can be implemented and the control unit 2 for the sensor matrix 1 can also be connected to further control units and vehicle systems in order to make its data available to these systems.
• Pressure sensors are arranged in a matrix in the sensor matrix 1. With increasing pressure, the pressure sensors show a decreasing resistance. The sensor matrix 1 is measured column by row with respect to the resistance, it then being possible to determine the resistances of the individual pressure sensors and the pressure load. This measurement is done in such a way that currents are measured become. The individual pressure sensors are initially subjected to voltage potentials in the columns and rows so that no currents flow. By changing the voltage potentials by the control device 2, it is now possible for currents to flow through a respective one
• the processor 3 can then determine the resistance value for the respective pressure sensor.
• the individual pressure sensors are queried sequentially by changing the voltage potentials on the rows and columns, so that the current values arrive in succession via a line to the control unit 2. These current values are digitized by the control unit 2.
• the control unit first calculates the resistance values and creates the seat profile of the sensor matrix 1. With the resistance values it is now possible to determine the center of gravity of the seat profile, because the center of gravity is located where the lowest resistance values are to be measured, i.e. the highest pressure was exerted on the sensor matrix.
• the control unit 2 determines the center of gravity by a calculation according to the known formula for the
• control unit 2 is shown as a block diagram.
• an analog-digital converter 6 receives the measured values, that is to say the current values, from the individual sensors.
• the analog-digital converter 6 digitizes these measured values, which are then fed to a processor 5 as a digital data stream.
• the processor 5 uses this data to calculate the center of gravity and the changes in the individual sensors.
• a memory 7 which is connected to the processor 5 via a data input / output
• Center of gravity data changes in the center of gravity can be recorded as a function of time. The positions of the center of gravity are therefore saved continuously. This change in the center of gravity is converted into a percentage by assigning the change in position to a percentage in millimeters. The sum of the amounts from the changes in the x and y directions is used. However, it is also possible for the actual change in position to be calculated by forming the square root from the sum of the squares of the changes in the x and y directions.
• FIG. 3 is a diagram which shows the changes in the center of gravity ⁇ CG on the abscissa and a percentage change in the center of gravity on the ordinate.
• the absolute changes in the center of gravity on the abscissa are related to the percentage changes in the center of gravity on the ordinate via a ramp.
• a change in the center of gravity of 9 between the current focus and the previous focus was found here. This has been translated into a change of focus of 72%.
• the value of 72 is then included in the summation for the dynamic factor, this value 72 then being weighted with a weighting factor which is stored in the memory 7.
• the processor 5 calculates the second component for the dynamic factor from the changes in the sensor measured values.
• the measured value from the individual sensors is compared with a predetermined threshold value, which is stored in the memory 7, in order to determine whether the sensor has changed or not.
• the absolute sensor measured values can also be compared here in order to then evaluate these changes. The changes are then added up and are used as the second summand in the calculation of the dynamic factor.
• DynCG means the value that resulted from the change in the center of gravity
• A weighting factor for the change in the center of gravity
• DynProfil means the value that resulted from the change in the sensors
• B the weighting factor for the change in the sensors.
• FIG. 4 shows the application of the holding function to the calculation of the dynamic factor as a function of time.
• a function 10 in the dynamic factor-time diagram reproduces the determined dynamic factors at successive times.
• the dashed line represents an alternative course of the dynamic factor function.
• the dynamic factor determined at time 50 is higher than the previous value.
• the function 11 then decays with a holding function 11 until the holding function 11 intersects again with the determined dynamic factors, which is achieved at the point in time 55. This avoids steep jumps in the dynamic factors depending on the time.
• the holding function has the task of setting a calculated dynamic factor in a temporal relationship to the previous dynamic.
• the dynamic factor at time t is compared with the dynamic factor at time t-1. If the dynamic has increased, the current value is used as the basis for a decay function.
• the decay function can be implemented as follows:
• variable C stored in the memory indicates the value of the decay behavior.
• the counter indicates how often the current dynamic factor is smaller than the base value used for the disconnection function.
• FIG. 5 shows the method according to the invention as a flow chart.
• the measured values are recorded with the sensors of the sensor matrix 1, digitized with the analog-digital converter 6 and received by the processor 5.
• the processor 5 receives the measured values from the sensors of the sensor matrix 1, digitized with the analog-digital converter 6 and received by the processor 5.
• the processor 5 receives the measured values from the sensors of the sensor matrix 1, digitized with the analog-digital converter 6 and received by the processor 5.
• Processor 5 first calculates the center of gravity and, in method step 14, processor 5 determines the changes in the center of gravity and then, as shown in FIG.
• processor 5 determines the changes in the sensors and then, as shown in FIG.
• the changes in the sensors are then determined either by means of a threshold value or the absolute changes in the measured values. An assessment of the changes is also carried out for this.
• the dynamic factor is then determined from the weighted sum of the changes in the center of gravity and the changes in the seat profile.
• method step 17 it is determined whether the holding function should be applied to the dynamic factor. If so, process step 18 is carried out, as shown above, if not, process step 19 is continued immediately in that the quality parameter with which the seat profile is evaluated is now first weighted by the dynamic factor.
• the process according to the invention runs continuously over time.
• Sensor values can also be exchanged. It is also possible that either only the change in the center of gravity or only the change in the sensors is used.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Aviation & Aerospace Engineering (AREA)
• Transportation (AREA)
• Air Bags (AREA)
• Seats For Vehicles (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7660013

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (7)

Citations (4)

Family Cites Families (6)

• 2000
  • 2000-10-17 DE DE10051312A patent/DE10051312C2/de not_active Expired - Fee Related
• 2001
  • 2001-09-15 US US10/399,376 patent/US6950776B2/en not_active Expired - Lifetime
  • 2001-09-15 WO PCT/DE2001/003553 patent/WO2002032716A1/de not_active Ceased
  • 2001-09-15 DE DE50105326T patent/DE50105326D1/de not_active Expired - Lifetime
  • 2001-09-15 JP JP2002535919A patent/JP2004511792A/ja active Pending
  • 2001-09-15 EP EP01974047A patent/EP1328418B1/de not_active Expired - Lifetime

Patent Citations (4)

Non-Patent Citations (1)

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