Method for controlling a vehicle seat hinge and an associated vehicle seat

Abstract

TITLE: Method for controlling a vehicle seat articulation. The invention relates to a method for controlling a vehicle seat hinge (3) comprising a backrest (1) rotatably mounted on a seat (2) by means of the hinge (3), said hinge (3) comprising a pre-tensioned spring system capable of tilting the backrest (1) forward, and the method comprising an emergency actuation method for the hinge having a sequence comprising: / a / Detection of contact between a seat occupant and a seating surface (11) of the backrest (1), / b / Triggering an emergency action comprising: / b1 / If the contact detection is negative, a release of the spring system that tilts the backrest (1) forward, followed by a return to operation / a / of detecting contact between the occupant and the seating surface (11) of the backrest (1) for repetition of the sequence, / b2 / If the contact detection is positive, a locking of the hinge (3). Figure 4

Description

Title of the invention: Method for controlling a vehicle seat joint and an associated vehicle seat technical field

[0001] The scope of this disclosure is that of vehicle seating and vehicle safety. Previous technique

[0002] It is known to control the position or tilt of vehicle seats to improve occupant safety.

[0003] Indeed, a mechanism and method for adjusting a vehicle backrest are known from document DE 102018202455, in which the seat includes a joint allowing angular movement of the backrest and a motor capable of adjusting it to a desired angular position. The method aims to reduce a gap between the seat occupant and the backrest that occurs during a collision, during which the seat occupant is propelled forward and away from the backrest. To this end, the proposed method includes the forward folding of the backrest by the motor immediately after the collision.

[0004] US20200130680 also knows of a method for adjusting the position of a seat back comprising the detection of an imminent accident and the triggering of an adjustment operation during which the back is brought into a particular angular position.

[0005] According to the inventors' findings, the method and mechanism of prior art DE 102018202455 and US20200130680 can be improved. The present disclosure enhances this situation; for example, the economical pre-collision seat adjustment using the existing seat system, the highly responsive backrest adjustment thanks to the spring system, the system can be used normally after the hazardous situation, unlike the sole use of the airbag, and the system's operation will not increase the occupant's stress level, as they will only experience improved contact with the seat back. Summary

[0006] The objectives mentioned above are achieved in particular by a method for controlling a vehicle seat joint, in particular a car seat, the seat comprising a backrest mounted on a seat base, said joint allowing the backrest to rotate relative to the seat base forward and backward relative to the direction of travel of the vehicle, said joint comprising a preloaded spring system capable of tilting the backrest forward around the joint, the method comprising an emergency actuation mode of The joint is configured to lock in a position minimizing any potential gap between the seat back and a seat occupant prior to an accident. The emergency actuation mode of the joint includes a sequence comprising: - / a / Detection of contact between a seat occupant and a surface receiving the file, - / b / Triggering an emergency action including: • / b 1 / If contact detection is negative, a release of the spring system that tilts the backrest forward, followed by a return to operation / a / of contact detection between the occupant and the backrest's support surface for repetition of the sequence, • / b2 / If the contact detection is positive, a blocking of the joint to prevent the backrest from rotating relative to the seat forwards and backwards.

[0007] Indeed, the inventors have determined that the effectiveness of the vehicle's active safety systems depends greatly on the presence or absence of contact between the seat occupant and the seat back. Thus, by first checking for the existence of such contact and then rotating the seat back forward, the method according to this disclosure makes it possible to re-establish contact between the seat occupant and the seat back to increase the effectiveness of the active safety systems.

[0008] Indeed, and particularly advantageously, the method described in this disclosure allows the seat back to fold forward quickly to re-establish contact with the occupant. Thanks to the pre-tensioned spring system, there is a high degree of responsiveness and occupant safety is further improved.

[0009] Furthermore, it is not a specific angular position of the seat back that is sought, but rather the occupant's position relative to the seat back. If, for example, the occupant is positioned so as to be slightly leaning forward relative to the seat back, the seat back will be folded down until it reaches the occupant to re-establish contact, and will then be locked in that position. If the occupant is "correctly positioned" from the start of the emergency actuation sequence, and contact is detected immediately, the seat back will not be folded down. In this case, the seat back will simply be locked in the position that corresponds to an optimal occupant position. Thus, thanks to the method according to the preceding disclosure, the occupant's position is taken into account, and it is ensured that the occupant is in an optimal position before the accident.

[0010] In other words, the method for controlling a vehicle seat hinge according to this disclosure makes it possible to minimize the gap between the seat back and the occupant before an accident, thereby improving the effectiveness of the vehicle's active safety systems. By first detecting contact between the occupant and the seat back's mounting surface, and then by By tilting the seat back forward if no contact is detected, the process ensures that the occupant is correctly positioned against the seat back before a probable collision.

[0011] The emergency action sequence, which includes releasing the spring system to tilt the seatback forward and locking the joint once contact is established, ensures a rapid and reliable response. This approach allows for the rapid restoration of contact between the occupant and the seatback, thus increasing the protection offered by safety devices such as airbags.

[0012] The pre-tensioned spring system used to tilt the backrest forward offers an efficient and rapid solution, as it has stored energy ready to be released when needed. This allows for an immediate response to an emergency situation, without requiring additional components or complex mechanisms.

[0013] Furthermore, the method does not merely seek a particular angular position of the backrest, but aims to guarantee an optimal position of the occupant relative to the backrest. This allows it to adapt to different morphologies and positions of the occupant, thus ensuring maximum protection in various situations.

[0014] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other:

[0015] According to an improvement, the method includes a step / a0 / of detecting a risky situation in which a probability of an accident of the vehicle is greater than a threshold value, and in which the emergency actuation mode of the joint is triggered when the risky situation is detected.

[0016] In this way, the emergency actuation mode sequence can be triggered before an accident occurs, and thus allow the occupant to adopt an optimal position before the possible triggering of a vehicle safety system.

[0017] By incorporating a risk detection step, the method makes it possible to trigger the emergency actuation mode before an accident occurs. This increases the probability that the occupant will be in an optimal position at the time of impact, thus improving safety in the vehicle.

[0018] According to an improvement, the detection / a0 / of the risk situation includes a detection by a data acquisition device of an obstacle on a vehicle trajectory and the detection of the risk situation includes the detection of a vehicle advance speed greater than or equal to a threshold speed.

[0019] Advantageously, the data acquisition device is an element of a vehicle driver assistance system. In this way, the control method according to this improvement is implemented by a device already existing on the vehicle.

[0020] According to an improvement, contact detection / a / is performed by a pressure sensor. In this way, it is possible to distinguish simple contact from actual pressure exerted by the occupant on the backrest. The use of a pressure sensor makes it possible to distinguish simple contact from actual pressure exerted by the occupant on the backrest. This improves the accuracy of contact detection, ensuring that the emergency actuation mode is triggered only when the occupant is not correctly positioned against the backrest.

[0021] According to an improvement, contact detection is performed in a contact zone located in an upper area of ​​the backrest, preferably near two-thirds of the height H of the backrest. By targeting a contact zone located in an upper area of ​​the backrest, the method ensures that the occupant is correctly positioned against the backrest, even if their lower back is in contact with the backrest but they are leaning forward. This provides better protection in the event of a collision, as the occupant is kept in an optimal position.

[0022] According to an improvement, the forward tilting of the backrest and / or the locking of the joint is achieved by a seat tilt adjustment mechanism comprising an electrically controlled brake configured to lock the joint at several angular locking positions, and wherein, in the emergency actuation mode of the joint, the release / b1 / of the spring system is effected by unlocking the joint via the electrically controlled brake, and / or the locking in / b2 / is effected by the electrically controlled brake. Preferably, the preloaded spring system implementing the emergency action / b1 / is a preloaded spring system of the seat adjustment mechanism. In this way, the control method can be implemented by the adjustment mechanism already present in the seat and may not require any additional components for its implementation.

[0023] According to an improvement, the method includes a nominal manual control mode for the joint, comprising an adjustment of the backrest tilt by an occupant, comprising: - a release of the pre-tensioned spring system by unlocking the brake in response to a user command, - an adjustment of the backrest, brought back against the occupant by the spring system, by a movement of the occupant to a backrest adjustment position, - a locking of the backrest, by the electrically controlled brake, in the adjustment position.

[0024] According to an improvement, the seat includes a human-machine interface, and the method further includes, after a predetermined time period starting from the triggering of the locking in / b2 / of the joint has elapsed, a step / d / of The joint is unlocked, and a step (e) prompts the occupant via the human-machine interface to adjust the backrest angle according to the joint's nominal control mode. This allows the occupant to return to a desired backrest angle for their comfort.

[0025] Such an improvement thus allows the occupant to return to a comfortable position after the emergency mode has been activated: after the predetermined time has elapsed since the joint locking mechanism was activated, the process includes the step of unlocking the joint. This allows the occupant to return to a comfortable position after an emergency situation, thereby improving the user experience.

[0026] According to an improvement, the joint comprises a motor configured to tilt the backrest forward in the direction of a return force from the spring system and backward against the return force of the joint's spring system, in a nominal motorized control mode, as well as an electrically controlled clutch system configured to move from a position of coupling the motor to the joint to a position of decoupling the motor. The method includes, prior to triggering the emergency actuation mode, switching the motor to a position of decoupling the clutch system. Thus, the joint between the backrest and the seat is free from the motorized transmission intended for adjusting the backrest tilt when the emergency action of the control method is triggered.

[0027] Another aspect of the present disclosure relates to a vehicle seat comprising a backrest mounted on a seat, the seat comprising a joint allowing the backrest to rotate relative to the seat forward and backward in a direction of forward movement of the vehicle, said joint comprising a preloaded spring system capable of tilting the backrest forward around the joint, and the seat comprising a computer, a memory and instructions configured to cooperate with the computer and the memory to implement the method as previously claimed.

[0028] Another aspect of this disclosure relates to a vehicle seat comprising a backrest mounted on a seat base, the seat comprising a joint allowing the backrest to rotate relative to the seat base forward and backward in the direction of travel of the vehicle, said joint comprising a preloaded spring system capable of tilting the backrest forward around the joint, and the seat comprising a computer, memory, and instructions configured to cooperate with the computer and memory to, in said at least one emergency actuation mode of the joint, implement a sequence comprising: - / A / Detect contact between a seat occupant and a reception surface of the file - / B / Trigger an emergency action including: a. / B 1 / If the contact detection is negative, release the spring system that tilts the backrest forward, and return to operation / A / of detecting contact between the occupant and the backrest's support surface, b. / B2 / If the contact detection is positive, block the joint to prevent the backrest from rotating relative to the seat forwards and backwards. Brief description of the drawings

[0029] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0030] [Fig. 1] shows a schematic side view representation of a vehicle passenger compartment, which includes a seat on which an occupant is seated, the seat back being in an initial position according to an example,

[0031] [Fig.2] shows a schematic side view representation of a similar passenger compartment to that of [Fig. 1], in which the seat back is in an optimal position according to an example,

[0032] [Fig.3] shows a schematic perspective representation of a seat, on in which one can see a contact area on the backrest's mounting surface as well as different portions of the backrest's height, as an example,

[0033] [Fig.4] shows a flowchart of the process according to an example of the present disclosure. Description of the implementation methods

[0034] The drawings and description below contain, essentially, elements of a definite nature. They may therefore not only serve to better understand this disclosure, but also contribute to its definition, if necessary.

[0035] In the various figures, the same reference numerals designate identical or similar elements. For the sake of brevity, only the elements that are useful for understanding the described embodiment are shown in the figures and are described in detail below.

[0036] In the following description, when reference is made to absolute positional qualifiers, such as the terms "front," "back," "top," "bottom," "left," "right," etc., or relative positional qualifiers, such as the terms "above," "below," "superior," "inferior," etc., or to orientational qualifiers, such as "horizontal," "vertical," etc., reference is made, unless otherwise specified, to the orientation of the figures or of a vehicle in its normal operating position. Furthermore, the term "approximately" is to be interpreted as indicating that the result obtained is as precise as the known method for measuring it.

[0037] Reference is now made to [Fig. 1].

[0038] This figure represents a vehicle seat and an occupant seated in it. Figure 1 shows, as an example, an occupant in the driving position, holding a steering wheel. Of course, other seating positions can be considered, for example, the passenger side in row 1 or even rows 2 or higher, without departing from the scope of this disclosure.

[0039] Furthermore, the vehicle shown in this example is a motor vehicle. It is understood that this disclosure may also apply to other types of vehicles, including commercial vehicles, heavy goods vehicles or machinery, or public transport vehicles such as buses.

[0040] Generally, the seat comprises a seat 2 on which a backrest 1 is mounted. The backrest 1 is mounted on the seat 2 in a rotational manner, by means of a joint 3 allowing the rotation of the backrest 1 forwards and backwards relative to the seat 2.

[0041] It is understood throughout this text, unless otherwise stated, that the directions "forward" and "backward" are defined according to the direction of travel of the vehicle. In other words, generally speaking, forward rotation of the backrest tends to close an angle 0 between the backrest 1 and the seat 2, thereby decreasing it, and backward rotation tends, conversely, to open angle 0, thereby increasing it. Angle 0 is notably illustrated in Figures 1 and 2. According to the specific and non-limiting example of Figures 1 and 2, when the occupant is a driver of the vehicle, forward rotation of the backrest 1 tends to move it towards the steering wheel of the vehicle, while backward rotation of the backrest 1 tends to move it away from said steering wheel.

[0042] Typically, the backrest includes a seating surface 11 extending over all or part of a front face of the backrest 1. Generally, the seating surface 11 is configured to accommodate an occupant of the seat 1. In particular, the seat is classically configured so that the occupant can lean back against the seating surface 11 of the backrest 1.

[0043] According to the example in [Fig.3], the seating surface 11 extends over a height H, typically measured from a lower edge of the backrest 1, at the level of the junction with the seat 2, to a higher edge of the backrest 1, which may optionally carry a headrest.

[0044] The method for controlling the seat articulation according to this disclosure will now be described, in particular with reference to the example flowchart in [Fig.4],

[0045] The control method includes an emergency actuation mode, configured to lock the joint 3 in a position minimizing any gap between the backrest 1 and a seat occupant, advantageously before an accident.

[0046] To this end, the seat joint 3 includes a pre-stressed spring system capable of tilting the backrest forward around the joint, in response to a particular instruction of said control method.

[0047] In general, the preloaded spring system is such that, in its rest state, it contains a quantity of stored energy, and is capable of releasing this energy, in its working state, to transmit a torque that induces a forward tilt of the backrest. Such a system, having a quantity of energy available at all times, makes it possible to respond effectively, quickly, and reliably to a seat tilt command from the emergency actuation mode of the control method.

[0048] Such a spring may be of the torsion bar type, or of the helical spring type, or comprising a compressed gas, etc...

[0049] According to this disclosure, the method includes a step / a / for detecting contact between a seat occupant and the seat backrest surface. This detection step / a / returns either a positive value, if contact is detected, or a negative value, if no contact is detected between the occupant and the seat backrest.

[0050] Generally, the detection / a / of the contact can be carried out by any type of suitable sensor, coupled to a data processing and calculation device such as a seat or vehicle processor.

[0051] For the purposes of this disclosure, piezoelectric sensors, capacitive sensors, resistive sensors, Hall effect sensors, optical sensors, inductive sensors, mechanical sensors... may be considered

[0052] Depending on the types of sensors, and depending on the implementation of the control method, the positive or negative value may come from one or more "on or off" digital sensors, detecting in a binary way whether there is a contact or not.

[0053] In other examples, in cases where one or more analog sensors are used, the positive or negative value may come from a comparison to a predetermined threshold value.

[0054] It is of course possible to use several sensors, including of different types to combine different acquisitions of values, in different areas of the reception surface 11 of the folder 1.

[0055] In particular, detection / a / can be performed by one or more pressure sensor(s). In this case, it is possible to deduce a force exerted on the backrest and compare this force to a threshold value. In this way, it is possible to distinguish a a light touch which would result in a negative detection (although there is then contact), of sufficient pressure of the occupant's back on the backrest which would result in a positive detection.

[0056] According to examples, the detection / a / of the contact can be carried out in a local contact zone 12 of the receiving surface 11 of the file 1, for example located at the level of a midpoint of the height H of the receiving surface 11.

[0057] According to particular examples, the contact zone 12 is located in the vicinity of a midpoint of the height H of the receiving surface 12. Preferably, the contact zone is located in an upper part of the height H of the receiving surface, for example in the vicinity of three-quarters, or two-thirds of the height H of the receiving surface 12.

[0058] For this last particular example represented in [Fig.3], in which the height H has been subdivided into three equal height thirds H1, H2 and H3, the contact zone 12 is then located at a height substantially equal to H1+H2, measured from the vicinity of a junction between the backrest 1 and the seat 2.

[0059] Thanks to a contact zone 12 positioned in the middle or upper part of the seat back, it is possible to avoid registering a positive contact value when the occupant is not in a suitable position. For example, step / a / would advantageously indicate a negative value when the occupant, while properly seated at the back of the seat with their lower back in contact with the seat back, is leaning forward so that no contact is established in the upper part of the seat back. Conversely, step / a / would advantageously indicate a positive value when the occupant is not properly seated at the back of the seat but has their upper back in contact with the seat back. Indeed, the inventors were able to determine that the effectiveness of the vehicle's safety devices depends more on contact in the middle or upper part of the seat back than on contact in the lower part of the seat back.

[0060] According to examples, the detection / a / can be carried out using several detection modules distributed in different areas of the reception surface 11 of the file 1 so as to be able to deduce a distribution of the contact of the occupant with the file 1. In the same way, such a measure of contact distribution can be compared to a threshold value so as to determine whether the detection / a / of the contact is negative, below the threshold value, or positive, when it is greater than or equal to the threshold value.

[0061] In addition, the method also includes triggering / b / an emergency action depending on the outcome of the contact detection, positive or negative, carried out in / a / .

[0062] Indeed, if the contact detection / a / is negative, the method includes a step / b 1 / of releasing the pre-stressed spring system of the joint 3 to tilt the backrest 1 forward, from an "initial" backrest position to a position "Optimal" of file 1. The optimal position corresponds to the position at which contact is established by the detection step / a / which then becomes positive.

[0063] An example of the initial position of the backrest 1 is shown in [Fig. 1], and an example of the optimal position of the backrest 1 is shown in [Fig. 2]. It can be seen in particular in [Fig. 1] that contact is not established in the initial position of the backrest in the contact zone 12, and that the backrest 1 is thus tilted forward during step / bl / until it reaches the optimal position in which contact is indeed established in the contact zone 12.

[0064] According to one example, such a release is advantageously achieved in a very short time so as to meet safety requirements. In particular, such a release / b 1 / can be carried out in less than 100 ms from the negative detection of the contact.

[0065] The release / b 1 / of the spring system causes the receiving surface 11 to move closer to the occupant, so that, following this release, contact can be detected during the detection step / a / . The release step / b 1 / is therefore followed by a repetition of the sequence, and in particular of the operation / a / of detecting contact with the receiving surface 11 of the backrest 1, to determine again whether the contact is positive or negative. This repetition is carried out until the contact detection is positive and the optimal position of the backrest is reached.

[0066] In practice, the spring system, once released during step / b 1 / , can be configured to deliver a force (a torque) to tilt the backrest 1 forward over a distance at least greater than a normal seating position for an occupant. For example, such a normal seating position could be a vertical position of the backrest corresponding to an angle 0 approximately equal to 90°. The force delivered by the spring system can thus be sufficient to move beyond this normal seating position to an extreme tilt position of the backrest 1, corresponding to an angle 0 less than 90°, for example, approximately equal to 75°. In this way, it is ensured that contact between the occupant and the backrest will be detected as positive at an intermediate position between the initial position of the backrest and the extreme tilt position of the backrest.

[0067] In practice, the detection / a / of the contact is carried out "continuously" as the backrest 1 tilts forward following the release / b 1 / of the spring system of the joint 3.

[0068] The method further includes, when the detection / a / of the contact is positive, where appropriate after release / b 1 / of the spring system, a step / b2 / of blocking the joint to prevent the rotation of the backrest 1 relative to the seat 2. Thus, the backrest 1 is locked in an optimal tilt position of the backrest 1.

[0069] Such a locking mechanism can be achieved using means known to those skilled in the art. In particular, by means of an inductive or friction brake, or by other suitable mechanical locking means for vehicle seat joints.

[0070] In addition, the process may include a step / a0 / in which a risk situation is detected. Typically, this step / a0 / is performed prior to the contact detection operation / a / and, if positive, triggers the emergency actuation sequence of the process according to this disclosure.

[0071] For example, the detection of a risk situation / a0 / is declared positive when the probability of a vehicle accident is greater than a threshold value. For example, such a probability threshold value may be greater than or equal to 30%.

[0072] An “accident” is considered to be any event that can induce a sudden deceleration of the vehicle, including in particular sudden braking or a collision with any object such as another vehicle, an obstacle (such as street furniture for example), a person or an animal.

[0073] Such a "risky" situation can be detected by a data acquisition device, for example, an optical sensor in a vehicle driver assistance system. A situation can be considered "risky" when an obstacle is detected in the vehicle's path, and / or when the vehicle is traveling at a speed equal to or greater than a predetermined threshold speed. For example, such a threshold speed could be 30 km / h.

[0074] According to examples, it is also possible that the situation may be considered "at risk" without any condition regarding the speed of the vehicle.

[0075] Following this risk situation detection step / a0 / , the emergency actuation mode sequence is triggered so that, if such an accident actually occurs and a safety device such as an airbag is triggered, this occurs while the backrest 1 is locked in its optimal position, in which the occupant is positioned so that the effectiveness of the safety device is maximized.

[0076] Furthermore, according to this improvement, the emergency actuation mode can be triggered very quickly following the detection of the "at-risk" situation, so that the sequence has time to be fully executed before the event occurs. Such a triggering delay can be on the order of 50 ms.

[0077] According to a particular example, the seat may include a mechanism for adjusting the joint 3 of the backrest 1, typically controlled by a human-machine interface, capable of allowing the occupant to choose a backrest tilt in order to improve their seating comfort, or of allowing the seat to adapt to different morphologies. Such adjustment mechanisms can allow either manual adjustment, assisted or not, or motorized adjustment of joint 3.

[0078] According to one example, the method may further include a step of unlocking / d / the seat tilt, for example, once an accident or the activation of a safety device has occurred. In this way, if the optimal position of the backrest does not correspond to a position that the occupant would have chosen for their comfort, they can then readjust the backrest tilt as desired using the adjustment mechanism of the joint 3 of the backrest 1.

[0079] Advantageously, according to one example, the emergency actuation mode of the control method is implemented by this seat tilt adjustment mechanism. In particular, one and / or both of the release / b 1 / operations of the spring system and the locking / b2 / of the joint 3 are carried out by components of the seat tilt adjustment mechanism.

[0080] In particular, according to examples, the backrest tilt adjustment mechanism is configured to implement a nominal manual adjustment mode for the occupant's comfort and includes a pre-tensioned spring system and a brake. In this adjustment mode, the occupant can release the spring system so that the backrest folds down against their back. The backrest, free to rotate forward and backward but held forward against the occupant's back, can be brought into the desired comfort position by leaning forward or extending backward against the spring force to a position chosen by the occupant. The backrest is then locked in this position by the brake.

[0081] In the case of such a nominal manual adjustment mode, the preloaded spring system enabling the implementation of step / b 1 / of the emergency actuation mode of the control method can be the preloaded spring system configured to implement said nominal manual control mode of the seat joint 3.

[0082] Additionally or alternatively, the brake configured to lock the backrest in the position chosen by the occupant in this manual adjustment mode can also be configured to implement the / b2 / locking step of the emergency actuation mode of the control method according to this disclosure.

[0083] Such a brake is preferably electrically controlled.

[0084] According to another example in which the seat adjustment mechanism is configured to implement a nominal motorized control mode, and thus includes a motor configured to tilt the backrest forward in the direction of a restoring force from the spring system and backward against the restoring force from the spring system of the joint, the seat may include a means for decoupling the motor from the joint. In this way, the control method according This disclosure may include, prior to the activation of the emergency actuation mode, a step of decoupling the motorization. In this way, the joint 3 is free from the motorized transmission intended for seat adjustment when the spring system is released for the backrest tilt / b 1 / of the emergency actuation mode.

[0085] According to one example, the decoupling means may be an electrically controlled clutch system configured to move from a coupling position of the motor to said joint to a decoupling position of the motor.

[0086] According to one example, the decoupling means comprises a solenoid mounted around a movable rod, a rocker arm, and an engagement pinion. In this case, the solenoid is capable of creating a magnetic field that allows the movable rod to translate. The rocker arm has a first end connected to the rod and a second end connected to the engagement pinion. The mechanism is configured so that the translation of the rod, by the action of the rocker arm, causes a translation of the engagement pinion, which can then disengage from the transmission between the motor and the backrest joint and release the joint 3.

[0087] In addition, this disclosure also relates to a vehicle seat comprising a computer configured to execute instructions to implement the process as described above.

[0088] In particular, the computer preferably has an input comprising a signal from the pressure sensor and an output comprising a control signal for an electric actuator configured to lock the joint in rotation or release its rotation, and the instructions are configured to cooperate with the computer and a memory to implement, in emergency actuation mode, the sequence comprising: - / A / Detect contact between a seat occupant and a reception surface 11 of file 1, - / B / Trigger an emergency action including: • / B 1 / If the contact detection is negative, electrically release the spring system that tilts the backrest 1 forward, followed by returning to operation / A / of contact detection between the occupant and the reception surface 11 of the backrest 1 to repeat the sequence, • / B2 / If the contact detection is positive, block electrically the joint 3 to prevent the rotation of the backrest 1 relative to the seat forwards and backwards.

[0089] The cycle time between two successive reiterations implemented by the computer can be less than 10ms.

[0090] Typically, the computer is a main seat computer, which may also be responsible for implementing other seat adjustment processes, for example, adjusting the forward or backward movement of the seat on slides, or adjusting the seat height.

[0091] The seat control unit can be in operational communication with a central vehicle safety control unit, which may also be capable of triggering a vehicle safety device such as an airbag, and / or processing data collected by a hazard detection device. In this case, the seat control unit can occupy a slave position of the central vehicle safety control unit, which can then occupy a master position.

Claims

Demands

1. A method for controlling a vehicle seat joint (3), in particular a car seat, the seat comprising a backrest (1) mounted on a seat (2), said joint (3) allowing the backrest (1) to rotate relative to the seat (2) forward and backward relative to a forward direction of the vehicle, said joint (3) comprising a preloaded spring system capable of tilting the backrest (1) forward around the joint (3), the method comprising an emergency actuation mode for the joint configured to lock the joint in a position minimizing any gap between the backrest and a seat occupant prior to an accident, the emergency actuation mode for the joint having a sequence comprising: - / a / Detection of contact between a seat occupant and a seating surface (11) of the backrest (1),- / b / Triggering an emergency action comprising: • / b 1 / If contact detection is negative, a release of the spring system that tilts the backrest (1) forward, followed by a return to operation / a / of contact detection between the occupant and the reception surface (11) of the backrest (1) for repetition of the sequence, • / b2 / If contact detection is positive, a blocking of the joint (3) to prevent rotation of the backrest (1) relative to the seat forwards and backwards.

2. Method according to the preceding claim comprising a step / aO / of detecting a risky situation in which a probability of an accident of the vehicle is greater than a threshold value, and in which the emergency actuation mode of the joint (3) is triggered when the risky situation is detected.

3. Method according to the preceding claim wherein the detection / aO / of the risk situation includes a detection by a data acquisition device of an obstacle on a vehicle trajectory and the detection of the risk situation includes the detection of a vehicle advance speed greater than or equal to a threshold speed.

4. A method according to any one of the preceding claims, wherein the detection / a / of contact is carried out by a pressure sensor.

5. Method according to the preceding claim, wherein the contact detection is carried out in a contact zone (12) located in the vicinity of two-thirds of the height H of the backrest.

6. A method according to any one of the preceding claims, wherein the forward tilting of the backrest and / or the locking of the joint is achieved by a seat tilt adjustment mechanism comprising an electrically controlled brake configured to lock the joint, according to several angular locking positions, and wherein, in the emergency actuation mode of the joint, the release / b 1 / of the spring system is operated by a release of the joint by the electrically controlled brake, and / or the locking in / b2 / is operated by the electrically controlled brake.

7. Method according to claim 6, comprising a nominal manual control mode of the articulation, comprising an adjustment of the backrest tilt by an occupant, comprising: - a release of the pre-stressed spring system by unlocking the brake in response to a command from the user, - an adjustment of the backrest, brought back against the occupant by the spring system, by a movement of the occupant to a backrest adjustment position, - a locking of the backrest, by the electrically controlled brake, in the adjustment position.

8. Control method according to claim 7, the seat comprising a human-machine interface, the method further comprising, after a predetermined time starting from the triggering of the block in / b2 / of the joint (3) has elapsed, a step / d / of unlocking the joint, and a step ld of inviting the occupant by the human-machine interface to adjust a tilt of the backrest (1) according to the nominal control mode of the joint (3).

9. A method according to any one of claims 1 to 6, wherein the joint comprises a motor configured to tilt the backrest forward in the direction of a restoring force from the system.

10. spring and rearward against the restoring force of the spring system of the joint (3), in a nominal motorized control mode, and an electrically controlled clutch system configured to move from a coupling position of the motor to said joint (3) to a decoupling position of the motor, and the method comprising, prior to triggering the emergency actuation mode, moving the clutch system to a decoupling position of the motor.Vehicle seat comprising a backrest (1) mounted on a seat (2), the seat comprising a joint (3) allowing the backrest (1) to rotate relative to the seat (2) forward and backward in the direction of travel of the vehicle, said joint (3) comprising a preloaded spring system capable of tilting the backrest (2) forward around the joint (3), and the seat comprising a computer, a memory and instructions configured to cooperate with the computer and the memory to implement the method according to any one of the preceding claims.