Method and system for detecting end of life of tire

Abstract

To provide a reliable tire monitoring system having a simple structure and detecting the end of life of a tire.SOLUTION: A tire monitoring system includes: a first tire wear indicator and a second tire wear indicator integrated with a tire or disposed on the tire; an accelerometer integrated with the tire or disposed on the tire; and a detection algorithm for analyzing an accelerometer signal, and detecting vibration of the tire indicating an end of life of the tire, where the first tire wear indicator and the second tire wear indicator are spatially separated along a circumference of the tire, where at least a portion of each of the first tire wear indicator and the second tire wear indicator is harder than the tread, and where the accelerometer generates an accelerometer signal configured to represent vibration of the tire when the tire is sufficiently worn such that the indicators come into contact with a road surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the field of tire monitoring systems. In particular, the present invention relates to a system and method for detecting the end of the life of a tire of a motor vehicle.

Background Art

[0002] Tire monitoring systems have become an important component in the modern automotive industry and are used to improve traffic safety and extend tire life. Currently, most of these systems focus on detecting tire pressure, but few provide an effective method for monitoring tire wear.

[0003] Accurately detecting tire wear is important to ensure optimal performance, maximize fuel economy, and improve safety. In existing methods for monitoring tire wear, in many cases, accuracy and reliability are limited. Also, most existing systems are functional but structurally complex.

[0004] These complex systems often consist of many components such as sophisticated sensors, extensive communication networks, and large-scale data processing units. Such structural complexity not only increases the cost of installation and maintenance but also can lead to operational problems because a failure can occur in one of these many elements.

Summary of the Invention

Problems to be Solved by the Invention

[0005] One object of the present invention is to overcome at least some of the above problems associated with tire monitoring systems.

[0006] According to a first aspect, the present invention provides a tire monitoring system for detecting the end of the life of a tire of a vehicle according to claim 1.

[0007] The present invention offers numerous advantages, with an emphasis on structural simplicity, ease of integration with existing tires, and a reliable ability to detect the end of a tire's life, compared to existing tire monitoring systems. In particular, in contrast to existing tire monitoring systems, the present invention is characterized by its structural simplicity. By reducing the number of required components, not only is the manufacturing process simplified, but a cost-effective approach in terms of production and maintenance costs is provided. This improvement in simplicity contributes to an increase in operational reliability by minimizing the risk of malfunctions due to excessive complexity. Further, a second advantage of the present invention is its ability to be easily integrated with existing tires already on the market. Due to its design, the monitoring system according to the present invention can be effectively installed on various tires, thus providing flexibility in use on different types of vehicles such as automobiles. Such ease of integration reduces constraints on availability and expands the scope of application of the present invention. The present invention further solves the problem of accurately detecting the end of a tire's life. The system according to the present invention enables reliable monitoring of tire wear and detection as soon as the tire reaches its safe usage limit. Thus, this function contributes to an improvement in traffic safety.

[0008] According to a second aspect, the present invention provides a method for detecting the end of the life of a vehicle tire as described in claim 15.

[0009] Other aspects of the present invention are described in the dependent claims.

[0010] Other features and advantages of the present invention will become clear by reading the following description of embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0012] One embodiment of the present invention will be described in detail with reference to the accompanying drawings. The same or corresponding functional and structural elements shown in different drawings are assigned the same reference numerals. As used herein, "and / or" indicates one or more elements of a list joined by "and / or". For example, "x and / or y" refers to any element within the set of three elements {(x), (y), (x, y)}. That is, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" means any element of the set of seven elements {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. That is, "x, y and / or z" means "one or more of x, y and z". Also, the term "comprising" is used herein as a non-exclusive term. That is, a matter includes all the elements mentioned, but may also include additional elements not mentioned. Therefore, the term "comprising" is interpreted in the broadest sense of "including" or "having".

[0013] FIG. 1 shows a side view of a tire monitoring system 1 including an automotive tire 2 configured such that a tread 3 contacts a road surface (not shown). FIG. 2 shows a cross-sectional view of the tire 2 along line A-A as shown in FIG. 1. FIG. 2 further shows a tire wear indicator 4, also referred to as a “tread wear indicator” or a “tread depth indicator”. A tire wear indicator of a traditional tire is a feature that visually indicates the depth of the remaining tread. The tire wear indicator can be incorporated and integrated into the tire or disposed on the tire. The tread depth is important for maintaining traction, load holding and overall safety, especially in wet or slippery conditions. The tire wear indicator is intended to contribute to the driver's assessment of when to replace the tire.

[0014] According to the present invention, the tire 2 includes at least two tire wear indicators 4 disposed at at least two distinct locations on the tire 2. FIG. 1 shows a first indicator region or zone 5 and a second indicator region or zone 5 spaced apart from each other along the circumference of the tire 2. In this example, the tire 2 includes two tire wear indicators 4 spaced apart from each other along the circumference of the tire 2. In this example, the tire wear indicator 4 is a small, raised rubber bridge or bar disposed on the circumference of the tire and, in this example, perpendicular to the tread pattern of the tire. In this example, the tire wear indicator is disposed within one or more grooves 6 of the tire tread pattern. The grooves 6 extend longitudinally along the circumference of the tire 2. Alternatively or additionally, the tire wear indicator 4 can be located within the grooves of the tread pattern. These tire wear indicators 4 are typically arranged to form a depth corresponding to a legal minimum tread depth for safe driving. In many regions, the legal minimum tread depth is about 1.6 mm. If there are more than two tire wear indicators on the tire, the indicators can be arranged at regular or irregular intervals around the circumference of the tire.

[0015] Through normal use, the tread of the tire wears, and thus the height of the tire rubber decreases. When the tread depth reaches a specific depth, the wear indicator becomes the same height as the remaining part of the tread, i.e., the same height as the height of tread 3, generating a visual feature. In other words, when the tire has worn until these tire wear indicators become the same height as the other treads, this indicates that the tire has reached the legal minimum tread depth and it is time to replace the tire. In this way, the tire reaches the end of its life.

[0016] According to the present invention, the first tire wear indicator 4 has a first hardness, the second tire wear indicator 4 has a second hardness, the tread has a third hardness, and the first and second hardnesses are greater than the third hardness. In particular, the first hardness and / or the second hardness is at least 5%, preferably at least 15%, more preferably at least 30%, greater than the third hardness. That is, the tire wear indicator is slightly harder or more rigid than the tread, and / or the indicator has mechanical properties different from those of the tread. This means that after the tire has worn sufficiently such that the tire wear indicator contacts the road surface, the wear of the indicator is slower than the wear of the tread, and specific vibrations occur when the tire rotates on the road surface. This vibration is not perceived by the user and does not affect the safety of the vehicle. However, even if the indicator wears at the same rate as the tread, the method proposed by the present invention still functions. Theoretically, the simple fact that the indicator is harder can be detected by the accelerometer 7 as described below.

[0017] Strengthening the tire wear indicator can be achieved, for example, by depositing a resin after the tire has been manufactured or developed by a potential partner tire manufacturer. The resin deposited on the surface forms a coating or material coating containing a resinous substance. The resin used in this context is often a polymeric substance that creates a harder layer or protective layer when applied to the surface. This type of resin is usually liquid during application but then cures to form a solid resistant coating. Thus, a coating such as an epoxy coating can be realized using the resin, creating a surface with durability and wear resistance.

[0018] Another approach is to overmold the zone of the tire wear indicator during tire manufacturing.

[0019] In a third approach, the core of the tire, i.e., the inner part of the tire, can be made of a rubber / tire material having mechanical properties different from those of the tread. Thus, the core forming the tire wear indicator is harder than the tread. Thanks to this difference, after the tread wears, the characteristics become different. Thus, in this alternative embodiment, the first tire wear indicator and / or the second tire wear indicator form an element within the tire material, and this element is not exposed on the tread 3 if the tire 2 is new.

[0020] The tire monitoring system 1 further includes an accelerometer 7 configured to sense slight periodic vibrations when the wear indicator is reached due to tread wear. The accelerometer is connected to or includes an energy supply element such as a battery. FIG. 3 shows the signal generated by the accelerometer. This signal can be referred to as the accelerometer signal. The X-axis represents time, and the Y-axis represents the amplitude of the signal. Two high peaks or spikes can be clearly seen. This is due to two tire wear indicators coming into contact with the road surface. The signal shown in FIG. 3 corresponds to one rotation of the tire. The two peaks are repeated at regular intervals each time the tire rotates, assuming a constant vehicle speed. Therefore, the indicator needs to be sufficiently hard and resistant to be detected by the accelerometer while considering environmental and safety constraints, but flexible enough to be imperceptible to the vehicle user.

[0021] The accelerometer 7 can be arranged at almost all positions of the tire. For example, it can be integrated with the valve. Some tire valves in the prior art include a tire pressure monitoring system. In such cases, optionally, the accelerometer 7 can be integrated with the tire pressure monitoring system. In one alternative embodiment, the accelerometer 7 can be arranged, for example, on the inner or outer side surface of the tire.

[0022] The tire monitoring system 1 further comprises an analysis circuit or a microcontroller implementing a detection algorithm configured to analyze the signals of the accelerometer, which can be integrated with the accelerometer or can be in the form of an autonomous element such as a vehicle's central system configured to communicate with the accelerometer wirelessly or the like. When the algorithm is too complex to be integrated with the accelerometer, there is a method in which the raw data is transmitted to a central system with high computing power capable of performing the detection. This method can be considered because the wear of normal tires is quite slow and it is not necessary to perform the detection very frequently. When the detection system is integrated with the central system, the measurement frequency can also be linked to the number of kilometers of the driving distance in order to save energy and focus more during important periods. The detection algorithm can be based on frequency analysis. For example, the fast Fourier transform (FFT) can extract the coherent frequencies and phases corresponding to the distribution of tire wear indicators on the tire, thereby eliminating the simple vibrations caused by small stones getting stuck in the grooves. The FFT is an algorithm for calculating the discrete Fourier transform (DFT). The phase between two signals is a measure of the relative time shift or displacement of their waveforms. The phase is often expressed in degrees or radians and represents a portion less than one full cycle that has elapsed.

[0023] The signals of the accelerometer are configured to indicate the vibration of the tire 2 when the indicator 4 contacts the road surface due to sufficient tire wear. The signals of the accelerometer have a series of features such as a series of peaks representing the vibration of the tire 3. The detection algorithm is configured to analyze the signals of the accelerometer, identify features such as peaks, and detect the vibration of the tire indicating the end of the tire's life.

[0024] To reliably remove vibrations caused by small stones, the angular distance between two tire wear indicators 4 on the circumferential part of the tire 2 deviates from 180°. In particular, the angular distance deviates from 180° by at least 10°, preferably at least 20°, more preferably at least 30°. The angular distance between two points along the circumferential part of the tire is called the "central angle". It represents the angular distance between two radii drawn from the center (circle) of the tire to two tire wear indicators on the circumferential part. That is, this angle is the angle formed by the intersection of the lines from the center to two points (indicators) on the circle. Therefore, preferably, the two tire wear indicators 4 are not on opposite sides of the same diameter. In this specific example, the angular distance between the two tire wear indicators is substantially 90°. If the angles of the two tire wear indicators are 180° apart, assuming the vehicle speed "V" is constant, the signal of the accelerometer will be such that the peaks are repeated at regular intervals. When the vehicle speed is V×2, a similar signal may be generated by small stones when the small stones catch on the tire tread.

[0025] The detection algorithm can alternatively or additionally be an artificial intelligence network such as an artificial neural network. This network can first be trained using vibration training data so that the network learns to correctly detect specific vibration patterns from the accelerometer signal which may be relatively noisy. In this way, the algorithm forms an intelligent algorithm. Therefore, although the peaks may not be clearly visible in the accelerometer signal, based on a signal that may appear to be completely noisy, the neural network can detect the end of the tire's life.

[0026] Alternatively or additionally, the detection algorithm can be, or can include, a filter such as a Kalman filter, which is a signal processing algorithm used to estimate the state of a dynamic system from a series of noisy observations. To correctly extract peaks from the signals of the accelerometers, one or more criteria for extracting peaks from the signals can be defined. For example, if the peaks are associated with state values that exceed a threshold, these values can be monitored to identify the peaks.

[0027] The tire monitoring system 1 can be configured to communicate wirelessly with the vehicle's control system or a central system so that the system can warn the driver as soon as the end of life of one or more tires is detected. This event can be recorded at the control system, central system, or elsewhere so that the event can be inspected at a later date. The warning can be displayed on one or more screens of the vehicle and / or an acoustic warning can be issued.

[0028] In one alternative embodiment of the present invention, the tire monitoring system 1 further comprises one or more gyroscopes and / or gyroscopes that provide the angular velocity of the tire. Thus, the tire monitoring system 1 includes an inertial measurement unit (IMU). In this alternative embodiment, the gyroscope contributes to detecting the end of life of the tire.

[0029] Considering the above, one of the main advantages of the present invention compared to prior art tire monitoring systems is based on adding the function of detecting the end of life of a tire with very few additional means compared to what already exists in modern tires.

[0030] The present invention further relates to a method for detecting the end of the life of a vehicle tire 2 using the tire monitoring system as described above. This method includes a detection algorithm, a step of analyzing using the signal of an accelerometer to detect all peaks corresponding to the vibration of tire 2 representing the end of the life of tire 2, and a step of transmitting the result of the detection by wireless communication means to an autonomous control module.

[0031] Although the present invention has been described in detail in the above description with reference to the drawings, such description should be considered as an example for explanation and not as a limitation. Therefore, the present invention is not limited to the disclosed embodiments. When implementing the invention defined by the claims, those skilled in the art can understand and implement other embodiments and alternative forms based on the consideration of the drawings, the specification, and the appended claims.

[0032] In the claims, the term "comprising" does not exclude other elements or steps, and the term "one" does not exclude a plurality. Just because different features are described in different dependent claims does not mean that the combination of these features cannot be used advantageously. The reference signs in the claims should not be construed as limiting the scope of the present invention.

Explanation of Signs

[0033] 1 Tire monitoring system 2 Tire 3 Tread 4 Tire wear indicator 6 Groove 7 Accelerometer

Claims

1. A vehicle tire monitoring system (1) for detecting the end of life of a tire (2), comprising: a first tire wear indicator (4) integrated with or disposed on the tire (2); A second tire wear indicator (4) integrated with or located on the tire; an accelerometer (7) integrated with or placed on the tire (2); a detection algorithm configured to analyze the accelerometer signal to detect vibrations of the tire (2) indicative of an end of life of the tire (2); the first tire wear indicator (4) and the second tire wear indicator (4) are spatially separated along a circumference of the tire; At least a portion of each of the first tire wear indicator (4) and the second tire wear indicator (4) is harder than a tread (3) of the tire (2); The accelerometer (7) is configured to generate an accelerometer signal that is configured to represent vibrations of the tire (2) when the tire (2) is sufficiently worn such that the indicator (4) comes into contact with the road surface. A system (1).

2. The first tire wear indicator (4) and the second tire wear indicator (4) are not located on diametrically opposite sides of the tire.

2. The system (1) according to claim 1 .

3. The angle between the first tire wear indicator (4) and the second tire wear indicator (4) on the circumference of the tire (2) deviates from 180° by at least 10°, or at least 20°, or at least 30°.

2. The system (1) according to claim 1 .

4. The detection algorithm is based on frequency analysis and / or includes an artificial intelligence module and / or includes a filter.

2. The system (1) according to claim 1 .

5. The artificial intelligence network includes an artificial neural network and / or the filter is a Kalman filter.

5. The system (1) according to claim 4.

6. The accelerometer signal is a substantially periodic signal when the vehicle is moving at a substantially constant speed.

2. The system (1) according to claim 1 .

7. the accelerometer signal has a series of features, such as a series of peaks, which are indicative of vibrations of the tire (2); the detection algorithm is configured to analyze the accelerometer signal to detect the set of characteristics and to detect tire vibrations; and / or The accelerometer (7) is integrated into the valve of the tire (2).

2. The system (1) according to claim 1 .

8. the first tire wear indicator (4) has a first hardness; the second tire wear indicator (4) has a second hardness; The tread (3) has a third hardness, The first hardness and / or the second hardness is at least 5% greater than the third hardness, preferably at least 15%, more preferably at least 30% greater.

2. The system (1) according to claim 1 .

9. the first tire wear indicator (4) and / or the second tire wear indicator (4) form an element within the material of the tire (2); said element is not exposed to the tread (3) when the tire (2) is in new condition; The element has different mechanical properties than the tread (3).

2. The system (1) according to claim 1 .

10. The first tire wear indicator (4) and the second tire wear indicator (4) are disposed in grooves (6) of the tread (3) of the tire (2).

2. The system (1) according to claim 1 .

11. The first tire wear indicator (4) and / or the second tire wear indicator (4) have a coating that forms a harder layer than an inner portion of the tire wear indicator.

11. The system (1) according to claim 10.

12. The coating comprises a resinous material.

12. The system (1) according to claim 11.

13. The first tire wear indicator (4) and / or the second tire wear indicator (4) are one or more overmolded elements.

11. The system (1) according to claim 10.

14. The accelerometer (7) is equipped with wireless communication means for transmitting the detection result to the autonomous control module.

2. The system (1) according to claim 1 .

15. A method for detecting the end of life of a vehicle tire (2) using a tire monitoring system (1) according to any one of claims 1 to 14, comprising the steps of: using said detection algorithm and analysing said accelerometer signals to detect vibrations of said tire (2) indicative of the end of the tire's (2) life; and transmitting the result of the detection using the wireless communication means to the autonomous control module. A method comprising:

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