Abstract:
The present invention relates to equipment ( 80, 80 A,  80 B,  80 C,  80 D,  80 E) for an airplane seat ( 36 A) having at least two states comprising a first antenna ( 150 A) able to transmit a state signal ( 158 A) relative to the state of the equipment ( 80, 80 A,  80 B,  80 C,  80 D,  80 E) and a second antenna ( 154 A) able to receive a control signal ( 182 ) to change the state of the equipment ( 80 A).

Description:
CROSS-REFERENCE 
       [0001]    This claims the benefit of the French Patent Application FR 14/58 593, filed Sep. 12, 2014 and hereby incorporated by reference herein. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to equipment for an airplane seat. The present invention also relates to a controller for a set of equipment for one or more airplane seats, a group of at least one airplane seat module, an inner airplane space, and a communication method between the controller and equipment for an airplane seat. 
       BACKGROUND OF THE INVENTION 
       [0003]    Airplane seat equipment is for example an actuator making it possible to modify the configuration of the seat by moving movable parts of the seat, by for example causing the seat to go from a seated configuration to a reclined configuration. 
         [0004]    In general, the airplane seat includes several pieces of equipment, in particular a power source for electrical outlets, entertainment screens, several actuators, a light source and an adjustable tablet. 
         [0005]    The adjustable tablet is provided with a control screen allowing the passenger seated in the seat to choose several seat configurations, such as the seated or reclined configuration, as well as the intensity of the light source or the orientation of the tablet. 
         [0006]    It is known that each seat includes a central control unit that receives signals transmitted by the tablet, and returns control signals to the equipment to provide an appropriate response as chosen by the passenger. Such communications are done using electrical wires. For example, if the passenger chooses to take the seat from a seated configuration to a reclined configuration and to turn off the light source, the tablet sends the central unit of the seat one or more signals. The central unit will analyze the signal(s) in order to return a signal to the various actuators and the light source so as on the one hand to take the seat from the seated configuration to the reclined configuration, and on the other hand take the light source from an on state to an off state. 
         [0007]    It is also known to be able to control the seats remotely, independently from a command coming from the tablet, so as for example the return all of the seats to the seated configuration during landing or takeoff of the airplane. In that case, the central unit of each seat receives a signal in order to command all of the seats and meet the safety conditions set out during the landing and takeoff phases. 
         [0008]    The tablet and the central unit can also send all or part of new software configurations to the equipment of one or more seats. 
         [0009]    Furthermore, the tablet and the central unit can receive information on the state of the equipment of one or more seats via signals sent by the equipment. The state comprises statuses on the operation, internal property measurements or onboard test results. 
         [0010]    Such devices, comprising such seats, such equipment and such control units, are for example described in patent EP 0,973,079 B1. 
         [0011]    In both of the preceding cases, the total onboard mass of the airplane is too large. 
         [0012]    There is therefore a need for an airplane having a decreased onboard mass. 
       SUMMARY OF THE INVENTION 
       [0013]    To that end, the invention relates to equipment including at least two states comprising a first antenna able to send a state signal relative to the state of the equipment and a second antenna able to receive a control signal to modify the state of the equipment. 
         [0014]    According to the embodiments, the equipment according to the invention comprises one or more of the following features, considered alone or according to any possible combinations:
       the equipment is an actuator.   the equipment is an actuator and the states of the equipment are different positions of the actuator.   the first antenna and the second antenna are respectively able to send and receive a signal whose frequency is greater than or equal to 800 MHz and less than or equal to 850 MHz, advantageously equal to 830 MHz.   the equipment comprises a body defining an inner volume, the first antenna and the second antenna being included in the inner volume.   the first antenna and the second antenna are the same.   the first antenna is able to receive a control signal to change the state of the equipment and the second antenna is able to send a state signal relative to the state of the equipment, each of the two antennas being different, the equipment further including a member for detecting the operating state of each antenna and a member for selecting an antenna able to select one of the two antennas based on the operating state of each antenna.       
 
         [0021]    The invention also relates to a controller for a set of equipment for airplane seats, the set including at least one piece of equipment as previously described. The controller includes a third antenna able to receive one or more state signals relative to the state of the equipment and a signal requesting a change of the state of the equipment, a control unit able to generate control signals for changing the state of the equipment based on the state signals received by the third antenna, and a fourth antenna able to send one or more control signals to modify the state of the equipment. 
         [0022]    The invention also relates to a group of seat modules, each seat module comprising at least two seats, the group including a single controller as previously described. 
         [0023]    The invention also relates to an inner airplane area including at least two seat modules, each seat module comprising at least two seats, and one or two controllers as previously described. 
         [0024]    The invention also relates to a communication method between a controller, the controller including a third antenna, a control unit and a fourth antenna, and equipment of a seat having at least two states and comprising a first antenna and a second antenna. The method comprises the following steps:
       transmitting a state signal relative to the state of the equipment via the first antenna of the equipment;   receiving the state signal via the third antenna of the controller and a signal requesting a change of the state of the equipment;   generating a control signal via the control unit, to modify the state of the equipment as a function of the state signal and of the signal requesting to change the state of the equipment received by the third antenna;   transmitting the control signal via the fourth antenna to the equipment, the control signal depending on the state signal received by the third antenna;   receiving the control signal via the second antenna of the equipment, and   changing the state of the equipment based on the control signal received by the second antenna of the equipment.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    The invention will be better understood upon reading the following description, provided solely as an example and done in reference to the appended drawings, in which: 
           [0032]      FIG. 1  shows a top cutaway view of an example airplane according to the invention; 
           [0033]      FIG. 2  is a diagrammatic side view of one example seat according to the invention; 
           [0034]      FIG. 3  is a diagrammatic side view of two seats according to the invention, and 
           [0035]      FIG. 4  is a diagram of a flow chart illustrating an example implementation of the communication method according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0036]      FIG. 1  shows an airplane  10 . Hereinafter, the terms “front” and “rear” have the typical meaning given to them in the case of an airplane. 
         [0037]    The airplane  10  is elongated along a direction parallel to a longitudinal axis A-A′ shown in  FIG. 1 . The airplane  10  comprises a central body  11 , two wings  12  fastened to the central body  11  of the airplane  10 , a control surface  13  and two engines  14 , each engine  14  being carried by a wing  12 . 
         [0038]    The central body  11  is elongated in the longitudinal direction A-A′. The central body  11  comprises a floor  15  delimiting a lower part (not shown in  FIG. 1 ) of the central body  11  and an upper part (not shown in  FIG. 1 ) of the central body  11 . The lower part comprises a baggage compartment  16  (shown in dotted lines in  FIG. 1 ). The upper part comprises a cockpit  18  and an inner area  20 . 
         [0039]    The wings  12  are across from one another in a symmetrical position relative to the central body  11 . 
         [0040]    The control surface  13  is situated at the rear of the airplane. The control surface makes it possible to ensure the stability of the airplane  10  during the flight of the airplane  10 . 
         [0041]    The engines  14  are for example turbojet engines. 
         [0042]    The cockpit  18  is situated at the front of the airplane  10 . The cockpit  18  allows one or several pilots to pilot the airplane  10 . 
         [0043]    The inner space  20  extends between a front end  22  and a rear end  24 . 
         [0044]    The inner space  20  comprises two side parts  26 ,  28 , a central row  30 , at least one side row  32  of seat modules, a first controller  33  and a second controller  33 . 
         [0045]    The central row  30  extends along the longitudinal direction A-A′ between the front end  22  and the rear end  24 . 
         [0046]    The central row  30  includes several central seat modules  34  aligned behind one another along a longitudinal direction A-A′. According to the example embodiment shown in  FIG. 1 , each central seat module  34  includes four motorized seats  35  adjacent in a transverse direction, the transverse direction being perpendicular to the longitudinal direction A-A′ and parallel to the floor  15 . 
         [0047]    The side row  32  extends in the longitudinal direction A-A′ along the side part  26 ,  28 . The side row  32  includes a first side seat module  36  and at least one second side seat module  37 . The first side seat module  36  and the second side seat module  37  are aligned behind one another along the longitudinal direction A-A′. 
         [0048]    According to the embodiment shown in  FIG. 1 , the first side seat module  36  includes a first seat  36 A and a second seat  36 B. The first seat  36 A and the second seat  36 B are motorized and are adjacent in the transverse direction. 
         [0049]    Furthermore, the second side seat module  37  also includes a third seat  37 A and a fourth seat  37 B. The third seat  37 A and the fourth seat  37 B are motorized and are adjacent in the transverse direction. 
         [0050]    The first side seat module  36  and the second side seat module  37  form a group  40  of seat modules. 
         [0051]    In reference to  FIG. 2 , only the first seat  36 A is described, with the understanding that similar remarks apply to the other seats  36 B,  37 A and  37 B. 
         [0052]    The first seat  36 A is able to receive the passenger. 
         [0053]    The first seat  36 A includes a structure  44 , a leg assembly  52 , a seat bottom  54 , a backrest  56 , a leg rest  58 , a foot rest  60 , and an armrest  62 . 
         [0054]    The first seat  36 A further comprises a set of equipment, more simply referred to as equipment  80  hereinafter. The set of equipment  80  comprises a first piece of equipment  80 A, a second piece of equipment  80 B, a third piece of equipment  80 C, a fourth piece of equipment  80 D and a fifth piece of equipment  80 E. The first seat  36 A also includes a control tablet  82  for the equipment  80 , a power source  84  for the equipment  80  and the control tablet  82 , and electrical wires  86  connecting the power source  84  to the equipment  80 . 
         [0055]    The structure  44  is fastened on the floor  15 . The structure  44  includes a base  88  and a side face  89 . The structure  44  serves as a support for the first seat  36 A. 
         [0056]    The base  88  is fastened to the floor  15  along the longitudinal direction A-A′. 
         [0057]    The side face  89  extends in a vertical direction perpendicular to the longitudinal direction A-A′ and the transverse direction. The side face  89  is fastened to the base  88  while forming a right angle with the face  88 . 
         [0058]    The leg assembly  52  is fastened to the base  88  and serves as a support for the seat bottom  54 , the backrest  56 , the leg rest  58  and the foot rest  60 . 
         [0059]    The seat bottom  54  rests on the leg assembly  52  along the longitudinal direction A-A′. 
         [0060]    The backrest  56  is connected with a first end of the seat bottom  54 . The backrest  56  is movable between an upright position along the vertical direction and a folded down position along the vertical direction A-A′. 
         [0061]    The leg rest  58  is connected with a second end of the seat bottom  54 . The leg rest  58  is movable between a position folded down along the vertical direction below the seat bottom  54  and a position extend along a longitudinal direction A-A′ in the extension of the seat bottom  54 . 
         [0062]    The foot rest  60  is mounted to be slidingly movable relative to the leg rest  58 , between a position retracted inside the leg rest  58  and an extended position, in which the foot rest  60  extends the leg rest  58  and is practically completely deployed from the leg rest  58 . 
         [0063]    The armrest  62  rests on the seat bottom  54  in the longitudinal direction A-A′. 
         [0064]    The pieces of equipment  80  each include a body  90  defining an inner volume  92 . 
         [0065]    The first piece of equipment  80 A is mounted between the seat bottom  54  and the backrest and is able to see to the movement of the backrest  56  between the raised position and the folded down position. 
         [0066]    The second piece of equipment  80 B is mounted between the seat bottom  54  and the leg rest  58  and is able to see to a movement of the leg rest  58  between the folded down position and the extended position. 
         [0067]    The third piece of equipment  80 C is mounted between the leg rest  58  and the foot rest  60  and is able to see to the movement of the foot rest  60  between the retracted position and the extended position. 
         [0068]    The first piece of equipment  80 A, the second piece of equipment  80 B and the third piece of equipment  80 C are for example electric actuators. 
         [0069]    The fourth piece of equipment  80 D is integrated into the side face  89 . The fourth piece of equipment  80 D is for example a light source making it possible to light the passenger. 
         [0070]    The fifth piece of equipment  80 E is fastened on the armrest  62 . The fifth piece of equipment  80 E forms a support for the control tablet  82 , movable between several positions, for example an extended position, in which the fifth piece of equipment  80 E extends in the longitudinal direction A-A′, and an inclined position, in which the fifth piece of equipment  80 E forms an angle smaller than 90° with the longitudinal direction A-A′. 
         [0071]    The pieces of equipment  80  have at least two states. For example, the first piece of equipment  80 A, the second piece of equipment  80 B and the third piece of equipment  80 C have at least two states corresponding to at least two different positions, for example a first position and a second position. The fourth piece of equipment  80 D has several states, for example corresponding to several light intensity levels. The fifth piece of equipment  80 E has several states corresponding to several positions, for example the extended position and the inclined position. 
         [0072]    In order to simplify the description, and without changing the general nature of this description, only the first piece of equipment  80 A will now be described, knowing that similar remarks apply to the second piece of equipment  80 B, the third piece of equipment  80 C, the fourth piece of equipment  80 D and the fifth piece of equipment  80 E with adapted references. 
         [0073]    The first piece of equipment  80 A includes, inside the inner volume  92 , a first antenna  150 A and a second antenna  154 A. 
         [0074]    Alternatively, the first antenna  150 A and the second antenna  154 A are comprised outside the inner volume  92  of the first piece of equipment  80 A. 
         [0075]    According to the embodiment shown in  FIG. 2 , the first antenna  150 A and the second antenna  154 A are the same. 
         [0076]    According to another embodiment that is not shown, the first antenna  150 A and the second antenna  154 A are separate. Each antenna  150 A and  154 A is able to emit a state signal  158 A relative to the state of the equipment  80 A and to receive a control signal  182  to modify the state of the equipment  80 A. 
         [0077]    According to one preferred embodiment, the equipment  80 A further includes a member for detecting the operating state of each of the two antennas  150 A and  154 A. Usually, the operating state of antenna is binary, i.e., either the antenna is able to operate or the antenna is not able to operate (failure of the antenna). The detection member is for example a computer monitoring a property of each of the antennas. As an illustration, such a property is the voltage supplying the antenna in question. 
         [0078]    Preferably, the equipment  80 A is also provided with an antenna selection member able to select one of the two antennas  150 A and  154 A based on the operating state of each antenna  150 A and  154 A. The state of each antenna  150 A and  154 A for example comes from the member detecting the operating state. 
         [0079]    According to one particular case, the antenna selection member is a two-position switch making it possible to switch between two positions, a first position in which the first antenna  150 A operates while the second antenna  154 A does not operate, and a second position in which the second antenna  154 A operates while the first antenna  150 A does not operate. 
         [0080]    In such a particular case, the first antenna  150 A is a primary antenna that operates by default. The expression “operates by default” means that the primary antenna  150 A is the antenna that is used during normal operation. The second antenna  154 A is a backup antenna used only if the first antenna  150 A fails. 
         [0081]    The first antenna  150 A is able to emit a state signal  158 A relative to the state of the first piece of equipment  80 A. 
         [0082]    The state signal  158 A can be received and interpreted by one of the controllers  33 . 
         [0083]    The state signal  158 A is an electromagnetic wave that can be transmitted aerially. Aerially means that the signal propagates in the air without a wired connection. 
         [0084]    The frequency of the state signal  158 A is comprised in the radio range, i.e., the frequency of the state signal  158 A is greater than or equal to 3 Hz, and less than or equal to 300 GHz. 
         [0085]    The frequency of the state signal  158 A is greater than or equal to 800 MHz, and less than or equal to 850 MHz. 
         [0086]    Advantageously, the frequency of the state signal  158 A is chosen to be as non-harmful as possible, for example comprised between 820 MHz and 840 MHz. A frequency is considered to be less harmful compared to another frequency if the considered frequency causes less damage to humans than the other frequency. Preferably, such a harmfulness comparison is done for a same amplitude of the two signals. Furthermore, the damage, according to one particular case, is potential damage. In such a case, the damage is comparable to the risk incurred by the human being. Typically, over the long term, a frequency may risk causing deafness. This is considered to be damage in the aforementioned context. 
         [0087]    The second antenna  154 A is able to receive and interpret a signal coming from the controller  33 . 
         [0088]    The control tablet  82  comprises an antenna  162  able to emit a change request signal  166 . 
         [0089]    The control tablet  82  makes it possible to control each piece of equipment  80 . Only its interaction with the first piece of equipment  80 A is outlined below. The control tablet  82  for example makes it possible to change the configuration of the first seat  36 A. The configuration of the first seat  36 A is for example a seated configuration or a reclined configuration. In the seated configuration, the leg rest  58  is in the folded down position, the backrest  56  is in the raised position, and the foot rest  60  is in the position retracted inside the leg rest  58 . In the extended configuration, the leg rest  58  is in the extended position, the seat bottom  56  is in the folded down position, and the foot rest  60  is in the extended position. 
         [0090]    The change request signal  166  can be received and interpreted by the controller  33 . 
         [0091]    The change request signal  166  is an electromagnetic wave that can be transmitted aerially. 
         [0092]    The frequency of the change request signal  166  is comprised in the radio range. 
         [0093]    The frequency of the change request signal  166  is greater than or equal to 800 MHz, and less than or equal to 850 MHz. 
         [0094]    Advantageously, the frequency of the change request signal  166  is chosen to be as non-harmful as possible, for example comprised between 820 MHz and 840 MHz. 
         [0095]    In reference to  FIG. 3 , the power source  84  is separately connected to the first piece of equipment  80 A, the second piece of equipment  80 B, the third piece of equipment  80 C and the fifth piece of equipment  80 E by means of electrical wires  86 . 
         [0096]    The power supply  84  of the third seat  37 A is suitable for supplying electricity to at least one of the pieces of equipment  80  of the first seat  36 A. 
         [0097]    Advantageously, and as shown in  FIG. 3 , the power supply  84  of the third seat  37 A of the second side seat module  37  is suitable for supplying electricity to the fourth piece of equipment  80 D of the first seat  36 A of the first side seat module  36 . Indeed, the distance separating the power source  84  of the third seat  37 A from the fourth piece of equipment  80 D of the first seat  36 A is shorter than the distance separating the power supply  84  of the first seat  36 A from the fourth piece of equipment  80 D of the first seat  36 A. 
         [0098]    The first controller  33  and the second controller  33  are able to control the equipment  80  of the first seat  36 A. The second controller  33  is a backup controller that is used only if the first controller  33  fails. 
         [0099]    According to one preferred embodiment, each controller  33  is a computer. 
         [0100]    In the example embodiment shown in  FIG. 1 , the first controller  33  is installed at the front end  22 , and the second controller  33  is installed at the rear end  24 . 
         [0101]    Alternatively, the inner space  20  only includes one controller  33 . 
         [0102]    Only the first controller  33  is described, the second controller  33  being similar. 
         [0103]    The controller  33  includes a third antenna  170 , a control unit  174  and a fourth antenna  178 . 
         [0104]    The third antenna  170  is able to receive the state signal  158  emitted by the second antenna  154 A of the first piece of equipment  80 A and the change request signal  166  emitted by the antenna  162  of the control tablet  82 . 
         [0105]    The control unit  174  makes it possible to analyze the state signal  158  and the change request signal  166  received by the third antenna  170 . 
         [0106]    The fourth antenna  178  is able to emit a control signal  182 . 
         [0107]    The control signal  182  can be received and interpreted by the second antenna  154 A. 
         [0108]    The control signal  182  contains instructions relative to the state of the equipment  80 . Depending on the case, the instructions seek to keep or modify the state of the equipment  80  in question. 
         [0109]    The control signal  182  is an electromagnetic wave able to be transmitted aerially. 
         [0110]    The frequency of the control signal  182  is comprised in the radio range. 
         [0111]    The frequency of the control signal  182  is greater than or equal to 800 MHz, and less than or equal to 850 MHz. 
         [0112]    Advantageously, the frequency of the control signal  182  is substantially equal to 830 MHz. 
         [0113]    Alternatively, the controller  33  is suitable for communicating with the equipment  80  of the first seat  36 A, the second seat  36 B, the third seat  37 A and the fourth seat  37 B. 
         [0114]    In one preferred embodiment, the controller  33  is suitable for communicating with the equipment  80  of all of the seat modules  34 ,  36 ,  37  of the inner space  20 . 
         [0115]    One operating example of the different elements of the inner space  20  interacting with one another will now be described. To that end, reference is in particular made to a communication method between the controller  33  and the first piece of equipment  80 A of the first seat  36 A as illustrated by the flowchart of  FIG. 4 . 
         [0116]    The communication method includes a step  200  for transmitting a state signal  158 A. 
         [0117]    The transmission step  200  is carried out by the first antenna  150 A of the first piece of equipment  80 A. 
         [0118]    The state signal  158 A contains information relative to the state of the first piece of equipment  80 A. According to the considered example, the information relative to the state of the first piece of equipment  80 A makes it possible to know that the first piece of equipment  80 A is in the first position (seatback  56  in the upright position). 
         [0119]    The state signal  158 A is transmitted aerially at a frequency advantageously equal to 830 MHz. 
         [0120]    The communication method includes a step  202  for receiving the state signal  158 A. 
         [0121]    The third antenna  170  of the first controller  33  receives the state signal  158 A. 
         [0122]    Furthermore, the first controller  33  is capable of determining the origin of the state signal  158 A. 
         [0123]    Preferably, such a determination is implemented by a spatial recognition system. 
         [0124]    The passenger installed in the first seat  36 A then decides to change the position of the backrest  56  of the first seat  36 A. To that end, the passenger interacts with the control tablet  82 , requesting that the seatback  56  of the first seat  36 A enter the reclined position. 
         [0125]    The control tablet  82  then interprets the request from the passenger by transmitting a change request signal  166 . 
         [0126]    As before, the change request signal  166  is transmitted aerially. 
         [0127]    The communication method also includes a step for receiving the change request signal  166 . 
         [0128]    The communication method then includes a step  204  for generating a control signal  182 . 
         [0129]    The control signal  182  depends on the state signal  158 A received by the third antenna  170  and the change request signal  166 . 
         [0130]    In the case at hand, since the state (first position) of the first piece of equipment  80 A is different from the state desired for the first piece of equipment  84 A, i.e., the second position, the control signal  182  makes it possible to modify the state of the first piece of equipment  80 A. 
         [0131]    The generation of such a control signal  182  by the control unit  174 . 
         [0132]    The communication method then includes a step  206  for transmitting the control signal  182  via the fourth antenna  104  to the first piece of equipment  80 A. 
         [0133]    The control signal  182  is transmitted aerially. 
         [0134]    The communication method includes a step  208  for receiving the control signal  182  by the first antenna  154 A of the first piece of equipment  80 A. 
         [0135]    Lastly, the communication method includes a step  210  for modifying the state of the first piece of equipment  80 A as a function of the control signal  182  received by the second antenna  154 A of the first piece of equipment  80 A. 
         [0136]    In the case at hand, the first piece of equipment  80 A goes from the first position to the second position. As a result, the seatback  56  of the first seat  36 A enters the reclined position. 
         [0137]    Preferably, steps  200 ,  202 ,  204 ,  206 ,  208  and  210  of the communication method are reiterated from step  200  at regular time intervals. This time interval is long enough to perform all of the computations involved in the movements of the moving parts of one or more seats  36 A,  36 B,  37 A,  37 B. Preferably, the time interval is greater than or equal to 25 milliseconds (ms) per seat  36 A,  36 B,  37 A,  37 B. Preferably, the time interval is less than or equal to 100 ms per seat  36 A,  36 B,  37 A,  37 B. For example, the time interval is equal to 50 ms per seat  36 A,  36 B,  37 A,  37 B. 
         [0138]    The communication method has the advantage of involving only signals transmitted aerially. 
         [0139]    Furthermore, the communication method previously described is simultaneously applicable to several pieces of equipment  80  of the first seat  36 A. 
         [0140]    The communication method previously described is also simultaneously applicable to the pieces of equipment  80  of at least one seat  36 A,  36 B of the first side seat module  36 , and at least one seat  37 A,  37 B of the second side seat module  37 . 
         [0141]    Advantageously, the communication method previously described makes it possible to control all of the equipment  80  of all of the seat modules of the airplane  10 . 
         [0142]    The airplane  10  has the advantage of having a decreased mass relative to the airplanes described in the state of the art. Indeed, the transmission of signals between the equipment and the control tablets of the seats of the seat modules of the airplane on the one hand, and the controller(s) on the other hand, is done wirelessly. 
         [0143]    Furthermore, only one or two controllers  33  are involved in the centralized control of the equipment  80  of all of the seats  36 A,  36 B,  37 A and  37 B of the airplane  10 . Mass savings are thus achieved on all of the wires that are no longer used in the case of wireless transmission, and on the number of controllers  33 . 
         [0144]    Furthermore, the absence of communication wires makes it possible to simplify the installation of the seat modules and maintenance of the inside space  20 . 
         [0145]    Furthermore, the possibility of supplying electricity to equipment  80  of a first seat  36 A from the power supply of a second seat  36 B when the distance between the equipment and the power source of the second seat is smaller than the distance between the equipment and the first seat, makes it possible to save a certain distance of electrical wires, and therefore mass. 
         [0146]    Each described embodiment can be combined with another described embodiment to provide another embodiment when it is technically possible.