Abstract:
The invention essentially concerns an aircraft seat ( 1 ), comprising control units ( 17.2, 22.2, 27 ), at least one node ( 11 - 15 ) to execute a particular action or function, and a display ( 22.1 ) for viewing video data. Said node ( 11 - 15 ) and said display ( 22.1 ) are capable of being actuated by the control units ( 17.2, 22.2, 27 ). A keyboard ( 17.1 ) for transmitting a command signal addressed to the control units ( 17.2, 22.2, 27 ) is connected to said control units ( 17.2, 22.2, 27 ). The control units are shared between the display ( 22.1 ), the key board ( 17.1 ) and the node ( 11 - 15 ).

Description:
RELATED APPLICATIONS 
     This application claims priority from PCT/FR2006/051032 filed Oct. 13, 2006 and French application No. FR 05 53118 filed Oct. 13, 2005, both incorporated by reference in their entireties. 
     TECHNICAL FIELD 
     The present invention concerns an aircraft seat with shared control architecture. The invention is aimed especially at limiting the number of electrical connections between the pieces of equipment of this seat. The invention finds particularly advantageous application in the field of airline seats but can also be applied in the field of automobile seats. 
     BACKGROUND OF THE INVENTION 
     The fact that non-stop flight times are getting longer requires that passengers be provided with the maximum comfort by being offered the possibility of working, relaxing or even resting. This is the main reason why first-class seats or business-class seats are equipped with electromechanical actuators, such as motors, making it possible to obtain every position from that of an armchair to that of a bed. This is also why the passenger today has at his disposal a video screen, a telephone, a reading light and increasing numbers of information technology tools. 
     A control unit is used to control the screen and the other elements of the seat, such as the actuators or the reading light, which are capable of fulfilling a defined function. These seat elements, other than the screen, controlled by the control unit, are called nodes and generally form a network. The passenger can activate a node or the screen by means of a keyboard linked to the control unit. 
     In a traditional configuration, each position of a seat comprises a control unit in the form of a box. From this box emerge, in a star pattern, as many cables as there are nodes that have to be made to work and that have to be controlled. The fact that this control unit is situated beneath the seat gives rise to many cables which, with the box, take all the space available under this seat. These cables burden the structure of the seat and give rise to malfunctions. 
     In another configuration, a control unit common to several seats, and electronic modules offset in each node are connected to one another by means of a CAN type multiplexed node. The wiring of the seat is thereby considerably lightened. However, a group of several seats can happen to be deprived of node functions in the event of a malfunctioning in a central processing unit. 
     In another configuration, such as the one described in the patent application FR-2817810, each seat has a central processing unit connected to the nodes of the seat by means of a CAN type multiplexed electrical network. A system of this kind limits the risks of malfunctioning of a seat unit when a central processing unit is defective. However, the number of cables under the seat remains great. 
     SUMMARY AND OBJECTION OF THE INVENTION 
     The invention proposes specially to limit the number of electrical links of the seat while at the same time making this seat autonomous. 
     To this end, in the invention, a control unit of the nodes is shifted to the keyboard, this control unit being connected to the nodes by means of a CAN type multiplexed network. Each of the nodes has control circuits to communicate with the control unit. Furthermore, a control unit of the screen is shifted in this screen, this control unit being connected to the other control units of the screen via a high-bit-rate network, of the Ethernet type for example. 
     Thus, in one embodiment, the control unit of the nodes and the keyboard are placed within one and the same pack, this pack being placed example in an armrest of the seat. And the control unit of the screen and the screen are placed inside one and the same pack, this control unit being situated behind the screen. Thus, the number of electrical links is limited by eliminating a first link between the control unit for the nodes and the keyboard and a second link 
     Furthermore, there is redundancy between certain programs and certain pieces of data of the different control units in order to ensure minimum comfort for the passenger in the event of malfunctioning of one of the units. Indeed, the control unit for the nodes is capable of controlling the screen in the event of dysfunction of the screen control unit. And the screen control unit is capable of controlling certain nodes in the event of dysfunction of the node controlling unit. 
     Furthermore, the control unit of the screen comprises a memory for the storage therein of films and pieces of music offered to the passenger. In a particular embodiment, this control unit is connected to the high-bit-rate network through a radio link device in order to receive video data sent out by a single portable radio player/recorder device itself also connected to the high-bit-rate network. 
     In a particular embodiment, the power source that feeds the nodes and a switch that connects the control unit to the other control unit of the aircraft are placed inside a same pack, this pack being placed in a frame of the seat. 
     In another embodiment, the seat has a camera to detect the presence of a passenger in its seat. 
     The invention also relates to an aircraft seat comprising:
         at least one node to perform a particular action or fulfill a particular function,   a first control unit comprising means to actuate the node, and   a keyboard to send out an instruction signal to the first control unit,       

     characterized in that:
         this first control unit, the node and the keyboard are connected to one another by means of a multiplexed communications bus;   this first control unit being borne by the keyboard and being positioned behind this keyboard, this first control unit and this keyboard being situated inside one and the same first pack,       

     The invention also relates to an aircraft seat comprising:
         a screen to display video information, and   a control unit comprising means to control the screen,       

     characterized in that:
         this control unit is borne by the screen and positioned behind the screen, this second control unit and this screen being situated within one and the same pack,   this control unit comprises video and/or audio data in its memory.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be understood more clearly from the following description and from the accompanying figures. These figures are given purely by way of an illustration and in no way restrict the scope of the invention. 
         FIG. 1  is a schematic view of the seat according to the invention comprising nodes, a screen and a keyboard within which control units are situated; 
         FIG. 2  is a more detailed schematic view of the links between the control units, the nodes and the screen of a seat according to the invention; 
         FIG. 3  is a schematic view of a pack according to the invention comprising a power source and a repeater for the high-bit-rate network. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The elements common to several figures keep the same reference from one reference to another. 
       FIG. 1  shows a seat attached to a floor  2  of an aircraft by means of a base  3  comprising two fastening legs. This base  3  is generally hooked to rails (not shown) which extend parallel to each other on the floor  2 . 
     This seat  1  has a seating  4  which is on the whole parallel to the plane of the floor  2 . The seating  4  is mobile in translation relative to the floor  2  in a vertical direction, along the arrow  9 . The movement in translation of the seating  4  enables the passenger to adjust it to his height. 
     A seat back  5  is hooked to one end  4 . 1  of the seating  4 . This seat back  5  is mobile in rotation along the arrow  6 , about an axis perpendicular to the sheet which passes through the end  4 . 1 . The seat back  5  is capable of passing from a horizontal position to a vertical position, and vice versa. 
     Furthermore, an arm-rest  8  is fastened to one side of the seating  4  so as to be situated above the seating  4 . As a variant, this arm-rest  8  is hooked to one side of the seat back  5 . 
     A foot-rest  7  is fastened to one end  4 . 2  of the seating  4  opposite the end  4 . 1 . This foot-rest  7  is mobile in rotation, along the arrow  10 , about an axis perpendicular to the sheet which passes through the end  4 . 2 . This foot-rest  7  is capable of passing from a vertical position to a horizontal position and vice versa. 
     To enable the different parts of the seat to move relative to one another, the seat  1  has electromechanical actuators  11 - 14 , such as dc motors. These actuators  11 - 14  provide respectively for the rotational shifting of the foot-rest  7 , the shifting in translation of the seating  4 , the rotational shifting of the seat back  5 . Furthermore, the seat  1  has an actuator  14  that provides for massaging the passenger&#39;s back. The seat also has a reading light  15  fastened for example to the top of the seat back  5 . 
     The actuators  11 - 14  and the seat back  15  form the nodes of a CAN type network. Indeed, these nodes are connected to one another by means of an CAN type bus  16 . As a variant, other nodes, such as other actuators or sensors, can be connected to this network. This number of nodes is limited by a bit rate of the CAN network which is typically 125 kbits/s. 
     Furthermore, a pack  17  is connected to the bus  16 . This pack  17  comprises a first control unit and a keyboard, the first control unit being integrated into the keyboard. This first control unit  17  may be situated for example behind the keyboard and may be placed directly against it so that a plane of the keyboard and this control unit are parallel to each other. As a variant, when the control unit  17  is placed in the arm-rest  8  of the seat, it is situated perpendicularly to a plane of the keyboard. 
     This pack  17  controls an actuation of the different nodes  11 - 15  of the network. The control unit of the pack  17  is active, sending instructions to be executed or information requests to the different nodes  11 - 15 , while the nodes  11 - 15  are passive, sending out information signals or performing actions at the request of the control unit. To this end, the nodes  11 - 15  each comprise a control unit to communicate with the control unit of the pack  17 . 
     In one particular embodiment, the pack  17  is placed in the arm-rest  8 . As a variant, the pack  17  is a pull-out pack and is attached to a seat back  20  of a front seat  21  situated facing the seat  1 . With a pull-out pack of this kind, the passenger can access the different keys of the keyboard, even when he is in a reclining position. These keys are mechanical and/or touch keys and may take the form of a wheel. 
     Furthermore, a pack  22  is placed on the back of the seat back  20 . This pack  22  has an LCD type screen for example, and a second control unit which manages this screen. This second control unit is placed flat against the back of the screen so as to form a single-piece unit with the screen. 
     In a particular embodiment, the pack  22  communicates with the pack  17  by means of a high-bit-rate link  22  connected to a common Ethernet bus (not shown) of the aircraft. This bus is connected to the Internet, for example by means of a router. 
     Generally, a headset-microphone unit  18  is connected to the pack  17  by means of an audio type link  19 . This unit  18  enables the passenger to listen to the music or soundtrack of a film stored, as shall be seen, in a memory of the pack  17  or  22 . 
     As a variant, instead of being in the same pack, the node control unit is placed in a receptacle that receives a pack of the keyboard. And the control unit of the screen is placed in another receptacle that receives a pack of the screen. 
       FIG. 2  provides a detailed schematic view of the different elements of the seat  1  and of the links between them. More specifically, the nodes  11 - 15  are connected to the CAN bus, each by means of a CAN interface  27 - 31 , enabling the nodes  11 - 15  to communicate with each other and with the pack  17  through the bus  16 . 
     This pack  17  comprises the keyboard  17 . 1  and the control unit  17 . 2  which controls the nodes  11 - 15 . More specifically, this control unit  17 . 2  has a microprocessor  33 , a program memory  34 , a data memory  35 , an Ethernet interface  36  and a CAN interface  37  connected to one another and to the keyboard  17 . 1  through an internal bus  32 . The CAN interface  37  is used especially to receive data sent by the nodes  11 - 15  and to send data to these nodes  11 - 15  through the bus  16 . To this end, this interface  37  provides especially for a serialization and de-serialization of data on the bus  16 . 
     Furthermore, as in the case of the node  11 , each node  11 - 15  has a control unit  27 . This control unit  27  comprises a microprocessor  38 , program memory  39 , a data memory  40 , a CAN interface  41  and an activatable element  42  such as a direct current motor. These circuits  38 - 42  connected to one another through an internal bus  43 . The CAN interface  41  is used to receive data sent out by the control unit  17 . 2  and send out data to this control unit  17 . 2  through the bus  16 . To this end, this interface  41  provides especially for the serialization and the de-serialization of data on the bus  16 . 
     In one particular embodiment, the control unit  17 . 2  executes a program  43  and awaits reception of an electrical signal from the keyboard  17 . 1 . Upon reception of the signal, the control unit  17 . 2  executes a program  44  and sends instructions to a particular node  11 - 15  or to a set of nodes. 
     This node or these nodes  11 - 15 , which receive the instruction in the form of a program for example, then execute a program  45  in which the instruction is interpreted. The control unit  27  of the node can then store the pieces of interpreted information in the memory  40  to execute them immediately or with a delay. The execution of these instructions causes, for example, an actuation of the element  42  which corresponds for example to a shifting of this element. The control unit  27  can control a shifting of the element  42  while at the same time achieving a feedback control over its position, this open-loop or closed-loop feedback control being defined through a program  51 . 
     Furthermore, during a shifting of the seat  1 , the control unit  17 . 2  can make state requests  47  to a node  11 - 15  to obtain knowledge especially of a position of its actuator  42 . In executing the program  48 , the node receives and interprets the state requests signals. The node then sends the requested pieces of information in executing the program  49 . The control unit  17 . 2  then executes a program  50  to receive and process these pieces of state information. These pieces of state information generally sent by several nodes are processed by the control unit  17 . 2  by means of a mathematical model  46  in order to prevent the different actuators  11 - 14  of the seat from making the seat  1  take prohibited positions liable to inconvenience another passenger or positions in which the mechanical elements of the seat could be damaged. 
     When the system is powered on, the control unit  17 . 2  updates its register of nodes  52  in which it lists the number of nodes  11 - 15  connected to the CAN bus  16 . The control unit  17 . 2  thus detects any addition of new nodes or removal of nodes. To this end, each node  11 - 15  has, in its memory, its characteristics  53  such as an identification number, which will be sent to the control unit  17 . 2  so that it can identify the type of node connected to the CAN network. 
     Furthermore, each node  11 - 15  has its operating characteristics in its memory  40 , for example its furthest shifts, which it can transmit to the control unit  17 . 2 . This control unit  17 . 2  is furthermore capable of keeping the operating information on the nodes in its memory  54  and can, if necessary, combine this information with the mathematical model  46 . 
     Each node furthermore executes a program  55  to perform a test on whether the instructions sent by the control unit  17 . 2  have been correctly executed. In the event of dysfunction of a node, an error signal is sent to the control unit  17 . 2 . This control unit  17 . 2  manages the error signals sent by the nodes in executing a program  56  and, as the case may be, sending an information signal to the passenger or hostess. 
     Each node may comprise a program  57  enabling the calibration of the element  42  at the time of its first connection to the CAN network. This calibration may enable the calibration, for example, of the travel of a thruster element of an actuator, or the luminosity of the reading light. 
     Furthermore, the pack  22 , called a media pack, has a screen  22 . 1  and a control unit  22 . 2  which controls this screen  22 . 1 . The control unit  22 . 2  has a microprocessor  60 , a program memory  61 , a data memory  62  and an Ethernet interface  63 . These elements  60 - 63  are connected to one another and to the screen  22 . 1  by means of a bus  64 . 
     The control circuit  22 . 2  executes a program  65  to carry out a management of the screen  22 . 1 , especially its display. The actuation of the screen  22 . 1  is achieved by means of the keyboard  17 . 1  or by means of a tactile keyboard  67  of this screen  22 . 1 . 
     The control unit  22 . 2  is connected to the control unit  17 . 2  by means of a switch or a network repeater  65 . 1 . This element  65 . 1  is connected to a common Ethernet bus  65  of the aircraft to which all the control units of the seats are connected. More specifically, the Ethernet interface  36  of the control unit  17 . 2  and the Ethernet interface  63  of the control unit  22 . 2  are connected to the switch  65 . 1  respectively by means of a high-bit-rate link  23 . 1  and a high-bit-rate link  23 . 2 . These high-bit-rate links may be RJ45 type wire links, optical links or radio links. 
     Through the common Ethernet bus  65 , the passenger has access to the Internet and to musical or video data. However, in a preferred embodiment, the control unit  22 . 2  already has audio and video data  66  in its data memory  62 . Thus, even when the control unit  22 . 2  is not connected to the bus  65 , a passenger can view films on his screen. In one example, a space of 100 GB, 200 GB or more is available in the memory  62  for the storage of more than hundred films, compressed in the MPEG4 format for example and musical data compressed in the MP3 format for example. The transfer of the information from a common reader (not shown) connected to the bus  65  up to the memories of some or all the screens of the aircraft is done through the Ethernet network. 
     As a variant, this information transfer is achieved by radio, when the wire links of the Ethernet network are replaced by radio links of a WiFi type for example. In this case, the switch  65 . 1  is capable of sending and receiving radio signals to communicate with the player connected to the Ethernet bus  65 . In one particular embodiment, the keyboard  17 . 1  also has a screen and items of video and audio information are transmitted to this screen via the Ethernet bus  65 . 
     Furthermore, there is a redundancy of data and control programs so that, in the event of dysfunction of the control unit  22 . 2 , the control unit  17 . 2  can manage the display of the screen  22 . 1 . To this end, the control unit  17 . 2  comprises a program  68  and films  73  to control and transmit video information to the screen  22 . 1  via the Ethernet network. The memory  73  generally stores a smaller number of films than the memory  66 . 
     Conversely, in the event of dysfunction of the control unit  17 . 2 , the control unit  22 . 2  comprises at least one program  71  that enables it to listen to the command that the passenger may make through the keyboard  17 . 1  or the keyboard  22 . 1 . And the unit  22 . 2  also has a pro-gram  72  to provide for the transmission of instructions to the nodes  11 - 15 . This transmission of instructions to the nodes  11 - 15  may be done by means of the bus  65 , the switch  65 . 1  and the interface  37 . 
     As a variant, the control unit  22 . 2  comprises a CAN interface (not shown) connected to the bus  64  and to the CAN bus  16  to communicate with the nodes  11 - 15  of the network. Furthermore, the control unit  22 . 2  may also have the mathematical model  69  in memory for the control of the nodes and the information  70  on the number and type of nodes connected to the network  16 . 
     In one particular embodiment, when the unit  22 . 2  controls the nodes, it is capable of performing only a limited number of actions such as for example making the seat  1  go from a reclining position to a sitting position. In the, it is essential that the passenger should return to a seated position during a landing. 
     As a variant, the unit  22 . 2  furthermore comprises an audiophonic module (not shown) linked to the bus  64  and to the headset/microphone unit  18 . This module comprises a codec unit and can convert electrical sound signals into IP type packets. The control unit  22 . 2  can thus enable passengers to communicate with one another and with the exterior via the bus  65 . 
     The seat  1  furthermore comprises a power source  75  which powers the nodes  11 - 15  and the control unit  17 . 2 ,  22 . 2  via a power bus  76  which generally delivers a 24V voltage. More specifically, the active elements of the nodes, such as the element  42 , are connected to the network  76  by means of a power module  42 . 1 . And the control unit  17 . 2  and  22 . 2  comprise power modules  77  and  78  connected to the network  76 . In one embodiment, this power module  75  is treated as a node of the CAN network and is connected to this network by means of a link  81 . 
     Furthermore, to ensure management of the values of power consumed by the different nodes  11 - 15 , the control unit  17 . 1  executes a program  79  used to limit a speed or turn off one of the nodes when a value of total consumed power of the nodes reaches a determined threshold. Each node  11 - 15  can also comprise an internal power management program  80  enabling the distribution of the power between the different circuits of the node and, as the case may be, the different elements managed by the node. It is indeed possible for one and the same node to control several motors and/or several sensors for example. 
     As a variant, the set of programs and data of the control units may be stored without distinction in one or other of the memories of the above-mentioned seat control units. 
     As a variant, the nodes  11 - 15  do not comprise any control units  27 . They then take the form of simple electronic actuators which do not comprise any embedded intelligence, i.e. they do not have any microprocessor or memory. 
     As a variant, only one control unit  17 . 2  or  22 . 2  controls the nodes  11 - 15  and the screen  22 . 1 , the other unit being eliminated. 
     As a variant, the seat according to the invention comprises the nodes  11 - 15 , and the control unit  17 . 2  for the control of these nodes but not the screen  22 . 1  or the control unit  22 . 2  of this screen. In another variant, the seat according to the invention comprises the screen  22 . 1  and its control units  22 . 2  but not the nodes  11 - 15  or the control unit  17 . 2  of these nodes  11 - 15 . 
     Naturally, the different programs described may be replaced by dedicated electronic circuits. 
       FIG. 3  gives a detailed view of the links that may exist between the control unit  17 . 2  and  22 . 2 , the switch  65 . 1  and the power module  75 . The Ethernet links are represented by heavy lines, the power links are represented by fine lines and the CAN type links are represented by dashes. 
       FIG. 3  shows that the repeater  65 . 1  and the power source  75  are placed within one and the same pack  84 . This pack  84  is located within a frame of the seat  1 , for example in a foot of the base  3 . 
     A connection  85  of the common Ethernet bus at 100 Mbits/s links another repeater (not shown) of another seat to the repeater  65 . 1 . And a connection  86  connects the repeater  65 . 1  again to another repeater (not shown) of another seat. Furthermore, as we have seen, the two connections  23 . 1  and  23 . 2  connect the switch  65 . 1  respectively to the unit  17 . 2  and the unit  22 . 2 . This architecture is repeated for each seat. 
     A power bus  87  is connected to the power source  75 . An ac voltage of 115 V and frequency 400 Hz can be observed on this bus  87 . The source  75  converts this ac voltage into a rectified and smoothened voltage of 24V, by means of a diode bridge and capacitors in particular. This 24V voltage is applied to the modules of the units  17 . 2  and  22 . 2  respectively via the links  88  and  89 . And a 24V electrical signal is conveyed to the nodes  11 - 15  by means of the bus  76 . As a variant, as we have seen, only the bus  76  powers the packs  17 . 2 ,  22 . 2  and the nodes  11 - 15 . 
     The CAN bus  16  is connected to the control unit  17 . 2  and to the nodes  11 - 15  as already seen. 
     In one particular embodiment, the bus  16  and the power bus  76  are placed physically within a same carrier to reach the different nodes  11 - 15  of the CAN network. Furthermore, the power bus  86  and the Ethernet bus  65  are placed together within rails of the aircraft to which the seats are fastened. These buses  65  and  67  may thus power and connect the seats to one another and to the Ethernet network. Furthermore, the power bus is connected to a common generator (not shown) and the Ethernet bus is connected to a router to be connected to the Internet network. 
     In one particular embodiment, the seat one is provided with a digital camera  91  (shown in  FIG. 1 ) which is fastened to an edge of the screen of the pack  22  or to the top of the front neighboring seat  21 . A lens of this camera  91  is pointed towards the seat back  5  of the seat  1 . 
     In a method of detection of the presence of a passenger according to the invention, a reference photo of the vacant seat is taken in a reference step by means of the camera  91 . This reference photo is stored in the memory  35  of the control unit  22 . 2 . Then, in the presence-determining step, an instantaneous photo is taken of the passenger&#39;s seat using the digital camera  91 . 
     In a comparison step, the reference photo is compared with the instantaneous photo of the seat. If the instantaneous photo of the place is identical to the reference photo, then the signal corresponding to the absence of the passenger in his seat is sent out on the Ethernet bus  65  to a computer of the aircraft crew. However, if the instantaneous photo of the place is different from the reference photo, a signal corresponding to the presence of the passengers sent out to the computer of the crew&#39;s. 
     In one mode of implementation of the method, to make the comparison, a correlation is made between the reference photo and the instantaneous photo of the seat. 
     It is possible to take the instantaneous photo of the seat at regular intervals. If the comparison of the photos reveals the presence of the passenger for a borderline period, then a signal is sent out to this passenger to inform him that has not moved during this borderline duration. This implementation is used to prevent blood circulatory problems for passengers who have moved far too infrequently in the aircraft.