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(11) EP 1 892 129 A2
(12) EUROPEAN PATENT APPLICATION
(43) Date of publication: (51) Int Cl.: 27.02.2008 Bulletin 2008/09 B60C 23/04 (2006.01)
(21) Application number: 07114932.2
(22) Date of filing: 24.08.2007
(84) Designated Contracting States: (72) Inventor: Logan, Brian Matthew AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Akron, OH 44302 (US) HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR (74) Representative: Kutsch, Bernd Designated Extension States: Goodyear S.A., AL BA HR MK YU Patent Department, Avenue Gordon Smith (30) Priority: 25.08.2006 US 467405 7750 Colmar-Berg (LU)
(71) Applicant: THE GOODYEAR TIRE & RUBBER COMPANY Akron, OH 44316-0001 (US)
(54) Aircraft tire condition monitoring system and method
(57) An aircraft tire condition monitoring system in- the aircraft. The antenna (16) is electrically coupled to cludes a reader (20) mounted in the fuselage (32) of an the reader (20) to facilitate the communication of signals aircraft and an antenna (16) that defines a peripheral from a transponder (14) located within the tire (12). The boundary proximate the circumference of a tire (12) of antenna (16) may be located within the tire (12), or it may be located on the aircraft fuselage (32). EP 1 892 129 A2
Printed by Jouve, 75001 PARIS (FR) 1 EP 1 892 129 A2 2
Description comings and drawbacks of tire condition monitoring sys- tems heretofore known for use in vehicles. Dependent Technical Field claims refer to preferred embodiments of the invention. [0007] According to one preferred aspect of the inven- [0001] The present invention pertains generally to an 5 tion, an aircraft tire condition monitoring system includes apparatus for monitoring the condition of a tire, and more a reader mounted in the fuselage of an aircraft for receiv- particularly to an apparatus for monitoring the condition ing signals from an instrumented aircraft tire, and an an- of a pneumatic aircraft tire. tenna that defines a peripheral boundary proximate the circumference of the tire. The antenna is electrically con- Background 10 nected to the reader for transmission of electrical signals, either by electromagnetic coupling between two conduc- [0002] The benefits of proper inflation of aircraft tires tors or by direct physical connection therebetween. are well known. For example, properly inflated aircraft [0008] The system preferably further includes a tire tires protect against tire failure due to extreme deflection having a transponder located on the interior of the tire. of the tires during take-off and landing, and also help to 15 The transponder is configured to sense are pressure reduce dynamic stresses in the tires to thereby extend and/or temperature associated with the tire. The trans- the working life of the tires. ponder generates a signal related to the sensed pressure [0003] It is well known to monitor the condition of a and/or temperature. The signal is communicated to the pneumatic tire using one or more sensors disposed within reader via the antenna. In one embodiment, the antenna the tire or on a wheel rim upon which the tire is mounted. 20 may be located within the interior of the tire. In another Conventional tire monitoring systems typically utilize ra- embodiment, the antenna is located exteriorly of the tire, dio frequency (RF) transponders that are provided with such as in the fuselage of the aircraft. sensors for detecting various conditions of a tire, such [0009] These and other features, objects and advan- as the internal pressure and temperature of the tire. The tages of the invention will become more readily apparent transponders may be active or passive. Active trans- 25 to those skilled in the art in view of the following detailed ponders have their own power supply (e.g., a battery), description, taken in conjunction with the accompanying while passive transponders are powered by the energy drawings. of an incoming RF signal from a reader device, as known in the art. The transponder generates a signal to be re- Brief Description of the Drawings ceived by the reader device and which includes informa- 30 tion related to the sensed conditions of the tire. [0010] [0004] Because RF transponders have a relatively lim- ited communication range, reader devices must be lo- FIG. 1 is a perspective view illustrating an instru- cated relatively close to the transponders to receive the mented pneumatic tire in accordance with the prin- signals. Conventional instrumented tires have utilized a 35 ciples of the present invention. transponder fixed to an interior surface of the tire, and FIG. 2 is a perspective view of a second exemplary an antenna which extends circumferentially around the instrumented pneumatic tire in accordance with the tire to facilitate communication between the transponder principles of the present invention. and the reader device regardless of the angular orienta- FIG. 3 is a perspective view of a third exemplary tion of the transponder in the rotating tire relative to the 40 instrumented pneumatic tire in accordance with the reader device. One drawback of using circumferentially principles of the present invention. extending antennas mounted within the interiors of pneu- FIG. 4 is a fourth exemplary instrumented pneumatic matic tires is that cyclic tensile and flexural loading of the tire in accordance with the principles of the present tires as they rotate causes stress fractures in the antenna invention. which may degrade performance and/or cause the an- 45 FIG. 5 is a schematic plan view illustrating an exem- tennas to break. The problem is compounded in pneu- plary installation of an instrumented pneumatic tire matic tires used in aircraft, which must not only handle on an aircraft, in accordance with the principles of heavy loads, but must also accommodate high forces the present invention. when the tires impact the ground during landing maneu- vers. 50 Detailed Description of the invention [0005] A need therefore exits for a system to monitor the conditions of aircraft tires that overcomes these and [0011] FIG. 1 depicts an exemplary aircraft tire condi- other drawbacks of the prior art. tion monitoring system 10 in accordance with the princi- ples of the present invention. The monitoring system 10 Summary of the invention 55 includes a pneumatic aircraft tire 12. A transponder 14 and an antenna 16 are mounted to tire sidewall 18 within [0006] The present invention refers to a tire according the interior of the tire 12. The transponder 14 is configured to claim 1. It overcomes the foregoing and other short- to sense various parameters of the pneumatic tire 12,
2 3 EP 1 892 129 A2 4 such as pressure and temperature of the interior of the 20 located outside the tire, as discussed above with re- tire 12. The antenna 16 is electrically connected to the spect to FIGS. 1 and 2. In this embodiment, however, transponder 14 and extends circumferentially around the the antenna 16 is also located outside the tire 12b and sidewall 18 of the tire 12. Because the antenna 16 in this is operatively electrically connected to the reader device embodiment is mounted to the sidewall 18, it should com- 5 20. The antenna 16 defines a peripherally extending prise material suited to accommodate the cyclic tensile boundary generally corresponding to a path traced by and flexural stresses experienced during service. transponder 14 as tire 12b rotates about its geometric [0012] The monitoring system 10 further includes a center. Accordingly, communication between the trans- reader device 20 positioned exteriorly of the tire 12, at a ponder 14 and the reader device 20 is facilitated regard- location in an aircraft fuselage. Accordingly, the trans- 10 less of the angular orientation of the transponder 14 with- ponder 14 can communicate with the reader 20 to trans- in tire 12b relative to reader device 20. mit information related to the sensed conditions of the [0016] FIG. 4 illustrates yet another exemplary embod- tire 12. Because the antenna 16 extends circumferential- iment of an aircraft tire condition monitoring system 12c. ly around the sidewall 18 of the tire 12, communication In this embodiment, a transponder 14 is located within between the reader 20 and transponder 14 may occur 15 the interior of a pneumatic aircraft tire 12c, on an interior regardless of the angular orientation of the transponder surface of the circumferential sidewall 24 of the tire 12c. 14 within tire 12, relative to the reader 20. The reader 20 The reader device 20 and an antenna 16 are disposed may be configured to record information received from outside the tire 12c. The antenna 16 extends circumfer- the transponder 14, or to perform calculations or math- entially around the outer surface of the tire 12c to define ematical and/or statistical operations using the informa- 20 a peripheral boundary which generally corresponds to a tion. Reader 20 may also transmit some or all of the in- path traced by the transponder 14 as the tire 12c rotates formation to another device (not shown), such as a dis- about its geometric center. Communication between the play for indicating the conditions of the tire 12 to a user. transponder 14 and the reader device 20 can occur re- The transmission of information or other signals from gardless of the angular orientation of the transponder 14 reader 20 may be in the form of radio frequency signals, 25 within the tire 12c, relative to the reader device 20, as or signals transmitted by a communication line 22. discussed above. [0013] While the monitoring system 10 has been de- [0017] While FIGS. 1-4 depict antennas 16 that are scribed above as being configured to sense pressure and physically connected to transponders 14 or readers 20, temperature conditions within a tire 12, it will be recog- it will be appreciated that the antennas may alternatively nized that various other parameters may be sensed. For 30 be spaced from the transponders 14 or readers 20 dis- example, monitoring systems in accordance with the tances suitable for permitting communication of signals principles of the invention may sense rotational speed, between the antennas 16 and the transponders 14 or slip, vertical displacement, or various other parameters readers 20, such as by electromagnetic coupling. FIG. 5 related to the condition of the tire and/or operation of the depicts an exemplary installation of an aircraft tire con- tire or aircraft. 35 dition monitoring system, as described above, used with [0014] FIG. 2 depicts another exemplary embodiment the landing gear 30 of an aircraft. The landing gear 30 is of a tire condition monitoring system 10a wherein fea- coupled to the aircraft fuselage 32 and is movable be- tures similar to those discussed above with respect to tween an extended condition (not shown) for supporting FIG. 1 are similarly numbered. A transponder 14 and an the aircraft during take off and landing, and a retracted antenna 16 are disposed within the interior of an aircraft 40 position within a landing gear bay 34 in the fuselage 32. tire 12a, on an inner surface of a circumferential wall 24 [0018] The landing gear 30 further includes one or of the tire 12a. The system further includes a reader de- more pneumatic aircraft tires 36 instrumented with a vice 20 positioned outside the tire 12a for communication transponder (not shown) as discussed above. In the em- with the transponder 14. Information regarding the con- bodiment shown, the tire condition monitoring system in- dition of the tire 12a is communicated from the trans- 45 cludes antennas 38 mounted outside the tires 36 and ponder 14 to the reader 20. The reader 20 may store the defining a peripheral boundary around the tires 36, in a information for subsequent transmission to another de- manner similar to that described above with respect to vice, or the reader 20 may perform operations or calcu- FIGS. 3 and 4. lations using the information. Thereafter, the information [0019] The antennas 38 are coupled to respective may be communicated to a third device, such as by radio 50 reader devices 40 configured to communicate with the frequency transmission, or by communication line 22, in transponders to thereby receive information related to a manner similar to that described above. the conditions of the respective tires 36. [0015] FIG. 3 illustrates another exemplary embodi- [0020] While FIG. 5 illustrates an aircraft tire condition ment of an aircraft tire condition monitoring system 10b, monitoring system wherein the antennas 38 are disposed in accordance with the principles of the present invention. 55 outside the tires 36, it will be recognized that antennas In this embodiment, a transponder 14 is disposed within may alternatively be provided on the interior surface of a pneumatic aircraft tire 12b, on the interior surface of a the tires as discussed above with respect to FIGS. 1 and sidewall 18. The system further includes a reader device 2. The reader devices 40 may perform functions on the
3 5 EP 1 892 129 A2 6 information received from the transponders, and may sensing an operating parameter associated with record the information or further transmit the information the tire (12); generating a signal related to the to other devices so that the information may be recorded sensed parameter using a transponder (14) or acted upon as appropriate. mounted within [0021] An aircraft tire condition monitoring system in 5 the tire (12); and transmitting the signal to a read- accordance with the principles of the present invention, er (20) located on an aircraft fuselage (32). as described above, is capable of monitoring various pa- rameters of an aircraft’s tires in service to ensure that the 8. The method of claim 7, wherein transmitting the sig- tires are in good condition. Information related to the con- nal to the reader (20) comprises transmitting the sig- dition of the tires may be recorded or communicated to 10 nal via an antenna (16) located on the aircraft fuse- users of the system, so that appropriate action can be lage (32). taken to service or replace tires, as may be required. Information related to sensed conditions of a tire can be 9. The method of any of claims 7 or 8, wherein the communicated from a transponder within a tire to a reader sensed operating parameter is at least one of a pres- located outside the tire regardless of the angular position 15 sure and a temperature associated with the tire. of the transponder due to tire rotation.
Claims 20 1. An aircraft tire condition monitoring system compris- ing a reader (20) mounted in the fuselage (32) of an aircraft and an antenna (16) defining a peripheral boundary proximate the circumference of a tire (12) of an aircraft landing gear (30) at least when the tire 25 (12) is in a stowed position, said antenna (16) being operatively electrically connected to said reader (20) for the transmission of signals therebetween.
2. The aircraft tire condition monitoring system of claim 30 1, further comprising a tire (12) and a transponder (14) disposed within said tire (12), said transponder (14) being adapted to sense at least one of a pres- sure and a temperature of said tire (12) and to com- municate information related to the sensed pressure 35 or temperature to said reader (20) via said antenna (16).
3. The aircraft tire condition monitoring system of claim 2, wherein said antenna (16) is disposed within an 40 interior of said tire (12).
4. The aircraft tire condition monitoring system of claim 2 or 3, wherein said antenna (16) is mounted to a sidewall (18) of said tire (12). 45
5. The aircraft tire condition monitoring system of claim 2 or 3, wherein said antenna (16) is mounted to a circumferential wall (24) of said tire (12). 50 6. The aircraft tire condition monitoring system of at least one of the previous claims, wherein said an- tenna (16) is mounted to the fuselage (32) of the aircraft. 55 7. A method of monitoring the condition of an aircraft tire, the method comprising:
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