Patent Application
20220024266
The present disclosure relates to a tire sensing system. More particularly, the present disclosure relates to a system for measuring deflection in a tire as it rolls over a surface.
As a tire rolls over a surface, any given portion of the crown region of the tire will experience deflection as it rolls into and out of contact with the surface. If a tire is inflated to a relatively low pressure, the tire experiences greater deflection and has a greater footprint (i.e., a surface contact area). If a tire is inflated to a relatively high pressure, the tire experiences less deflection and has a smaller footprint. It is known to place sensors inside of a tire cavity to measure pressure and temperature, or to measure tire deflection.
In one embodiment, a tire and wheel assembly includes a wheel having a through hole and a tire mounted on the wheel, thereby forming a cavity. The assembly further includes a valve extending through the wheel, from a location outside the cavity to a location inside the cavity. The valve is spaced away from the through hole. The assembly also includes a deflection sensor mounted on the wheel over the through hole, at a location outside the cavity such that no portion of the deflection sensor is inside the cavity.
In another embodiment, a method of regulating pressure in a tire includes providing a tire mounted on a wheel of a vehicle. The tire and wheel define a cavity. The wheel has a through hole disposed therein. The method further includes providing a deflection sensor on the wheel over the through hole, at a location outside the cavity such that no portion of the deflection sensor is inside the cavity. The method also includes monitoring, with the deflection sensor, a selected area of an inner wall of the tire opposite the through hole. The method further includes calculating a tire deflection based on the monitoring of the selected area of the inner wall of the tire opposite the through hole. The method also includes determining a desired tire deflection of the tire based at least in part on non-tire data and adjusting air pressure inside the tire until the calculated tire deflection is within a predetermined amount of the desired tire deflection.
In yet another embodiment, a tire and wheel assembly includes a wheel having a portal and a tire mounted on the wheel, thereby forming a cavity. The assembly further includes a deflection sensor mounted on the wheel over the portal, at a location outside the cavity such that no portion of the deflection sensor is inside the cavity.
In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. Like elements are identified with the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration.
The following includes definitions of selected terms employed herein. The definitions include various examples or forms of components that fall within the scope of a term and that may be used for implementation. The examples are not intended to be limiting. Both singular and plural forms of terms may be within the definitions.
“Axial” or “axially” refer to a direction that is parallel to the axis of rotation of a tire.
“Bead” refers to the part of the tire that contacts the wheel and defines a boundary of the sidewall.
“Circumferential” and “circumferentially” refer to a direction extending along the perimeter of the surface of the tread perpendicular to the axial direction.
“Equatorial plane” refers to the plane that is perpendicular to the tire's axis of rotation and passes through the center of the tire's tread.
“Radial” and “radially” refer to a direction perpendicular to the axis of rotation of a tire.
“Sidewall” refers to that portion of the tire between the tread and the bead.
“Tread” refers to that portion of the tire that comes into contact with the road under normal inflation and load.
Directions are stated herein with reference to the axis of rotation of the tire. The terms “upward” and “upwardly” refer to a general direction towards the tread of the tire, whereas “downward” and “downwardly” refer to the general direction towards the axis of rotation of the tire. Thus, when relative directional terms such as “upper” and “lower” or “top” and “bottom” are used in connection with an element, the “upper” or “top” element is spaced closer to the tread than the “lower” or “bottom” element. Additionally, when relative directional terms such as “above” or “below” are used in connection with an element, an element that is “above” another element is closer to the tread than the other element.
The terms “inward” and “inwardly” refer to a general direction towards the equatorial plane of the tire, whereas “outward” and “outwardly” refer to a general direction away from the equatorial plane of the tire and towards the sidewall of the tire. Thus, when relative directional terms such as “inner” and “outer” are used in connection with an element, the “inner” element is spaced closer to the equatorial plane of the tire than the “outer” element.
A valve 130 extends through the wheel 110, from a location outside the cavity to a location inside the cavity. The valve 130 allows compressed air to be injected into the cavity from an external source. The valve also allows air from inside the cavity to be released into the atmosphere. In the illustrated embodiment, the valve 130 is connected to an air regulator 135. The air regulator 135 may be connected to the valve 130 as needed to inflate or deflate the tire 105. Alternatively, the air regulator 135 may remain connected to the valve 130 during operation of the vehicle, thereby allowing the tire 105 to be inflated or deflated during use of the vehicle. In an alternative embodiment, an air regulator is not employed and the tire may instead be manually inflated by an external air source.
A sensor 140 is mounted on the wheel 110 at a location outside the cavity such that no portion of the sensor 140 is inside the cavity. While the sensor 140 is shown as mounted at the center of the wheel 110, it should be understood that the sensor may be offset from the center of the wheel. Mounting a sensor 140 at a location outside the cavity allows the sensor to be removed or serviced while the tire 105 remains mounted on the wheel 110. Additionally, by mounting the sensor 140 outside of the cavity, the vehicle may provide power to the sensor through a wired connection or through wireless transmission.
The sensor 140 is mounted over a portal 145 that is spaced away from the valve 130. In one embodiment, the portal 145 is a through hole, or a pin hole. In such an embodiment, the sensor 140 is exposed to the air inside of the cavity. In an alternative embodiment, the portal 145 is a window made of glass or a polymeric material. In such an embodiment, the sensor 140 is not exposed to the air inside of the cavity.
The sensor 140 includes at least a deflection sensor that monitors an area 150 of an inner wall of the tire 105. In the illustrated embodiment, the area 150 being monitored is an underside of the tread 115 and is opposite the portal 145. In an alternative embodiment, the area that is monitored is at a location on the underside of the tread that is not directly opposite the portal. In another alternative embodiment, the area that is monitored is an interior surface of the sidewall of the tire, or a shoulder region of the tire.
The deflection sensor may employ any sensing means. For example, the deflection sensor may be an optical sensor (or a laser sensor) that senses light reflected off the area 150 of the inner wall of the tire 105. An optical sensor may include a light source, such as a laser, an LED, an incandescent light, or other light source.
The area 150 of the inner wall of the tire may be marked with indicia to aid in the optical detection of tire deflections.
The deflection sensor is not limited to an optical sensor or a laser sensor. In alternative embodiments, the deflection sensor may be, without limitation, an ultrasonic sensor, radar, millimeter wave radar, structured light sensors, a radio frequency sensor, or a magnetic sensor.
By monitoring the area 150 of the inner wall of the tire 105, the deflection sensor detects deflections or deformations in that portion of the tire as it rolls into and out of contact with a surface.
On some vehicles, it may be desirable for tires to have different footprints for different applications. For example, in an agricultural vehicle, it may be desirable for a tire to have a large footprint and greater deflection when the vehicle is traveling over a field to avoid damaging crops or damaging the tires. It may be further desirable for a tire on an agricultural vehicle to have a small footprint and less deflection when the vehicle is traveling over a road at a higher speed. Likewise, in other vehicles such as off road vehicles, trucks, and passenger cars, it may be desirable to adjust the footprint of a tire as the vehicle travels on different surfaces or at different speeds.
Returning to
The sensor 140 may also include a temperature and pressure sensor. While the deflections of a tire are correlated to the internal temperature and pressure of a tire, other factors may affect the amount of deflection that occurs. Thus, the data obtained from a temperature and pressure sensor can be used to confirm the monitored deflections and also identify other issues with the tire. In embodiments in which the portal 145 is a through hole, a temperature and pressure sensor in the sensor 140 may be able to obtain meaningful data while mounted entirely outside of the cavity. If the portal 145 is a window, or if it is otherwise desirable to monitor the temperature and pressure from a sensor located inside the cavity, a second sensor 155 may be employed. In the illustrated embodiment, the second sensor 155 is mounted to the wheel 110. In an alternative embodiment (not shown), the second sensor is mounted to an inner surface of the tire. In another alternative embodiment, the second sensor may be omitted. In another alternative embodiment, the sensor includes a separate temperature sensor. In yet another alternative embodiment, the sensor includes a separate pressure sensor.
The sensor 140 may also include a humidity sensor. The humidity inside of the cavity may affect the pressure, and thus may affect the amount of deflection that occurs. The data obtained from a humidity sensor can therefore be used to confirm the monitored deflections and also identify other issues with the tire. In embodiments in which the portal 145 is a through hole, a humidity sensor in the sensor 140 may be able to obtain meaningful data while mounted entirely outside of the cavity. If the portal 145 is a window, or if it is otherwise desirable to monitor the humidity from a sensor located inside the cavity, the humidity sensor may be employed in the second sensor 155. In an alternative embodiment (not shown), the humidity sensor may be a third sensor mounted internally in the cavity. In another alternative embodiment, the humidity sensor may be omitted.
The sensors described above may be integrated into a system for monitoring a tire. Additionally, the sensors described above may be employed in a system for regulating air pressure in a tire.
Each of the other components is shown as being in signal communication with the processor 405. The communication may be through wires or other physical media, or it may be through wireless communication means, such as through radio frequency (RF) transmissions. The communications may also be a combination of wired and wireless communication. Additionally, certain components may be in signal communication with each other in a manner not illustrated here.
The processor 405 is in communication with a deflection sensor 410, such as one of the deflection sensors described above. The deflection sensor 410 transmits data related to the deflection of the monitored area of the tire to the processor 405. Additionally, a position sensor 415 transmits data related to the position of the deflection sensor 410 to the processor 405. An accelerometer 420 may also transmit data related to the acceleration of the deflection sensor 410. Based on the data from the deflection sensor 410, the position sensor 415, and the accelerometer 420, the processor calculates the deflection of the tire as rolls over a surface. In an alternative embodiment, the processor 405 may calculate the deflection of the tire with fewer inputs than are shown. In another alternative embodiment, an orientation sensor may be employed instead of a position sensor.
The processor 405 also is in signal communication with a temperature and pressure sensor 425. The temperature and pressure sensor 425 transmits data related to the temperature and pressure inside of the cavity of the tire. While the sensor 425 is identified as a single sensor that detects both temperature and pressure, it should be understood that a first sensor may be detect temperature while a second sensor detects pressure. The first and second sensor may be disposed in the same housing or in different housings.
The processor 405 is also in signal communication with a humidity sensor 430. The humidity sensor 430 transmits data related to the humidity inside of the cavity of the tire. The processor may incorporate the temperature, pressure, or humidity data when determining the deflection of the tire.
The data transmitted by the deflection sensor 410, the position sensor 415, the accelerometer 420, the temperature and pressure sensor 425, and the humidity sensor 430 may be referred to collectively as sensors that collect tire-related data, or tire data, because the data are related to and extracted from a tire. Additional tire sensors may be employed to monitor and transmit other tire-related data, such as tire identification, strain, wear, and other properties.
With continued reference to
The processor 405 is also in signal communication with an engine sensor 440 that monitors an engine, such as by monitoring engine strain. Engine strain data may be used by the processor 405 to calculate a load on the vehicle.
Additionally, the processor 405 is in signal communication with a weight sensor 445. The weight sensor may directly sense weight in a vehicle, a portion of the vehicle, or in a trailer connected to the vehicle.
The processor 405 is also in signal communication with a speedometer 450 that measures the speed of the vehicle. The processor may also be in signal communication with other sensors, such as a vehicle accelerometer or a suspension sensor. Such sensors may provide data to the processor that indicates whether the vehicle is traveling over smooth or bumpy terrain. Additionally, the processor may receive input from a user, such as an indication of terrain or environmental conditions.
Based at least in part on the non-tire data, the processor 405 determines a desired tire deflection. For example, the processor 405 may determine a desired tire deflection based on one or more of the vehicle speed, vehicle acceleration, terrain data, vehicle load, and engine strain. The determination may be based on an algorithm, machine learning, or by referring to lookup tables. The lookup tables may be populated manually based on test results, or through machine learning. For example, based on the non-tire data, the processor 405 may determine that the vehicle is carrying heavy equipment on a dirt road at medium speed. In such conditions, a medium level of deflection may be desired. As another example, the processor 405 may determine that the vehicle is not carrying a load and is traveling across a field at low speed. In such conditions, a high level of deflection may be desired. As yet another example, the processor 405 may determine that the vehicle is not carrying a load, and is travelling over a road at high speeds. In such conditions, a low level of deflection may be desired.
Based on additional data, such as the temperature, pressure, or humidity inside the tire cavity, the processor calculates a pressure that corresponds to the desired tire deflection. In the illustrated embodiment, the processor 405 is in signal communication with an air regulator 455. The processor 405 transmits signals to the air regulator 455 to inflate or deflate the tire, and thus adjust the air pressure inside the tire until the observed tire deflection is within a predetermined amount of the desired tire deflection. In other words, the pressure adjustment may be based in part on at least one of the measured temperature, the measured pressure, or the measured humidity.
In an alternative embodiment (not shown) the processor displays inflation status and recommendations to a user. Thus, when an air regulator is not employed, the user may manually inflate or deflate the tire to achieve the desired tire deflection. In all embodiments, the data may be displayed to a user or stored. The data may be employed in an iterative process to refine the desired tire deflection for certain conditions.
In the illustrated embodiment, the tire 105 is mounted on a modified wheel 510. Instead of a single external sensor, a first external sensor 540A is mounted on the wheel 510 over a first portal 545A and a second external sensor 540B is mounted on the wheel 510 over a second portal 545B. Each of the first and second sensors 540A,B may be the same as the external sensor 140 described above. In one embodiment, the first sensor 540A is the same type of sensor as the second sensor 540B. In an alternative embodiment, the first sensor 540A is a different type of sensor than the second sensor 540B. For example, one of the external sensors may be an optical sensor while the other sensor is a radio frequency sensor.
In the illustrated embodiment, the first and second external sensor 540A,B monitor the same area 150 of the tire 105, with each sensor 540A,B monitoring the area 150 at a different angle. By monitoring the same area 150 at different angles, the deflection of the area may be measured more accurately. In an alternative embodiment (not shown), each of the external sensors monitors a different area of the tire.
In each of the embodiments described above, the components described may be dedicated for use with a single tire. However, some of the components may be used for multiple tires. For example, a single processor may be in signal communication with sensors from multiple tires. Additionally, a single air compressor can connected to multiple tires.
While it may be desirable to employ sensors on every tire of a vehicle, it may be acceptable to only monitor a single tire on each axle, and regulate the pressure of all of the tires on that axle based on the monitoring of the single tire. In some instances, it may be acceptable to only monitor a single tire on the vehicle, and regulate the pressure of all of the tires on the vehicle based on the monitoring of the single tire.
To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or components.
While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/065835 | 12/12/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62783292 | Dec 2018 | US |
