FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
1. Title of the invention: DETECTION OF A TIRE FAILURE DURING AN ENDURANCE
TEST
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian CEAT Ltd At: Get Muwala Po: Chandrapura Ta: Halol - 389 350 Dist: Panchmahal, Gujarat, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

TECHNICAL FIELD
[0001] The present subject matter relates, in general, to an endurance test
of a tire to be installed in a vehicle and, particularly but not exclusively, to systems and methods for detection of failure of the tire during the endurance test.
BACKGROUND
[0002] In recent times, the tire industry has had very rapid growth, and
important changes have been made in the design of tires. Many new developments in rubber compounding and the construction of tires have taken place, and with such changes, a need for reliable and reasonably rapid means for testing tires for endurance other than the slow and expensive process of road testing has amplified.
BRIEF DESCRIPTION OF DRAWINGS
[0003] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a reference
number identifies the figure in which the reference number first appears. The
same numbers are used throughout the drawings to reference like features
and components.
[0004] Figure 1 illustrates a system for detection of a tire failure in an
endurance test, in accordance with an implementation of the present subject
matter;
[0005] Figure 2 illustrates a control device for determination of an instance
of an occurrence of the tire failure, in accordance with an embodiment of the
present subject matter; and

[0006] Figure 3 illustrates a method for detecting the tire failure in the
endurance test, in accordance with an implementation of the present subject matter.
DETAILED DESCRIPTION
[0007] The present subject matter relates to aspects concerning the
detection of a failure in a tire during an endurance test.
[0008] Due to various limitations associated with the road testing method
of conducting the endurance tests, various attempts have been made to develop means for the indoor testing of the endurance of the tires. Indoor endurance tests on new tires are generally conducted by tire manufacturers to assess the durability of the tires in an environment that is closer to an actual on-road environment.
[0009] During an indoor endurance test, a tire’s performance is assessed
with respect to various parameters, such as endurance at high speed; tire characteristics/force and moment; rolling resistance; noise levels; tire stiffness; foot-printing, including dynamic foot-printing; and wheel fatigue and so on. The indoor endurance test is carried out by freely rotating the tire on a smooth surface metal wheel or drum at a fixed speed, increasing load stepwise up to a certain kilometer limit or till failure. In a high-speed test, the tire is rotated on the drum at a step-wise increasing speed with a constant load, by holding the tire for a fixed period at every speed step, till failure occurs or to a maximum speed limit.
[0010] In conventionally known methods, the tire failure may be determined
when either a predetermined amount of local distortion or cracking occurs on surface of the tire. This type of failure can only be confirmed by visual inspection of the tire by an operator and requires periodical interruption in the test. Thus, it cannot be detected promptly when a crack occurs, thereby decreasing detection accuracy for the crack failure.

[0011] Further, in most conventional indoor endurance test set-ups, during
the endurance testing, the tire often bursts before the occurrence of the failure can be identified, thereby rendering the tire useless for further inspection to determine the cause of the tire failure. When the tire bursts, it becomes challenging to analyze the root cause of the tire failure by visual inspection as the bursting may result in complete physical damage to the tire. Thus, it becomes difficult to determine a definite location on the tire from where the defect may have started propagating to the surface of the tire. Likewise, endurance tests in which the rolling speed is examined at regular time intervals may often not reveal when the burst occurs since the occurrence of bursting varies from the tire to tire.
[0012] For these reasons, it may not be possible to stop the endurance test
immediately before the bursting of the tire and to accurately identify the location of the defect in the tire, and investigate the cause of the defect. Hence, it is desirable to stop the endurance test just at the initiation of the tire failure, so that it may be possible to analyze the root cause of the tire failure. In other words, when a failure starts to occur in the tire, it is desirable to immediately detect the start of the failure and end stop the endurance test.
[0013] In accordance with an embodiment of the present subject matter, a
system, and a method for detection of a tire failure in an endurance test are provided. The system comprises at least one sensing element that is disposed of in an endurance test environment, for example, an endurance test chamber. The sensing element is positioned at a static location in proximity of a tire that is to be tested. Whenever the tire is about to burst, the tire may start emitting some specific gases from a location in the tire from where the defect originates. The sensing element is thus configured to monitor concentration levels of those gases emitted by the tire during the endurance test. The system further comprises a control device that is coupled to the sensing element and

configured to record data pertaining to the concentration levels of the gas. Based on the recorded data, the control device further predicts an instance of the occurrence of the tire failure before the bursting of the tire.
[0014] For instance, when the endurance test starts, the sensing element
placed inside the endurance test chamber measures the concentration level
of the gases inside the test chamber. As the test progresses and if the tire that
is being tested starts failing, emission of the gases may start taking place from
one or more failure initiation points of the tire. This may result in a change in
the concentration of the gases within the endurance test chamber. The
sensing element measures the concentration level of the gases within the
endurance test chamber on an ongoing basis. The data pertaining to the
concentration level of the gases are then sent to the control device that
predicts the concentration levels of the gases for the near future. The
concentration level of the gases for the near future is predicted by the control
device based on historic data relating to the concentration level of the gas. If
the predicted value reaches a predetermined threshold value or goes beyond
the predetermined threshold value, then the control device may generate a
signal, for example, an alarm or a flashlight to stop the endurance test.
[0015] Accordingly, the present invention provides techniques for stopping
the endurance test of the tire just at the beginning of the tire failure, thereby making it possible to analyze the root cause of the tire failure, for example, by cutting the tire at a specific location.
[0016] Thus, the technique of the present invention is aimed at overcoming
the above-described problems associated with the conventional approach of conducting the indoor endurance tests, wherein the tire bursts before the location or cause of the failure occurrence is identified. Further, the technique of the present invention also addresses the other problems associated with the conventional methods of tire endurance testing, where the tire failure is

detected only when there are visible physical deformations in the tire, such as bulges and cracks in the tire.
[0017] The above-described technique for the detection of the tire failure in
the endurance test is further described with reference to Figures 1 to 3. It should be noted that the description and figures merely illustrate the principles of the present subject matter along with examples described herein and should not be construed as a limitation to the present subject matter. It is thus noted that various arrangements may be devised that, although not explicitly described or shown herein, describe the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0018] Figure 1 illustrates a system 100 for performing an indoor endurance
test in endurance test chamber 102 according to an example of the present subject matter. The system 100 may include a test drum 104, a tire 106 to be tested, and a support device 108 that rotatably supports the tire 106. As shown in Figure 1, the test drum 104 and the support device 108 are arranged inside the endurance test chamber 102 in such a manner that they enable outmost surface of the tire 106 to remain in physical contact with the test drum 104 so that the tire 106 that is supported by the support device 108 may be rotated during the endurance test. The test drum 104 serves as a road surface when the tire 106 is mounted on a vehicle. The support device 108 may be moved in a direction to approach or leave the outermost surface of the tire 106 as indicated by an arrow A by a load signal output from a system control device (not shown). Further, a rotation speed of the test drum 104 may also be freely adjusted based on the rotation speed signal output from the system control device.

[0019] In an example implementation, the system control device may be a
wall-mounted device such as a dimmer switch, a remote control device, or a retrofit remote control device that may be configured to control different functionalities of the test drum 104 and the support device 108, for example, rotation speed, rotation direction, axial movement, etc. In another example implementation, the system control device may also be a wireless or wired local area network (WLAN)-capable remote control device that utilizes WLAN communication protocols to communicate with and control the operation of the test drum 104.
[0020] When the tire 106 moves towards failure or bursting during the
endurance test, the tire 106 may start releasing some specific gases, such as sulfur gases. For example, rotation of the tire 106 at a high speed or high load may increase stress and strain in the body of the tire 106 which generates heat at some components of the tire 106 and may ultimately lead to the deformation of the tire 106. The generation of the heat from the tire 106 may cause the release of the gases from the deformed component of the tire 106. If the temperature of the tire 106 goes beyond a predetermined tolerance limit of the tire 106, the tire 106 may burst, thereby rendering the tire 106 useless for the inspection. However, if the concentration level of the gases being emitted by the tire 106 is known before the bursting of the tire 106, the endurance test may be stopped just at the beginning of the failure of the tire 106.
[0021] To achieve this, the system 100 comprises at least one sensing
element 110 disposed of at a static location in proximity of the tire 106. The sensing element 110 is configured to detect and monitor concentration levels of one or more gases emitted by the tire 106 during the endurance test. For instance, the sensing element 110 may detect and monitor the gases in the endurance test chamber 102 generated by a failure or decomposition of rubber of the tire 106 caused by heat generation in the tire 106.

[0022] In particular, the sensing element 110 illustrated in Figure 1 may be
a non-contact gas sensor for sensing the gases generated from the tire 106. Also, the nearest static location to the tire 106 where the sensing element 110 is mounted may be any location near the tire 106 from where the sensing element 110 may easily detect the presence of the gases without requiring establishing a physical connection with the tire 106. In an example embodiment, there may be just one sensing element 110 in the system 100. In another example implementation, more than one sensing element 110 in the system 100 is also possible, for example, one each for sensing different gases, such as carbon monoxide, carbon dioxide, sulfur dioxide, etc., during the endurance test.
[0023] The system 100 further comprises a control device 112 that is
communicatively coupled to the sensing element 110. The control device 112 continuously interacts with the sensing element 110 to retrieve data pertaining to the concentration levels of the gases emitted by the tire 106 throughout the duration of the endurance test. The recorded data may then be compared with historic data pertaining to the concentration levels of the gases collected during previous endurance tests and stored in the system 100. Furthermore, based on the comparison of the recorded data with the historic data, an instance of an occurrence of the failure for the tire 106 may be predicted. The system 100 may include an alarm device 114 that may be communicatively coupled to the control device 112 and configured visually (e.g., via an LED that is illuminated when the alarm device 114 is activated) and/or audibly (e.g., via beeping and/or other audio signals, a prerecorded message, speech synthesis, etc.) to notify users of the system 100 based on the detection of the instance of the occurrence of the failure of the tire 106. For example, the alarm device 114 may be triggered when the concentration levels of the gases being

emitted by the tire 106 reach near a predefined concentration range. Here the alarm may be indicative of a need to stop the endurance test.
[0024] Accordingly, the system 100 according to the present invention is
useful for testing the endurance of the tire 106, and in particular, reliably detects the failure of the tire 106 at an early stage. Further description of the implementation and working of the control device 112 is given in detail with respect to Figure 2.
[0025] Figure 2 illustrates the control device 112 in detail that is configured
to determine the instance of the occurrence of the failure of the tire 106, according to another example implementation of the present subject matter. The system 100 with the help of the control device 112 of the present invention provides a data-driven platform for determining the instance of the occurrence of the failure in the tire 106 that may be used to detect the failure in the tire 106 at the early stage during the endurance test.
[0026] In an example, the control device 112 may include any combinations
of the components shown in Figure 2. The components of the control device
112 may be implemented as integrated circuits (ICs) or portions thereof,
discrete electronic devices, or other modules, logic, hardware, software,
firmware, middleware, or a combination thereof adapted in the control device
112, or as components otherwise incorporated within the system 100.
[0027] The control device 112 may be an embedded system or other like
computer device that may be used to control the functioning of various components of the system 100, such as the test drum 104, the alarm device 114, etc., through its interfacing with the system control device. As depicted in Figure 2, in an example implementation, the control device 112 may include at least one processor 202 and a memory 204 coupled to the processor 202. In an example, the processor 202 may be implemented as microprocessors, microcomputers, microcontrollers, digital signal processors, central

processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. The memory 204 may include any computer-readable medium known in the art including, for example, volatile memory (e.g., RAM), and/or non-volatile memory (e.g., EPROM, flash memory, etc.). The memory 204 may also be an external memory unit, such as a flash drive, a compact disk drive, an external hard disk drive, or the like.
[0028] Also, as depicted in Figure 2, in an example implementation,
interface(s) 206 may be coupled to the processor 202. The interface(s) 206 may include a variety of software and hardware interfaces that allow interaction of the control device 112 with other communication and computing devices, such as network entities, external repositories, and peripheral devices, for instance, the sensing element 110. The interface(s) 206 may also enable the coupling of components of the system 100 with the control device 112 and components of the control device 112 with each other.
[0029] The control device 112 may also comprise module(s) 208 and data
222 coupled to the processor 202. In one example, the module(s) 208 and data 222 may reside in the memory 204. In an example, the data 222 may comprise the recorded data 224, the historic data 226, rate of change data 228, and other data 230. The module(s) 208 may include routines, programs, objects, components, data structures, and the like, which perform particular tasks or implement particular abstract data types. The module(s) 208 may further include modules that supplement applications on the control device 112 for determining the instance of the occurrence of the failure of the tire 106, for example, modules of an operating system. The module(s) 208 further includes modules that implement certain functionalities of the control device 112, such as processing the information received by the control device 112 from the sensing element 110.

[0030] The data 222 serves, amongst other things, as a repository for
storing data that may be fetched, processed, received, or generated by one or more of the module(s) 208. In an example, the recorded data 224 may be collected through continuous interaction with the sensing element 110 during a course of an endurance test on the tire 106. The historic data 226 comprises information on the concentration levels of the gases collected during previous instances of endurance tests and stored in the memory 204. The rate of change data 228 may comprise data pertaining to a rate of change in the concentration levels of the gases emitted by the tire 106 which is being subjected to the endurance test.
[0031] In an example embodiment, the system 100 may also include a
display device (not illustrated), The display device may be communicatively
coupled with the control device 112 and configured to display the speed of the
test drum 104, the support device 108, load on the tire 106, the temperature
of the test chamber 102, etc. The display device may include a CRT or liquid
crystal screen to display a GUI (to be described later) and the like.
[0032] To determine the instance of the occurrence of the failure in the tire
106, the control device 112 may require data pertaining to the concentration levels of the gases emitted by the tire 106 which is currently being subjected to the endurance test, and the historic data 226 based on which the failure of the tire 106 may be reliably detected at the initial stage.
[0033] Accordingly, in an example embodiment, the control device 112 may
include a sensing data communication module 210 that may be adapted to communicate with the sensing element 110 to retrieve recorded data 224 pertaining to the concentration levels of the gases emitted by the tire 106. Further, the control device 112 accesses the historic data 226 comprising information on the concentration levels of the gases collected during previous instances of endurance tests. In other words, the control device 112 may be

provided with historic data 226 relating to the previous endurance tests to enable processing of a current endurance test that is being conducted on the tire 106 to be influenced by the previous endurance tests.
[0034] In an example embodiment, the historical data may be understood
as the threshold level of % voltage change. The sensing element 110 senses the PPM of the gases in a given environment, i.e., the test chamber 102. This is then calibrated against a voltage value in order to be read by the control device 112. The voltage change may be given by:
voltage change = (RMS value of voltage for current T seconds) -
(RMS value of voltage for previous T seconds). The value of the voltage change may be plotted in terms of % and checked against the historical data. It may be a % change of standard deviation or crest factor as well. Here, the "change" is a big shift in the PPM of the gases and not the minor variations in the PPM.
[0035] In this manner, a tire failure determination module 212 of the control
device 112 may, in determining the instance of the occurrence of the tire failure
at the current endurance test, consider at least some historic data 226
pertaining to the concentration levels of the gases that were processed during
the previous endurance tests. This allows the control device 112 to be
especially proficient at detecting the failure in the tires at the early stage.
[0036] Further, based on an analysis of the historic data 226, a
predetermined threshold value of the concentration level change in terms of % of each of the gases that are generally emitted from the tires while conducting the endurances test may be defined and stored in the memory 204 of the control device 112 by the processor 202.
[0037] Thereafter, based on the comparison between the recorded data
224 and the predetermined threshold value, if the tire failure determination module 212 determines the concentration level change of the gases for the

near future for the tire 106 to be equal to or more than the predetermined threshold value of the concentration level change of the gases, a signal generation module 218 may generate a signal to cause the alarm device 114 to get triggered, thereby signaling that the endurance test needs to be stopped to avoid the bursting of the tire 106.
[0038] Alternatively, instead of the concentration levels of the gases as the
predetermined threshold value, a standard deviation or crest factor of the concentration of the gases may also be used to define the failure of the tire 106. For example, the control device 112 may include a rate of change determination module 216 that may be configured to determine a rate of change in the concentration levels of the gases. Here the determination of the rate of change in the concentration levels of the gases includes calculating at least one of crest factor and standard deviation of the concentration levels of the gases.
[0039] Thereafter, the signal generation module 218 may generate a signal
to cause the endurance test to stop if the rate of change determination module 216 determines that the rate of change of either the crest factor or the standard deviation is greater than the predetermined threshold value.
[0040] In an example embodiment, the modules of the control device 112
may be trained in an end-to-end fashion using various open-source machine learning models. For example, the sensing data communication module 210 may be trained using a deep machine learning model to enable it to automatically fetch data pertaining to the concentration levels of each of the gases generated during the endurance testing process.
[0041] Likewise, in another example, the tire failure determination module
212 may be trained using an open-source machine learning model that enables it to determine the concentration levels of the gases for the near future for the tire 106 and compare it with the predetermined value of the

concentration levels of the gases by analyzing the recorded data 224, as discussed above. Also, some or all parameters of the modules may be learned through the training process.
[0042] For example, a machine learning model may be trained using
training data that includes input data, such as the recorded data 224, historic data 226, rate of change data 228, etc., and the correct or preferred output of the model for the corresponding input data. The machine learning model may repeatedly process the input data, and the parameters of the machine learning model may be modified, for instance, in a trial-and-error process until the model produces or “converges” on the correct or preferred output, such as performing a correct determination of the instance of the occurrence of the failure of the tire 106. This way, the control device 112 of the system 100, by using a collaborative filtering deep learning model, may detect a tire failure at an early stage.
[0043] Thus, the technique of failure detection disclosed in the present
invention facilitates accurately predicting the failure in the tires in advance of
the occurrence of failure so that the endurance test can be immediately
stopped to avoid physical damage to the tires. Since the physical damage to
the tire is prevented, the exact location on the periphery of the tire from where
the defect might have started propagating to the surface and the root cause of
failure may be identified by cutting the tire at that specific location.
[0044] Figure 3 illustrates a method 300 for detecting the failure in the tire
106 during the endurance test, in accordance with an implementation of the present subject matter.
[0045] The order in which the method 300 is described is not intended to
be construed as a limitation, and any number of the described method blocks may be combined in any order to implement method 300, or an alternative method. Furthermore, the method 300 may be implemented by processor(s)

or computing device(s) through any suitable hardware, non-transitory
machine-readable instructions, or combination thereof.
[0046] It may be understood that blocks of the method 300 may be
performed, for example, by the system 100, as illustrated in Figure 1. In an
example, the system 100 for carrying out the method 300 of failure detection
is described in reference in Figure 1.
[0047] The blocks of the method 300 may be executed based on
instructions stored in a non-transitory computer-readable medium, as will be
readily understood. The non-transitory computer-readable medium may
include, for example, digital memories, magnetic storage media, such as
magnetic disks and magnetic tapes, hard drives, or optically readable digital
data storage media.
[0048] Referring to Figure 3, at block 302, the sensing element 110
monitors the concentration levels of the gases being emitted by the tire 106
during the endurance test. As discussed earlier, the tire 106 may release some
specific gases, such as oxides of carbon and sulfur gases, during the course
of the endurance test.
[0049] At block 304, the sensing data communication module 210 interacts
with the sensing element 110 and records the data pertaining to the
concentration levels of the gases generated by the tire 106 during the
endurance test.
[0050] At block 306, the tire failure determination module 212 determines
the concentration levels of the gases for the near future to be equal to or more
than the predetermined threshold value.
[0051] For example, the inventors of the present invention have observed
that whenever a tire fails, a significant amount of gases are released and
hence voltage rises significantly. Therefore, in an example implementation of
the present invention, the voltage change for different types of tires is

previously recorded and fed to the control device 112. Subsequently, during the actual endurance test, the control device 112 may compare the historical voltage change against the present voltage change value. If the present voltage change value crosses the historical predefined threshold, then the signal generation module 218 generates the signal to cause the alarm device 114 to get triggered, thereby indicating that the endurance test needs to be stopped to avoid the bursting of the tire 106.
[0052] Hence, the systems and methods of the present subject matter
enable faster and more accurate identification of the tire failure at an early stage, such that, endurance testing may be stopped immediately before the tire is physically damaged. There are several other advantages, such as no chances of damage to the machine/environment due to tire burst as well as lower cost of repair and tire development.
[0053] Although implementations have been described in a language
specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as examples of a system for recommending likely tire SKUs for the purposes such as selecting an appropriate tire SKU before placing the order.

I/We claim:
1. A system (100) for detection of a tire (106) failure in an endurance test,
the system (100) comprising:
at least one sensing element (110) disposed of at a static location in proximity of the tire (106) to be tested, the at least one sensing element (110) being configured to monitor concentration levels of at least one gas emitted by the tire (106) during the endurance test; and
a control device (112) communicatively coupled to the at least one sensing element (110) and configured to:
record data pertaining to the concentration levels of the at
least one gas; and
determine, based on the recorded data, an instance of an
occurrence of the tire failure.
2. The system (100) as claimed in claim 1, wherein the control device (112) is configured to detect, based on the recorded data, the instance of the occurrence of the tire (106) failure prior to the occurrence.
3. The system (100) as claimed in any of claims 1-2, further comprising an alarm module (114) configured to generate an alarm based on the detection of the instance of the occurrence of the tire failure, the alarm being indicative of a need to stop the endurance test.
4. The system (100) as claimed in claim 1, wherein the control device (112) is configured to compare the recorded data (224) to historic data (226) for determining the instance of the occurrence of the tire failure, wherein the historic data (226) is collected during a plurality of previous endurance tests.

5. The system (100) as claimed in claim 1, wherein the control device
(112) is further configured to:
determine a rate of change in the concentration levels by calculating at least one of crest factor and standard deviation of the concentration levels of the at least one gas; and
generate a signal to cause the endurance test to stop if the rate of change of the at least one of crest factor and standard deviation is greater than a predetermined threshold value.
6. A method (300) for detecting a tire (106) failure in an endurance test,
the method (300) comprising:
monitoring (302) concentration levels of at least one gas emitted by the tire during the endurance test;
recording (304) data pertaining to the concentration levels of the at least one gas; and
determining (306), based on the recorded data, an instance of an occurrence of the tire failure.
7. The method (300) as claimed in claim 6, further comprising detecting, based on the recorded data, the instance of the occurrence of the tire (106) failure prior to occurrence.
8. The method (300) as claimed in any of claims 6-7, further comprising generating an alarm based on the detection of the instance of the occurrence of the tire failure, wherein the alarm is indicative of a need to stop the endurance test.

9. The method (300) as claimed in claim 6, further comprising comparing
the recorded data (224) to historic data (226) for determining the instance of
the occurrence of the tire failure, wherein the historic data (226) collected
during a plurality of previous endurance tests.
10. The method (300) as claimed in claim 6, further comprising:
determining a rate of change in the concentration levels, wherein the
determining the rate of change in the concentration levels comprises calculating at least one of crest factor and standard deviation of the concentration levels of the at least one gas; and
generating a signal to cause the endurance test to stop if the rate of change of the at least one of crest factor and standard deviation is greater than a predetermined threshold value.