# US 11,440,646 B2 · Remaining tire tread depth management system

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- Number: US 11,440,646 B2
- Document ID: US11440646B2
- Status: Granted
- Kind: B2
- Application number: 16/772,484
- Filed: 2018-11-06
- Published: 2020-12-24
- Granted: 2022-09-13
- Earliest claimed: 2017-12-14
- Assignees: Bridgestone Corporation
- Applicants: Bridgestone Corporation
- Inventors: Hayato Toda; Seigo Hata
- Web page: https://patentgrep.com/patent/US11440646B2

## CPC

- B64C 25/36: Arrangements or adaptations of wheels, tyres or axles in general
- G01M 17/027: {using light, e.g. infrared, ultraviolet or holographic techniques}
- B60C 11/246: {Tread wear monitoring systems}
- B60C 19/00: Tyre parts or constructions not otherwise provided for
- B64F 5/60: Testing or inspecting aircraft components or systems
- G01B 11/02: for measuring length, width or thickness (G01B11/08 takes precedence)
- G01M 17/02: Tyres
- G05B 23/0283: {Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] (preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06)}
- B60C 2019/004: {Tyre sensors other than for detecting tyre pressure}
- B60C 2200/02: for aircrafts
- G05B 2219/45071: Aircraft, airplane, ship cleaning manipulator, paint stripping
- B64C: AEROPLANES; HELICOPTERS
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B64F: GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)

## Abstract

A remaining tire tread depth management system includes a remaining tire tread depth measurement device configured to measure a remaining tread depth of at least one of aircraft tires mounted on an aircraft, a tire wear amount estimation device configured to estimate a wear amount of all of the aircraft tires mounted on the aircraft including the aircraft tires, and a tire management server configured to estimate a remaining tread depth and a number of available flight times of all of the aircraft tires in accordance with measurement data output from the remaining tire tread depth measurement device and estimation data output from the tire wear amount estimation device.

## Claims

### Claim 1

A remaining tire tread depth management system comprising:
a remaining tire tread depth measurement device configured to measure a remaining tread depth of at least one of first aircraft tires mounted on an aircraft;
a tire wear amount estimation device configured to estimate a wear amount of all aircraft tires mounted on the aircraft including the first aircraft tires; and
a tire management server configured to estimate a remaining tread depth of all of the aircraft tires in accordance with measurement data output from the remaining tire tread depth measurement device and estimation data output from the tire wear amount estimation device,
the tire management server including:
an acquisition unit configured to acquire the remaining tread depth of the corresponding first aircraft tire measured by the remaining tire tread depth measurement device, and the wear amount of the corresponding first aircraft tire estimated by the tire wear amount estimation device;
an error calculation unit configured to calculate an error of the wear amount of the first aircraft tire based on the remaining tread depth of the first aircraft tire and the wear amount of the first aircraft tire acquired by the acquisition unit;
a first error correction unit configured to correct the error of the wear amount of the first aircraft tire calculated by the error calculation unit;
a second error correction unit configured to correct the wear amount of the aircraft tires other than the first aircraft tire in accordance with a correction coefficient regarding the error corrected by the first error correction unit;
a remaining tread depth estimation unit configured to estimate a remaining tread depth of all of the aircraft tires in accordance with the wear amount of all of the aircraft tires corrected by the first error correction unit and the second error correction unit;
a number-of-times estimation unit configured to estimate a number of available flight times of all of the aircraft tires mounted on the aircraft in accordance with the wear amount of all of the aircraft tires corrected by the first error correction unit and the second error correction unit and a flight schedule; and
a notification unit configured to notify a predetermined notification target of the remaining tread depth estimated by the remaining tread depth estimation unit and the number of available flight times estimated by the number-of-times estimation unit.

### Claim 2 (depends on 1)

The remaining tire tread depth management system according to claim 1, wherein:
the tire wear amount estimation device includes:
a calculation unit configured to calculate wear energy EP, which depends on an internal pressure of the aircraft tires, in accordance with the internal pressure and wear energy EFR of the aircraft tires in a state of a free rolling run in which the aircraft runs straight by rolling without braking force acting on the aircraft tires; and
an estimation unit configured to estimate the wear mount wear of the aircraft tires,
the calculation unit being configured to:
calculate wear energy EL, which depends on a load acting on the aircraft tires, in accordance with the load and the wear energy EFR;
calculate wear energy EV, which depends on a velocity of the aircraft, in accordance with the velocity and the wear energy EFR;
calculate wear energy ΔES, which depends on a slip angle caused in the aircraft tires, in accordance with the slip angle and the wear energy EFR; and
calculate wear energy ΔEB, which depends on a braking force of the aircraft, in accordance with the braking force and the wear energy EFR,
the estimation unit being configured to estimate the wear amount wear of the aircraft tires in accordance with the wear energy EP, the wear energy EL, the wear energy EV, the wear energy ΔES, the wear energy ΔEB, and a wear resistance R indicating a relationship between predetermined wear energy and a predetermined wear amount,
wherein the state of the free rolling run is included in a state of taxiing indicating a state in which the aircraft runs on a ground under a power of the aircraft.

### Claim 3 (depends on 2)

The remaining tire tread depth management system according to claim 2, wherein:
wear energy EW of the aircraft tires generated during a predetermined period of time is calculated in accordance with the wear energy EP, the wear energy EL, the wear energy EV, the wear energy ΔES, and the wear energy ΔEB; and
the wear amount wear of the aircraft tires is estimated such that the wear energy EW is divided by the wear resistance R.

### Claim 4 (depends on 2)

The remaining tire tread depth management system according to claim 2, wherein the wear energy EP, the wear energy EL, the wear energy EV, the wear energy ΔES, and the wear energy ΔEB are calculated in accordance with a position of each rib of the respective aircraft tires in a state in which the aircraft tires are mounted on the aircraft.

### Claim 5 (depends on 4)

The remaining tire tread depth management system according to claim 4, wherein, when the position of each rib of the respective aircraft tires is represented by use of a variable i,
the wear energy EP is calculated according to the following formula 1:
[Math. 1]
EPi(P)=aPP2+bPP+cP (1)
where P is the internal pressure, and aP, bP, and cP are constants,
the wear energy EL is calculated according to the following formula 2:
[Math. 2]
ELi(L)=aLL2+bLL+cL (2)
where L is the load, and aL, bL, and cL are constants,
the wear energy EV is calculated according to the following formula 3:
[Math. 3]
EVi(V)=aVV2+bVV+cV (3)
where V is the velocity, and aV, bV, and cV are constants,
the wear energy ΔES is calculated according to the following formula 4:
[Math. 4]
ΔESi(SA)=aS(SA)2+bS(SA)+cS−EFR (4)
where SA is the slip angle, and aS, bS, and cS are constants,
the wear energy ΔEB is calculated according to the following formula 5:
[Math. 5]
ΔEBi(GxBR)=aB(GxBR)2+bB(GxBR)+cB−EFR (5)
where GXBR is the braking force, and aB, bB, and cB are constants,
the wear energy EW is calculated according to the following formula 6:
[
Math
.
6
]
E
w
i
=
∑
E
P
i
(
P
)
·
E
L
i
(
L
)
·
E
V
i
(
V
)
·
{
E
F
⁢
R
i
+
Δ
⁢
E
S
i
(
S
)
+
Δ
⁢
E
B
i
(
B
)
}
·
V
⁢
Δ
⁢
t
2
⁢
π
⁢
r
(
6
)
where Δt is a predetermined time, and r is a circling radius of the aircraft, and
the wear amount weari of the aircraft tires is estimated according to the following formula 7:
[
Math
.
7
]
wear
i
=
E
w
i
R
(
7
)
where R is the wear resistance.

### Claim 6 (depends on 2)

The remaining tire tread depth management system according to claim 2, wherein the internal pressure and the velocity are acquired from an airline.

### Claim 7 (depends on 1)

The remaining tire tread depth management system according to claim 1, wherein the remaining tire tread depth measurement device includes:
a measurement mechanism configured to measure a depth of each groove formed on a tread of the respective aircraft tires with no contact with the tread;
a slide mechanism configured to cause the measurement mechanism to slide in a predetermined direction;
an output unit configured to output the measurement data indicating the depth measured by the measurement mechanism; and
a housing unit housing the measurement mechanism and the slide mechanism,
wherein the housing unit has an inclined surface which is to face the tread,
the inclined surface is provided with a measurement window, and
the measurement unit is arranged inside the measurement window.

### Claim 8 (depends on 7)

The remaining tire tread depth management system according to claim 7, wherein:
the housing unit has a box-like shape having at least the inclined surface, a pair of side surfaces, and a back surface opposed to the inclined surface;
the inclined surface and the back surface are longer than the paired side surfaces; and
the measurement window extends in the predetermined direction.

### Claim 9 (depends on 8)

The remaining tire tread depth management system according to claim 8, wherein the housing unit includes:
a vertical surface extending in a vertical direction and connected to a lower edge of the inclined surface; and
a top surface extending in a horizontal direction and connected to an upper edge of the inclined surface and an upper edge of the back surface.

### Claim 10 (depends on 7)

The remaining tire tread depth management system according to claim 7, wherein:
the remaining tire tread depth measurement device includes an identification information acquisition unit configured to acquire identification information about identifying the respective aircraft tires; and
the output unit outputs the measurement data associated with the identification information.