Method for determining a height / weight type of an occupant of a seat, and associated seat

Abstract

The invention relates to a method for determining a height / weight type of an occupant of a seat, the method comprising: - calculating (44) a first datum representative of the pressure exerted on the seating portion on the basis of the resulting capacitance value of a first capacitive sensor with interdigitated electrodes situated on the first bolster and a resulting capacitance value of a second capacitive sensor with interdigitated electrodes situated on the central part of the seating portion, - calculating (46) a second datum representative of the pressure exerted on the first bolster of the seating portion on the basis of the resulting capacitance value of the first capacitive sensor, - calculating (48) a first value as a function of the first datum and the second datum, - comparing (50) the first value against a first threshold, and, when the first value is below the first threshold, generating a signal.

Description

[0001] DESCRIPTION

[0002] TITLE: Method for determining the height and weight type of a seat occupant and associated seat

[0003] Technical field of the invention

[0004] According to one aspect, the present application concerns a method for determining the staturo-ponderal type of a seat occupant.

[0005] According to a second aspect, the present patent application relates to a vehicle seat and in particular a seat equipped with a device for determining the staturo-ponderal type of a seat occupant or for determining the position of the seat occupant.

[0006] Prior art

[0007] There is a growing demand for devices to determine the type of occupant of a seat, particularly a vehicle seat, whether it is a driver or a passenger.

[0008] These detection devices typically employ sensors such as a camera or a motion sensor located above the seat. However, measurements obtained using such devices generally have a long response time, on the order of several seconds, which is unsuitable for providing sufficiently rapid data in certain situations, particularly in the event of an accident.

[0009] For example, there is a need to be able to adapt the properties of an airbag system designed to protect a vehicle seat occupant in the event of an accident. Thus, the operation of existing systems could be improved by adjusting the properties of an airbag and / or a vehicle seat belt pretensioner based on real-time knowledge of parameters such as the type of user, their height, weight, etc.

[0010] Furthermore, the measurements obtained by such devices often lack robustness. In addition, the measurements taken by these devices exhibit drift over time. These devices are therefore unsuitable for applications in the automotive sector, where a reliability period of at least ten years is required.

[0011] The primary aim of the invention is to overcome the aforementioned drawbacks. Furthermore, in the field of vehicle seating, for example, there is a need to be able to adapt the properties of an airbag system designed to protect a vehicle seat occupant in the event of an accident. These detection devices, in this case, make it possible to improve the operation of an airbag system and / or a seat belt pretensioner based on real-time data regarding parameters such as the user's type, height, weight, etc. These detection devices also make it possible to identify, in conjunction with appropriate software, poor posture in a seat occupant that could lead to neck or lower back pain.

[0012] The second objective of the invention is to provide a seat equipped with a more reliable determination system.

[0013] Summary of the object of the invention

[0014] To achieve the first objective, the invention primarily relates to a method for determining the height and weight of an occupant of a seat, particularly a vehicle seat; the seat comprising a cushion, the cushion comprising a central part and a first lateral support edge; the method comprising:

[0015] - a calculation of a first representative data of the pressure exerted on the seat from the resulting capacitance value of a first capacitive sensor with interdigitated electrodes located on the first lateral support edge and at least one resulting capacitance value of a second capacitive sensor with interdigitated electrodes located on the central part of the seat,

[0016] - a calculation of a second representative data point of the pressure exerted on the first lateral support edge of the seat, based on the resulting capacitance value of the first capacitive sensor,

[0017] - a calculation of a first value based on the first and second data points,

[0018] - a comparison of the first value to a first threshold, when the first value is less than the first threshold, generation of a signal representative of a child-type occupant.

[0019] The features described in the following paragraphs may optionally be implemented. They may be implemented independently or in combination with each other:

[0020] - The calculation of the first value includes a sum of the first and second data points.

[0021] - the calculation of the first data includes the calculation of a sum weighted by a weighting coefficient, of the resulting capacity values ​​of the capacitive sensors located on the base.

[0022] - the seat includes a second lateral support rim, and the first data is calculated from the resulting capacitance value of the first capacitive sensor, the resulting capacitance value of at least the second capacitive sensor and a resulting capacitance value of a third capacitive sensor with interdigitated electrodes located on the second lateral support rim of the seat; the second data being calculated from the resulting capacitance value of the first capacitive sensor and the resulting capacitance value of the third capacitive sensor; the second data being representative of the pressure exerted on the first lateral support rim and on the second lateral support rim.

[0023] - the weighting coefficient includes a ratio between a non-zero natural number and a representative value of the pressure exerted on at least the first lateral edge.

[0024] - the weighting coefficient includes a ratio between a non-zero natural number and an average of a resulting capacitance value from the first capacitive sensor and a resulting capacitance value from the third capacitive sensor.

[0025] - the second data includes the sum of a resulting capacitance value from the first capacitive sensor and a resulting capacitance value from the third capacitive sensor.

[0026] - the second piece of data is the resulting capacitance value of the first capacitive sensor.

[0027] The process involves:

[0028] - the initialization of a first counter and a second counter,

[0029] - a comparison of the second data to a second threshold, if the second data is less than the second threshold then increment the first counter by a first number, if the second data is greater than the second threshold then increment the second counter by said first number; said first number being strictly greater than zero.

[0030] - The method includes calculating a second value based on a resultant value from the second capacitive sensor and a resultant value from a fourth capacitive sensor with interdigitated electrodes located in a median area of ​​the central part of the base, the second capacitive sensor being located in a median area of ​​the central part of the base; comparing the second value to a third threshold, if the second value is less than the third threshold, then increment the first counter by a second number, if the second value is greater than the third threshold, then increment the second counter by the second number, the second number being strictly greater than zero.

[0031] - The method includes: defining a second value equal to (or setting a second value equal to) a resultant value from at least one second capacitive sensor, the second capacitive sensor being located in a median area of ​​the central part of the seat;

[0032] - a comparison of the second value to a third threshold, if the second value is less than the third threshold, then increment the first counter by a second number, if the second value is greater than the third threshold, then increment the second counter by the second number, the second number being strictly greater than zero.

[0033] - The second number is less than the first number.

[0034] - The process includes:

[0035] - a calculation of a third value by subtracting a resultant value from a fifth capacitive sensor with interdigitated electrodes located in a rear area of ​​the central part of the seat, from the second value,

[0036] - a comparison of the third value to a fourth threshold, if the third value is less than the fourth threshold, then increment the first counter by a third number, if the third value is greater than the fourth threshold, then increment the second counter by the third number, the third number being strictly greater than zero.

[0037] - The third number is less than the second number.

[0038] - The process involves a comparison of the value of the first counter and the value of the second counter, when the value of the first counter is greater than the value of the second counter then generation of a signal representative of an occupant of a first staturo-ponderal type, when the value of the first counter is less than the value of the second counter then generation of a signal representative of an occupant of a second staturo-ponderal type, the second staturo-ponderal type having a stature and a weight greater than the first staturo-ponderal type.

[0039] - At least one capacitive sensor among the second capacitive sensor and the fourth capacitive sensor, has an "L" shape; and in which the second capacitive sensor and the fourth capacitive sensor are located symmetrically on either side of a central line extending in a longitudinal direction, said central line being centered with respect to the lateral edges of the central part of the seat.

[0040] - The second capacitive sensor is located on a median area of ​​the seat, the second capacitive sensor being the only sensor located on the median area, the second capacitive sensor having the shape of an "I" extending along the transverse direction Y over a length at least equal to half the width of the seat.

[0041] - The seat includes a sixth capacitive sensor with interdigitated electrodes, the sixth capacitive sensor being located on a front area of ​​the central part of the seat, the sixth capacitive sensor having the shape of an "I" extending along the transverse direction Y over a length at least equal to half the width of the seat.

[0042] According to another aspect of the invention, and in order to achieve the second objective, the invention has as its second object:

[0043] - a seat, particularly for a vehicle, the seat comprising:

[0044] - a seat comprising a central part having two opposing lateral edges and at least one first lateral support rim integral with a lateral edge of the central part, the first lateral support rim extending projecting from the central part, the central part comprising a rear zone, a middle zone and a front zone, characterized in that the seat comprises:

[0045] - a capacitive sensor with interdigitated electrodes arranged on the first lateral support edge, called the first capacitive sensor,

[0046] - at least one capacitive sensor with interdigitated electrodes arranged in the median area of ​​the central part, called the second capacitive sensor,

[0047] - a capacitive sensor with interdigitated electrodes disposed on the rear area of ​​the central part, called the fifth capacitive sensor, said fifth capacitive sensor being the only capacitive sensor located on the rear area, said fifth capacitive sensor being centered, in a transverse direction Y, with respect to the lateral edges of the central part.

[0048] - Seat in which the second capacitive sensor has an "L" shape. - Seat in which the seat has a second lateral support rim attached to another lateral side of the central part, the second lateral support rim extending outward from the central part, the seat comprising a capacitive sensor with interdigitated electrodes arranged on the second lateral support rim, called the third capacitive sensor.

[0049] - Seat which includes a fourth capacitive sensor with interdigitated electrodes arranged on the median area of ​​the central part, called the fourth capacitive sensor.

[0050] - Seat in which the second capacitive sensor and the fourth capacitive sensor are located symmetrically on either side of a central line extending in a longitudinal direction, said central line being centered with respect to the lateral edges of the central part.

[0051] - Seat in which the second capacitive sensor is the only sensor disposed on the median area, said second capacitive sensor has an "I" shape, said second capacitive sensor extends in a transverse direction Y over a length at least equal to half the width of the central part, the second capacitive sensor being centered with respect to the lateral edge of the central part.

[0052] - Seat which also includes a single capacitive sensor with interdigitated electrodes located on the front area of ​​the central part, called the sixth capacitive sensor.

[0053] - Seat in which the sixth capacitive sensor has an "I" shape, said sixth capacitive sensor being centered in the transverse direction with respect to the lateral edges of the central part, said sixth capacitive sensor extending in the transverse direction over a length at least equal to half the width of the central part of the seat.

[0054] - Seat in which the fifth capacitive sensor comprises two branches arranged in the shape of a "T", one branch of the fifth capacitive sensor extending along the transverse direction Y over a length at least equal to half the width of the central part of the seat, said branch being centered with respect to the lateral edges of the central part.

[0055] - A seat in which the fifth capacitive sensor has an "I" shape, said fifth capacitive sensor being centered in the transverse direction Y with respect to the lateral edges of the central part, said fifth capacitive sensor extending in the transverse direction Y over a length at least equal to half the width of the central part of the seat. - A seat in which the first capacitive sensor has a center of gravity located at a distance of between 60 millimeters and 70 millimeters from point H in the longitudinal direction.

[0056] - Seat in which the first capacitive sensor and the third capacitive sensor are connected to each other.

[0057] - Seat in which the second capacitive sensor and the fourth capacitive sensor are connected to each other.

[0058] Brief description of the figures

[0059] [Fig. 1] is a perspective view from above of a seat of a determination system according to a first embodiment, this system allowing to implement a determination method according to a first embodiment of the first object of the invention;

[0060] [Fig. 2] is a top view of a flexible support for the determination system illustrated in Figure 1;

[0061] [Fig. 3] is a flowchart representing the steps of the determination process according to the first embodiment of the first object of the invention;

[0062] [Fig. 4] is a top view of a flexible support of a determination system according to a second embodiment, and allowing to implement a determination method according to a second embodiment of the first object of the invention;

[0063] [Fig. 5] is a top view of a flexible support of a first variant of the determination system according to the first embodiment of the first object of the invention.

[0064] [Fig. 6] is a top perspective view of a seat according to a first embodiment of a seat according to a second object of the invention;

[0065] [Fig. 7] is a perspective view of a flexible support arranged on the seat illustrated in figure 6;

[0066] [Fig. 8] is a top view of a flexible seat support according to a third variant of a seat according to the second object of the invention;

[0067] [Fig. 9] is a top view of a flexible support according to a fifth variant of the seat according to the second object of the invention.

[0068] Detailed description of the invention In the different figures, the same references designate identical or similar elements.

[0069] In the following description, spatial positioning indications such as up, down, superior, inferior, horizontal, vertical, etc., are given for clarity, based on the usual position of a seat, but are not exhaustive. Specifically, orientations relative to the front and back of the seat refer to the seat's usual position of use.

[0070] The longitudinal direction X refers to a horizontal direction extending from the front to the back of the seat. The transverse direction Y refers to a horizontal direction extending from one side of the seat to the other side of the vehicle seat. The vertical direction Z refers to the direction perpendicular to the longitudinal direction X and the transverse direction Y.

[0071] The method for determining the height and weight type of a seat occupant allows for the determination of the occupant's body size. In particular, the method allows for the selection of a height and weight type from among three characteristic types. These three characteristic types are a child type, an adult female type, and an adult male type. The method for determining the height and weight type of a seat occupant can, for example, be implemented by a determination system 2 according to a first embodiment of a first object of the invention. The first embodiment of the first object is illustrated in Figure 1.This determination system 2 comprises a seat 4 having a seat 6 and a backrest 8 supported by the seat, a flexible support 9, six capacitive sensors with interdigitated electrodes C1, C2, C3, C4, C5, C6 carried by the flexible support 9, and a controller 10 electrically connected to the capacitive sensors with interdigitated electrodes.

[0072] Seat 4 is for example a vehicle seat and in particular a motor vehicle seat.

[0073] The seat 6 includes a receiving face 12 designed to accommodate a seat occupant. The seat, and in particular the receiving face of the seat, comprises a central portion 14, a first lateral support edge 16, and a second lateral support edge 18. For the purposes of this description, the central portion 14 of the seat is said to be divided (or distributed) by two transverse lines Y1 and Y2 into three zones. These three zones have the same dimensions along the longitudinal direction X. A zone adjacent to the backrest is called the "rear zone 20." A zone located on the side opposite the backrest is called the "front zone 22." The zone located between the front and rear zones is called the "middle zone 24."

[0074] The lateral support edges 16, 18 are generally called "bolsters" in English. They are integral with and contiguous to the central part 14. They project beyond the central part. They extend along the lateral sides 28, 30 of the central part of the seat.

[0075] The flexible support 9 is placed on the seat foam or the network of wires forming the seat. The flexible support 9 is made of a plastic material such as, for example, thermoplastic polyurethane, known by the acronym TPU. The capacitive sensors with interdigitated electrodes C1, C2, C3, C4, C5, C6 are attached to the flexible support, for example, by gluing. The capacitive sensors with interdigitated electrodes are hereinafter referred to as capacitive sensors. These capacitive sensors are described in patent FR 2109436 granted to the applicant.

[0076] The flexible support 9 is fixed to the seat in such a way that the capacitive sensors are arranged at particular locations on the seat. According to a first embodiment of the first object of the invention, a first capacitive sensor C1 is located on the first lateral support edge 16. Specifically, the first capacitive sensor C1 is located on a face of the first lateral support edge adjacent to the central part.

[0077] A second capacitive sensor C2 and a fourth capacitive sensor C4 are arranged on the flexible support so as to be located on the central part 14 of the seat.

[0078] In particular, in the first embodiment of the first object of the invention shown in Figure 1, the second capacitive sensor C2 and the fourth capacitive sensor C4 are arranged in the central area 24 of the seat. The second capacitive sensor C2 and the fourth capacitive sensor C4 have an "L" shape. One arm of this "L" shape extends along the longitudinal direction X. The other arm of this "L" shape extends along the transverse direction Y. The second capacitive sensor C2 and the fourth capacitive sensor C4 are located symmetrically on either side of a central line X1 extending along a longitudinal direction X. The central line X1 is centered along the transverse direction Y with respect to the lateral edges 28, 30 of the central part of the seat.

[0079] A third capacitive sensor C3 is arranged on the flexible support 9 so as to be located on the second lateral support rim 18, in particular, on a face of the second lateral support rim adjacent to the central part.

[0080] A fifth capacitive sensor C5 is arranged on the flexible support 9 so as to be located on the rear area 20 of the central part of the seat. Preferably, the fifth capacitive sensor C5 is T-shaped. The fifth capacitive sensor C5 has a first arm extending along the transverse direction Y and a second arm extending along the longitudinal direction X. The second arm originates from the middle of the first arm. Preferably, the first arm extends along the transverse direction Y for a length at least equal to half the width of the central part 14 of the seat. In the present patent application, the width of the central part of the seat is measured along the transverse direction Y. Preferably, the first arm is centered along the transverse direction with respect to the lateral edges 28, 30 of the central part.Preferably, the second branch extends over a length less than one-third of the length of the first branch.

[0081] A sixth capacitive sensor C6 is positioned on the flexible support 9 so as to be located in the front area 22 of the central part of the seat. The sixth capacitive sensor C6 is shaped like an "I". The sixth capacitive sensor C6 extends along the transverse direction Y for a length at least equal to half the width of the central part of the seat.

[0082] The controller 10 includes a processor, memory connected to the processor, a first counter 25 and a second counter 26 connected to the processor. The processor further includes a voltage source, a ground and a capacitance measurement unit.

[0083] The voltage source generates a voltage of, for example, 5 Volts.

[0084] The processor implemented by hardware may be equipped with ASICs (application-specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field-programmable gate arrays), and the like.

[0085] The determination system 2 according to the first object of the invention further comprises electrical wires 32 fixed to the flexible support 9, an electrical connector 34 fixed to one end of the flexible support, and wiring 36 connecting the controller 10 to the electrical connector 34. Each electrical wire 32 is connected between an electrode of a capacitive sensor and the electrical connector 34. The electrical wires 32 and the wiring 36 electrically connect a first electrode of each capacitive sensor C1 to C6 to the voltage source of the controller and a second electrode of each capacitive sensor C1 to C6 to ground. The capacitance measurement unit is suitable for measuring the capacitance between the electrodes of each capacitive sensor.

[0086] According to a second embodiment of the first object of the invention, illustrated in figure 4, the flexible support 9 of the determination system 2 comprises only a first capacitive sensor C1 intended to rest on the first lateral support edge 16, a second capacitive sensor C2 and a fourth capacitive sensor C4 intended to rest on the median area 24 of the central part of the seat, a fifth capacitive sensor resting on the rear area 20 and a sixth capacitive sensor resting on the front area 22.

[0087] According to a first variant of the first embodiment of the first object of the invention, the flexible support of the determination system 2 comprises only one capacitive sensor in its central area 24, referred to as the second capacitive sensor. This second capacitive sensor C2 may be L-shaped and positioned on one side of the central line X1. This second capacitive sensor C2 may also be I-shaped, extending along the transverse direction Y for a length at least equal to half the width of the central portion of the seat. In this case, it is centered along the transverse direction with respect to the lateral edges 28, 30 of the central portion 14. This first variant of the first object of the invention is illustrated in Figure 5 on a flexible support according to the first embodiment of the first object of the invention.This first variant can also be applied to a flexible support according to the second embodiment of the first object of the invention.

[0088] According to a second embodiment of the first feature of the invention, the fifth capacitive sensor C5, located on the rear area 20, has an "I" shape instead of a "T" shape. The fifth capacitive sensor C5 is centered in the transverse direction with respect to the lateral edges 28, 30 of the central part 14. The fifth capacitive sensor C5 extends in the transverse direction Y over a length at least equal to half the width of the central part of the seat. This second embodiment can also be applied to a flexible support according to the second embodiment of the first feature of the invention.

[0089] According to a third variant of the first embodiment of the first object of the invention, the determination system 2 does not include the sixth capacitive sensor C6. No capacitive sensor is arranged on the flexible support so as to be located in the front area 22 of the central part. This third variant can also be applied to a flexible support according to the second embodiment of the first object of the invention.

[0090] According to a third embodiment of the first object of the invention, the flexible support of the determination system 2 comprises only the first capacitive sensor C1 arranged to rest on the first lateral support edge 16 and a second capacitive sensor C2 arranged to rest on the median area 24 of the central part of the seat. This second capacitive sensor C2 may be L-shaped and be positioned on one side of the central line X1. This second capacitive sensor C2 may also be I-shaped, extending along the transverse direction Y for a length at least equal to half the width of the central part of the seat. In this case, it is centered along the transverse direction with respect to the lateral edges 28, 30 of the central part 14.

[0091] According to a variant of the first, second, and third embodiments of the first object of the invention, the capacitive sensors C1 to C6 are arranged directly on the foam or the fiber mesh forming the seat. In this case, the determination system does not include a flexible support.

[0092] The method for determining the height and weight of a seat occupant according to the first embodiment of the first object of the invention is implemented by the determination system illustrated in Figures 1 and 2. This method for determining the first object of the invention begins with a step 40 that triggers a measurement phase of the capacitance values ​​of the electrodes of the capacitive sensors C1 to C6 by the measuring unit. The measurement phase lasts for the entire duration of the detection process. The measurement phase is divided into measurement periods. A measurement period has a duration of between 0.6 and 1 millisecond. During each measurement period, the processor's measuring unit measures the capacitance values ​​of the capacitive sensors C1 to C6 at a frequency, for example, of 100 milliseconds. The process then continues with the steps described below.

[0093] During a processing step 42, the capacitance values ​​measured during each measurement period are processed in order to determine the resulting capacitance values ​​of these capacitive sensors.

[0094] In this description, a resulting capacitance value from a given capacitive sensor may, for example, be an average capacitance value calculated from the capacitance values ​​measured over a period for that capacitive sensor.

[0095] A resulting capacitance value from a given capacitive sensor can also be a median value between a maximum capacitance value and a minimum capacitance value measured over a period for that capacitive sensor.

[0096] During a step 44, a first data D1 representative of the pressure exerted on the seat is calculated from a resultant capacitance value Cr1 of the first capacitive sensor C1, a resultant capacitance value Cr2 of the second capacitive sensor C2, a resultant capacitance value Cr3 of the third capacitive sensor C3, a resultant capacitance value Cr4 of the fourth capacitive sensor C4, a resultant capacitance value Cr5 of the fifth capacitive sensor C5 and a resultant capacitance value Cr6 of the sixth capacitive sensor C6.

[0097] In particular, the calculation of the first data D1 includes the calculation of a sum weighted by a weighting coefficient, of the resulting capacitance values ​​of the capacitive sensors resting on the seat namely on the central part of the seat and on the lateral support edges 16, 18. These capacitive sensors are the capacitive sensors C1 to C6 in the first embodiment of the first object of the invention.

[0098] Preferably, the weighting coefficient comprises a ratio between a non-zero natural number and the average of a resulting capacitance value Cr1 of the first capacitive sensor C1 and a resulting capacitance value Cr3 of the third capacitive sensor C3. Preferably, the non-zero natural number is equal to one. Thus, when the determination system is the system illustrated in Figure 1, the first datum D1 is calculated from the following formula: Cr1 + Cr2 + Cr3 + Cr4 + Cr5 + Cr6

[0099] DI = average (Crl+Cr3) in which Cr1, Cr2, Cr3, Cr4, Cr5, Cr6 are the resulting values ​​of the capacitive sensors C1 to C6.

[0100] The average value (-Crl+Cr3) is a weighting coefficient. This weighting coefficient is applied to each resulting capacitance value from each capacitive sensor.

[0101] In step 46, a second data point D2 is calculated from the resulting capacitance value Cr1 of the first capacitive sensor C1 and the resulting capacitance value Cr3 of the third capacitive sensor C3. The second data point D2 represents the pressure exerted on the first lateral support edge 16 of the seat and the pressure exerted on the second lateral support edge 18. In particular, the second data point D2 comprises the sum of a resulting capacitance value from the first capacitive sensor C1 and a resulting capacitance value from the third capacitive sensor C3.

[0102] In other words: D2 = Cr1 + Cr3 where Cr1 and Cr3 are the resulting values ​​of the first capacitive sensor C1 and the third capacitive sensor C3.

[0103] During step 48, a first value V1 is calculated based on the first data point D1 and the second data point D2. In particular, the first value

[0104] V1 is the sum of the first data point D1 and the second data point D2.

[0105] Cr1+Cr2+Cr3+Cr4+Cr5+Cr6

[0106] Thus VI = average (Crl+Cr3) + Cri + Cr3

[0107] During step 50, the first value V1 is compared to a first threshold S1.

[0108] The first threshold S1 is between 2 and 4 picofarads. Preferably, the first threshold S1 is equal to 3 picofarads. When the first value V1 is less than the first threshold, a signal representative of a child-type occupant is generated and transmitted by the controller during step 51. For example, a child-type occupant has a weight of approximately between 13 and 19 kilograms and a height of approximately between 88 and 125 centimeters.

[0109] Then, the process returns to step 42 to process the capacity values ​​for the next period. During step 52, the first counter 25 and the second counter 26 are initialized.

[0110] During step 54, the second data point D2 is compared to a second threshold

[0111] 52. If the second data D2 is less than the second threshold then the first counter 25 is incremented by a first number.

[0112] If the second value D2 is greater than the second threshold S2, then the second counter 26 is incremented by the first number. The first number is strictly greater than zero. For example, the first number is equal to 2. The second threshold S2 is between 6 and 8 picofarads. Preferably, the second threshold S2 is equal to 7 picofarads.

[0113] During a step 56, a second value V2 is calculated based on the resulting value Cr2 of the second capacitive sensor C2 and the resulting value Cr4 of the fourth capacitive sensor C4.

[0114] Preferably, the second value V2 is equal to the sum of the resulting value Cr2 of the second capacitive sensor and the resulting value Cr4 of the fourth capacitive sensor.

[0115] 72 = Cr2 + Cr4 where Cr2 and Cr4 are the resulting values ​​of the second capacitive sensor C2 and the fourth capacitive sensor C4.

[0116] During step 58, the second value V2 is compared to a third threshold

[0117] 53. If the second value V2 is less than the third threshold S3, then the first counter 25 is incremented by a second number. If the second value V2 is greater than the third threshold S3, then the second counter 26 is incremented by the second number. The second number is strictly greater than zero. Preferably, the second number is less than the first number. For example, the second number could be 1.5. The third threshold S3 is between 2 picofarads and 4 picofarads. Preferably, the third threshold S3 is equal to 3 picofarads.

[0118] During a step 60, a third value V3 is calculated by subtracting the second value V2 from the resulting value of the fifth capacitive sensor.

[0119] V3 = Cr5 - (Cr2 + Cr4)

[0120] Where Cr2, Cr4, and Cr5 are the resulting values ​​from the second capacitive sensor C2, the fourth capacitive sensor C4, and the fifth capacitive sensor C5. During step 62, the third value V3 is compared to a fourth threshold

[0121] 54. If the third value V3 is less than the fourth threshold S4, then the first counter 25 is incremented by a third number. If the third value V3 is greater than the fourth threshold S4, then the second counter 26 is incremented by the third number. The third number is strictly greater than zero. The third number is less than the second number. The third number is, for example, equal to 1. The fourth threshold S4 is between 9 picofarads and 11 picofarads. Preferably, the fourth threshold S4 is equal to 10 picofarads.

[0122] During step 64, the value of the first counter 25 is compared to the value of the second counter 26. When the value of the first counter 25 is greater than the value of the second counter, a signal representing an occupant of a first height-weight type is generated and transmitted by the controller. When the value of the first counter 25 is less than the value of the second counter 26, a signal representing an occupant of a second height-weight type is generated and transmitted. The second height-weight type has a greater height and weight than the first height-weight type.

[0123] The first height and weight type corresponds to what is known as the adult female type. These individuals fall within the 5th female percentile of the shortest and / or thinnest individuals in descriptive statistics, and in particular according to the female-specific curve of the Fisher-Snedecor distribution. These individuals have a weight of approximately between 46 and 52 kilograms and / or a height of approximately between 139 and 160 centimeters.

[0124] The second height and weight type corresponds to what is called the adult male type. It corresponds to the 50th percentiles of the tallest and heaviest individuals in descriptive statistics, and in particular according to the curve for men in the Fisher-Snedecor distribution. These individuals have a weight of approximately between 76 and 81 kilograms and / or a height of approximately between 172 and 182 centimeters.

[0125] The determination method according to the first object of the invention makes it possible to discriminate between different types of seat occupant in order to know whether or not the airbag should be triggered and possibly to know the quantity of air needed for the inflation of the airbag.

[0126] The method for determining the first object of the invention according to a second embodiment can be implemented using the determination system according to the second embodiment shown in Figure 4. It is identical to the method according to the first embodiment of the first object of the invention, except that:

[0127] - During step 44, the calculation of the first data D1 includes the calculation of a sum weighted by a weighting coefficient, of the resulting capacitance values ​​of the capacitive sensors resting on the base namely the capacitive sensors C1, C2, C4 to C6.

[0128] Preferably, the weighting coefficient comprises a ratio between a non-zero natural number and a resulting capacitance value Cr1 of the first capacitive sensor C1. Thus, when the determination system is the system illustrated in Figure 4, the first datum D1 is calculated from the following formula: in which Cr1, Cr2, Cr4, Cr5, Cr6 are the resulting values ​​of the capacitive sensors C1, C2, C4 to C6.

[0129] The weighting coefficient here is equal to

[0130] - During step 46, the second datum D2 is calculated from the resulting capacitance value Cr1 of the first capacitive sensor C1. The second datum D2 is solely representative of the pressure exerted on the first lateral support edge 14 of the seat. In particular, the second datum D2 is equal to the resulting capacitance value of the first capacitive sensor C1.

[0131] In other words: D2 = Cr1 where Cr1 is the resulting value of the first capacitive sensor C1.

[0132] - In addition, the value of the first threshold S1 and the value of the second threshold S2 is different when there is only one sensor on a lateral support edge.

[0133] A method for determining the first object of the invention according to a third embodiment can be implemented using the determination system according to the first variant of the first embodiment of the first object of the invention, shown in Figure 5. It is identical to the method according to the first embodiment of the first object of the invention except that:

[0134] - During step 44, the first data point D1 is calculated using the following formula: in which Cr1, Cr2, Cr3, Cr5, Cr6 are the resulting values ​​of the capacitive sensors C1 to C3, C5 and C6. - During step 56, the second value V2 is calculated based on the resulting value Cr2 of the second capacitive sensor C2 located on a median area of ​​the central part of the seat.

[0135] Preferably, the second value V2 is equal to the resulting value Cr2 of the second capacitive sensor.

[0136] 72 = Cr2 where Cr2 is the resultant value of the second capacitive sensor C2.

[0137] - During step 60, the third value V3 is calculated by subtracting the second value V2 from the resulting value of the fifth capacitive sensor.

[0138] V3 = Cr5 - Cr2

[0139] Where Cr2 is the resulting capacitance value of the second capacitive sensor, and Cr5 is the resulting capacitance value of the fifth capacitive sensor C5.

[0140] Furthermore, the value of the first threshold S1, the value of the third threshold S3 and the value of the fourth threshold S4 are adapted to the fact that there is only one sensor of a different shape in this embodiment.

[0141] In this application, an "I" shape is understood to mean a straight line shape.

[0142] Description of a second object of the invention

[0143] A second object of the invention relates to a vehicle seat and in particular to a seat equipped with a device for determining the staturo-ponderal type of a seat occupant or for determining the position of the seat occupant.

[0144] Figure 6 illustrates a seat 4 according to a first embodiment of a second object of the invention. This seat 4 comprises a seat 6, a backrest 8 supported by the seat, and a determination system 2 according to a first embodiment of the second object of the invention. This determination system 2 includes a flexible support 9 and six capacitive sensors with interdigitated electrodes C1, C2, C3, C4, C5, C6 carried by the flexible support 9.

[0145] Seat 4 is, for example, a vehicle seat and, in particular, a motor vehicle seat.

[0146] The seat 6 includes a receiving face 12 designed to accommodate a seat occupant. The seat, and in particular the receiving face of the seat, comprises a central portion 14, a first lateral support edge 16, and a second lateral support edge 18. For the purposes of this description, the central portion 14 of the seat is said to be divided, by two transverse lines Y1 and Y2, into three zones. These three zones have the same dimensions along the longitudinal direction X. A zone adjacent to the backrest is called the "rear zone 20." A zone located on the side opposite the backrest is called the "front zone 22." The zone located between the front and rear zones is called the "middle zone 24."

[0147] The lateral support edges 16, 18 are generally called "bolsters" in English. They are integral with and contiguous to the central part 14. They extend outward from the central part essentially in the vertical direction Z. They extend along the lateral sides 28, 30 of the central part of the seat.

[0148] The flexible support 9 is placed on the seat foam or the network of wires forming the seat. The flexible support 9 is made of a plastic material such as, for example, thermoplastic polyurethane, known by the acronym TPU. The capacitive sensors with interdigitated electrodes C1, C2, C3, C4, C5, C6 are attached to the flexible support, for example, by gluing. The capacitive sensors with interdigitated electrodes are hereinafter referred to as capacitive sensors. These capacitive sensors are described in patent FR 2109436 granted to the applicant.

[0149] The flexible support 9 is fixed to the seat in such a way that the capacitive sensors are arranged in particular locations on the seat.

[0150] According to a first embodiment of the second object of the invention and with reference to figure 6, a first capacitive sensor C1 is located on the first lateral support rim 16. Specifically, the first capacitive sensor C1 is located on a face of the first lateral support rim adjacent to the central part.

[0151] The first capacitive sensor C1 is the only capacitive sensor located on the first lateral support edge 16. The first capacitive sensor C1 has a rectangular shape and extends along the longitudinal direction X.

[0152] Referring to Figure 7, the first capacitive sensor C1 includes a center of mass B1. The center of mass B1 is located between 60 and 70 millimeters forward of point H along the longitudinal X direction. The center of mass B1 is located between 193 and 202 millimeters to one side of point H along the longitudinal Y direction. Finally, the center of mass B1 is located between -16 and -22 millimeters from point H along the longitudinal Z direction. More preferably, the center of mass B1 is located between 63 and 67 millimeters forward of point H along the longitudinal X direction. Point H (or hip point) is the theoretical and relative location of an occupant's hip.Specifically, the H-point is the pivot point between the torso and the upper legs of the body, as used in vehicle design, automotive design, and vehicle regulations. Technically, the positioning of the H-point has been defined as the hip articulation point of a male occupant in the 50th percentile. The H-point is defined in standard 20176:2006.

[0153] A second capacitive sensor C2 and a fourth capacitive sensor C4 are arranged on the flexible support so as to be located on the central part 14 of the seat.

[0154] In particular, in the first embodiment of the invention shown in Figure 1, the second capacitive sensor C2 and the fourth capacitive sensor C4 are arranged in the central area 24 of the seat. The second capacitive sensor C2 and the fourth capacitive sensor C4 have an "L" shape. One arm of this "L" shape extends along the longitudinal direction X. The other arm of this "L" shape extends along the transverse direction Y. The second capacitive sensor C2 and the fourth capacitive sensor C4 are located symmetrically on either side of a central line X1 extending along a longitudinal direction X. The central line X1 is centered along the transverse direction Y with respect to the lateral edges 28, 30 of the central part of the seat.

[0155] A fifth capacitive sensor C5 is arranged on the flexible support 9 so as to be located on the rear area 20 of the central part of the seat. Preferably, the fifth capacitive sensor C5 is T-shaped. The fifth capacitive sensor C5 has a first arm 25 extending along the transverse direction Y and a second arm 26 extending along the longitudinal direction X. The second arm 26 originates from the middle of the first arm 25. Preferably, the first arm 25 extends along the transverse direction Y for a length at least equal to half the width of the central part 14 of the seat. In the present patent application, the width of the central part of the seat is measured along the transverse direction Y. Preferably, the first arm is centered along the transverse direction with respect to the lateral edges 28, 30 of the central part.Preferably, the second branch extends over a length less than one-third of the length of the first branch.

[0156] A third capacitive sensor C3 is arranged on the flexible support 9 so as to be located on the second lateral support rim 18, in particular, on a face of the second lateral support rim adjacent to the central part.

[0157] A sixth capacitive sensor C6 is positioned on the flexible support 9 so as to be located in the front area 22 of the central part of the seat. The sixth capacitive sensor C6 is shaped like an "I". The sixth capacitive sensor C6 extends along the transverse direction Y for a length at least equal to half the width of the central part of the seat.

[0158] The determination system 2 further includes electrical wires 32 fixed to the flexible support 9 and an electrical connector 34 fixed to one end of the flexible support.

[0159] The electrical wires 32 are each connected between an electrode of a capacitive sensor and the electrical connector 34. The determination system 2 is intended to be connected to a controller 10 via a wiring 36.

[0160] Controller 10 includes a processor and memory connected to the processor.

[0161] The processor also includes a voltage source, a ground, and a capacitance measurement unit.

[0162] The voltage source generates a voltage of, for example, 5 Volts.

[0163] The processor implemented by hardware may be equipped with ASICs (application-specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field-programmable gate arrays), and the like.

[0164] Electrical wires 32 and wiring 36 electrically connect one electrode of each capacitive sensor C1 to C6 to the controller's voltage source and a second electrode of each capacitive sensor C1 to C6 to ground. The capacitance measurement unit is specific to measuring the capacitance between the electrodes of each capacitive sensor.

[0165] According to a first variant of the first embodiment of the seat according to the second object of the invention, the first capacitive sensor C1 and the third capacitive sensor C3 are connected to each other by an electrical wire 35. A single electrical wire 35 transmits an average capacitance of the two capacitive sensors.

[0166] Advantageously, this variant allows the use of a 34-pin output connector with fewer output pins. However, the amount of position information is reduced.

[0167] According to a second variant of the first embodiment of the seat of the second object of the invention, the second capacitive sensor C2 and the fourth capacitive sensor C4 are connected to each other by an electrical wire 35. A single electrical wire 35 transmits an average capacitance of the two capacitive sensors.

[0168] Advantageously, this variant allows the use of a 34-pin output connector with fewer output pins. However, the amount of position information is reduced.

[0169] According to a third variant of the seat according to the second object of the invention, illustrated in Figure 8, the flexible support of the determination system 2 comprises only one capacitive sensor in its median zone 24, called the second capacitive sensor. The second capacitive sensor C2 is the only sensor located in the median zone 24.

[0170] This second capacitive sensor C2 has the shape of an I which extends along the transverse direction Y over a length at least equal to half the width of the central part of the seat. It is centered along the transverse direction with respect to the lateral edges 28, 30 of the central part 14.

[0171] According to a fourth, unillustrated variant of the seat of the second object of the invention, the flexible support of the determination system 2 comprises only one capacitive sensor in its central area 24, referred to as the second capacitive sensor. This second capacitive sensor C2 is L-shaped. It is positioned on one side of the central line X1 in the same location as the second capacitive sensor of the first embodiment of the seat according to the second object of the invention.

[0172] According to a fifth variant of the seat of the second object of the invention, illustrated in Figure 9, the flexible support 9 of the determination system 2 comprises only a first capacitive sensor C1 intended to rest on the first lateral support edge 16, a second capacitive sensor C2 and a fourth capacitive sensor C4 intended to rest on the median area 24 of the central part of the seat, a fifth capacitive sensor C5 resting on the rear area 20, and a sixth capacitive sensor resting on the front area 22. According to a sixth variant of the seat of the second object of the invention, not illustrated, the fifth capacitive sensor C5, disposed on the rear area 20, has an "I" shape instead of a "T" shape. The fifth capacitive sensor C5 is centered in the transverse direction with respect to the lateral edges 28, 30 of the central part 14.The fourth capacitive sensor C4 extends along the transverse Y direction over a length at least equal to half the width of the central part of the seat.

[0173] According to a seventh variant of the seat of the second object of the invention, not illustrated, the flexible support of the determination system 2 does not include the sixth capacitive sensor C6. No capacitive sensor is arranged on the flexible support so as to be located in the front area 22 of the central part.

[0174] According to an eighth variant of the seat of the second object of the invention, not illustrated, the flexible support of the determination system 2 comprises only the first capacitive sensor C1 arranged to rest on the first lateral support edge 16 and a second capacitive sensor C2 arranged to rest on the median area 24 of the central part of the seat. This second capacitive sensor C2 may be L-shaped and be arranged on one side of the central line X1. This second capacitive sensor C2 may also be I-shaped, extending along the transverse direction Y for a length at least equal to half the width of the central part of the seat. In this case, it is centered along the transverse direction with respect to the lateral edges 28, 30 of the central part 14.

[0175] According to a ninth variant of the seat of the second object of the invention, the capacitive sensors C1 to C6 are arranged directly on the foam or the fiber mesh forming the seat. In this case, the determination system does not include a flexible support.

[0176] These different variations can be combined with each other.

[0177] In this patent application, the term "I-shaped" means a rectilinear shape.

[0178] The second object of this invention may eventually be the subject of a divisional application.

Claims

DEMANDS 1. A method for determining the height and weight type of a seat occupant, in particular a vehicle seat (4); the seat comprising a cushion (6), the cushion comprising a central part (14) and a first lateral support edge (16); the method comprising: - a calculation (44) of a first data (D1) representative of the pressure exerted on the seat from the resulting capacitance value of a first capacitive sensor (C1) with interdigitated electrodes located on the first lateral support edge (16) and at least one resulting capacitance value of a second capacitive sensor (C2) with interdigitated electrodes located on the central part (14) of the seat, - a calculation (46) of a second data point (D2) representing the pressure exerted on the first lateral support edge (16) of the seat from the resulting capacitance value of the first capacitive sensor (C1), - a calculation (48) of a first value (V1) as a function of the first data and the second data, the calculation (48) of the first value (V1) comprising a sum of the first data (D1) and the second data (D2), - a comparison (50) of the first value (V1) to a first threshold (S1), when the first value is less than the first threshold, generation of a signal representative of a child-type occupant.

2. Method of determination according to claim 1, wherein the calculation (44) of the first data (D1) includes the calculation of a sum weighted by a weighting coefficient, of the resulting capacitance values ​​of the capacitive sensors located on the base.

3. A method for determining according to any one of claims 1 and 2, wherein the seat (4) comprises a second lateral support rim (18), and wherein the first datum (D1) is calculated from the resulting capacitance value of the first capacitive sensor (C1), the resulting capacitance value of at least a second capacitive sensor (C2), and a resulting capacitance value of a third capacitive sensor with interdigitated electrodes located on the second lateral support rim (18) of the seat; the second datum (D2) being calculated from the resulting capacitance value of the first capacitive sensor (C1) and the resulting capacitance value of the third capacitive sensor (C3); the second datum being representative of the pressure exerted on the first lateral support edge (16) and on the second lateral support edge (18).

4. Method of determination according to claim 2, wherein the weighting coefficient comprises a ratio between a non-zero natural number and a value representative of the pressure exerted on at least the first lateral rim (16).

5. Method of determination according to the combination of claims 2 and 3, wherein the weighting coefficient comprises a ratio between a non-zero natural number and an average of a resulting capacitance value from the first capacitive sensor (C1) and a resulting capacitance value from the third capacitive sensor (C3).

6. Method of determination according to the combination of claims 2 and 3, wherein the second data (D2) comprises the sum of a resulting capacitance value from the first capacitive sensor (C1) and a resulting capacitance value from the third capacitive sensor (C3).

7. Method of determination according to any one of claims 1 and 2, wherein the second data (D2) is the resulting capacitance value of the first capacitive sensor (C1).

8. A method for determining according to any one of claims 1 to 7, comprising: - an initialization (52) of a first counter (25) and a second counter (26), - a comparison of the second data (D2) to a second threshold (S2), if the second data (D2) is less than the second threshold (S2) then increment the first counter (25) by a first number, if the second data (D2) is greater than the second threshold (S2) then increment the second counter (26) by said first number; said first number being strictly greater than zero.

9. A method for determining the value according to claim 8, wherein the method comprises: - a calculation (56) of a second value (V2) as a function of a resultant value of the second capacitive sensor (C2) and a resultant value of a fourth capacitive sensor (C4) with interdigitated electrodes located on a median area (24) of the central part of the seat, the second capacitive sensor (C2) being located in a median area (24) of the central part of the seat, - a comparison (58) of the second value (V2) to a third threshold (S3), if the second value (V2) is less than the third threshold (S3), then increment the first counter (25) by a second number, if the second value is greater than the third threshold (S3), then increment the second counter (26) by the second number, the second number being strictly greater than zero.

10. A determination method according to claim 8, wherein the method comprises: - a definition of a second value (V2) equal to a resultant value from at least one second capacitive sensor, the second capacitive sensor (C2) being located in a median area (24) of the central part of the seat; - a comparison of the second value (V2) to a third threshold (S3), if the second value (V2) is less than the third threshold (S3), then increment the first counter (25) by a second number, if the second value is greater than the third threshold (S3), then increment the second counter (26) by the second number, the second number being strictly greater than zero.

11. Method of determination according to any one of claims 9 and 10, wherein the second number is less than the first number.

12. A method for determining according to any one of claims 9 to 11, wherein the method comprises: - a calculation (60) of a third value (V3) by subtracting a resulting value from a fifth capacitive sensor (C5) with interdigitated electrodes located in a rear area (20) of the central part of the seat, from the second value (V2), - a comparison (62) of the third value (V3) to a fourth threshold (S4), if third value (V3) is less than the fourth threshold (S4), then increment the first counter (25) by a third number, if the third value (V3) is greater than the fourth threshold (S4), then increment the second counter (26) by the third number, the third number being strictly greater than zero.

13. Method of determination according to claim 12, wherein the third number is less than the second number.

14. A method for determining the value of a counter according to any one of claims 8 to 13, comprising a comparison (64) of the value of the first counter (25) and the value of the second counter (26), where the value of the first counter is greater than the value of the second counter, a signal representative of an occupant of a first height-weight type is generated, and where the value of the first counter (25) is less than the value of the second counter (26), a signal is generated representing the occupant's size and weight. The generation of a signal representative of an occupant of a second staturoponderal type, the second staturoponderal type having a stature and weight greater than the first staturoponderal type.

15. A method of determination according to any one of claims 1 to 9 and 11 to 14, wherein at least one capacitive sensor among the second capacitive sensor (C2) and the fourth capacitive sensor (C4) has an "L" shape; and wherein the second capacitive sensor (C2) and the fourth capacitive sensor (C4) are located symmetrically on either side of a central line (X1) extending in a longitudinal direction X, said central line (X1) being centered with respect to the lateral edges (28, 30) of the central part of the seat.

16. Method of determination according to any one of claims 1 to 8 and 10 to 14, wherein the second capacitive sensor (C2) is located on a median area (24) of the seat, the second capacitive sensor (C2) being the only sensor located on the median area (24), the second capacitive sensor (C2) having the shape of an “I” extending along the transverse direction Y over a length at least equal to half the width of the seat.

17. Method of determination according to any one of claims 1 to 16, wherein the seat (6) comprises a sixth capacitive sensor (C6) with interdigitated electrodes, the sixth capacitive sensor (C6) being located on a front area (22) of the central part of the seat, the sixth capacitive sensor (C6) having the shape of an “I” extending along the transverse direction Y over a length at least equal to half the width of the seat.

18. Seat (4), in particular for a vehicle, the seat comprising: - a seat (6) comprising a central part (14) having two opposing lateral edges (28, 30), and at least one first lateral support edge (16) integral with a lateral edge of the central part, the first lateral support edge (16) projecting outward from the central part, the central part (14) comprising a rear zone (20), a middle zone (24) and a front zone (22), characterized in that the seat (6) comprises: - a capacitive sensor with interdigitated electrodes (C1) disposed on the first lateral support edge (16), called the first capacitive sensor (C1), - at least one capacitive sensor with interdigitated electrodes (C2) located on the median area 24 of the central part, called the second capacitive sensor (C2), - a capacitive sensor with interdigitated electrodes (C5) located on the rear area (20) of the central part, called fifth capacitive sensor (C5), said fifth capacitive sensor being the only capacitive sensor located on the rear area, said fifth capacitive sensor being centered, in a transverse direction (Y), with respect to the lateral edges (28, 30) of the central part.

19. Seat (4) according to claim 18, wherein the second capacitive sensor (C2) has an "L" shape.

20. Seat (4) according to any one of claims 18 and 19, wherein the seat (6) comprises a second lateral support rim (18) integral with another lateral side of the central part, the second lateral support rim (18) extending in projection relative to the central part (14), the seat comprising a capacitive sensor with interdigitated electrodes disposed on the second lateral support rim (18), referred to as the third capacitive sensor (C3).

21. Seat (4) according to any one of claims 18 to 20, wherein the seat (4) comprises a fourth capacitive sensor (C4) with interdigitated electrodes disposed on the median area (24) of the central part, referred to as the fourth capacitive sensor (C4).

22. Seat (4) according to claim 21, wherein the second capacitive sensor (C2) and the fourth capacitive sensor (C4) are located symmetrically on either side of a central line (X1) extending in a longitudinal direction (X), said central line (X1) being centered with respect to the lateral edges (28, 30) of the central part.

23. Seat (4) according to any one of claims 18 to 21, wherein the second capacitive sensor (C2) is the only sensor disposed on the median area (24), said second capacitive sensor (C2) has an "I" shape, said second capacitive sensor (C2) extends in a transverse direction (Y) over a length at least equal to half the width of the central part (14), the second capacitive sensor (C2) being centered with respect to the lateral edges (28, 30) of the central part.

24. Seat (4) according to any one of claims 18 to 23, further comprising a single capacitive sensor with interdigitated electrodes (C6) disposed on the front area of ​​the central part, referred to as the sixth capacitive sensor.

25. Seat (4) according to claim 24, wherein the sixth capacitive sensor (C6) has an "I" shape, said sixth capacitive sensor (C6) being centered in the transverse direction (Y) with respect to the lateral edges (28, 30) of the part central, said sixth capacitive sensor (C6) extending along the transverse direction (Y) over a length at least equal to half the width of the central part (14) of the seat.

26. Seat (4) according to any one of claims 18 to 25, wherein the fifth capacitive sensor (C5) comprises two branches arranged in the shape of "T", a branch (25) of the fifth capacitive sensor extending along the transverse direction (Y) over a length at least equal to half the width of the central part (14) of the seat, said branch (25) being centered with respect to the lateral edges (28, 30) of the central part.

27. Seat (4) according to any one of claims 18 to 25, wherein the fifth capacitive sensor (C5) has an "I" shape, said fifth capacitive sensor (C5) being centered in the transverse direction (Y) with respect to the lateral edges (28, 30) of the central part, said fifth capacitive sensor (C5) extending in the transverse direction (Y) over a length at least equal to half the width of the central part (14) of the seat.

28. Seat (4) according to any one of claims 18 to 27, wherein the first capacitive sensor (C1) comprises a barycenter (B1) located at a distance between 60 millimeters and 70 millimeters from point H along the longitudinal direction (X).

29. Seat (4) according to any one of claims 20 to 28, wherein the first capacitive sensor (C1) and the third capacitive sensor (C3) are connected to each other.

30. Seat (4) according to any one of claims 21 to 29, wherein the second capacitive sensor (C2) and the fourth capacitive sensor (C4) are connected to each other.

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