Classifications

• • 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
• • 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
  • B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
  • B60N2/0224—Non-manual adjustments, e.g. with electrical operation
  • B60N2/0244—Non-manual adjustments, e.g. with electrical operation with logic circuits
• • 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
  • B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
  • B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
  • B60N2/0224—Non-manual adjustments, e.g. with electrical operation
  • B60N2/02246—Electric motors therefor
• • 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
  • B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
  • B60N2/04—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the whole seat being movable
  • B60N2/16—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the whole seat being movable height-adjustable
• • 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
  • B60N2210/10—Field detection presence sensors
  • B60N2210/14—Inductive; Magnetic field
• • 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
  • B60N2220/20—Computerised treatment of data for controlling of seats using a deterministic algorithm

Definitions

• the present invention relates to a device for evaluating the weight of an occupant of a seat of a motor vehicle.
• the sensor web is an additional component that significantly increases the cost of the seat and especially since the shape of the web must be adapted specifically to each seat.
• the implantation of the sheet of sensors in the seat cushion is incompatible with certain methods of manufacturing the seat, in particular the manufacturing processes where the foam of the seat is molded directly inside the seat. headdress of this seat.
• the object of the invention is to provide a device for evaluating the weight of a low-cost occupant.
• the subject of the invention is a device for evaluating the weight of an occupant of a seat of a motor vehicle, the motor vehicle comprising at least one seat, at least one moving device of at least one a part of this seat and an electric motor equipped with a rotary output shaft for driving the displacement device, characterized in that the evaluation device comprises:
• the evaluation device comprises one or more of the following characteristics:
• the supply means are adapted to supply the electric motor by a pulse width modulated supply signal and to rotate its output shaft at a speed depending on the torque applied to the output shaft of the motor;
• the determination means comprise a self-position sensor generating a periodic position signal as a function of the rotational position of the output shaft, and a measuring unit suitable for measuring the duration of at least one period of the position signal; ; the duration of a rotation turn of the output shaft of the motor corresponds to the duration of a period of the position signal;
• the determination means comprise monitoring means suitable for verifying that the duration of the or each revolution of rotation is determined solely during the displacement of the or each part of the seat;
• the monitoring means comprise means for memorizing a predefined duration of recovery of the mechanical clearances of the seat, a unit for detecting a predefined value of the position signal and a comparison unit, and the unit of measure is suitable. measuring the transition time elapsed between the time of activation of the electric motor and the detection time of the preset value of the position signal, the comparison unit being adapted to compare the recovery time with the transition time and authorizing transmission of the duration of the position signal period only when the transition time is less than the recovery time;
• the supply means are suitable for supplying the electric motor with a continuous supply signal, the measurement unit being able to measure the total duration of rotation of the output shaft of the electric motor, and the determining means are adapted to count the number of revolutions made by the output shaft of the electric motor and to calculate the duration of a single rotation turn by dividing the total duration of the rotation by the number of revolutions made by the output shaft of the electric motor;
• the evaluation means are suitable for classifying the occupant of the seat in a weight category according to the evaluated weight, and the evaluation means comprise means for mapping occupant weight categories as a function of ranges of weight. duration of a turn and selection means adapted to select a weight category from the duration of the determined rotation round; and
• a weight category corresponds to the absence of occupant on the seat so that the device is suitable to be used as a detector of the presence of an occupant on the seat.
• the invention also relates to a motor vehicle comprising at least one seat, at least one device for moving at least a portion of this seat and an electric motor equipped with a rotary output shaft for driving the displacement device, characterized in that it further comprises comprising a device for evaluating the weight of an occupant of a seat according to any one of the characteristics mentioned above.
• FIG. 1 is a schematic sectional view of the front of a vehicle equipped with an evaluation device according to the invention
• FIG. 2 is a graph representative of a position signal generated by a position sensor, when the position signal starts after a period of recovery of the mechanical clearances of a seat and a raising device;
• FIG. 3 is a graph representative of a position signal generated by a position sensor, when the position signal begins before the recovery time of the mechanical clearances of the seat and of the up-winding device;
• FIG. 4 is a graph representative of the evolution of the duration of the period of the position signal as a function of the evolution of the weight of the occupant of the seat.
• a motor vehicle 2 is partially illustrated in FIG. 1. It comprises a seat 4 consisting of a backrest 6 and a seat 8, the backrest being articulated with respect to the seat around an articulation axis 10.
• the seat 8 is supported by a floor 12 by means of a raising device 14 for raising or lowering the seat 8 relative to the floor 12 in a vertical direction.
• the raising device 14 is able to be driven by an electric motor 16 equipped with an output shaft 18.
• the electric motor 16 is of course self-rotating its output shaft 18 at a speed depending on the torque applied to the output shaft 18, for the same weight supply control.
• the device 19 for evaluating the weight of an occupant comprises a device 20 for supplying the electric motor 16 controlled by a control keyboard 21 or by a central console 22 for managing the electrical functions of the vehicle 2.
• the feed device 20 is also suitable for supplying the electric motor 16 with a DC voltage when the occupant of the seat controls the movement of the latter by the keyboard 21.
• the feed device 20 is adapted to feed the electric motor 16 by a pulse width modulated voltage, fixed frequency and duty cycle, when the displacement of the seat 4 is controlled by the central console 22 for the evaluation of the weight of the occupant.
• the feed device 20 is adapted to be actuated by the central console 22 in a periodic manner and / or event.
• this operation is performed at the time of crossing the 15 km / h and then repeated periodically in order to intersect the results of the evaluations between them and consequently to gain precision.
• the device 19 for evaluating the weight of an occupant according to the invention comprises means 23 for determining the duration T2 of a rotation turn of the output shaft 18 of the motor and evaluation means 24. the weight of the occupant of the seat 4 according to the duration of this turn.
• the means 23 for determining the duration of a revolution of rotation comprise a position sensor 26, a detection unit 27 connected to the position sensor 26 and a measuring unit 28 connected to the detection unit 27.
• the position sensor 26 is constituted, for example, by a hall effect sensor 30 disposed vis-à-vis the output shaft 18 of the electric motor and a ferric or magnetic element 32 mounted only on half of the around the output shaft 18.
• the output signal of the position sensor 26 is shown in FIGS. 2 and 3.
• This position signal is an alternating periodic square wave signal.
• the duration T2 of the period of the position signal corresponds to a rotation turn of the output shaft 18 of the motor. This duration T2 varies according to the torque applied to the output shaft 18 of the engine.
• the detection unit 27 is adapted to receive the position signal generated by the position sensor 26 and to detect the presence of a first rising or falling edge F1 therein.
• the detection unit 27 is able to transmit a signal signaling the presence of a first rising or falling edge F1 to the measurement unit 28.
• the measurement unit 28 comprises a first input for receiving a signal indicating the activation of the electric motor 16 and a second input for receiving the signal signal generated by the detection unit 27.
• the measurement unit 28 is adapted to measure the transition time T1 elapsed between the arrival of the signal indicating the activation of the electric motor and the arrival of the signal signaling a first rising or falling edge F1.
• the determination means 23 are able to measure a period T2 of the position signal only during the displacement of the seat 4.
• the determination means 23 are adapted to wait for the electric motor 16 to rotate to make up all the mechanical clearances of the seat 4 and the raising device 14.
• the determination means 23 also comprise storage means 34 and a comparison unit 35 connected to the storage means 34 and to the measurement unit 28.
• the storage means 34 for example of the EE-PROM memory type, are suitable for storing a pre-recorded recovery time Tmin.
• the recovery time Tmin is the time necessary to recover the mechanical clearances of the seat 4 and the raising device 14 between the moment when the activation command of the motor 16 is sent and that where the first rotation of the output shaft 18 of the motor is detected. This parameter is variable depending on the type and wear of the seat 4 and the raising device 14 used.
• the comparison unit 35 is able to compare the transition time T1 with the recovery time Tmin. When the transition time T1 is greater than the recovery time Tmin, as can be seen in FIG. 2, the comparison unit 35 is adapted to transmit a control signal to the measurement unit 28 so that it transmits to the evaluation means 24 the duration T2 of the period of the position signal measured directly after the first rising or falling edge F1.
• the comparison unit 35 does not immediately transmit a control signal to the measurement unit 28.
• the detection unit 27 is capable of detecting the presence of a second rising or falling edge F2 and transmitting a second signal indicating the presence of a second rising or falling edge F2 to the measuring unit 28.
• the measurement unit 28 is adapted to receive, on the one hand, an indication signal of the activation of the electric motor 16 and, on the other hand, the second signal of signaling.
• the measurement unit 28 is able to measure the transition time T3 elapsed between the arrival of the signal indicating the activation of the electric motor 16 and the arrival of the second signaling signal.
• the measurement unit 28 is able to transmit the transition time T3 to the comparison unit 35.
• the comparison unit 35 is able to compare the transition time T3 with the recovery time Tmin. If the transition time T3 is less than the recovery time Tmin, as can be seen in FIG. 3, the comparison unit 35 is then able to generate a control signal to the measurement unit 28 so that it transmits the evaluation means the duration T2 of the period of the position signal measured directly after the second rising or falling edge F2.
• the duration T2 of the period of the position signal corresponding to a rotation of an electric motor 16 is measured only when the mechanical clearances of the seat 4 and the raising device 14 have been caught.
• the determination means 23 furthermore comprise parameterization means 36 able to modify the recovery time Tmin as a function of the old age and the number of uses of the seat 4 and the raising device 14.
• the duration of a rotation turn corresponds to the duration T2 of a period of the position signal.
• the duration of a revolution of rotation corresponds to the average duration of a revolution, as explained below.
• the evaluation means 24 comprise a map 38 and selection means 40.
• the map 38 defines by a curve 39 the weight of the occupant of the seat according to the duration of a turn.
• the curve 39 was obtained during a test phase carried out with a predefined motor supply voltage and for a certain type of seat 4 and raising device 14 having a predefined wear.
• FIG. 4 shows the results of measurements made with a power supply signal of the electric motor 16 having an 80% duty cycle and a 90 Hz hashing frequency on a used seat.
• the profile of this curve 39 is modified by the setting means 36 during the life of the seat 4 and the raising device 14.
• the selection means 40 are able to select the corresponding weight on the curve 39 to the duration T2 of a turn of rotation.
• Mapping 38 further includes predefined occupant weight categories as a function of time ranges of one turn.
• the selection means 40 are able to select a weight category from the duration of the rotation turn determined by the determination means 23.
• a weight category 42 between 0 and 5 kg corresponds to a range of a period 43 between 1.5 and 1.6 ms. This range 43 is predefined as an absence of occupant on the seat.
• a weight category 44 between 5 and 37 kg corresponds to a range of a period 45 between 1.6 and 1.82 ms. This range 45 is predefined as the presence of a child in a child restraint fixed on the seat 4.
• a weight category 46 between 37 and 63 kg corresponds to a range of a period 47 between 1.82 and 2.05 ms. This range 47 is predefined as the presence of a woman on the seat 4.
• a weight category 48 between 63 and 86 kg corresponds to a range of a period 49 between 2.05 and 2.2 ms.
• This range 43 is predefined as the presence of a man on the seat 4.
• the weight of a seat occupant is determined when the occupant of the seat actuates a command to perform a voluntary movement of the seat by the seat.
• the electric motor 16 is powered by a direct current. The imprecision of the measurement due to an unmodulated control in pulse width is compensated by the fact that it is performed on a generally large number of periods of rotation.
• the position sensor 26 is able to deliver a position signal for the duration of the displacement of the seat 4.
• the measurement unit 28 is able to measure the total duration of movement of the seat 4 elapsed between the arrival of the activation signal of the motor and the end of the position signal delivered by the position sensor 26.
• the detection unit 27 is adapted to count the number of revolutions made by the output shaft 18 of the electric motor by counting the number of rising and falling edges.
• the detection unit 27 is also able to calculate the average rotation period of the output shaft 18 of the engine by dividing the total duration of the displacement of the seat 4 by the total number of revolutions of the output shaft 18 of the engine .
• the evaluation means 24 are able to evaluate the weight corresponding to the average rotation time of the output shaft 18 of the engine.
• the raising device 14 is replaced by a device for pivoting the backrest 6 or the seat 8 around the hinge axis 10.
• the detection unit 27 when the position signal is not a square signal, the detection unit 27 is able to detect the presence of a predefined value in the position signal.
• the storage means 34 and the setting means 36 are replaced by means for detecting the displacement of the seat 4.
• the evaluation device 19 is able to perform two successive measurements, each in a different direction of movement of the seat 4 in order to increase the accuracy of the measurements and prevent the raising device 14 from going out of order.
• the duty cycle used is determined by a compromise between the accuracy of the desired evaluation and the feeling of the user. Indeed, in increasing the measurement time, the feeling of the user is amplified but the measurement accuracy is increased.
• the evaluation device according to the invention is suitable for being used as a detector of the presence of an occupant on the seat 4.
• the evaluation device can be applied to many torque devices because the system adapts to any detection strategy, characterization as well as any type of actuator.
• This evaluation device makes it possible to detect the presence of an occupant on the seat and to classify the type of occupant.
• This evaluation device is inexpensive because it requires little software modification. Indeed, it is possible to use the computer of the central console 22 to control the electric motors of the seat and perform the detection and characterization of the occupant. This evaluation device meets the regulatory standards of occupant detection and classification and consumer requirements.
• the adjustment of the detection / classification thresholds makes it possible to adapt the different strategies at the level of the retaining means according to the conditions of use, for example, for the frontal airbag, its activation or its inhibition or its low risk deployment.
• the knowledge of the weight of the occupant makes it possible to adapt the settings relating to postural comfort, such as the automatic adjustments of the seat, the adaptation of the massage functions, the adaptation to thermal comfort such as the adjustment of air conditioning and other adaptations such as the inclination of the lights or the adjustment of mirrors.

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• Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Mathematical Physics (AREA)
• Theoretical Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Seats For Vehicles (AREA)

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Family Cites Families (2)

• 2006
  • 2006-10-11 FR FR0654194A patent/FR2907063B1/fr not_active Expired - Fee Related
• 2007
  • 2007-10-08 WO PCT/FR2007/052096 patent/WO2008043949A1/fr not_active Ceased
  • 2007-10-08 EP EP07858527A patent/EP2071920A1/de not_active Withdrawn

Non-Patent Citations (1)

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