Abstract:
A system for inductive contactless power transfer between a first vehicle part and at least one collector that can be variably positioned relative to the first vehicle part in a passenger cabin of a vehicle includes primary windings (P 1 -PN) that with secondary windings (S 1 , S 2 ) on collectors or second vehicle parts can form a transducer. Depending on operating-mode switching of the vehicle, the operation of collectors is prevented, which collectors for the purpose of providing electrical power for operating external cleaning or maintenance devices are brought into the vehicle. Because of the expansion of the function of an existing contactless power and data transfer system, the system is particularly cost-effective and flexible, and in addition is of a very lightweight design.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of International Application No. PCT/EP2011/064306, filed Aug. 19, 2011, which claims the benefit of the filing date of German Patent Application No. 10 2010 036 061.9 filed Sep. 1, 2010 and of U.S. Provisional Patent Application No. 61/378,991 filed Sep. 1, 2010, the disclosure of which applications is hereby incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a system for contactless power transfer between a first vehicle part and at least one collector that can be variably positioned relative to the first vehicle part; to a method for the transfer of power between a first vehicle part and at least one collector that can be variably positioned relative to the first vehicle part in a passenger cabin of a vehicle; as well as to an aircraft comprising such a system that can carry out said method. 
       BACKGROUND OF THE INVENTION 
       [0003]    Systems for power transfer between a vehicle part and a moveable collector are known from the state of the art. In particular for providing re-configurability of a cabin in an aircraft in the most flexible manner possible, frequently seat-to-seat cabling is used for connecting devices in passenger seats to a current network or a data network; and as an alternative also connecting lines from the vehicle floor to passenger seats, galleys or other monuments that are arranged on said vehicle floor. 
         [0004]    When cleaning cabins of larger vehicles, for example of commercial aircraft, vacuum cleaners, steam cleaners, carpet shampooing appliances and other cleaning appliances can be used which need to be supplied on board with electric current. To this effect, electrical outlets can be provided in the passenger cabin, which electrical outlets are firmly connected to conventional vehicle cabling, and in the case of a commercial aircraft after landing, when the vehicle is situated on the ground, supply the respective appliances with power only when a service switch is activated, which service switch is specially provided for this and is located in the entrance region of front doors. Special protection mechanisms, e.g. fault-current circuit breakers, protect the user against injury or death in the case of malfunction. Such conventional cabling is disadvantageous, especially in the case of aircraft, as a result of its increased weight. 
         [0005]    Printed publication DE 10 2008 024 217 A1 discloses a system for contactless inductive transfer of data and power between a first vehicle part and a second vehicle part by means of transducers formed by primary windings and secondary windings, which system relates to the provision of a power supply to devices and equipment in passenger seats or other second vehicle parts, while at the same time it also makes it possible to transfer a data flow that is high-frequency-modulated on the present alternating voltage. The second vehicle parts that are supplied with power and data can be arranged at various locations within the passenger cabins, without there being any need for modification of elaborate seat-to-seat cabling. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    Accordingly, an aspect of the invention proposes a system for power transfer in a passenger cabin of a vehicle, which system is as lightweight as possible, while nevertheless without expensive modification work to existing systems provides for a reliable supply of power to devices that are brought on board, in particular to cleaning appliances and maintenance equipment. 
         [0007]    An embodiment of the invention includes a system for contactless power transfer between a first vehicle part and at least one collector that is variably positionable relative to the first vehicle part in a passenger cabin of a vehicle, which system comprises a first control unit with a voltage input and at least one primary voltage output; a multitude of primary windings that can be positioned on the first vehicle part, which primary windings can be connected to the primary voltage output of the first control unit; a second control unit with a secondary voltage input and a voltage output; and a secondary winding arranged on the collector, which secondary winding can be connected to the secondary voltage input of the second control unit. The collector is positionable in such a manner relative to the primary windings that between the secondary winding and a primary winding a transducer is formed for inducing a voltage from the primary winding to the secondary winding and thus for the transfer of electrical power from the first control unit to the second control unit. 
         [0008]    According to an embodiment of the invention the collector is a voltage provision unit with a connection for supplying external electrical loads, and the first control unit is connected to an operating-mode switching device that is equipped, in an operating mode of the vehicle, to interrupt the connection between those primary windings and the first control unit, which primary windings form a transducer with a secondary winding of the voltage provision unit. 
         [0009]    Some aspects of the system according to an embodiment of the invention thus consist of forming transducers in a location-variable manner by means of primary windings and secondary windings, which transducers are able to transfer electrical power in a contactless manner, by induction, from primary windings to secondary windings. The system according to an embodiment of the invention could thus be designed as a power transfer and data transfer system in which second vehicle parts can be arranged on the first vehicle part, where between corresponding primary windings and secondary windings they form transducers for the transfer of power and data. The second vehicle parts could, for example, be passenger seats on which secondary windings are arranged. The first control unit could comprise a modulation device that allows high-frequency modulation of data flows on a voltage to be induced, wherein at the same time in the second vehicle parts second control units can be arranged which by means of a corresponding demodulation device convert the data modulated on the induced voltage back to usable data flows. According to an embodiment of the invention, for this purpose in addition further collectors can also be positioned on the first vehicle part, which collectors are designed as voltage provision units that make it possible to operate devices for cleaning or maintenance, which devices are used on-board the vehicle, wherein a safety function is implemented by the operating-mode switching device, which safety function prevents inadvertent operating during a predetermined operating mode, i.e. in particular during passenger transport. 
         [0010]    The voltage provision unit is preferably a compact, lightweight, easily portable design unit which during maintenance or cleaning can be brought into the vehicle cabin where it can be positioned relative to the first vehicle part when required. As an alternative to the above, said design unit could also be locked to the first vehicle part during conventional aircraft operation. The voltage provision unit could thus be considered to be a “mobile electrical outlet” that could comprise a mounting frame with a locking unit that makes possible locking, for example on a commonly used seat rail with a one-inch pitch, and that can be affixed completely variably within the cabin or relative to the first vehicle part, and that can be affixed practically to any location that comprises primary windings, thus providing a connection for electrical loads. 
         [0011]    The system according to an embodiment of the invention comprises a safety device, in the form of the operating-mode switching device, which safety device prevents inadvertent activation of the voltage provision unit. This is advantageous in particular in those cases where a voltage provision unit after cleaning or maintenance on board the vehicle is forgotten, and its secondary winding forms a transducer with a primary winding even during conventional passenger conveyance operations. By means of interrupting the supply to this primary winding, potential malfunction or error sources of an electrical system or danger to passengers can be prevented. 
         [0012]    The type of operating-mode switching device can be implemented in various ways, for example in the form of a mechanical switch which can disconnect, from the first control unit, predetermined primary windings that are provided for operating voltage provision units. As an alternative to this, an electronics unit is also imaginable in which signaling a passenger-conveyance operating mode switches off the corresponding primary voltage outputs. 
         [0013]    In an advantageous embodiment the first control unit comprises a group of first primary voltage outputs and a group of second primary voltage outputs, wherein the operating-mode switching device comprises an operating-mode signal input and is designed to connect the group of second primary voltage outputs to the primary windings, or to disconnect these connections. By dividing the primary voltage outputs into two different groups, combined with the evaluation of a signal present at the operating-mode signal input, two states can be switched by operating or disconnecting the group of second primary voltage outputs, and in this manner two operating modes can be considered which are predetermined by the signal at the operating-mode signal input. The group of first primary voltage outputs could, for example, be connected to primary windings which with secondary windings of second vehicle parts form transducers that are connected to second control units of passenger seats or other second vehicle parts. The group of second primary voltage outputs could be connected to primary windings that relate to the operation of voltage provision units. Activation of the second primary voltage outputs can consequently be prevented in the conventional passenger conveyance operation of the vehicle in that a service switch or a corresponding signal from a control computer of the vehicle indicates passenger conveyance operation. It should be pointed out that operation of the group of second primary voltage outputs does not necessarily lead to parallel disconnection of the group of first primary voltage outputs. Instead, it is imaginable, in particular during short stays for cleaning the vehicle without passengers present therein, not to switch off the devices installed in the second vehicle parts, which devices are supplied with power, and optionally also with data, by the group of first primary voltage outputs. 
         [0014]    The above-mentioned decoupling of groups of primary voltage outputs could implicitly also mean that on the first vehicle part special primary windings can be provided for the purpose of in each case forming a transducer exclusively with secondary windings of voltage provision units. Accordingly, in this embodiment particular positions within the passenger cabin could be selected on the first vehicle part, at which positions a voltage provision unit is to be arranged. This is sensible in those regions where due to spatial or constructional restrictions it is not possible to arrange passenger seats or monuments, and consequently arranging a mobile electrical outlet appears to be particularly practical. 
         [0015]    In an advantageous embodiment the second control unit comprises an identification device, wherein the first control unit is connected to at least one acquisition device that is designed to acquire the identification device of a second control unit that is connected to a secondary winding, which together with a primary winding that is connected to the first control unit forms a transducer. The identification device is preferably equipped on call to transmit identification that allows inference relating to the electrical load concerned, which electrical load is connected to the second control unit. Consequently, by means of identification it would be possible to determine whether at a particular primary winding a transducer is present that leads to a voltage provision unit or some other device that is used during normal vehicle operation. By detecting all the identifications of all the electrical loads situated in proximity to primary windings, the system according to the invention could intelligently react to the respective electrical loads, and in a predetermined operating mode could operate only permitted devices by selectively disconnecting or connecting primary voltage outputs of the first control unit and the respective primary windings. In other words this means that a voltage provision unit with corresponding identification results in impingement of a primary winding, provided for this or located in close proximity, with a primary voltage only in those cases where the operating mode “maintenance” or “cleaning” is present. This embodiment is very flexible, because by means of it a voltage provision unit can be operated practically at any position within the passenger cabin, in which position there is a first vehicle part with primary windings. 
         [0016]    Particularly preferably, the operating-mode switching device is equipped, after changeover of a predetermined operating mode, to detect all the available identification devices in order to subsequently adapt the linkage of the primary windings. Manual initiation of this process is then not required. 
         [0017]    In a preferred embodiment this identification device is a transponder, wherein the associated acquisition device is a reading device for transponders. Particularly well-known and in widespread use are so-called RFID-transponders that, excited by an external voltage, transmit a predetermined data record, which according to the invention could comprise identification data of a second control device, details relating to the device type, a permitted operating mode, or the like. If transponders are used, preferably each primary winding comprises a corresponding reading device, or is equipped or adapted to be connected to a central reading device. 
         [0018]    In an advantageous embodiment the identification device is adapted to induce recognizable response behavior in a primary winding, and the first control unit is designed to measure this response behavior. Modification of a response behavior, i.e. of a current/voltage profile over time, in a transducer is possible based on Lenz&#39;s law or mutual inductance behavior on the primary winding, and a correspondingly modified response signal could be distinguishable from other response behavior. It is thus imaginable, in the case of cleaning or maintenance, to exclusively permit operation of such second control devices that are connected to secondary windings which in a particular manner cause modified response behavior in a transducer. 
         [0019]    In an advantageous embodiment, by applying an impedance, a capacitance and/or a resistance to the secondary winding, a particular response behavior of a transducer could be modified, which response behavior can be determined by means of a measuring device and can be differentiated from other response behavior. 
         [0020]    In a likewise preferred embodiment of the system, the first control unit is designed, by means of the primary voltage outputs, at each primary winding to check whether a transducer with a secondary winding is formed. By measuring the response behavior following a voltage pulse or the like, the first control unit can detect whether a transducer with a secondary winding is present, which can be determined for example by the presence of a significantly higher measurable amperage than is the case in the absence of a secondary winding. The system according to an embodiment of the invention would then preferably connect only the primary windings permanently to the primary voltage outputs of the first control unit, which primary windings form a transducer with a secondary winding, in each case depending on the present operating mode. In this manner, the electrical dissipation resulting from primary windings that are not required can be eliminated, which results in overall optimization of the required electrical power. 
         [0021]    In a furthermore advantageous embodiment, by means of modulated-on high-frequency alternating voltage signals between the primary winding and the secondary winding of a transducer, a half-duplex data connection can be established, by way of which it is possible for a first control unit to send an identification query to the second control unit, wherein within a predetermined waiting time, a response to said query, from the second control unit, can be issued in the form of an identification data record. 
         [0022]    Furthermore, according to a preferred embodiment, the first control unit is connected to a checking device that is designed to check whether a vehicle-external voltage supply is available. This makes it possible for the system according to an embodiment of the invention, and in particular for the first control unit, to deactivate an on-board voltage supply for supplying the primary windings so that, for example in the case of complete switch-off of equipment units or engines of the vehicle, no interruption to the voltage supply on a primary winding connected to a primary voltage output occurs. Moreover, an external voltage supply is frequently less expensive than an on-board voltage supply. 
         [0023]    Another aspect of the invention further includes a method for power transfer between a first vehicle part and a collector in a vehicle, which collector can be variably positioned relative to the first vehicle part. Likewise, another embodiment of the invention includes an aircraft that comprises a passenger cabin on whose floor a multitude of primary windings are arranged that can form a transducer with secondary windings of equipment units, and at the same time a first control unit with an operating-mode switching device as well as at least one voltage provision unit according to the above-mentioned characteristics are provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Further features, advantages and application options of the present invention are disclosed in the following description of the exemplary embodiments and of the figures. All the described and/or illustrated characteristics per se and in any combination form the subject of the invention, even irrespective of their composition in the individual claims or their interrelationships. Furthermore, identical or similar components in the figures have the same reference characters. 
           [0025]      FIG. 1  shows an isometric view of a first vehicle part with primary windings arranged therein. 
           [0026]      FIG. 2  shows a diagrammatic view of a system according to the invention. 
           [0027]      FIG. 3  shows an exemplary embodiment of a second control unit. 
           [0028]      FIG. 4  shows an aircraft comprising a cabin and a system arranged therein. 
           [0029]      FIG. 5  shows a diagrammatic block-based view of a method according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIG. 1  shows an isometric view of a first vehicle part  2  that comprises a multitude of primary windings  4  that as an example are elongated and arranged so as to be equidistant from each other. In the illustration shown, the first vehicle part  2  is designed as part of a cabin floor of a vehicle, which cabin floor comprises seat rails  6  on which passenger seats, monuments or other equipment units can be positioned, preferably with a one-inch pitch. The illustration of  FIG. 1  is to be interpreted only as an example; in principle it would also be possible for a seat rail  6  itself to comprise several primary windings  4 ; as an alternative to this also wall surfaces, in close proximity to the floor, of a cabin interior lining, or other aircraft parts installed in the cabin. 
         [0031]      FIG. 2  diagrammatically shows a series of primary windings  4  that are designated P 1 , P 2 , P 3 , P 4 , P 5 , P 6  and PN. On two primary windings, P 1  and P 2 , a second vehicle part  8  in the form of a passenger seat is arranged, at the bottom of which a secondary winding S 1  is arranged. The secondary winding S 1  forms a transducer with the primary winding P 1 , but it cannot entirely cover the adjacent primary winding P 2 , and consequently in that location no complete transducer is formed. On two primary windings P 5  and P 6 , which are spaced apart along the floor, a collector in the form of a voltage provision unit  10  is arranged that at it bottom comprises a secondary winding S 2  that forms a transducer with the primary winding P 5 , but does not form a complete transducer with the adjacent primary winding P 6 . The voltage provision unit  10  is designed as a kind of mobile electrical outlet and comprises a connection  12  for connecting external devices that are supply with voltage by way of the transducer formed from S 2  and P 5 . It would thus be desirable to connect the inverter  18  to the primary voltage outputs  16  that lead to the primary windings P 1  and P 5 , wherein, in order to save power, the remaining primary windings P 2 -P 4  and PN should not be connected to the primary voltage outputs  16 . Further below, a modification of the circuit arrangement is shown, which modification depends on the operating mode. 
         [0032]    Furthermore, a first control unit  14  is shown, which comprises a series of primary voltage outputs  16  that can be connected to the individual primary windings P 1 -PN. The primary voltage outputs  16  derive from an inverter  18 , which from an incoming direct voltage generates an alternating voltage of a frequency suitable for transmission to a secondary winding S 1  or S 2 . 
         [0033]    For operation of the first control unit  14  an internal voltage supply unit  20  is provided which from a so-called input circuit  22  provides a voltage suitable for the function. In the example shown, the input circuit  22  comprises two connections  24  and  26  for voltage supplies that in a commercial aircraft can be connected to two different electrical line networks, e.g. to a “normal power bus” and to a “service power bus”. The input circuit  22  is preferably designed to check whether and what external voltage supply is available at a given time. The “service power bus” is, for example, used when service or maintenance work is carried out on the aircraft and when flight-relevant systems are switched off. 
         [0034]    In addition to this, the first control unit  14  comprises an operating-mode signal input  28  at which, for example, the switching state of a service switch  30  can be acquired. If said service switch  30  is in the position “1” or “service” an operating-mode switching device  32  causes the voltage provision unit to be supplied with electrical power by way of the primary winding P 5 . In contrast to this, if the service switch  30  is in the position “0” or “normal operation”, then the operating-mode switching device  32  causes the connection between the respective primary voltage output  16  and the primary element P 5  to be interrupted. 
         [0035]    The first control unit  14  further comprises a ground contact signal input  24 , which is connected to the operating-mode switching device  32 , in order to check, for example in the case of evaluation of a ground sensor arrangement of an aircraft, a park position sensor of a train, of a bus, of a ferry or of some other vehicle, as well as a corresponding position of the service switch  30 , whether engines or equipment units have been started up, whether the system has been set back to a normal operating state or whether an operating mode required for cleaning and service can be activated by means of the operating-mode switching device  32 . 
         [0036]    The secondary windings S 1  and S 2  are in each case connected to a second control unit  36  which makes it possible to process the transferred electrical power for the intended electrical loads, for example to the passenger seat  8  or the voltage provision unit  10 . At the same time a second control unit  36  can comprise an identification device  38  which is able, upon request, to convey an identification data record to the first control unit  14 . This can be carried out with data transfer by way of the transducers formed with S 1  and P 1  or S 2  and P 5 , wherein for this purpose modulation and demodulation units (not shown in detail) can be used. On the other hand, it is also possible to use transponders and corresponding reading devices for this purpose. 
         [0037]    The first control unit is preferably equipped, by applying a short voltage pulse by way of the primary voltage outputs  16  and by measuring a signal response by means of a measuring device  40 , to detect on all primary windings whether a secondary winding S 1  or S 2  forms a transducer with a primary winding P 1  to PN. In the case shown, the result of this would show the transducer formed from P 1  and S 1  as well as P 5  and S 2 . At the respective primary windings P 1  and P 5  preferably a subsequent check takes place as to which device type is present on S 1  or S 2  in that the identification data sent by the identification devices  38  is queried by an acquisition device  41 , which as an example is connected to the operating-mode switching device  32 , which as an example by means of a demodulator receives the modulated-on identification data sent by way of a transducer or some other data transfer means. After the respective information has been received, the operating-mode switching device  32  is in a position, based on the state represented by the service switch  30  and optionally the signal on the ground contact signal input  34 , to initiate or prevent operation of P 1  and P 5 . In the case shown, the service switch  30  is in the position “1”, while on the ground contact signal input  34  likewise a “1” is present. This signifies the operating mode “service”, and that the vehicle is not in passenger transport mode so that the primary winding P 5  can be supplied with voltage from the corresponding primary voltage output  16 . The connection  12  thus provides a voltage for operating an external device. At the same time, due to the presence of a transducer on P 1 , operation of the primary winding P 1  is initiated. The switches, in the diagram shown on inverter  18 , are thus open, except for the switches leading to P 1  and P 5 . 
         [0038]    In order to take into account possibly changing identification data from identification devices  38  a configuration unit  42  can be used that comprises updated identification data and associated operating modes. 
         [0039]    At the same time a central cabin management system  44  can establish a connection with the first control unit  14  in order to, by way of cabin attendant input via a so-called “cabin attendant panel”, vehicle operator input or vehicle state data, transmit a current status to the operating-mode switching device  32 . 
         [0040]      FIG. 3  as an example shows a second control unit  36  that is connected to the secondary winding S 2  and comprises a downstream rectifier  42 , an intermediate circuit  44  as well as an inverter  46  that feeds a voltage of a suitable frequency to the connection  12  for operating an electrical load  56 . The intermediate circuit  44  can be connected to an internal voltage supply  50  that supplies a voltage to a central control device  52  within the second control unit  36 , with the aforesaid furthermore also comprising a device  54  for storing and providing an identification data record so that by way of the identification device  38  the voltage provision unit  10  can indeed be identified as such. 
         [0041]      FIG. 4  shows an aircraft  58  that comprises a passenger cabin  60  with at least one system installed therein. 
         [0042]      FIG. 5  in a diagrammatic block-based view shows the method according to an aspect of the invention, which method commences with checking  60  as to which primary windings form a transducer with secondary windings, and depending on an operating state disconnects  62  connections between primary voltage outputs  16  and primary windings P 1  to PN, which connections together with secondary windings S 1  and S 2  form a transducer, which are connected to electrical loads that in the then present operating mode must not be operated. Optionally, identification devices  38  are queried  64  in order to obtain identification data from electrical loads, which identification data allows inference as to their type. After activation of an operating-mode switch  30  or after changing the operating mode, the method could be implemented once more. 
         [0043]    In addition, it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “one” does not exclude a plural number. Furthermore, it should be pointed out that characteristics or steps which have been described with reference to one of the above exemplary embodiments can also be used in combination with other characteristics or steps of other exemplary embodiments described above. Reference characters in the claims are not to be interpreted as limitations.