EP1191862B1 - Method for managing the control system of a seat with pre-programmed positions and seat therefor - Google Patents

Description

The present invention relates to a method for managing the kinematics of a seat comprising at least three movable seat elements relative to each other and at least two actuators for moving the three elements relative to each other, the method comprising a step of joint control of the two actuators to change the configuration of the seat.

Such a seat is used in particular in passenger aircraft.

In order to improve the comfort of passengers, many seats are provided with electrical actuation devices to change the configuration of the seat by moving movable elements thereof.

It is common for each seat to have a reclining backrest articulated at one end of a seat, and an articulated legrest at the other end of the seat. The backrest and the legrest are both movable, under the control of a clean electric actuator, between a substantially vertical position and substantially horizontal position thus allowing the seat to take several configurations.

In addition, in order to increase the length of the legrest, it is known to associate with it a footrest movable to slide relative to the legrest, the footrest being also controlled by an electric actuator for its movement relative to the legrest between a retracted position and an extended position.

The seat advantageously comprises devices allowing, by a single command, to cause the displacement of the leg rest, the footrest and possibly the backrest and this, to bring the seat, by this single command, in a predetermined configuration in which each seat element has a predetermined position specific to the configuration considered.

For example, among these configurations are provided a sleeping configuration in which the backrest and the legrest are both horizontal, the footrest being extended and a seat configuration in which the backrest and the legrest are both substantially vertical, the footrest then being in its retracted position.

In addition, each of the actuators associated with the different moving parts of the seat can be controlled independently of the others, so that the seat can be brought by the passenger in multiple configurations different from the predetermined configurations.

When the passenger presses on a command allowing the seat to return to a predetermined configuration such as the sleeping position or the sitting position, the actuators are started successively in order to move one after another the elements of the seat to their position. target position. The starting of one of the actuators is determined by the end of the operating phase of another actuator. Thus, at every moment, only one actuator is in motion.

It is conceivable that the successive operation of the different action-neurs, makes relatively long passage of the seat to the predetermined configuration chosen.

It has been envisaged to operate all the actuators simultaneously. However, in this case, it is found that, depending on the speeds specific to each actuator, certain parts of the seat may strike elements present in the immediate environment of the seat, such as a neighboring seat, or the floor of the seat. plane. In addition, some intermediate configurations of the seat during its passage to the target configuration can be extremely uncomfortable for the passenger.

US 5,755,493 discloses a method according to the preamble of claim 1.

The object of the invention is to propose a vehicle seat, and a method of managing its kinematics allowing the seat to be brought into predetermined configurations as quickly as possible, without, however, unwanted intermediate configurations being taken by the seat when from its passage to the predetermined configuration.

For this purpose, the subject of the invention is a method according to claim 1.

Particular modes of implementation are specified in the dependent claims.

The invention also relates to a vehicle seat according to claims 8 or 9.

• la figure 1 est une vue schématique d'un siège de véhicule selon l'invention ;
• la figure 2 est un organigramme explicitant le fonctionnement du siège par mise en oeuvre d'un procédé de gestion de sa cinématique selon l'invention ; et
• les figures 3 et 4 sont des courbes illustrant le mouvement de deux actionneurs du siège en fonction du temps lors de la mise en oeuvre du procédé de gestion de la cinématique du siège selon l'invention.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which:

• the figure 1 is a schematic view of a vehicle seat according to the invention;
• the figure 2 is a flowchart explaining the operation of the seat by implementing a method of managing its kinematics according to the invention; and
• the Figures 3 and 4 are curves illustrating the movement of two seat actuators as a function of time during the implementation of the method of managing the kinematics of the seat according to the invention.

The seat 10 shown on the figure 1 is a passenger seat of an airplane. This seat is fixed on the ground 12 of the aircraft.

The seat 10 has a base 14 secured to the ground. 12 on which rests a substantially horizontal seat 16. At one end of the seat is articulated a backrest 18 movable between a raised position substantially vertical and a folded position substantially horizontal.

At the other end of the seat 16, is articulated a leg rest 20 movable between a substantially vertical folded position below the seat 16 and a substantially horizontal extended position in the extension of the seat 16.

The seat 10 further comprises a footrest 22 mounted slidably movable relative to the legrest 20 in the extension thereof.

The footrest 22 is movable between a retracted position within the legrest 20 and an extended position in which it extends the legrest and is substantially fully extended.

A first electric actuator 24 is mounted between the seat 16 and the legrest 20 to ensure a movement of the latter between its folded position and its extended position.

Similarly, a second actuator 26 is provided between the legrest 20 and the footrest 22 to ensure the displacement of the footrest between its retracted position and its extended position.

A third actuator 27 is mounted between the seat 16 and the back 18 to ensure the movement of the backrest between its raised position and its folded position.

The three actuators operate at constant speeds that can be different from one actuator to another.

Each of the three actuators 24, 26 and 27 is supplied with electric current from a central control unit 28. This control unit is connected separately to each of the actuators 24, 26 and 27 to ensure their independent control.

In addition, the seat comprises an armrest 30, on which is fixed a control keyboard 32 for independent control of the actuators 24, 26 and 27 to cause their movement.

The keyboard 32 also includes keys allowing the passenger to reach, by a single command acting on several actuators, one of two predetermined configurations. The number of predetermined seat configurations may be reduced to one or greater than two.

In the embodiment considered, the keyboard 32 has two buttons each associated with a predetermined configuration. These configurations are a seating configuration and a sleeping configuration.

In the seat configuration, the legrest 20 and the backrest 18 are both in predetermined positions in which they are substantially vertical and define an angle of 90 ° with the plane of the seat. In this seat configuration, the footrest 22 is retracted inside the legrest 20.

In the sleeping configuration, the legrest 20 and the backrest 18 are in predetermined positions in which they extend the seat 16 and thus extend substantially in the plane thereof. In this sleeping configuration, the footrest 22 is in its extended position.

The unit 28 comprises a source 34 for supplying the actuators. The latter is formed for example of a transformer connected to the general power supply network of the aircraft by suitable connection means.

For each actuator is provided a power supply interface 36, 38 and 39 supplying the actuators, 24, 26 and 27, respectively, from the power source 34. These interfaces ensure the shaping of the power supply. supply of the actuators according to the desired direction of actuation.

The supply interfaces 36, 38 and 39 are driven by an information processing unit 40. This unit 40 is connected to the control keyboard 32, in order to collect the passenger control commands.

The information processing unit 40 comprises for example a microprocessor for implementing a suitable program described in the following description.

The unit 40 further comprises a clock allowing the microprocessor to manage one or more delays allowing a time shift in the triggering of the movement of the various actuators.

Finally, each actuator 24, 26 and 27 is equipped with one or more position sensors for detecting that the actuator is in a position such that the seat element that it controls reaches a position proper to a predetermined configuration of the actuator. seat.

These sensors, designated by the reference 44, 46 and 47 respectively for the actuators 24, 26 and 27, are connected to the information processing unit 40. Thus, the unit 40 is informed when one of the actuators is in a position such that the element which it controls is in the position which it must occupy in the desired predetermined configuration.

These sensors are formed for example by potentiometers or microswitches implanted between the fixed and movable parts of the actuators.

For the operation of the seat, the information processing unit 40 implements a program known per se adapted to control the supply interfaces 36, 38 and 39 so that they supply power to the actuators 24, 26. and 27 in one direction or the other by reversing the current direction, depending on the information received from the unit 40.

On the figure 2 is represented the algorithm of the routine implemented by the information processing unit 40 to bring the seat into its sleeping configuration.

During this modification of the configuration of the seat, the backrest is brought into its folded position upon the depression by the passenger of the keyboard key 32 dedicated to this particular configuration of the seat. Simultaneously, when pressing this key, the routine whose algorithm is given on the figure 2 is implemented.

Thus, when detecting the depression of this key in step 100, a first test step is implemented in step 101 to determine if a problem is detected on the legrest or more exactly on the actuator 24 controlling the legrest. This problem can be for example a malfunction of the actuator potentiometer providing an outlier or any other type of problem that can be detected by the information processing unit 40. If no problem is detected, the actuator 24 controlling the legrest is immediately started at step 102. If a problem is detected, step 102 is omitted.

As illustrated in the left branch of the flowchart, a test is then performed at step 104 to verify that the button controlling the sleeping position is still depressed by the passenger. It is also verified in step 105 that no problem on the legrest is detected. If either of these conditions is not satisfied, the leg rest actuator 24 is stopped in step 106. As long as the seat supply control in its sleeping configuration is maintained by the passenger, the information processing unit 40 scans the sensor installed on the leg rest actuator 24 in step 108 to determine whether or not the legrest is in the target position it occupies relative to to the seat when the seat is in its sleeping configuration. As long as this position is not reached, the tests of steps 104, 105 and 108 are implemented. When the legrest is brought to its target position, the stop of the legrest is controlled in step 106.

In addition, and as illustrated on the right branch of the organization chart of the figure 2 immediately after starting the actuator moving the leg rest in step 102, or after step 101, if a problem has been detected, a timer is started in step 110. This delay has a predetermined duration denoted T1. This duration is determined experimentally according to the nature and structure of the seat. It is for example equal to one second.

It is then verified in step 112 that the control of the sleeping position is still maintained at the keyboard 32. If this is not the case, the actuator 24 controlling the legrest is stopped in step 114 if this one was already moving.

On the contrary, if the control of the sleeping configuration is still maintained by the passenger, it is verified in step 116 that the time delay initiated in step 110 has not expired. If it has not expired, the information processing unit 40 determines in step 118 whether the actuator 24 is stopped, or that the leg rest 24 has reached its target sleeping position, that a problem has been detected at either of the steps 101 and 105. If not, the tests of steps 112 and 116 are again implemented.

If at step 116, the unit 40 finds that the timer has expired or if in step 118, it is found that the actuator 24 is stopped, the start of the actuator 26 controlling the footrest is triggered in step 120. In this second case, the actuator 26 is started before the expiry of the timer T1.

It is understood that unless the legrest is in its target position and therefore the actuator commander is stopped before the expiry of the timer T1, the start of the actuator 26 controlling the footrest is triggered qu with a delay of a duration T1 relative to the start of the actuator 24 controlling the legrest.

After step 120 of setting footrest 22 in motion, it is verified in step 122 that the control of the coating configuration is still valid. If this is not the case, the actuator 26 controlling the footrest is stopped in step 114. If this is the case, the information processing unit 40 checks in step 124 the state the position sensor of the actuator 26 controlling the footrest to verify whether the footrest 22 occupies or not its target position specific to the seat configuration of the seat. If this is the case, the stop of the actuator 26 controlling the footrest is controlled at step 114. As long as the sleeping configuration control is still validated, and the footrest is not in its target position, steps 122 and 124 are implemented.

On the figure 3 is schematically represented the combined movement of the leg rest 20 and the footrest 22 during the implementation of the algorithm of the figure 2 .

In this figure, the time t is given in abscissa while the amplitude A of displacement of the actuators is given in ordinate. The displacement curve of the legrest is designated C ₂₀ and the displacement curve of the footrest is designated C ₂₂ .

It is found that the implementation of the algorithm causes an immediate start of the leg rest at the instant O. If the leg rest is initially far from its target position defined for the predetermined configuration chosen, the displacement of the rest -jambs is performed for a period longer than the time period T1 defined by the timer. Thus, the leg rest 20 reaches its target position only at a time T2 subsequent to T1, so that the condition of the step 108 allowing the stop of the actuator 24 of the leg rest in step 106 is checked only after expiry of the timing initiated in step 110. Thus, the test performed in step 116 is checked at time T1, so that the actuator 26 for moving the rest -foot is triggered only at time T1, the latter being kept at a standstill during the initial phase of operation of the legrest.

Under these conditions, it is found that the initiation of movement of the footrest relative to the legrest is initiated with a delay T1 relative to the initiation of movement of the leg rest relative to the seat. By imposing such a delay, it is ensured that the legrest is already sufficiently raised to allow an exit of the footrest, without risk that the free end of the latter does hit the ground when leaving.

The duration T1 of the delay is determined, so that when the legrest is initially in its extreme position, that is to say, its folded position, and the displacement of the seat to its sleeping configuration is controlled, then the delay T1 is sufficient to ensure that the footrest does not touch the ground during the simultaneous movement of the legrest and the footrest, even if the movement speed of the footrest is much greater than the movement speed of the legrest.

On the figure 4 is illustrated, on a graph identical to that of the figure 3 , moving the footrest and legrest when the seat is brought into its sleeping configuration while the legrest is initially in a position very close to its extended position. In this case, the implementation of the algorithm of the figure 2 first causes the legrest to start moving towards its extended position which it reaches at a time T3 prior to the time of expiration T1 triggered in step 110. Thus, the condition of the step 118 is satisfied before the expiry of the timer verified in step 116. Upon stopping of the actuator 24 controlling the legrest, the actuator 26 controlling the footrest is triggered to bring the rest feet to his extended position.

Similarly, when the seat is brought into its seating configuration, the movements of the actuators 24 and 26 are also synchronized by implementing a predetermined delay between their start times to prevent the footrest from colliding. floor. In this case, the actuator 26 controlling the footrest is first triggered to retract the footrest, then only after the expiry of a delay, the actuator 24 controlling the legrest is triggered to fold the legrests. If the footrest reaches its retracted position and therefore the commander actuator stops working before the expiration of the timer, then the actuator 24 is triggered immediately before the expiration of the timer.

The kinematic management method described herein can also be implemented for the joint control of two seat elements only, without this control being intended to bring the seat elements to a predetermined configuration.

Thus, for example, one of the buttons of the keyboard can be intended for the movement of the legrest and the footrest, at least partially simultaneously, this button, when it is depressed, causing the displacement of both the legrest and the footrest to their extreme position with, according to the invention, an offset in the starting times of the actuators. In this case, the movement of the actuators stops only when they reach their extreme position, or when the control button is released by the user.

Claims (9)

1. A method for controlling the dynamics of a seat (10) comprising at least three seats parts (16, 20, 22) which can move with respect to one another, and at least two actuators (24, 26) for moving the three parts (16, 20, 22) with respect to one another, the method comprising a step of operating the two actuators (24, 26) jointly to modify the configuration of the seat, the said step of joint operation comprising the following successive steps:

   - activating a first actuator (24) at a first instant; and

   - activating a second actuator (26) at a second instant subsequent to the said first instant and separated from the first instant by a predetermined length of time,

   characterized in that said length of time separating the first instant and the second instant is set to ensure that the seat does not take undesirable intermediate configurations.
2. The method as claimed in claim 1, characterized in that it comprises a step of detecting that the first actuator (24) has stopped during the said predetermined length of time and a step of activating the second actuator (26) as soon as it is detected that the first actuator (24) has stopped.
3. The method as claimed in claim 1 or 2, characterized in that the said step of joint operation of the two actuators is a step of bringing the seat into a predetermined configuration in which two of the moving parts (20, 22) are in predetermined positions specific to the said predetermined configuration.
4. The method as claimed in claims 2 and 3 taken together, characterized in that the step of detecting that the first actuator (24) has stopped comprises a step of detecting that the seat part (20) operated by the first actuator (24) has reached its predetermined position.
5. The method as claimed in claim 3 or 4, in which the seat (10) comprises a seat cushion (16), a leg rest (20) articulated to the seat cushion (16) between a folded-back position and a deployed position, a foot rest (22) that can move with respect to the leg rest (20) between a retracted position and a deployed position, and two actuators (24, 26) arranged, one of them between the seat cushion (16) and the leg rest (20), and the other one, between the leg rest (20) and the foot rest (22), in which method the phase of joint operation of the two actuators (24, 26) is designed to move the leg rest (20) into its deployed position, and the foot rest (22) into its deployed position, characterized in that the first actuator triggered at the said first instant is the actuator (24) arranged between the seat cushion (16) and the leg rest (20), and the second actuator triggered at the said second instant subsequent to the first instant is the actuator (26) arranged between the leg rest (20) and the foot rest (22).
6. The method as claimed in claim 3 or 4, in which the seat (10) comprises a seat cushion (16), a leg rest (20) articulated to the seat cushion (16) between a folded-back position and a deployed position, a foot rest (22) that can move with respect to the leg rest (20) between a retracted position and a deployed position, and two actuators (24, 26) arranged, one of them between the seat cushion (16) and the leg rest (20), and the other one, between the leg rest (20) and the foot rest (22), in which method the phase of joint operation of the two actuators (24, 26) is designed to move the leg rest (20) into its folded-back position and the foot rest (22) into its retracted position, characterized in that the first actuator triggered at the said first instant is the actuator (26) arranged between the leg rest (20) and the foot rest (22), and the second actuator triggered at the said second instant subsequent to the first instant is the actuator (24) arranged between the seat cushion (16) and the leg rest (20).
7. The method as claimed in claim 5 or 6, characterized in that the said predetermined length of time separating the first and second instants is set to make sure that the foot rest (22) does not strike the floor over which the seat is installed when the seat configuration is being modified.
8. A seat (10) comprising at least three seat parts (16, 20, 22) which can move with respect to one another, and at least two actuators (24, 26) for moving the three parts (16, 20, 22) with respect to one another, and means (28, 32) for operating the two actuators (24, 26) jointly to modify the configuration of the seat, the said joint operating means (28, 32) comprising:

   - means for actuating a first actuator (24) at a first instant; and

   - means of actuating a second actuator (26) at a second instant subsequent to the said first instant and separated form the first instant by a predetermined length of time,

   characterized in that said length of time separating the first instant and the second instant is set to ensure that the seat does not take undesirable intermediate configurations.
9. The seat as claimed in claim 8, characterized in that the said joint operating means comprise means (44, 46) of detecting that the first actuator (24) has stopped during the said predetermined length of time and means (28) of actuating the second actuator (26) as soon as it is detected that the first actuator (24) has stopped.

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