Abstract:
The invention relates to a device for monitoring the integrity and soundness of a mechanical structure, such as an aircraft. The device comprises a control unit, a radio frequency transmission means, and an electric battery. The control unit recovers data from a set of digital and/or analog sensors. The radio frequency transmission means enables the control unit to transmit the data received from the sensors to a man/machine interface. The electric battery powers the device and is rechargeable. The device further comprises a module for recovering electromagnetic energy capable of converting the recovered electromagnetic energy into electric power so as to recharge the battery and/or directly power the device.

Description:
RELATED APPLICATIONS 
     This application is a §371 application from PCT/FR2012/050201 filed Jan. 31, 2012, which claims priority from French Patent Application No. 11 50700 filed Jan. 31, 2011, each of which is herein incorporated by reference in its entirety. 
     TECHNICAL FIELD OF INVENTION 
     The present invention concerns a device for observing the entirety and the wholeness of a mechanical structure and a method of functioning for such a device. It applies itself in particular, to the observation of mechanical entirety and wholeness of different composite material elements or objects, constituting an aeronautic structure. 
     BACKGROUND OF THE INVENTION 
     As is the technique, the observation of the mechanical entirety and wholeness of different composite material elements and objects forming a structure of an aircraft, is currently carried out by means of inspections. The said inspections are carried out by one or several operators. These inspections are generally carried out before and/or after each flight of the aircraft. These inspections represent a percentage of considerable accumulated time, in the lifecycle of the aircraft. 
     There is therefore a need of automation of these processes of observation to allow a saving of time and money for each one of the airlines. 
     However, arriving at such an automation of these processes is not possible in the aeronautic area, without interference of the said observation devices with the control system of the aircraft, or of the autonomy and of the size of the observation device, together with the costs required to put in place or to replace these devices. 
     So, in the aeronautic area, the skilled person uses certain software applications which explore the conditions of the structure of the aircraft when it is on the ground and/or control the mechanical entirety and wholeness of the objects or elements of the said structure, when, for example, the said objects or the said elements have been repaired during maintenance or upkeep of the aircraft. 
     These software applications are suitable for collecting data received from a set of sensors. These sensors are divided over the whole structure of the aircraft and connected in networks, so as to be able to observe the critical parts of the composite materials during upkeep or following emergency conditions subjected by the aircraft during a phase of flight. 
     However, none of the existing solutions are truly universal, since the sensors and software used are different from one airline to another and/or from one country to another. It is therefore difficult to ensure effective monitoring in these conditions of a history of the subjected constraints, together with the mechanical entirety and wholeness of the different objects and/or elements of the aircraft. That, so as to anticipate possible damage and/or wear and tear of the said objects, could consequently lead to more or less serious accidents for these aircrafts. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The present invention aims to remedy, in whole or part, the disadvantages of the techniques previously displayed. 
     For that, the invention proposes a device for observing the entirety and the wholeness of a mechanical structure, together with a method of functioning for such a device. The device, according to the invention, is suitable to be integrated with all types of object or element of the structure of the aircraft. This integration of the device, according to the invention is carried out either by bonding to the surface of the object or the element of the aircraft, or directly by insertion into the penultimate composite layer of the said object or of the said element. To do this, the said device has a shape, practically identical to that of a bank card, with a thickness of around a few millimeters, to ease its integration. 
     Despite its small size, the device, according to the invention, comprises wireless means, allowing it on the one hand, to send data to a human/machine interface or reader used by an operator, and on the other hand, to avoid the putting in place or the replacement of cabling for the sensors placed on the structure of the aircraft. 
     Additionally, the device, according to the invention, is not connected to a specific type of sensor. Indeed, the invention proposes a modular observation device, configured to offer a standardised interface, where all types of sensor can be connected in accordance with applications desired by the operator. 
     Also, the device, according to the invention, comprises a calculator or control unit equipped with a sufficient processing power, to process all necessary data for the observation of the object or of the element of the aircraft. This, so that the operator can carry out analyses via the human/machine interface put in the proximity of the device according to the invention, associated with an object or an element of the aircraft, and in accordance with different dynamically configurable parameters. So, the invention no longer requires, as is the technique, a support to make the software applications function, in order to collect and process the data from the sensors. 
     The device, according to the invention, also comprises means suitable for interfacing itself automatically with one or several energy salvage systems. These energy salvage systems are suitable for electrically supplying the device, according to the invention. The device, according to the invention, comprises means suitable for effectively operating and managing the electric energy received and/or accumulated. The device, according to the invention, is therefore suitable for ensuring its own autonomy of functioning during the whole lifecycle of the aircraft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be included in the reading of the following description, and in the examination of the figures which supports it. These are presented for information purposes only, and in no way limiting of the invention. 
         FIG. 1  illustrates a diagrammatic representation of the device, according to a way of carrying out the invention; 
         FIG. 2  shows a structure of different elements making up the device, according to a way of carrying out the invention; 
         FIG. 3  is a functional diagram of the device, according to a way of carrying out the invention; 
         FIG. 4  shows an example of using the device, according to way of carrying out the invention; 
         FIG. 5  shows an example of curves established from the data collected for different sensors associated with the device, according to a way of carrying out the invention; 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  shows a control unit  100  connected to a set of sensors  110  and a means  120  of wireless transmission/reception. The control unit  100 , the means  120  of transmission/reception and the set of sensors  110 , are supplied in electrical energy by an accumulator  130 , suitable to be recharged. In a preferred way of fulfillment, the accumulator  130  is a Li-ion type battery. This accumulator  130  is suitable to be electrically recharged by a means  120  of integrated electromagnetic connection, or by an outside unit  140  of energy salvage, in order to convert into electrical energy. This unit  140  of energy salvage is a nanoscale electrical generator. Indeed, this generator  140  is suitable for converting mechanical type energy into electrical energy, such as vibrations, a dispersal of fluid, a biological movement, or solar type energy, or electromagnetic type energy, or yet calorific type energy. 
     The control unit  100 , the means  120  of transmission/reception, and the accumulator  130  are suitable for being put in a case, of which the dimensions are equivalent to those of a credit card. In a way of fulfillment, the case has a length of 85 mm, a width of 55 mm, and a thickness of a few millimeters. These dimensions allow, in a preferred way of fulfillment, an integration of the device, according to the invention, in the penultimate composite material layer of an object  400  or of an element, making up the structure of an aircraft as shown in  FIG. 4 . Alternatively, the device is suitable for bonding itself to the surface of the said object or of the said element. 
       FIG. 2  shows a detailed view of the different elements making up the device, according to the invention. Indeed, the control unit  100  comprises a microprocessor  101 , a program memory  102  and a data memory  103  interlinked with each other via a set of communication buses  104 . In a way of carrying out the invention, the microprocessor  101 , the program memory  102 , the data memory  103  and the communication buses are integrated in a microcontroller  105 . The control unit  100  comprises an input/output interface  106 , having a digital analogue converter  107 , allowing the connection and the transfer of data between the microcontroller  105  and the set of sensors  110  via a set of communication buses. The set of sensors  110  comprises, in a non-exhaustive way, a temperature sensor  111 , a humidity sensor  112 , a pressure sensor  113 , an accelerometer  114 , a distortion sensor  115 , and an ultrasound sensor  116 . These sensors  110  have as a characteristic, the fact that each does not consume a lot of electrical energy. 
     The control unit  100  is connected in a bidirectional way, with the means of transmission/reception  120 . These means of transmission/reception  120  comprise a set of material layers, which are respectively, a radio layer  121 , an analogue band base layer  122 , a digital band base layer  123 , a data-link controller (not shown) and a data-link administrator (not shown). The radio layer  121  is connected to a radio frequency antenna  124 , so as to emit and receive data. In a way of carrying out the invention, the frequencies used to emit or receive data from the antenna are either 13.56 MHz or 900 MHz. 
     The control unit  100  also comprises a non-volatile data memory  108 , with which it communicates in a bidirectional way. 
     The control unit  100  is, as previously indicated, supplied by the battery  130 . However, as this control unit  100  is intended to end up irreversibly bonded to the surface or integrated in the penultimate composite material layer of an object or of an element of the aircraft, the invention is intended to recharge the battery  130 , the putting into place in the control unit  100  of an electromagnetic energy salvage unit  131 . So, during the reception or the emission of data by means of the antenna  124 , surrounding electromagnetic waves are absorbed to be converted into electrical energy. This salvaged electrical energy from the electromagnetic waves is then stored up by the battery  130  via a charge control unit  132 . Consequently, this unit  132  will be named charger. 
     To not quickly discharge the battery  130 , the invention intends for the presence of a mechanical energy salvage unit  140 , more particularly allowing the conversion of vibratory or seismic energy, in order to transform into electrical energy. This unit  140  is intended to supply the set of sensors  110 , connected to the control unit  100 . The interest of the putting in place of a vibratory energy salvage unit  140  is to be able to supply the sensor linked to the vibrations and the heat sensor, when the aircraft is functioning. In the description, it is understood by the fact that the aircraft is functioning, the fact that at least one of the aircraft&#39;s motors is working. So, when at least one of the aircraft&#39;s motors is working, the structure of the aircraft is subjected to more or less significant vibrations, but sufficient to supply the unit  140 . 
       FIG. 3  is a diagrammatic representation of the different interactions between each functional unit of the device, according to a way of carrying out the invention. On this  FIG. 3 , it is observed that the microcontroller  105  is suitable for communicating according to a master-slave diagram, via an SPI (Serial Peripheral Interface) link  200 , with different digital and analogue sensors  110 , the data memory  108  and the means of transmission  120 . In the way of fulfillment of  FIG. 3 , the means of transmission is an RFID (Radio Frequency, Identification) chip. 
     Alternatively, the different digital sensors communicate with the control unit  100  by means of an I 2 C (Inter Integrated Circuit) bus. 
     Actions led by the microcontroller  105 , are ordered by the microprocessor  101 . The microprocessor  101  produces, in response to the instruction codes recorded in the program memory  102 , orders intended for different systems of the control unit  100  of the device, according to the invention. 
     The management of supplying the control unit  100  and these systems  110 ,  108  is attributed to a unit  250 . This unit  250  is suitable for receiving electrical energy which either comes from the battery  130 , and/or comes from the supercapacitor, previously supplied by the vibratory energy salvage unit  140 , and/or coming directly from the electromagnetic energy salvage unit  131 . The unit  250  is suitable for electrically supplying the microcontroller  105 , the data memory  108  and the sensors  110 . The means  120  of transmission/reception is a passive element, not requiring any energy source outside of the one supplied by a human/machine interface (not shown) at the time of the collection of data. At the time of the data collection by the operator, the surrounding electromagnetic waves are converted into electrical energy by the unit  131 , and then directed towards the charger  132  of the battery  130 . Two units  251 ,  252  of control of the current are placed respectively before the charger  132 , and after the battery  130 , so that the unit  250  of management of supply, determines the current coming from the electromagnetic energy salvage unit  131 , but also the current supplied or stored up by the battery  130 . 
     The invention is not limited to only vibratory and electromagnetic energy salvagers. Indeed, other types of energy salvager can be connected to the device of the invention, in accordance with the area of application, in order to ensure an observation of the structure of the aircraft. 
       FIG. 5  shows an example of curves established from the data collected for different sensors associated with the device, according to a way of carrying out the invention. 
     In  FIG. 5 , three curves  510 ,  520 ,  530  can be seen, of which a first curve  510  relates to the distortion sensor  115 , a second curve  520  relates to the temperature sensor  111 , and a third curve  530  relates to the hygrometry sensor  112 . These curves  510 ,  520 ,  530  allow to see what the data is that will be recorded in accordance with the different phases of flight of the aircraft. The control unit  100  considers three phases of flight of the aircraft. A first phase  551 ,  553 ,  557  of flight of the aircraft corresponds to the fact that the aircraft is on the ground. A second phase  552 ,  554 ,  556  of the aircraft corresponds to the fact that the aircraft is carrying out a flight known as normal. In the invention, it is considered that the aircraft carries out a normal flight, when the signal received by the control unit  100  from the sensor  111 ,  112 ,  113 ,  114 ,  115 ,  116 , is included between a previously determined limit  541  of observation and a previously determined limit  542  of recording. A third phase  555  corresponds to the fact that the aircraft is subjected to an emergency situation during its flight, when the signal, received by the control unit  100  from the sensor  111 ,  112 ,  113 ,  114 ,  115 ,  116 , is higher than or equal to the limit of recording  542 , plus a few seconds preceding or succeeding this time. 
     So, it is understood from the curve  510 , that during a step  551 , the aircraft is on the ground, the sensor  115  is on standby. 
     At a step  552 , the aircraft is in a phase of flight, considered here as normal. The sensor  115  measures data all along this phase of flight, and the control unit  100  checks that this data is included purely between the limit  541  of observation and the limit  542  of recording. As there is nothing to signal, the control unit  100  does not record data. 
     At a step  553 , the aircraft is once again on the ground, the sensor  115  is on standby. 
     At a step  554 , the aircraft is in a phase of flight, considered as normal. The sensor  115  measures data all along this phase of flight, the control unit  100  checks that this data is included purely between the limit  541  of observation and the limit  542  of recording. As there is nothing to signal, the control unit  100  does not record data. 
     At a step  555 , the aircraft is subjected to a significant stress during its flight. The sensor  115  measures data all along this phase of flight, the control unit  100  checks that this data is included purely between the limit  541  of observation and the limit  542  of recording. As the signal received by the control unit  100  is higher than the limit of recording  542 , then the control unit  100  proceeds to record data. During this same phase of flight, data relating to the curve  520  of temperature and the curve  530  of hygrometry is also recorded. During a short period of a few seconds preceding and succeeding the significant stress, data from different sensors will also be recorded. These recordings will allow the operator to determine the source(s) of the problem which has led to this emergency situation during the flight. 
     At a step  556 , the aircraft is in a phase of flight, considered as normal. The sensor  115  measures data all along this phase of flight, the control unit  100  checks that this data is included purely between the limit  541  of observation and the limit  542  of recording. As there is nothing to signal, the control unit  100  does not record data. 
     At a step  557 , the aircraft is once again on the ground, and the sensor is on standby. 
     At a step  558 , the aircraft is in a phase of maintenance or upkeep, and an operator, having its human/machine interface (not shown), comes to salvage the data recorded by the device of the invention. During this phase, the battery  130  of the device of the invention is recharged via electromagnetic waves emitted by the human/machine interface or the reader.