Abstract:
The invention relates to equipment for refueling an aircraft, including a pipe ( 40 ) provided with means ( 42 ) for connecting onto an intake port ( 301 ) of the fuel tank of the aircraft ( 400 ) and, at or in the vicinity of the connection means ( 42 ), means ( 501 ) for determining the value of at least one parameter representative of a flow (E) of fuel passing through the connection means. Said equipment further includes at least one receiver onboard the refueling equipment ( 1 ), means ( 503, 504 ) for transmitting, to the receiver, a signal (Si(P)) representative of a parameter value predetermined by determination means ( 501 ) and an electronic unit capable of receiving, from the receiver, a signal representative of the parameter and of driving at least one flow control and monitoring device in accordance with the signal received from the receiver. The refueling method includes the steps of during a refueling operation, determining the value of at least one parameter representative of the flow (E) at or in the vicinity of the connection means ( 42 ), transmitting, to at least one receiver onboard the refueling apparatus, a signal (Si(P)) representative of a parameter value predetermined during the previous step, and automatically driving, in accordance with the signal received by the receiver, a flow control and monitoring device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a refueling equipment for refueling an aircraft as well as a method for refueling an aircraft using such equipment. 
     2. Brief Description of the Related Art 
     At civil and military airports and aerodromes, it is known to use refueling equipments that are moved near the aircrafts to fill their tanks with fuel. A first type of refueling equipment comprises “refueling tankers” which are vehicles provided with a tank from which fuel is drawn to be transferred to a fuel tank of an aircraft. A second type of refueling equipment comprises vehicles intended to connect to an outlet mouth of a fixed fuel distribution grid, sometimes called “hydrant system.” These vehicles of the second type are commonly called “servicers” and are provided to be connected, on the one hand, onto the hydrant system, and on the other hand, onto the fuel tank of the aircraft, while allowing the hydrant system and that fuel tank to be connected. 
     With these two types of refueling equipment, a flexible hose is used to connect a fuel circulation system from the tank or hydrant system, to the inlet of a fuel tank of the aircraft. To that end, the downstream end of the flexible hose is provided with means for connecting on the intake port of the aircraft fuel tank. A refueling equipment is generally equipped with means for monitoring, metering and controlling the flow of fuel, such as flow meter(s), volume counter(s) and a pressure regulator, these devices being mounted on the equipment and making it possible to drive the flow in an open loop. When it leaves the pipe formed on the chassis of the equipment through rigid hoses, the flow penetrates the flexible hose under enslaved, but not continuously monitored, pressure, which poses a reliability problem. Given the position of the flexible hose, the pressure losses it causes are variable, to the point that the pressure of the fuel penetrating the fuel tank of the aircraft is not precisely controlled, whereas it must be limited to 3.5 bar so as not to damage the structure of the aircraft, while also being as high as possible so as not to needlessly extend the refueling time for an aircraft. Furthermore, the control and monitoring devices mounted on the refueling equipment must be subject to periodic verification, because they alone set the pressure of the fuel entering the aircraft&#39;s fuel tank. This periodic verification time decreases the actual operating time, and therefore the availability, of each refueling equipment. 
     It is known from U.S. Pat. No. B-6,234,224 to mount a pressure gauge at the downstream end of a fuel supply hose of an aircraft. This gauge is not very accessible and the detection of an overpressure depends on the operator&#39;s concentration. Furthermore, even if he detects an overpressure, the operator, who then stays near the fuel tank of the aircraft, cannot act on the flow to decrease its pressure. 
     SUMMARY OF THE INVENTION 
     The invention more particularly aims to resolve these drawbacks by proposing new refueling equipment having a more reliable operation. 
     To that end, the invention relates to equipment for refueling an aircraft, said equipment comprising a pipe provided with means for connecting onto an intake port of a fuel tank of an aircraft. Said equipment comprises, at or in the vicinity of the connection means to the aircraft, means for determining the value of at least one parameter representative of a flow of fuel passing through the connection means. The equipment is characterized in that it comprises at least one receiver onboard the refueling equipment, means for transmitting, to the receiver, a signal representative of a parameter value predetermined by the aforementioned determination means and an electronic unit capable of receiving, from the receiver, a signal representative of the aforementioned parameter and of driving at least one flow control and/or monitoring device in accordance with the signal received from the receiver. 
     Within the meaning of the present invention, the determination means are in the vicinity of or at the connection means in that they are close to the transfer point of the fuel between the refueling system and the fuel tank of the aircraft. This transfer point is defined by the downstream end of the connection means, which in turn are mounted at the downstream end of the flexible hose of the refueling equipment. In practice, the means for determining the value of the parameter are arranged less than 50 cm from said transfer point. 
     Owing to the invention, it is possible to know the value of the flow parameter, for example its pressure, immediately before the fuel penetrates the fuel tank. The transmission means and the receiver make it possible for the value of that parameter to be taken into account by the control system onboard the equipment, in particular through the electronic unit, so as to keep that value in a predetermined range corresponding to the recommendations by the aircraft builder and the aeronautic and oil authorities. 
     According to other advantageous, but non-obligatory aspects of the invention, such equipment can incorporate one or more of the following features, in any technically allowable combination:
         The determination means comprise a flow pressure sensor, a flow volume sensor, potentially of metrological precision, and/or a flow temperature sensor. These means may be completed by measurements of the turbidity of the distributed fuel, its density, etc.   The equipment also comprises, at or near the connection means, means for identifying an aircraft and means for transmitting, toward a receiver onboard the refueling equipment, a signal representative of the result of the identification obtained by the identification means.   The transmission means are wireless transmission means.   The transmission means can transmit the representative signal, for comparison purposes for validation, on at least two distinct channels, preferably three distinct channels, or toward at least two distinct addresses, preferably three distinct addresses.   The equipment comprises means for recording determined values of the parameter(s) and, possibly, identification data for the aircraft.   The equipment comprises, at or near the connection means, independent supply means for the determination means, the transmission means, and, if applicable, the identification means.   The refueling equipment is a servicer equipped with a hose making it possible to connect it onto an output mouth of a fixed fuel distribution grid and the electronic unit drives devices that control and monitor the flow between the mouth and the inlet of the aircraft&#39;s fuel tank, based on the signal received from the receiver.   Alternatively, the refueling equipment is equipped with a tank and the electronic unit drives devices that control and monitor the flow between the tank and the inlet of the fuel tank of the aircraft, based on the signal received from the receiver.       

     The invention also relates to a method for refueling an aircraft that can be implemented using equipment as mentioned above and, more specifically, a method in which one connects, using connection means, a pipe supported by refueling equipment to the intake of a fuel tank of an aircraft and causes a flow of fuel to circulate in the pipe as far as the fuel tank. This method comprises the steps of, during a refueling operation: 
     a) determining the value of at least one parameter representative of the flow at or in the vicinity of the connection means, 
     b) transmitting, to at least one receiver onboard the refueling apparatus, a signal representative of a parameter value predetermined during step a); and 
     c) automatically driving, in accordance with the signal received by the receiver, at least one flow control and monitoring device. 
     Advantageously, the method comprises the additional steps of: 
     d) upon receipt of a signal by the receiver, comparing the value of the parameter to a reference value, and 
     e) based on the result of the comparison in step c), continuing, in normal or degraded mode, or interrupting the refueling operation in progress. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Furthermore, it is possible to provide that steps a) and b) are carried out continuously or repeatedly during a refueling operation and that the values of the parameters determined during step a) are recorded over the duration of the refueling operation. 
       The invention will be better understood and other advantages thereof will appear more clearly in light of the following description of one embodiment of a refueling equipment and a refueling method according to its principle, provided solely as an example and done in reference to the appended drawings, in which: 
         FIG. 1  is a schematic diagram illustrating refueling equipment according to the invention during use to fill the fuel tank of an aircraft with fuel, 
         FIG. 2  is a larger-scale schematic diagram illustrating the downstream end of a flexible hose for connecting the equipment to the fuel tank, placed on the intake port of a fuel tank. 
         FIG. 3  is a partial block diagram of a refueling method implemented using the equipment of  FIGS. 1 and 2 , and 
         FIG. 4  is a view similar to  FIG. 2 , for equipment according to a second embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The refueling equipment or servicer  1  shown in  FIG. 1  generally assumes the form of an industrial vehicle and includes a chassis  11  that rests on the ground via wheels, two of which are visible with reference  12 , and which supports an internal combustion engine  13  above which a cab  14  is positioned for the equipment&#39;s driver. 
     The equipment  1  is equipped with a flexible hose  20  making it possible to connect it onto an outlet mouth  200  belonging to a fixed fuel distribution grid R in an airport. The mouth  200  is positioned under the surface S of the ground, in the vicinity of a parking space for an aircraft. The hose  20  is equipped with a connector  21  for connecting onto the mouth  200 . At its end opposite the connector  21 , the hose  20  is equipped with another connector  22  for connecting onto a connector  31  making up the nozzle of a fixed pipe  32  of the equipment  1 . In other words, the hose  20  makes it possible to connect the outlet mouth  200  that belongs to the fixed grid R to the pipe  32 , which belongs to the equipment  1 . 
     The pipe  32  emerges into a filter  33  provided to rid the fuel of any residue, in particular aqueous, that it may contain. 
     Downstream of the filter  33 , a pipe  34  extends as far as a connector  35  on which an upstream connector  41  of a second flexible hose  40  is connected whereof the downstream end is equipped with a “wing fastener”  42 , which constitutes a means for connecting the hose  40  on an intake port  301  of a fuel tank  300  incorporated into the wing  400  of an airplane. 
     For the clarity of the drawings, the flexible hoses  20  and  40  are shown, in  FIG. 1 , by lines with axes corresponding to their respective longitudinal axes. 
     The wing fastener  42  comprises a cylindrical body  421  equipped with a ring  422  allowing it to be locked through shape cooperation on a corresponding connector (not shown) delimiting the port  301 . The wing fastener  42  is also provided with a handwheel  423  in the shape of a circular tube surrounding the body  421  and connected thereto by two rigid arms  424 . Alternatively, said handwheel may be replaced by handles. 
     The elements  32  to  34  together define a fixed flow path for the fuel in the equipment  1 , between two flexible lines respectively formed by the hoses  20  and  40 . This fixed flow path and these flexible lines extend between the first connection means  21  on the grid R and the second connection means  42  on the port  301 . 
     E denotes the flow of fuel between the mouth  200  and the fuel tank  300 . 
     The equipment  1  is equipped with a counter  50  that makes it possible to measure the quantity of fuel passing through the pipe  34 , i.e. the quantity of fuel delivered to the fuel tank  300 . The equipment also includes a pressure regulator  60  that makes it possible to monitor the pressure of the flow E in the pipe  34 . 
     The equipment  1  supports a hydraulic cylinder  70  whereof the shaft  71  is equipped with a platform  72  on which an operator stands who can manipulate the downstream part of the hose  40 , in particular the wing fastener  42 . The shaft  71  allows the operator, through an ascending or descending vertical movement represented by the double arrow F 1 , to access the intake port  301 . 
     An electric-motor hydraulic pump  73  is used to provide the cylinder  70  with a sufficiently pressurized quantity of oil to maneuver the shaft  71 , upward or downward. A solenoid valve set  74  makes it possible to monitor the flow of pressurized oil from the pump  73  toward the cylinder  70 . 
     An electronic unit  110  is mounted on the chassis of the equipment  1  and monitors, via adapted electronic signals S 50 , S 60  and S 74 , the counter  50 , pressure regulator  60  and solenoid valve set  74 , respectively. 
     Elements  73  and  110  are supplied with electrical current by means that are not shown. 
     A module  500  is positioned between the downstream end  43  of the hose  40  and the wing fastener  42 . Said module is shown in cross-section in  FIG. 2 , while the wing fastener  42  and the hose  40  are shown in side view. 
     The module  500  assumes the form of a connecting ring between the end  43  and the wing fastener  42 . It comprises a cell  501  for measuring the pressure of the flow E penetrating the wing fastener  42 . 
     Given the location of the module  500 , which is in the immediate vicinity of the wing fastener  42 , the cell  501  makes it possible to know, with a satisfactory degree of precision, the pressure of the flow E when it penetrates into the fuel tank  300 , through the port  301 . In other words, the location of the module  500 , at the connection means formed by the wing fastener  42 , allows the cell  501  to give a value representative of the pressure P of the flow E passing through the wing fastener  42 . 
     In the example, the module  500  is in contact with the wing fastener  42 , so that the distance between the cell  501  and the transfer point A for transferring fuel from the refueling system toward the aircraft is less than 50 cm. 
     The transfer point of the fuel A is defined at the outlet of the wing fastener  42  as the point where the ownership of the fuel goes from the company supplying the fuel to the company operating the aircraft. 
     The cell  501  is supplied with electrical energy from a battery  502 , incorporated into the module  500  and recharged when the wing fastener  42  is stored in a receptacle  80  provided to that end on the equipment  1 . The receptacle  80  is equipped with a charger  82  positioned so that the battery  502  comes opposite said charger when the wing fastener  42  is arranged in the receptacle  80 , which makes it possible to charge the battery  502  by induction. 
     Alternatively, the battery  502  can be replaced by a capacitor, in which case the charger  82  is adapted accordingly. 
     The cell  501  is electrically connected to a radio transmitter  503 , which in turn is powered by the battery  502 . The cell  501  supplies the transmitter  503  with an electronic signal S 0 (P) corresponding to the value of the pressure it detects. 
     The transmitter  503  is equipped with an antenna  504  that allows it to transmit a non-wired signal S 1 (P) including data corresponding to the value of the pressure P detected by the cell  501 . 
     As an example, the transmission mode of the signal S 1 (P) can be by radio, infrared, etc. 
     Furthermore, the equipment  1  is equipped with a receiver  600  matched to the module  500 . Its antenna or sensor  604  allows it to receive the signal S 1 (P). 
     The receiver  600  can then transmit, to the electronic monitoring unit  110 , a signal S 2 (P) representative of the pressure of the flow E detected by the cell  501 . 
     The unit  110  can then take the value of that pressure P into account to drive, in particular, the pressure regulator  60  using the appropriate electronic signal S 60 . The counter  50  in turn provides the unit  110  with a signal S′ 50  representative of the counting it does. 
     As shown in  FIG. 3 , when a refueling operation is initiated in an initial step  1001 , the electronic control unit  110  controls electronic devices for controlling and monitoring the flow E between the mouth  200  and the fuel tank  300 , in particular the pressure regulator  60 . This occurs in a second step  1002  of the method. 
     In a third step  1003 , the cell  501  determines the flow pressure E in the module  500 , i.e. in the vicinity of the transfer point A. 
     This pressure being determined, it is incorporated into the non-wired signal S 1 (P) that is emitted by the transmitter  503  during a subsequent step  1004 . 
     Steps  1003  and  1004  are repeated at regular intervals throughout the entire duration of the refueling operation, for example every 10 ms. 
     During a subsequent step  1005 , the signal S 1 (P) emitted by the transmitter  503  is received by the receiver  600  and transmitted to the unit  110  in the form of signal S 2 (P). 
     During a subsequent step  1006 , the unit  110  extracts the value of the pressure P from the signal S 2 (P) and compares that value to a threshold value P 0  equal, for example, to 3.5 bar. If the signal S 1 (P) is encoded, it is decoded during this step. During this step, the value P of the pressure is stored in a memory  120  associated with the unit  110 . 
     If the pressure P is greater than said reference value, an automatic cycle is activated in step  1007 . First, this cycle corrects the value to try to return the deviation to an acceptable level. Said deviation is measured again in step  1006 . If the deviation does not decrease, then the system forces a secured mode that tends toward limitation of the pressure, i.e. operation in degraded mode. And if this pressure does not decrease toward the imposed instruction, then the refueling operation is stopped in step  1008 . An alarm is then activated so that the operator can take appropriate withdrawal measures. 
     If the value of the pressure P is below the reference value P 0 , then that pressure value P is compared to a reference value P 1  in step  1009 . If the value P can be considered substantially equal to value P 1 , for example with a configurable deviation smaller than 5%, the refueling operation continues without modifying the setting parameters of the pressure regulator  60 , in step  1010 . If the pressure P deviates from the value P 1  by more than 5%, the setting of the regulator  60  is adjusted in step  1011  before the refueling operation is continued in step  1010 . 
     Steps  1005  to  1011  are implemented after each receipt of a signal S 1 (P). In particular, the pressure values P successively received from the cell  501  are stored in the memory  120  throughout the entire refueling operation. 
     To reliabilize the transmission of the signal S 1 (P) between the transmitter  503  and the receiver  600 , this transmission occurs simultaneously, on three different channels or with different addresses. In that case, the data transmitted on the different channels or recovered by the different addresses is compared and validated if its values remain within the deviations deemed acceptable, for example 1%. In case of failure of a transmission chain, on a channel or by a specific address, the failing chain is automatically isolated and a pre-alert is sent to the operator. In the unlikely event that two signal transmission chains fail at the same time, operation in degraded mode is established, in which the pressure regulator  60  is driven to regulate the pressure at the outlet of the pipe  34  at a value strictly below the value P 0  so that, given the pressure losses that must occur in the hose  40 , the pressure at the transfer point A is necessarily below that value. 
     In non-degraded operating mode, the invention makes it possible to drive the pressure regulator  60  with a reference value higher than the value P 0 , so that the flow pressure E at the transfer point and within the wing fastener  42  is as close as possible to the value P 1 , which can be equal to the value P 0 , 3.5 bar in the example, or lower. 
     In addition to or in place of the cell  501 , the module  500  can be equipped with a cell for detecting the temperature of the flow E, a cell for measuring, possibly metrologically, the volume of said flow, and/or a cell for measuring the turbidity or density of the distributed fuel, the value of these parameters being transmitted to the unit  110  as previously explained for the signal representative of the pressure. The transmission means can be shared by the various measuring cells when several cells are incorporated into the module  500 . 
     Furthermore, according to one advantageous but optional aspect of the invention, an identification sensor  700  is mounted on the body  421  of the wing fastener, near the ring  422 . This sensor, supplied with electrical current by the battery  502  only, is connected to the transmitter  503 . This sensor is adapted to read a label  800  fixed on the wing  400  of the airplane, near the port  301  and containing identifiers I of the airplane, for example its registration, the type of fuel required and/or administrative data relative to payment for the refueling transaction. For example, the label  800  can be of the RFID type and the sensor  700  is adapted to recover data from that label. 
     The data collected using the sensor  700  is sent to the transmitter  503  in the form of an electronic signal S 700  and the transmitter  503  transmits it in the form of a non-wired signal S 1 (I) to the unit  110 , via the receiver  600 . This identification of the aircraft takes place automatically at the beginning of the refueling operation. This avoids the serious risks of incompatibility on the type of fuel supplied to the aircraft requiring refueling. 
     In the second embodiment of the invention shown in  FIG. 4 , the elements similar to those of the first embodiment bear the same references. The wing fastener  42  of this embodiment is associated with a module  500  that comprises a cell  501  for measuring the pressure, temperature and volume, possibly metrological, of the flow E. In other words, the cell  501  of this embodiment is a triple cell making it possible to determine three physical parameters of the flow E. This does not exclude the determination of new parameters, such as the turbidity of the fuel, its density, and more generally all of the useful physical characteristics, specific to the delivered fuel and specific to the progression of the refueling operation. 
     In place of the battery  502  of the first embodiment, the propeller  506  of a turbine  505  is installed on the flow E path. This turbine  505  is coupled to an alternator  507  and a rectifier  508  making it possible to supply direct current to the cell  501 , three transmitters  503  and a sensor  700  similar to those of the first embodiment. 
     In practice, the rotor of the alternator  507  can be made up of magnets mounted on the shaft of the propeller  506  and positioned opposite a fixed coil. It is also possible to provide for the induction charging of a battery or capacitor when the module  500  is stored in a receptacle similar to that of the first embodiment. This makes it possible to have electrical energy for the elements  501  and  502  even before the flow E is established. 
     Thus, in the two considered embodiments, autonomous means formed by the battery  502  of the first embodiment or by the assembly  505 - 508  of the second embodiment make it possible to power the measuring cell  501 , the transmitter(s)  503  and the sensor  700 . It is therefore not necessary to supply the module  500  and its accessories with current from the servicer  1 . 
     The propeller  506  can constitute the primary or secondary counting means, possibly metrological, of the distributed fuel volume. 
     In this embodiment, three transmitters  503  are used while being distributed around the body  421  of the wing fastener  42 , so that their antennas or transmission means  504  can transmit in several directions, which guarantees good transmission of the signal such as the signal S 1 (P) mentioned for the first embodiment, to the receiver  600 . These transmitters  503  can be configured to transmit to three distinct receiver addresses, several receivers  600  being able to be provided on the equipment  1 , with the aim of securing and reliabilizing the non-wired exchanges of data. 
     In this second embodiment, the signal transmitted by the transmitters  503  is representative of the values of the pressure P, temperature T and volume V of the flow E from the beginning of the refueling operation. This signal S 1 (P, T, V) is processed by the receiver(s)  600  and by the unit  110  in a manner comparable to that explained for the first embodiment. In particular, a signal S 2 (P, T, V) representative of the pressure, temperature and volume values is transmitted by the receiver(s)  600  to the electronic unit  110 . The comparison with threshold values is done by the unit  110  for each of the concerned physical parameters or for only some of them. The values of these parameters are stored in the memory  120 , as in the first embodiment. 
     In both embodiments, storing values representative of certain parameters of the flow E in the memory  120  enables an a posteriori analysis of the proper operation of the equipment  1  during a refueling operation. It is in particular possible for the company distributing the fuel to provide the aircraft&#39;s operator or the authorities with a statement showing all of the values of the parameter(s), for example the pressure, noted near the transfer point A during a refueling operation. This makes it possible to ensure that no threshold values have been exceeded and limits the periodic audit of flow E monitoring apparatuses such as the regulator  60 . The memory  120  can also be used to store the identification data I collected by the sensor  700 , which covers the traceability needs of the refueling operations while also making the task of imputing refueling costs easier. 
     The invention is described above in the case where it is implemented using a module  500  inserted between the downstream end  43  of the hose  40  and the wing fastener  42 , which makes it possible to use a standard wing fastener, by potentially affixing an identification sensor  700  on the outside of its body. Alternatively, the means for determining the value of the flow parameter, the transmission means and, possibly, the identification means, such as the aforementioned elements  501 ,  503  and  700 , are incorporated into a wing fastener designed to that end. 
     The invention is described above in the case of implementation with a servicer connected on a hydrant system. It can, however, be implemented with a refueling tanker equipped with a tank for transporting fuel to the vicinity of the aircraft to be refueled. 
     Although the invention has been described above during the use thereof to fill an airplane fuel tank, it can be used to fill a fuel tank of any type of aircraft, in particular a helicopter.