AIRCRAFT CABIN SEAT MONITORING

Abstract

The invention relates to an automatic seat monitoring system for an aircraft cabin, comprising: - a radio frequency reader (108) designed to emit a radio frequency interrogation wave; and - on each of the seats, a monitoring device (110) comprising: • a processor (202), • a radio frequency antenna (204), • a piezoelectric generator (206) fixed to a part of the seat (104), and • a power supply module (208) designed to provide the processor (202) with electrical power, called radio frequency power (RFP), from the radio frequency interrogation wave received by the radio frequency antenna (204) and, concurrently, with electrical power, called piezoelectric power (PZ), from the piezoelectric generator (206).The processor (202) is designed to control the radio frequency antenna (204) so ​​that the latter emits a radio frequency response wave carrying an identifier of the monitoring device (110). The radio frequency reader (108) is designed to receive the radio frequency response wave and retrieve the identifier from it. Figure for the abbreviation: Fig. 1.

Description

Title of the invention: MONITORING OF SEATS IN AN AIRCRAFT CABIN Technical field of the invention

[0001] The present invention relates to an installation for automatically monitoring seats in an aircraft cabin, an aircraft cabin comprising such an installation and a corresponding method. Technological background

[0002] Monitoring the seats of an aircraft cabin, in particular their mechanical activity, can be useful in various situations, such as for example to monitor passenger activity or to monitor the structural health of the seats.

[0003] For the latter case, it is known to use a strain gauge to measure the deformation of a part of a seat. These deformation measurements are particularly interesting with regard to structural health if they are carried out during mechanical activity, in particular when a passenger sits or moves in his seat. These measurements can then be analyzed in the aircraft or on the ground.

[0004] To electrically power the strain gauges, it is known to use a wired power supply. However, this solution is expensive and the wiring it requires adds mass to the aircraft.

[0005] To avoid cables, the use of batteries is not desirable because this is difficult to certify, particularly due to the risk of fire.

[0006] For the wireless power supply of sensors, there are several energy harvesting solutions.

[0007] Among these solutions, there is radiofrequency energy harvesting (from the English "RFID energy harvesting") consisting of converting a radiofrequency electromagnetic wave into electrical power. More precisely, an RFID reader (also called an interrogator, coupler or base station) generates the radiofrequency wave, from which the sensor extracts the electrical energy necessary for its operation. This energy harvesting requires a short distance between the radiofrequency reader and the sensor. Thus, to cover a large area, it is necessary to multiply the number of radiofrequency readers.

[0008] It may thus be desirable to provide an automatic monitoring installation for seats in an aircraft cabin, which makes it possible to overcome at least some of the aforementioned problems and constraints. Summary of the invention

[0009] It is therefore proposed an automatic seat monitoring installation of a aircraft cabin, characterized in that it comprises: - a radio frequency reader designed to emit an interrogation radio frequency wave; and - on each of the seats, a monitoring device comprising: • a processor, • a radiofrequency antenna, • a piezoelectric generator attached to a part of the seat, and • a power supply module designed to provide the processor with electrical power, called radiofrequency power, from the interrogation radiofrequency wave received by the radiofrequency antenna and, jointly, electrical power, called piezoelectric power, from the piezoelectric generator, and the processor being designed to control the radio frequency antenna so that the latter emits a response radio frequency wave carrying an identifier of the monitoring device, the radio frequency reader being designed to receive the response radio frequency wave and recover the identifier therefrom.

[0010] Thus, thanks to the invention, the distance between the radiofrequency reader and the monitoring device can be greater than when using only radiofrequency energy harvesting. Thus, it is possible to cover all the seats in the cabin with a limited number of radiofrequency readers. Furthermore, the transmission of data to the radiofrequency reader is carried out when it is useful, i.e. when the seat is in use. Thus, the piezoelectric generator serves both as a supplementary power supply for the processor and as a seat activity detector.

[0011] The invention may further comprise one or more of the following optional features, in any technically possible combination.

[0012] Optionally, the monitoring device is at a distance from the radio frequency reader such that the radio frequency power is less than a minimum power required by the processor to start and operate.

[0013] Also optionally, the power supply module is battery-free.

[0014] Also optionally, in particular to carry out maintenance predictive and other applications requiring the evaluation of a static load on the seat, the monitoring device further comprises a strain gauge attached to a part of the seat, the processor being further adapted to bias the strain gauge to obtain at least one strain measurement and to control the radio frequency antenna so that the response radio frequency wave carries the strain measurement(s) with the identifier.

[0015] Also optionally, the processor is designed to compare the last deformation measurement(s) to the one(s) directly preceding them, and to controlling the radiofrequency antenna so that the latter emits the response radiofrequency wave carrying the last deformation measurement(s) if the last deformation measurement(s) are sufficiently different from the previous one(s), and not to control the radiofrequency antenna to emit the response radiofrequency wave carrying the last deformation measurement(s) otherwise.

[0016] An aircraft cabin is also proposed comprising: - seats; and - a seat monitoring installation according to the invention.

[0017] An aircraft comprising a cabin according to the invention is also proposed.

[0018] Also provided is a method for monitoring seats in an aircraft cabin, comprising: - a radiofrequency reader provides an interrogation radiofrequency wave; and - for each of the seats: • a power supply module of a monitoring device provides a processor of the monitoring device with electrical power, called radiofrequency power, from the interrogation radiofrequency base received by a radiofrequency antenna of the monitoring device, • in response to the deformation of a part of the seat to which a piezoelectric generator is attached, the power supply module provides the processor, together with the radiofrequency power, with electrical power, called piezoelectric power, from the piezoelectric generator, • with the radio frequency power and the piezoelectric power, the processor starts and controls the radio frequency antenna so that the latter emits a response radio frequency wave carrying an identifier of the monitoring device, and • the radiofrequency reader receives the response radiofrequency and retrieves the identifier from it. Brief description of the figures

[0019] The invention will be better understood with the aid of the following description, given solely by way of example and with reference to the appended drawings in which: - [Fig.l] is a schematic view of an aircraft cabin with an installation according to the invention for monitoring seats in the cabin, - [Fig.2] is a functional view of a radiofrequency reader and a monitoring device of the installation of [Fig.l], - [Fig.3] is a block diagram illustrating the steps of a method of operating the radiofrequency reader and the monitoring device of [Fig.2], and - [Fig.4] is a timing diagram representing the evolution over time of an electrical power supplied to a processor of the monitoring device of [Fig.2]. Detailed description of the invention

[0020] With reference to [Fig.l], an example of an aircraft cabin 102 in which the invention is implemented will now be described.

[0021] The cabin 102 comprises seats 104 for passengers. Each seat 104 comprises several parts forming a mechanical structure of the seat 104. Some of the parts are fixed relative to each other, and other parts are linked together by connections allowing them to move relative to each other. For example, each seat 104 may comprise a seat and a backrest that can be tilted relative to the seat.

[0022] The cabin 102 further comprises an installation 106 for structural monitoring of the seats 104. This installation 106 comprises a radiofrequency reader 108, for example fixed to a wall of the cabin 102, and, on each of the seats 104, a radiofrequency monitoring device 110.

[0023] With reference to [Fig.2], one of the monitoring devices 110 will now be described in more detail, the other monitoring devices 110 being similar.

[0024] The monitoring device 110 firstly comprises a processor 202 and a radiofrequency antenna 204, by which the processor 202 is designed to exchange data with the radiofrequency reader 108. The processor 202 comprises / is for example an electronic chip or a dedicated integrated circuit.

[0025] The monitoring device 110 further comprises a piezoelectric generator 206 fixed to one of the parts of the seat 104.

[0026] The monitoring device 110 further comprises a power supply module 208 designed to provide electrical power to the processor 202 from one or both of the radiofrequency antenna 204 and the piezoelectric generator 206, as will be described in more detail later with reference to [Fig. 3] and [Fig. 4]. The power supply module 208 is in particular devoid of a battery, i.e. of a device for storing electrical energy in chemical form. Thus, in the absence of power received by the radiofrequency antenna 204 and / or the piezoelectric generator 206, the power supply module 208 is not capable of electrically powering the processor 202. This absence of a battery is advantageous, because the presence of a battery requires significant qualifications in the aeronautical field. to ensure a low risk of fire starting.

[0027] The monitoring device 108 further comprises a strain gauge 210 fixed to one of the parts of the seat 104, which may be the same part or a different part from that on which the piezoelectric generator 206 is fixed. The strain gauge 210 is thus designed to measure a deformation of the part on which it is fixed.

[0028] With reference to [Fig.3] and [Fig.4], an example of a method 300 for operating the installation 106 will now be described.

[0029] During a step 302, the radiofrequency reader 108 emits an interrogation radiofrequency wave which is received by the radiofrequency antenna 204. Consequently, the power supply module 208 provides the processor 202 with electrical power, called radiofrequency power Prf, from the interrogation radiofrequency wave received by the radiofrequency antenna 204. For the seats 104 close to the radiofrequency reader 108, this radiofrequency power PRF may be greater than a minimum power Pmin required by the processor 202 to start and operate. However, for the seats further away, the radiofrequency power Prf may be lower than this minimum power Pmin, as illustrated in [Fig. 4], so that the processor 202 remains switched off.

[0030] During a step 304, a passenger sits on the seat 104 which causes a deformation of the part on which the piezoelectric generator 206 is fixed.

[0031] Consequently, during a step 306, the power supply module 208 then provides the processor 202, in addition to the radiofrequency power PRF, with electrical power, called piezoelectric power Pz, from the piezoelectric generator 206.

[0032] However, the sum of the radiofrequency power PRF and the piezoelectric power Pz is greater than that Pmin required by the processor 202 to start. Thus, the processor 202 starts, then automatically requests the strain gauge 210 to obtain at least one deformation measurement. Preferably, in particular with a view to evaluating the structural health of the seat 104, the processor 202 only transmits measurements in the event of movement of the seat 104 (for example when the seat back is inclined or when a passenger leans on the armrest), that is to say when these measurements are not constant. For this, for example, the processor 202 compares the last deformation measurement(s) with the one(s) directly preceding them.For example, if the last measurement(s) are obtained at times N to N+m (m integer greater than or equal to zero), then they are compared to the previous measurement(s) obtained at times Nlk to Nl (k integer greater than or equal to zero). If the last deformation measurement(s) are close to those previously obtained, the processor 202 does not transmit them to the radiofrequency reader 108 at . through the radio frequency antenna 204. If the last strain measurement(s) are sufficiently different, the processor 202 commands the radio frequency antenna 204 to transmit a response radio frequency wave carrying the last strain measurement(s), as well as an identifier of the monitoring device 110. Alternatively, the processor 202 could not perform this comparison and still transmit all strain measurements.

[0033] During a step 308, the radiofrequency reader 108 receives the response radiofrequency wave and recovers from the latter the deformation measurement(s).

[0034] In conclusion, it is clear that an installation such as that described above makes it possible to reduce the number of radiofrequency readers required to cover the entire cabin. This makes it possible to do away with storage devices while reducing the cost.

[0035] It will also be noted that the invention is not limited to the embodiments described above. It will indeed appear to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teaching which has just been disclosed to them.

[0036] In particular, the presence of the strain gauge is not essential. Indeed, to carry out simple monitoring of passenger presence, it is only necessary to transmit the identifier to the radiofrequency reader.

[0037] In addition, other types of sensors could be used in the monitoring device, instead of or in addition to the strain gauge, to access other information about the seats.

[0038] In the detailed presentation of the invention which is made above, the terms used must not be interpreted as limiting the invention to the embodiments set out in the present description, but must be interpreted to include all equivalents whose prediction is within the reach of those skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

Claims

1. Installation (106) for automatic monitoring of seats (104) of an aircraft cabin (102), characterized in that it comprises: - a radiofrequency reader (108) designed to emit an interrogation radiofrequency wave;and - on each of the seats (104), a monitoring device (110) comprising: • a processor (202), • a radiofrequency antenna (204), • a piezoelectric generator (206) fixed to a part of the seat (104), and • a power supply module (208) designed to supply the processor (202) with electrical power, called radiofrequency power (Prf), from the interrogation radiofrequency wave received by the radiofrequency antenna (204) and, jointly, with electrical power, called piezoelectric power (Pz), from the piezoelectric generator (206), and the processor (202) being designed to control the radiofrequency antenna (204) so ​​that the latter emits a response radiofrequency wave carrying an identifier of the monitoring device (110), the radiofrequency reader (108) being designed to receive the response radiofrequency wave and recover from this last identifier.;

2. Installation (106) according to claim 1, in which the monitoring device (110) is at a distance from the radiofrequency reader (108) such that the radiofrequency power (Prf) is less than a minimum power (Pmin) required by the processor (202) to start and operate.

3. Installation (106) according to claim 1 or 2, in which the power module (208) is battery-free.

4. An installation (106) according to any one of claims 1 to 3, wherein the monitoring device (110) further comprises a strain gauge (210) fixed to a part of the seat (104), the processor (202) being further adapted to request the strain gauge (210) to obtain at least one deformation measurement and to control the radiofrequency antenna (204) so ​​that the response radiofrequency wave carries the deformation measurement(s) with the identifier.

5. An installation (106) according to claim 4, in which the processor (202) is designed to compare the last deformation measurement(s) with the one(s) directly preceding them, and to control the radiofrequency antenna (204) so ​​that the latter emits a response radiofrequency wave carrying the last deformation measurement(s) if the last deformation measurement(s) are sufficiently different from the previous one(s), and not to control the radiofrequency antenna (204) to emit the response radiofrequency wave carrying the last deformation measurement(s) otherwise.

6. Aircraft cabin (102) comprising: - seats (104); and - an installation (106) for monitoring the seats (104) according to any one of claims 1 to 5.

7.

8. Aircraft comprising a cabinet (102) according to claim 6. Method for monitoring seats (104) of an aircraft cabin (102), comprising: - a radiofrequency reader (108) provides an interrogation radio frequency wave; and - for each of the seats (104): • a power supply module (108) of a monitoring device (110) provides a processor (202) of the monitoring device (110) with electrical power, called radiofrequency power (Prf), from the interrogation radiofrequency wave received by a radiofrequency antenna (204) of the monitoring device (110), • in response to the deformation of a part of the seat (104) to which a piezoelectric generator (206) is attached, the power supply module (108) provides the processor (202), together with the radiofrequency power (Prf), with electrical power, called piezoelectric power (Pz), from the piezoelectric generator (206), with the radio frequency power (Prf) and the piezoelectric power (Pz), the processor (202) starts and controls the radio frequency antenna (204) so ​​that the latter emits a response radio frequency wave carrying an identifier of the monitoring device (110), and the radiofrequency reader (108) receives the response radiofrequency wave and recovers the identifier from the latter.

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