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: DETERMINING MISALIGNMENT OF TYRE
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie
Besant Road, Worli, Mumbai-Maharashtra 400 030, 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 techniques for
fault determination in tyres and, in particular, to determine misalignment in the tyres.
BACKGROUND
[0002] Tyres play an important role in dynamics of a vehicle. Among
other things, they help in providing lateral, longitudinal & radial forces to the vehicle required for tracking, steering, traction and providing stability to the vehicle. Therefore, it is important for a tyre to be in a good condition. A fault in the tyre may affect the performance of the vehicle and may even become a cause for accidents of the vehicle, in worst case scenarios. Thus, it is essential to monitor the various parameters of the tyre so that, the corrective measures may be taken at a right time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference the same elements.
[0004] Figure 1 illustrates a system for ascertaining misalignment of a
tyre, in accordance with an example implementation of the present subject matter;
[0005] Figure 2 illustrates different planes of a tyre, in accordance with an
example implementation of the present subject matter;
[0006] Figure 3a-3c depict a tyre, a first acceleration, and a second
acceleration in accordance with an example implementation of the present subject matter.

[0007] Figure 4 shows the sensor assembly in accordance with an example
implementation of the present subject matter.
[0008] Figures 5 illustrates a system for ascertaining misalignment in a
tyre, in accordance with another example of the present subject matter.
[0009] Figure 6 describes a method of ascertaining misalignment of a tyre
of a vehicle, in accordance with an example implementation of the present subject matter.
DETAILED DESCRIPTION
[0010] Generally, misalignment in a tyre of a vehicle is detected by a user
based on his experience of driving a vehicle. In general, misalignment may occur in the tyre due to various factors, such as due to moving on an uneven surface, potholes on the road. Further, misalignment may also occur in the tyre due to regular and prolonged use of the vehicle. Misaligned tyres may cause various problems for the vehicle. For example, a misaligned tyre of a vehicle may put uneven and undue stress on suspension system of the vehicle, and as a result the suspension system may suffer immature damage. Further, the misaligned tyre may also create difficulties in steering of the vehicle when driving at high speeds. Furthermore, the misaligned tyre may also cause uneven wear and tear of the tyre, leading to premature ageing of the tyre.
[0011] Thus, timely detection of misalignments of the tyre is required,
along with timely corrective actions to avoid early wear-and-tear of the tyres. Currently, there are no techniques to determine the misalignment of the tyre and the same is determined by a person using the vehicle based on the person's experience of driving. Thus, detecting the misalignment in the tyre depends on the expertise of a person driving the vehicle. In some cases, it is possible that the misalignment in the tyre may not be noticeable or the person driving the vehicle may not be able to notice the misalignment due to his inadequate driving experience or due to other unforeseen reasons. In such cases, the person may drive the vehicle with misaligned tyre which may be detrimental to the tyre and the vehicle.

[0012] According to an example implementation of the present subject
matter, techniques for determining misalignment of a tyre of a vehicle are described. When a tyre moves on a surface there may be an acceleration associated with the tyre. When an aligned tyre rotates on a surface, the acceleration may be generated in a rotational plane of the tyre, however, when a misaligned tyre rotates on the surface, an acceleration may develop on planes other than the rotational plane. Thus, existence of acceleration on any other plane other than the rotational plane may imply misalignment.
[0013] According to the present subject matter, a first acceleration of a
tyre in at least one plane is determined. The at least one plane is different from the rotational plane of the tyre. The rotational plane is the plane of rotation of tyre or in other words, the plane in which the tyre is rotating. Thus, the present subject matter aims at detecting the first acceleration in any of the plane apart from the rotational plane. If the first acceleration is determined to be non-zero in any one of the plane apart from the rotational plane for a predetermined time period, it is ascertained that misalignment is present in the tyre.
[0014] Thus, according to the present subject matter, the misalignment is
ascertained by determining the first acceleration in a plane of the tyre wherein the plane is different from the rotational plane. Thus, the misalignment determination according to the teachings of the present subject matter is not based on experience or expertise of the driver, rather the misalignment determination is based on determination of first acceleration in a plane other than the rotational plane. Thus, the technique of the present subject matter is more effective and accurate in detecting the misalignment. After, the misalignment is determined, a user can take corrective actions and may prevent the vehicle and tyre from adverse effects of the misalignment.
[0015] It should be noted that the description and the 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 understood that various arrangements may be devised

that, although not explicitly described or shown herein, embody the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and implementations of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0016] Figure 1 illustrates a system 100 for ascertaining misalignment of a
tyre 102, in accordance with an example implementation of the present subject matter. The system 100 is coupled with the tyre 102. In an example of the present subject matter, the system 100 ascertains the misalignment of the tyre 102.
[0017] The system 100 comprises a sensor assembly 104 and a monitoring
engine 106. The sensor assembly 104 detects a first acceleration of the tyre 102 in at least one plane which is different from a rotational plane of the tyre 102. The rotational plane of the tyre 102 is the plane of rotation of the tyre 102, wherein the tyre is rotating in a direction 108 as shown in the figure 1. In the figure 1, the rotational plane is a plane XOY. The sensor assembly 102 detects the first acceleration in a plane which is different from the rotation plane, which is plane XOY in the figure 1.
[0018] Further, the monitoring engine 106 determines a duration for which
the first acceleration of the tyre is non-zero. If it is determined that the first acceleration is non-zero for a predetermined time period, then the monitoring engine 106 ascertains that there is a misalignment of the tyre 102. According to the present subject matter, to ascertain the misalignment of the tyre 102, the first acceleration, in a plane different from the rotational plane, is determined for a predetermined time period, because the first acceleration may develop in a plane different from the rotational plane in scenarios, such as negotiating a pothole, negotiating a curve etc., and in such cases the first acceleration may be for a very short time period. For example, during negotiating a curve, the first acceleration may develop for two seconds. Thus, to eliminate such situations, the first acceleration is determined for a predefined time period for ascertaining the misalignment. In an example, the predetermined time period may be ten seconds. Further, in an example, the determination of misalignment is shown for a single

tyre in an example, however, it should be understood that the similar techniques may be used for determining the misalignment for all tyres of a vehicle.
[0019] Figure 2 illustrates different planes of a tyre 202. Figure 2 shows
the tyre 202 in XYZ axis. The tyre is rotating in a direction 204. According to the present subject matter, the rotational plane is the plane formed by the line XOZ.
[0020] The tyre is rotating in the direction 204 as shown in the figure 2. In
case the tyre 202 is perfectly aligned, the linear acceleration of the tyre should only be in Z direction which in the rotational plane XOZ. The presence of acceleration in any other plane apart from the plane XOZ may indicate misalignment. Due to the misalignment, the rotation of the tyre 202, may deviate from a central axis and the first acceleration may be detected in any other plane other than the rotational plane XOZ. For example, a system, such as the system 100 may detect the first acceleration in planes other than the plane XOZ. In an example, the first acceleration may be determined in a plane XOY which is perpendicular to the plane XOZ and perpendicular to a surface 206 on which the tyre 202 is rotating. In another example, the first acceleration may be determined in a plane ZOY which is perpendicular to the plane XOZ and parallel to the surface 206 on which the tyre 202 is rotating. If the first acceleration is detected in any one of the planes XOY and ZOY for a predetermined time period, the misalignment may be ascertained. It is to be noted that for ascertaining the misalignment, the first acceleration is detected for a predetermined time period, because the first acceleration may also develop during negotiating a curve or other similar instances. However, during such instances, such as negotiating the curve, the first acceleration detected would be short lived, in an example for three seconds. According to the present subject matter, the predetermined time period may be fifteen seconds in an example, and thus, the misalignment may be ascertained when the first acceleration is detected for fifteen seconds. Ascertaining the misalignment based on detecting the first acceleration for the predetermined time period, eliminates the possibility of false ascertaining of the misalignment due to generation of the first acceleration in some other scenario, such as

negotiating a curve. In the figure 2, two planes XOY and ZOY are shown apart from the rotational plane XOZ, however, it should be understood that there may be more planes in which the first acceleration may be determined for ascertaining the misalignment. In an example, accelerations may be determined for all the planes XOY, XOZ, and ZOY and the acceleration for the planes XOY and ZOY may be considered and used for ascertaining the misalignment as described above.
[0021] Figure 3a-3c depict a tyre 302, a first acceleration 310, and a
second acceleration 304 in accordance with an example implementation of the present subject matter. The second acceleration 304 is the acceleration of the tyre 302 in a rotational plane of the tyre 302. Fig 3a shows a perfectly aligned tyre 302. When the tyre 302 is perfectly aligned, a second acceleration 304 is detected to be aligned with an axis 306 passing through a center 308 of the tyre 302. The second acceleration 304 of the tyre 302 is the acceleration of the tyre 302 in the rotational plane of the tyre 302.
[0022] Figure 3b shows the tyre 302 which is misaligned. According to the
present subject matter, when a tyre 302 is misaligned, the first acceleration 310 is detected in the tyre 302 for a predetermined time period. The first acceleration 310 may in a plane other than the rotational plane of the tyre 302 for a predetermined time period. Further, according to the present subject matter, the second acceleration 304 is also detected. Thereafter, a shift in the second acceleration 304 is detected. In the figure 3b, the second acceleration 304 is shifted by an angle 312 from the axis 306. In an example implementation of the present subject matter, degree of shifting of the second acceleration 304, which is equal to the angle 312, is the degree of the misalignment of the tyre 302.
[0023] Further, figure 3c shows the tyre 302 which is misaligned such that
the center 308 of the tyre 302 is shifted from a horizontal axis 314. In an example implementation of the present subject matter, the first acceleration 310 is detected for a predetermined time period in a plane other than the rotational plane of the tyre 302. Thus, according to the present subject matter it is ascertained that the misalignment is present. Further, the second acceleration 304 is also detected

which is shifted by an angle 316 from the axis 306. According to the present subject matter, the degree of misalignment is the degree of deviation of the second acceleration 304 from the axis 306. Thus, the angle 316 is the degree of misalignment. Further, in an example, the second acceleration 304 may be the angular acceleration of the tyre 302 in the rotational plane of the tyre 302.
[0024] Figure 4 shows the sensor assembly 104 in accordance with an
example implementation of the present subject matter. The sensor assembly 104 comprises a sensor 402 and a gyroscope 404. The sensor 402 measures a first acceleration and a second acceleration. In an example, one sensor is shown in the figure 4, however, it should be understood that there may be more than one sensors in the sensor assembly. The sensor 402 may be coupled in the sensor assembly using a poke-yoke arrangement. For example, the sensor 402 may have two or more fins which may couple with grooves of the sensor assembly 104. In an example, the two or more fins may have different shape such that a specific fin fits into a specific groove. Thus, this arrangement ensures that the sensor 402 is fitted in the sensor assembly 402 in right orientation. In an example, the sensor 402 may be an accelerometer. The gyroscope 404 may be used to determine an angular acceleration of the tyre 302.
[0025] Figures 5 illustrates a system 500, in accordance with another
example of the present subject matter.
[0026] The system 500, among other things, includes a memory 502, a
sensor assembly 504, and engine(s) 506. The memory 502 may include any computer-readable medium including, for example, volatile memory (e.g., RAM), and/or non-volatile memory (e.g., EPROM, flash memory, etc.).
[0027] The engine(s) 506 may be implemented as a combination of
hardware and programming (for example, programmable instructions) to implement certain functionalities of the engine(s) 506, such ascertaining misalignment of tyres. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the engine(s) 506 may be processor executable

instructions stored on a non-transitory machine-readable storage medium and the hardware for the engine(s) 506 may include a processing resource (for example, implemented as either a single processor or a combination of multiple processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement engine(s) 506. In such examples, the system 500 may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the system 500 and the processing resource. In other examples, engine(s) 506 may be implemented by electronic circuitry. In an example, in addition to the monitoring engine 508, the engine(s) 506 may also comprise other engine(s) 510 that supplement functions of the system 500.
[0028] Data 512 serves, amongst other things, as a repository for storing
data that may be fetched, processed, received, or generated by the engine(s) 506. The data 512 comprises other data 518 corresponding to the other engine(s) 510. In the illustrated example, the data 512 of the system 500 also comprises sensor data 514, notification data 516.
[0029] In operation, the sensor assembly 504 detects a first acceleration of
a tyre of a vehicle in at least one plane which is different from a rotational plane. The rotational plane is the plane of rotation of the tyre . The sensor assembly 504 may save the data relating to the first acceleration in the sensor data 514. In an example, whenever the first acceleration is detected in any of the plane different from the rotational plane, the sensors assembly 504 notifies the monitoring engine 508 of the same. The monitoring engine 508 retrieves the value of the first acceleration from the sensor data 514 and further determines if the first acceleration is non-zero for a predetermined time period. If the first acceleration is determined to be non-zero for a predetermined time period, the monitoring engine 508 ascertains that there is a misalignment of the tyre .
[0030] In an example, the predetermined time period may vary for
different type of vehicles. For example, consider a smaller vehicle which takes

three seconds at an average for negotiating a curve and thus, the first acceleration may develop for three seconds. Similarly, the vehicle may develop the first acceleration for a duration of two seconds, when a tyre moves in a pothole. In such cases, for smaller vehicle, the predetermined time period may be ten seconds such that the cases of determination of first acceleration due to negotiating a curve or moving in a pothole is not ascertained as misalignment. The misalignment would be ascertained only when the first acceleration is determined for ten seconds. Further, in the case of heavy vehicle, the predetermined time period may be twenty seconds, in an example.
[0031] Further, in an example, the sensor assembly 504 may measure a
second acceleration of the tyre. The second acceleration is the acceleration of the tyre in the rotational plane. In an example, the second acceleration may be an angular acceleration of the tyre in the rotational plane. The monitoring engine 508 may detect a deflection of the second acceleration from an axis passing through a center of the tyre and perpendicular to the ground. The angle of deflection of the second acceleration from the axis (passing through the center of the tyre and perpendicular to the surface on which the tyre is rotating) is the degree of misalignment of the tyre . The monitoring engine 508 further notifies the user about the misalignment and the degree of misalignment. In an example, the notification data 516 may store the notification message templates and the monitoring engine 508 may retrieve the notification message template and add details, such as degree of misalignment and thereafter send it to the user. In an example, the monitoring engine 508 may display the notification or may transmit the notification message to a user device of the user.
[0032] Figure 6 describes a method 600 of ascertaining misalignment of a
tyre of a vehicle, in accordance with an example implementation of the present subject matter. The order in which the method 600 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 the method 600, or an alternative method.

[0033] At block 602, a first acceleration of a tyre of a vehicle in at least
one plane is determined. The at least one plane is different from a rotational plane wherein the rotational plane is the plane of rotation of the tyre. In an example, the rotational plane is the plane ZOX shown in the figure 2. Thus, at block 602, a first acceleration is determined in any of the plane apart from the rotational plane.
[0034] At block 604, the first acceleration is determined to be zero for a
predetermined time period. When the first acceleration is determined to be non-zero for the predetermined time period, misalignment is ascertained at block 606. As explained earlier, the first acceleration may develop in a plane other than the rotational plane, in other instances also, such as turning of vehicle, uneven surfaces. However, the first acceleration, developed in such instances, may be very short lived and thus, detecting the first acceleration for the predetermined time period eliminates the possibility of false ascertainment of misalignment. In an example, the predetermined time period may be ten seconds. In case, the first acceleration is detected for three seconds during turning of the vehicle, misalignment is not ascertained because the first acceleration is not detected for a predetermined time period (ten seconds in this case).
[0035] At block 608 a second acceleration is determined. As explained
earlier, the second acceleration is the acceleration of the tyre in the rotational plane. Further, at block 610, a deflection of the second acceleration from an axis passing thorough the center of the tyre and perpendicular to the surface on which the tyre is rotating, is detected.
[0036] At block 612, degree of misalignment is determined based on
the detection. In an example, an angle between the second acceleration and the axis passing thorough the center of the tyre and perpendicular to the surface on which the tyre is rotating, is the degree of misalignment. Finally, at block 614 a user is notified of the misalignment and the degree of misalignment.
[0037] Although implementations of ascertaining of a misalignment in
a tyre have been described in a language specific to structural features and/or applications, it is to be understood that the present subject matter is not limited

to the specific features or applications described. Rather, the specific features and applications are disclosed as exemplary implementations.

I/We Claim:
1. A method comprising:
determining a first acceleration of a tyre of a vehicle in at least one plane, wherein the at least one plane is different from a rotational plane of the tyre, and wherein the rotational plane is a plane of rotation of the tyre;
detecting the first acceleration in any one of the at least one plane to be non-zero for a predetermined time period;
ascertaining, based on the detecting, misalignment of the tyre.
2. The method as claimed in claim 1, wherein the at least one plane includes a plane perpendicular to a direction of rotation of the tyre and parallel to a surface on which the tyre is rotating.
3. The method as claimed in claim 1, wherein the at least one plane includes a plane perpendicular to the direction of rotation of the tyre and perpendicular to a surface on which the tyre is rotating.
4. The method as claimed in claim 1, wherein the misalignment is in the plane having a non-zero acceleration
5. The method as claimed in claim 1 further comprising:
determining a second acceleration of the tyre in the rotational plane;
detecting a deflection of the second acceleration from an axis passing
thorough the centre of the tyre and perpendicular to the surface on which the tyre is rotating;
determining, based on the detecting, degree of misalignment of the tyre.
6. The method as claimed in claim 5 wherein the acceleration is an angular acceleration.
7. The method as claimed in claim 1 further comprising, indicating a user about the misalignment of the tyre.
8. A system to ascertain misalignment of a tyre of a vehicle, the system comprising:
a sensor assembly coupled to the tyre, the sensor assembly is to:

detect a first acceleration of the tyre of the vehicle in at least one plane, wherein the at least one plane is different from a rotational plane, and wherein a plane of rotation of the tyre is the rotational plane; a monitoring system to:
determine the first acceleration to be non-zero for a predetermined time period;
ascertain, based on the determination, misalignment of the tyre.
9. The system as claimed in claim 8, wherein the at least one of the plane includes a plane perpendicular to a direction of rotation of the tyre and parallel to a surface on which the tyre is rotating.
10. The system as claimed in claim 8, wherein the at least one of the plane includes a plane perpendicular to a direction of rotation of the tyre and a surface on which the tyre is rotating.
11. The system as claimed in claim 8, wherein the monitoring system is to
determine a second acceleration in the rotational plane;
detect a deflection of the second acceleration from an axis passing thorough the centre of the tyre and perpendicular to the surface on which the tyre is rotating;
determine an amount of misalignment based on the detected deflection.
12. The system as claimed in claim 8, wherein the sensor assembly comprises:
an enclosure mounted on the tyre;
sensors mounted in the enclosure wherein the sensors are mounted in the enclosure in a poke-yoke arrangement.
13. The system as claimed in claim 8, wherein the monitoring system is to
indicate, to a user, about the misalignment of the tyre and the degree of
misalignment of the tyre.