Tire sensing system and method

Abstract

A tire sensing system (126) operable to determine one or more physical characteristics of a tire (156) includes millimeter wave transmitting and receiving devices (128T; 128R). A processor (218) is communicatively coupled with a memory (220) that includes instructions for transmitting and receiving millimeter waves (TX s ; TX g ,RX s ; RX g ) to and from the tire (156). The memory (220) also includes instructions for imaging first and second radial extents (r s ; r g ) of the tire (156) based on received millimeter waves (RX s ; RX g ) and for determining a dimensional difference between the first and second radial extents (r s ; r g ) of the tire (156). Also included are a vehicle (100) including such a tire sensing system (126) and a non-transitory machine-readable storage medium (220) and method (300).

Description

[0001] Government permission rights

[0002] This invention was made with government support under Contract Numbers 1823235 and 1942902 awarded by the National Science Foundation (NSF). The United States Government can have certain rights in the invention. BACKGROUND

[0003] The subject matter of the present disclosure relates broadly to technology for tire sensing systems for vehicles, and more particularly to systems operable to determine instantaneous tire tread depth and / or monitor tire wear over an extended duration. Additionally, or in the alternative, systems operable to identify foreign objects lodged on or within a tire are also included. Further, and / or as another alternative, methods of determining instantaneous tire tread depth, monitoring tire wear, and / or identifying foreign objects are also included.

[0004] The subject matter of the present disclosure can be particularly applicable in connection with wheeled vehicle applications and uses, and will be shown and described herein with reference thereto. It should be understood, however, that the subject matter of the present disclosure can also be utilized in other applications and environments, and the particular uses shown and described herein are merely exemplary.

[0005] The most common method of monitoring tire condition involves somewhat tedious methods of visually inspecting tires and physically measuring tread depth. While this method is essentially costless, the frequency of this manual program performance and the attention of the owner and operator are generally considered inadequate. As a result, tire tread depth and tire wear patterns are considered to be under-monitored on commercial vehicles and passenger vehicles. Tire tread wear affects performance and is an important measure for deciding tire replacement, which is considered to be one of the largest maintenance costs for the global trucking industry. Small errors in assessing tread depth and / or tire wear when performing manual inspection procedures can result in replacing a tire before its useful life is over or inadvertently allowing a tire to remain in use beyond its useful life. Either of these situations results in increased costs for commercial trucking operations due to premature replacement of tires or increased breakdowns and road service calls. Similar issues apply to tires on passenger vehicles as this manual assessment is performed by the vehicle owner.

[0006] In some instances, electronic systems have been developed that utilize various wireless sensing technologies to monitor physical characteristics of tires. In some instances, components of the systems are supported externally from the tire, such as, for example, supported on or along a body, frame, or chassis of a vehicle. Unfortunately, known systems that utilize a demountable mounting arrangement have certain drawbacks that can limit the more widespread adoption and / or use of these types of arrangements. For example, certain systems known to utilize laser-based distance sensors to estimate the amount of tread remaining on a tire can experience errors due to the accumulation of debris and other foreign materials on and / or within the tire tread.

[0007] In other instances, systems have been developed that utilize tire pressure and / or sensors mounted within a tire chamber to estimate tire tread depth. However, at least in part due to the indirect nature of such measurements and / or the amount of tire material between the measurement conditions and the tire tread, such tread depth estimates can vary greatly from actual tread conditions and are sometimes considered somewhat unreliable. In other instances, systems have been developed that utilize sensors and / or devices embedded within the tread and / or body of a tire. Such sensors and / or devices are exposed to extreme conditions associated with the use of the tire on an over-the-road vehicle, which can include temperatures ranging from about -35 °C to about 85 °C, as well as high pressure and constantly changing load conditions during dynamic use of the tire. Because such sensors and / or devices should remain functional for the life of the tire, embedded sensors and / or devices can add cost to the manufacture of the tire, at least in part due to the cost of robust sensor components and additional steps associated with embedding the sensors and / or devices in the tire during assembly. As another drawback, such embedded sensors and / or devices are discarded once the tire reaches the end of its useful life.

[0008] In view of the foregoing, it is believed that there is a need to assess the tread depth and / or other characteristics of vehicle tires from time to time and / or continuously, such as to monitor certain wear conditions and / or possible changes in performance characteristics of such tires. Although known measurement and / or monitoring techniques have achieved overall success, it is believed that it would be desirable to develop systems and methods that can improve upon and / or otherwise advance the art of tire sensing technology. SUMMARY

[0009] An example of a tire sensing system according to the subject matter of this disclosure is operable to determine one or more physical characteristics of an associated tire. The tire sensing system may include a millimeter-wave transmitting device and a millimeter-wave receiving device. The tire sensing system may also include a processor communicatively coupled to a memory. The memory may include instructions for transmitting millimeter waves to the associated tire using the millimeter-wave transmitting device. The memory may also include instructions for receiving millimeter waves reflected from the associated tire at the millimeter-wave receiving device. The memory may also include instructions for imaging a first radial range and a second radial range of the associated tire based on the received millimeter waves. Furthermore, the memory may include instructions for determining a dimensional difference between the first radial range and the second radial range of the associated tire.

[0010] An example of a vehicle according to the subject matter of this disclosure may include a tire with tread grooves and a tire sensing system associated with the tire's operating location according to the foregoing paragraphs. In some cases, the tire may optionally include a plurality of differential reflective structures disposed on or along the tire. In some cases, the plurality of differential reflective structures may be disposed on or along the tire in a circumferential sequence. In some cases, the plurality of differential reflective structures may be disposed within the tread grooves of the tire.

[0011] An example of a non-transitory machine-readable storage medium according to the subject matter of this disclosure may have machine-readable instructions stored thereon that instruct a processor to transmit millimeter waves toward a relevant tire using a millimeter-wave transmitting device. The storage medium may also include instructions for instructing the processor to receive millimeter waves reflected from the relevant tire at a millimeter-wave receiving device. The storage medium may also include instructions for instructing the processor to image a first radial range and a second radial range of the relevant tire based on the received millimeter waves. Furthermore, the storage medium may include instructions for instructing the processor to determine a dimensional difference between the first radial range and the second radial range of the relevant tire.

[0012] An example of a method for sensing the physical properties of a relevant tire according to the subject matter of this disclosure may include transmitting millimeter waves to the relevant tire. The method may also include receiving millimeter waves reflected from the relevant tire. The method may further include imagerizing a first radial range and a second radial range of the relevant tire using the reflected millimeter waves and determining a dimensional difference between the first radial range and the second radial range of the relevant tire. Attached Figure Description

[0013] Figure 1 This is a side front view of an example vehicle that includes a tire sensing system according to the subject matter of this disclosure.

[0014] Figure 2 yes Figure 1 A schematic diagram of a tire sensing system installed on a relevant vehicle.

[0015] Figure 3 is a side elevational view of one example of a coordinate system suitable for use in conjunction with a tire sensing system according to the subject matter of the present disclosure.

[0016] Figure 4 is a top plan view of the exemplary coordinate system in Figure 3

[0017] Figure 5 is a side elevational view of one example of a sensing device positioned proximate to an associated wheel assembly including an associated tire having an associated tire tread.

[0018] Figure 6 is a cross-sectional view of the wheel assembly in Figure 5 Figures 1 to 5

[0019] Figures 6A to 6C is a top plan view of the associated tire in Figure 6

[0020] Figure 7 Figures 1 to 6

[0021] Figure 8 is a graphical representation of one example of a method according to the subject matter of the present disclosure.

[0022] Figure 9 is a schematic diagram of one example of a controller for a tire sensing system according to the subject matter of the present disclosure.

[0023] Figure 10 DETAILED DESCRIPTION

[0024] As used herein, terms such as “data,” “values,” “information,” “signals,” and the like are used herein interchangeably to broadly refer to analog and / or digital content and / or communications such as can be transmitted, transferred, stored, retrieved, processed, and / or exchanged in any suitable manner by and / or between components and / or systems.

[0025] ​​​​​​​It should be appreciated and understood that terms such as “may,” “can,” “might,” and the like should be interpreted as permissive rather than causal. Accordingly, any reference to items using terms such as “may,” “can,” “might,” and the like should be interpreted as optional and not required for the subject matter of the present disclosure, unless otherwise specifically noted herein.

[0026] Turning now to the drawings, it should be understood that the illustrations are for exemplification of the subject matter of the present disclosure and such examples are not intended to be limiting. Additionally, it should be understood that the drawings are not to scale and portions of certain features and / or elements can be exaggerated for clarity and / or ease of understanding.

[0027] It should be appreciated that the tire sensing system according to the subject matter of the present disclosure can be used with any type, kind, and / or configuration of wheeled vehicle. As non-limiting examples, such wheeled vehicles can include passenger vehicles, motor homes, buses, light trucks and other vehicles (e.g., U.S. FHWA Classes 1-3 vehicles), medium trucks and other vehicles (e.g., U.S. FHWA Classes 4-6 vehicles), heavy trucks and other vehicles (e.g., U.S. FHWA Classes 7 and 8 vehicles), trailers, agricultural equipment, and off-road vehicles. In connection with Figure 1 and Figure 2 One non-limiting representation of a vehicle on which a tire sensing system according to the subject matter of the present disclosure can be installed is shown and described. As shown herein, vehicle 100 is shown in the form of a tractor-trailer combination including a tractor 102 and a trailer 104 that is operatively connected to the tractor for long distance transport. Tractor 102 is shown as including a frame 106 that is supported on a plurality of wheel assemblies 108 by a suspension system. Tractor 102 will also typically include a motor or rotary power source (not shown) and a powertrain (not shown) that are supported on the frame and that provide prime mover power to one or more of the wheel assemblies 108. Tractor 102 can include a power storage device 110 (e.g., a fuel tank and / or a battery) and can optionally include an exhaust pipe 112 that is operatively associated with the motor. Tractor 102 can also include an operator’s room or cab 114 that can be supported on or along frame 106 in any suitable manner, such as for example by one or more cab mounts and / or one or more cab suspensions.

[0028] The trailer 104 is shown as including a trailer frame 116 that is supported on a plurality of wheel assemblies 118 by a suspension system. The trailer 104 can also include a trailer body 120 that is at least partially supported on the trailer frame 116 and that is generally sized to receive and retain a quantity of cargo. As noted above, the vehicle 100 can include one or more suspension systems that are operably connected between sprung masses of the vehicle, such as the frame 106, the operator compartment 114, the trailer frame 116, and / or the trailer body 120, for example, and unsprung masses, such as the wheel assemblies 108, the wheel assemblies 118, and / or the wheel engagement components 122 (e.g., axles, suspension arms), for example. In Figure 1 and Figure 2 In the example arrangement shown, such a suspension system is schematically represented by the reference numeral 124 and can include a spring device (e.g., coil spring, leaf spring, air spring) and / or one or more dampers that, together with the spring device, allow for movement of the sprung and unsprung masses relative to one another in a somewhat controlled manner.

[0029] The vehicle 100 also includes a tire sensing system 126 in accordance with the subject matter of the present disclosure that is operatively associated with one or more wheel assemblies of the vehicle (e.g., one or more of the wheel assemblies 108 and / or 118). The tire sensing system 126 can include one or more sensing devices 128 that are disposed proximate to a corresponding one of the wheel assemblies of the vehicle. In Figure 1 and Figure 2 In the example arrangement shown, the tire sensing system 126 can include a plurality of sensing devices 128, with one sensing device supported on the vehicle adjacent to a corresponding one of the wheel assemblies 108 and / or 118. However, it should be appreciated that such an arrangement is merely exemplary and that other configurations can be used without departing from the subject matter of the present disclosure.

[0030] The tire sensing system 126 can also include a control system 130 to which the sensing devices 128 can be communicatively coupled. The control system 130 can also optionally be communicatively coupled with other systems and / or components of the vehicle 100 in order to, such as, exchange data, information, and / or signals and / or for selective operation and / or control of such other systems, for example. The control system 130 can include, for example, a controller or electronic control unit (ECU) 132 that is communicatively coupled with the sensing devices 128, such as by electrical conductors or leads 134. It should be appreciated that the controller 132 can be of any suitable type, kind, and / or configuration, such as described below, for example.

[0031] As noted above, the control system 130 can optionally be communicatively coupled with one or more other systems and / or devices of the vehicle 100. By way of non-limiting example,Figure 2 The vehicle 100 is shown in FIG. 1 in which the controller 132 is communicatively coupled with one or more associated systems, modules, and / or devices, collectively represented by the block 136 and communicatively coupled with the controller 132 by electrical conductors or leads 138. Additionally or in the alternative, the control system 130 can optionally include one or more communication interface systems and / or devices 140, such as can be suitable for sending and / or receiving data, information, and / or signals to and / or from remote systems and / or devices, such as remote data storage devices and / or remote computer systems (e.g., fleet management systems). If included, any such one or more communication interface systems and / or devices 140 can be communicatively coupled with the controller 132 in any suitable manner, such as by electrical conductors or leads 142.

[0032] Additionally, or as another alternative, the control system 130 can optionally include and / or otherwise interface with a visual communication device 144 that is communicatively coupled with the controller 132 in a suitable manner (e.g., such as by electrical conductors or leads 146). In some cases, the visual communication device 144 can take the form of a graphical input / output device, such as a capacitive or resistive touch screen, for example. In such cases, the additional user input device can optionally be omitted. In other cases, the visual communication device 144 can take the form of a graphical output device, such as a conventional display screen, for example. In such cases, the control system 130 can optionally include and / or otherwise interface with one or more additional user communication devices. For example, a haptic input device 148, such as a keyboard or keypad, for example, can optionally be communicatively coupled with the controller 132 in a suitable manner (e.g., such as by electrical conductors or leads 150). As another example, an audible output device 152, such as a speaker, for example, can optionally be communicatively coupled with the controller 132 in a suitable manner (e.g., such as by electrical conductors or leads 154). As non-limiting examples, the visual communication device 144 (e.g., a capacitive or resistive touch screen) and / or the haptic input device 148 can be used to identify, select, and / or otherwise input one or more details and / or specifications associated with the wheel assemblies 108 and / or 118 of the vehicle 100 (e.g., the brand, model, size, inflation pressure, and / or location of a given tire relative to a particular one of the sensing devices 128). As another non-limiting example, the visual communication device 144 and / or the audible output device 152 can be used to notify an operator of information, details, and / or events associated with the use and / or operation of one or more of the wheel assemblies 108 and / or 118 (e.g., the identification of a foreign object lodged on or within a particular tire of the vehicle).

[0033] As discussed above, one shortcoming of known electronic systems for monitoring tire tread wear is the susceptibility of such systems to foreign objects and debris that can be present on and / or within the tire. That is, known electronic systems are considered to be flawed and operate with reduced accuracy and / or provide false results when foreign objects and / or debris are present on or within the surface of the tread features of the tire being monitored. However, even in the presence of foreign objects and debris, the tire sensing system and method according to the subject matter of the present disclosure can accurately measure tire wear by observing the reflection of radar signals from the tire surface and grooves. That is, according to the subject matter of the present disclosure, it has been discovered that the use of a sensing device that operates within the millimeter wave ("mmWave") band of the radio frequency ("RF") spectrum can overcome or otherwise avoid these and / or other shortcomings of known electronic systems. Accordingly, the sensing device 128 is preferably of a type, kind and / or configuration that transmits and / or receives electromagnetic waves having a frequency in the range from about 30 GHz to about 300 GHz and / or a wavelength in the range from about ten (10) millimeters to about one (1) millimeter. As one non-limiting example, the sensing device 128 can include any suitable number of one or more mmWave transmitting devices (such as collectively and illustratively represented by block 128T in Figure 5 ) and any suitable number of one or more mmWave receiving devices (such as collectively and illustratively represented by block 128R in Figure 5 ). In some cases, the sensing device 128 can be of a type and / or kind that operates as a frequency modulated continuous wave radar sensor. As a non-limiting example, a sensing device 128 can be used that can have an approximately 4 GHz bandwidth that operates in the frequency range from about 76 GHz to about 81 GHz. One example of such a sensing device is available from Texas Instruments Incorporated of Dallas, Texas under the name AWR1642. However, it should be understood that such a sensing device is merely exemplary and other sensing devices can be used without departing from the subject matter of the present disclosure.

[0034] Figure 3 and Figure 4An example of a coordinate system that can be used in conjunction with a tire sensing system (e.g., tire sensing system 126) according to the subject matter of this disclosure is shown. As shown, wheel 108 / 118 has an axis of rotation AXR, and a conventional Cartesian coordinate system has its origin at the centerline of wheel 108 / 118, where the "x" axis is generally horizontally oriented, the "y" axis is generally vertically oriented, and the "z" axis is coaxial with the axis of rotation AXR. However, it should be understood that other orientations of the x and y axes relative to the horizontal and vertical conventions may be used alternatively. Sensor 128 is spaced "D" from the origin in the "xy" plane. In some cases, the distance D may be generally aligned with at least one of the x-axis or y-axis. However, it should be understood that any other suitable orientation may be used alternatively.

[0035] As is well known, the range resolution of millimeter-wave radar sensors is given by the relationship c / 2B, where c is the speed of light and B is the bandwidth of the radar sensor. With a bandwidth of approximately 4 GHz, the range resolution of an exemplary millimeter-wave radar sensor (such as sensing device 128) is, for example, approximately 3.75 cm, which is significantly larger than the tread depth variation of approximately two (2) mm to approximately twenty (20) mm for a conventional off-road tire. As a result, reflections from both the outer surface of the tire and the tire grooves may be less than the optimal resolution of such an exemplary millimeter-wave radar sensor and therefore indistinguishable depending on the operating characteristics of the sensor used. Therefore, according to the subject matter of this disclosure, the tire sensing system 126 may optionally, together with sensor 128, utilize an inverse synthetic aperture radar (“ISAR”) process to take advantage of the natural rotation of the wheel about its axis of rotation AXR and improve the measurement resolution to the sub-millimeter range, enabling the radial difference between the outer surface of the tire and the depth of the tire tread grooves to be measured with high precision. However, it should be understood that this ISAR process is optional and depends on the desired radial resolution of the measurement and the operating characteristics of the sensing device used. The tire sensing system according to the subject matter of this disclosure can operate without such an ISAR process.

[0036] To facilitate the implementation of the ISAR process, the cylindrical coordinate system is oriented relative to the wheel 108 / 118 and the sensor 128, such that when the wheel rotates, a given imaginary point GPT on the tire surface... Figure 5 The travel distance can be modeled and measured or otherwise measured from different angles. In this regard, the origin of the cylindrical coordinate system is located along the axis of rotation of the wheel (AXR), as... Figure 3 As shown, the letter "r" indicates the radial direction, and the Greek letter "phi" indicates the azimuth or angular position, such as... Figure 4 As shown.

[0037] Now refer to Figures 3 to 6Wheel assemblies 108 and / or 118 may include a tire 156 mounted on a wheel or rim 158, which allows the operation and use of the tire on a wheeled vehicle. It should be understood that wheel assemblies 108 and 118, together with their tire 156 and rim 158, are merely exemplary and any other type, kind, construction, and / or configuration of tire and / or rim may be used alternatively. For example, tire 156 is shown and described herein as a type, kind, and construction commonly referred to as a pneumatic tire, which utilizes a certain amount of pressurized gas (e.g., compressed air) contained therein as a working medium. However, it should be understood that the subject matter of this disclosure is broadly applicable to tires of any type, kind, construction, and / or configuration, including any combination of tread-defined features (e.g., longitudinal grooves, lateral grooves, ribs, blocks, sipes) on or along the outer and / or rolling surfaces of the tire, and the tires and rims shown and described herein are merely exemplary and should not be construed as limiting.

[0038] Therefore, for the purposes of discussion, rim 158 is shown as including mounting hub 160 having a plurality of mounting holes 162 arranged in a suitable hole pattern. Figure 6 As shown, rim 158 also includes opposing rim walls 164 and 166, terminating at corresponding flanges 168 and 170. Bead seats 172 and 174 are formed adjacent to flanges 168 and 170 along rim walls 164 and 166, respectively. Tire 156 extends circumferentially about an axis of rotation AXR and includes an elastomer outer tire 176 having a crown portion 178 and axially spaced sidewalls 180 and 182 extending radially inward along the crown portion 178. The crown portion includes an outer surface 184 and optionally includes an inner surface 186, which, if included, at least partially defines a tire cavity 188. Any combination of one or more lateral and / or longitudinal grooves 190 may be arranged along the outer surface 184 of the crown portion 178 in any desired pattern or configuration to form a tire tread 192, as is known in the art.

[0039] The tire 156 can also include a bead region 194 (in some instances, the bead region can alternatively be referred to as a "mounting bead" or "mounting bead region") forming a radially inward extent of the sidewalls 180 and 182. In a state where the tire 156 is mounted on the wheel rim 158, the bead region is sized or otherwise adapted to form an air-tight relationship along the bead seats 172 and 174. Thus, when mounted on a wheel rim as an inflated tire, the tire 156 can be inflated by a conventional valve (not shown) operably connected with the tire cavity 188, such as through one of the rim walls 164 and 166 of the wheel 158. Moreover, it should be appreciated that bead regions having various combinations of shapes, sizes, components, features, and elements have been developed and can be included on the tire 156. Non-limiting examples of such components, features, and elements include toe features, heel features, bead apexes, bead cores, and interference bars.

[0040] Regardless of the one or more other components, features, and / or elements that can be included on or along the bead region of the tire 156, the bead region of the tire can also include at least one bead reinforcing element, such as a bead core 196 and / or a bead filler 198. The bead core 196 takes the form of a substantially inextensible endless loop embedded within the bead region 194. One function of the bead reinforcing element (e.g., the bead core 196) is to determine and maintain the cross-sectional dimension of the bead region 194 and the opening formed thereby to enable the tire to be mounted along the corresponding bead seat of the associated wheel (e.g., the bead seats 172 and 174 of the wheel rim 158), which can be determined by industry standards and practices.

[0041] Additionally, the tire 156, for example, also includes one or more plies containing a plurality of closely spaced radial reinforcing cords or wires that extend radially inward across the crown portion of the tire casing and along the sidewalls of the tire casing. For example, the tire casing 176 is shown reinforced by radial plies 200 that extend across the crown portion 178 and along the sidewalls 180 and 182 toward the bead region 194. The tire can be further reinforced, for example, with one or more annular belt layers (such as the belt layer 202) extending circumferentially along the crown portion 178. The radial plies 200 and the belt layer 202 can be fabricated from any suitable material or combination of materials as are well known in the art, such as steel wire or suitable textile fibers.

[0042] Another function of the bead reinforcing element (e.g., the bead core 196) is to, for example, anchor the radial plies (such as the radial plies 200) while extending across the tire carcass between the opposing bead regions. It should be appreciated that such radial plies can be anchored by the bead core 196 in any suitable manner. For example, the radial plies 200 are anchored by the bead core 196 at the bead region 194 and at the crown portion 178 of the tire 156. In some instances, the radial plies 200 can be anchored by the bead core 196 at the bead region 194 and at the sidewalls 180 and 182 of the tire 156. Figure 6The radial ply 200 extends along the axially inward side of the bead core 196 and through an opening formed by the bead core in a radially inward direction. The outer end 204 of the radial ply 200 is turned up along the axially outward side of the bead core 196 and returns in a radially outward direction along the sidewalls 180 and 182. The bead filler 198 is shown disposed adjacent the bead core 196 in a region between the radial ply 200 and the outer end 204 and is operable to at least partially fill any gap between the radial ply 200 and the outer end 204 and / or is operable to provide increased stiffness and / or rigidity to the bead region. However, it will be appreciated that other arrangements and / or configurations can alternatively be used and the arrangement shown is merely exemplary.

[0043] As discussed herein, the tire sensing system 126 is operable to measure and / or monitor tire wear. Additionally, or in the alternative, the tire sensing system 126 can optionally be operable to identify the presence and location of debris disposed within a tire tread. In some cases, the tire sensing system 126 can also optionally be operable to classify any such debris on or along a tire tread. Generally, tire wear corresponds to the erosion of an outer surface of a tire that reduces the height of ribs, tread blocks, and other features originally formed in the tire relative to a root surface portion of a tread groove that at least partially defines the ribs, tread blocks, and / or other features. It will be appreciated that this root surface portion of the tread groove generally remains unchanged due to tire wear and as the outer surface of the tire is eroded during use, the outer surface of the tire moves radially inward toward the root surface portion of the tread groove. Thus, it will be recognized and appreciated that the tire sensing system 126 can be operable to simply measure the tread depth as the difference between the distance of the outer surface of the tire and the root surface portion of the tire groove at any given point in time. For convenience, the distance of the outer surface of the tire is denoted herein by the radius "r Figure 5 " in s " and the distance of the root surface portion of the tire groove is denoted by the radius "r g ".

[0044] With further reference to Figure 5 it will be appreciated that the wheel assemblies 108 and / or 118 will rotate about the rotational axis AXR during use. In a preferred arrangement, the tire sensing system 126 is operable to measure and / or monitor tire tread depth during operational use, even at relatively low speeds (e.g., less than 10 miles per hour) that can be associated with vehicle start-up and / or stoppage. It is noted that tire wear occurs on a relatively slow time scale. Thus, in accordance with the subject matter of the present disclosure, periodic measurements such as can be performed when a vehicle is moving at low speeds can be sufficient to adequately monitor tire wear in many cases and / or applications.

[0045] Thus, the tire 156 is shown in Figure 5 as undergoing an angular displacement about the axis of rotation AXR, such as indicated by the rotational arrow ROT. In this case, the tire sensing system 126 can utilize the rotational motion of the tire 156 to improve the spatial resolution relative to the distance resolution available from the sensing device alone, as discussed above. The sensing device 128 is positioned proximate one of the wheel assemblies 108 and / or 118 such that the antenna 206 of the sensing device faces the tire 156. Thus, the sensing device 128 has a field of view of the tire tread along the outer surface 184 of the tire 156, such as indicated in Figure 5 by the reference dimension FVW. As the tire 156 rotates and a given hypothetical point GPT travels into and through the field of view FVW, the sensing device 128 images the tire surface by transmitting and receiving millimeter wave radar signals, such as indicated in Figure 5 by the arrows TX s and RX s for the tire surface and / or the arrows TX g and RX g for the tread groove surface portions, respectively. The signals transmitted and / or received by the sensing device 128 as the given hypothetical point GPT travels into, through, and then out of the field of view FVW are represented in Figure 5 by the functions hi to h N , which can be summed or otherwise combined to form an image of the tire surface, as discussed below.

[0046] That is, the tire sensing system 126 uses the sensing device 128 to measure the depth of different points along the surface of the tire 156. As the tire rotates, the tire sensing system 126 integrates or otherwise combines the signal reflections from the same point (e.g., the given hypothetical point GPT). That is, the signals received at the sensing device 128 are the sum of the reflected signals impinging on multiple points along the surface of the tire 156. As the tire rotates, these points also rotate at a rate corresponding to the speed of the tire. As some points move beyond the field of view FVW of the sensing device 128, they gradually disappear from the field of view, while other points appear in the field of view along the other side of the field of view. The tire sensing system 126 utilizes this tire surface trajectory to isolate the signals received from points across the tire surface. In this regard, the tire sensing system 126 models the travel of the hypothetical point on the tire surface to determine its dimensions. Then, by definition, the radius r s is directly related to the tread depth, as any wear of the tread automatically results in an equal decrease in the radius r s , such as already discussed above.

[0047] The trajectory of a given hypothetical point GPT over time (r, φ(t), z) represents the bearing as the wheel assembly 108 / 118 rotates. Where d(t) represents the distance between the point (r, φ(t), z) and (D, 0, 0), the point at which the signal from the sensing device is reflected, the wireless channel contribution h X (t) is given by the following relation:

[0048]

[0049] Where λ represents the wavelength. The tire sensing system 126 can operate to isolate the signal at t = 0 along any point located at (r, φ(t), z), thus along h X (t) actively projects the received channel. A modified Bartlett algorithm (similar to an inverse spatial Fourier transform) for inverse synthetic aperture radar can be used to account for the rotation of the tire 156. In this case, the power of the received signal reflected from a given hypothetical point GPT (i.e., (r, φ(t), z)) on the tire is:

[0050]

[0051] Where h X (t) is the wireless channel read at time t.

[0052] The sensing device 128 can include multiple antennas, such as from two to twenty antennas, for example. In this case, the above-described process can be jointly optimized across the antennas, such as by arranging the multiple antennas along the z-axis. Similar to the discussion above, the wireless reflection channel can be created from the point of each antenna, and then summed across the projections across all antennas in addition to summing across time. The modified Bartlett algorithm can be used at least in part due to the non-uniformity of the tire rotation, where the tire often rotates at non-uniform speeds or obtains data packet samples from the sensing device at non-equal times. However, it should be appreciated that other antenna algorithms, such as MUSIC or ESPRIT, can alternatively be used.

[0053] The above equation assumes perfect knowledge of the rotational dynamics of the tire over time. However, several dynamics of the tire can cause motion to be irregular and often noisy or unpredictable. Thus, it is beneficial for the tire sensing system 126 to be resilient to fluctuations in tire and / or vehicle dynamics. For example, vehicles often experience vibrations due to operation of the motor in cases where different parts of the vehicle vibrate differently, such as the body of the vehicle or wheel wells vibrate at different amplitudes than the tires. In efforts to address such undesirable inputs, measurements can be averaged across several data packets and outlier measurements discarded to reduce false readings due to vibrations. Additionally, or in the alternative, the z-coordinate of any point on the surface of the tire 156 can be modeled as fixed as the tire rotates about the rotational axis AXR. Thus, as the tire rotates, misalignment of the tire can cause variations in the z-value, which in turn can create spatial distortions and / or skewing of the tire surface boundary. The tire sensing system 126 can address tire misalignment by measuring or otherwise determining skewing of known features (e.g., tire face boundary) along the z-axis. In some cases, the tire sensing system 126 can utilize a cubic spline interpolation of the skewing to estimate a corresponding offset in the z-value as a function of time. The tire sensing system can then evaluate the sensed data with the appropriate offset in the z-value over time.

[0054] Additionally, it can be desirable to isolate the reflected signals associated with the surface of the tire 156 from other sources of reflected signals, such as from the wheel well of the vehicle, metal portions of the vehicle, and / or even objects along the road surface. Such extraneous reflectors can cause spurious peaks to appear within the measured ISAR image. In some cases, the tire sensing system 126 can utilize tire face pattern data corresponding to the brand, model, and size of the tire 156 (e.g., such as can be provided by manufacturer specifications). As shown, for example, such tire face patterns exist in the corresponding ISAR image, where the grooves, blocks, and / or other features of the tire face 192 of the tire produce variations along the radial and azimuth axes (r and φ). Figure 8 Figure 8 A sample tire face pattern and corresponding ISAR image are depicted, where the surface plot depicts P(r, φ, z), where φ and r represent the x and y axes, respectively, and the pixel intensity represents the value P(r, φ, z). Note that the tire face pattern is closely aligned with the corresponding ISAR image. As a result, the tire sensing system 126 can effectively identify points on the tire surface by correlating the ISAR image with known tire face pattern data.

[0055] ​In some cases, the tire sensing system 126 can account for changes in tire speed in addition to explicitly accounting for tire speed in the evolution of f(t), such as can help avoid slight stretching or squeezing of the tread image based on whether the tire speed is over or under estimated. Additionally, or in the alternative, sharp edges along the tread can appear too smooth due to vibrations and tire dynamics. In some cases, the tire sensing system 126 can optionally account for these and / or other effects by applying a spatially smooth Gaussian function (whose width is determined by the resolution of the image) over the known tread pattern. Furthermore, rather than applying a standard matched filter, the tire sensing system 126 can optionally apply a 2D version of dynamic time warping (such as can be used in speech and image processing) to correct for slight spatial stretching and squeezing of the signal received from the tire. If included, such a technique can allow the tire sensing system 126 to spatially map the exact location of the tire surface between grooves. The tire sensing system 126 can then average the depth information (defined by r) obtained across the rotation of the tire at these locations to report a radius r s (corresponding to the location of the outer surface of the tire 156).

[0056] Additionally, or in the alternative, the tire sensing system 126 can also optionally include background subtraction as a signal processing technique to counter signal multipathing from false objects surrounding the tire. If used, the tire sensing system 126 can subtract the received signal along two different time windows to preserve dynamic artifacts (e.g., the tire) while canceling static objects (e.g., the wheel well of the vehicle). Such a technique, if included, can effectively remove static objects (relative to the vehicle) close to the tire, such as the body of the vehicle or the wheel well. When applied to two adjacent ISAR images across time, background subtraction can also reveal another effect - false objects appearing on the tire surface, such as debris (e.g., mud picked up by the tire) quickly dissipate due to abrasion. In some cases, the tire sensing system 126 can effectively be resilient to this distortion of the surface depth measurements by identifying and rejecting these outliers. However, it will be recognized and understood that the effect of debris on the tire surface is different than the effect on the grooves. While debris on the tread surface inevitably wears off due to abrasion with the road surface, leading to (at worst) localized and short-term uncertainty, debris on the grooves of the tire can settle and cause long-term measurement error.

[0057] One aspect of the method of sensing the depth of the grooves of a tire in conjunction with the use of the tire sensing system 126 involves performing such sensing in the presence of debris (e.g., mud, rocks, dirt, etc.) within the grooves, which can cause false reflections of signals to and / or from the sensing device 128 that can partially and / or completely mask the true reflection signals from the tire. In some cases, the tire sensing system 126 can address such challenges by developing differential reflection structures disposed on or along the tire, such as within one or more of the tire grooves.

[0058] Accordingly, the tire sensing system 126 can optionally be configured to identify, locate, and / or otherwise sense differential reflection structures disposed on or along an associated tire, such as the tire 156. If included, such one or more differential reflection structures can exhibit a spatial code that can provide a unique and / or identifiable angular position and / or a unique and / or identifiable lateral position as the tire undergoes angular displacement. It will be appreciated that any such one or more differential reflection structures, if included, can be positioned or otherwise disposed on or along the tire 156 in any suitable configuration and / or arrangement. Various non-limiting examples of suitable configurations and / or arrangements are illustrated in Figure 7 In a preferred arrangement, at least one circumferential sequence of differential reflection structures is included on or along the tire. In some cases, the circumferential sequence of differential reflection structures can be at least partially disposed within one of the grooves 190. In other cases, the circumferential sequence of differential reflection structures can optionally be at least partially disposed on or along the blocks and / or annular ribs of the circumferential row of the tire.

[0059] In accordance with the subject matter of the present disclosure, the number, configuration, and location of the two or more differential reflection structures included in a given circumferential sequence disposed on or along the tire can vary according to the desired resolution, where the desired resolution is desired for angular orientation. That is, a greater number of differential reflection structures can be used to provide increased angular resolution. Additionally, it will be appreciated that the number of one or more circumferential sequences of differential reflection structures disposed about the tire can vary according to the desired positioning of the tire sensing in the z-axis or along the z-axis. That is, in some cases, a single circumferential sequence of differential reflection structures can be used. Alternatively, two or more unique or otherwise distinguishable circumferential sequences of differential reflection structures can be disposed in axially spaced apart relation to one another along the z-axis, such as can allow different portions of the tire tread spaced apart from one another along the z-axis to be independently identified, measured, and / or otherwise monitored.

[0060] In Figure 7In the exemplary arrangement, tire 156 is shown as including a root surface portion 214 disposed in groove 190A. Figures 6A to 6C The tire 156 may optionally include a circumferential sequence 208A of differential reflection structures 210A and 212A disposed on or along the root surface portion 214 of the groove 190B. Alternatively, the tire 156 may optionally include a circumferential sequence 208B of differential reflection structures 210B and 212B disposed on or along the root surface portion 214 of the groove 190C. Furthermore, as another alternative, the tire 156 may optionally include a circumferential sequence 208C of differential reflection structures 210C and 212C disposed on or along the root surface portion 214 of the groove 190D. Additionally, as yet another alternative, the tire 156 may optionally include a circumferential sequence 208D of differential reflection structures 210D and 212D disposed on or along the root surface portion 214 of the groove 190D. In addition to or instead of including one or more differential reflective structures within one or more portions of one or more grooves of tire 156, the differential reflective structures may optionally be included on or along one or more annular ribs and / or tread blocks of the tire. As a non-limiting example, tire 156 may include a circumferential sequence 208E of differential reflective structures 210E disposed on or along the circumferential rib portion 216E of tire 156. As another non-limiting example, tire 156 may include a circumferential sequence 208F of differential reflective structures 210F disposed on or along the circumferential rib portion 216F of tire 156. As yet another non-limiting example, tire 156 may include a circumferential sequence 208G of differential reflective structures 212G disposed on or along the circumferential rib portion 216G of tire 156.

[0061] It should be understood that any combination of details and / or features can be used to distinguish the differential reflective structures from one another. For example, in some cases, differential reflective structures of different shapes and / or sizes can be used. Alternatively, differential reflective structures with different circumferential spacings can be used. Furthermore, or as another alternative, two or more differential reflective structures that are distinguishable from and also distinguishable from the main base material of tire 156 can be used. It will be appreciated and understood that the type, kind, condition, and configuration of materials that at least partially define the differential reflective structures can vary depending on the desired level of distinguishability from the main base material used and / or the noise level present in the system. As a non-limiting example, a strip of a metallic material (e.g., aluminum) having a relatively high reflectivity relative to the rubber composition typically used to manufacture tires can be used. However, it should be understood that the foregoing is merely exemplary, and any other suitable materials or combinations of materials can be used without departing from the subject matter of this disclosure.

[0062] Additionally, it will be appreciated that the one or more differential reflection structures, if included, can be operatively attached or otherwise disposed on or along the tire 156 in any suitable manner. As one non-limiting example, the differential reflection structures 210 and / or 212 can be secured on or along the root surface portion 214 within the groove 190, for example such as shown in FIG. 6. As another non-limiting example, the differential reflection structures 210 and / or 212 can be secured within the material of the elastomeric outer tire 176 such that at least a portion of the differential reflection structures 210 and / or 212 are effectively reflective from within and / or along the groove 190, for example such as shown in FIG. 7. As yet another non-limiting example, the differential reflection structures 210 and / or 212 can be disposed on or along a circumferential layer of fabric material that is at least partially embedded within the material of the elastomeric outer tire 176 and is effectively reflective from within and / or along the groove 190, for example such as shown in FIG. 8. It will be appreciated, however, that other configurations and / or arrangements can alternatively be used without departing from the subject matter of the present disclosure. Figure 6A Figure 6B Figure 6C

[0063] It will be well appreciated that the root surface portion 214 of the groove 190 remains spaced from the road surface without contact. Accordingly, a relatively thin piece of material can be used to form the differential reflection structures 210 and / or 212 without significantly reducing or otherwise affecting the overall depth of the groove. As noted above, a reflective metallic material can be preferred in some cases as such material can provide a strong reflection capable of penetrating debris. It will be appreciated, however, that other materials and / or combinations of materials can alternatively be used without departing from the subject matter of the present disclosure. With respect to one or more circumferential sequences of the differential reflection structures, these can be analogous to a bar code having a pre-designed layout analogous to a space code. Such circumferential sequences or codes can allow the tire sensing system 126 to specifically look for reflections from a particular code in a particular groove within the reflected signals from the tire. This operability can help isolate the signals from the grooves of the tire from all other reflections (e.g., debris within the grooves) due to the high reflectivity of the metallic material (if used) and the encoding gain of the space code under certain conditions. Additionally or in the alternative, the tire sensing system 126 can use such circumferential sequences as an encoder to measure or otherwise identify the angular position of the tire relative to the sensing device 128.

[0064] ​​​It will be appreciated that the differential reflective structure and circumferential sequence on or along the tire grooves can help determine the depth of the grooves with relatively high precision, despite the limited area of the grooves themselves and / or the potential presence of debris that can be disposed within the grooves. Thus, it can be desirable for the differential reflective structure and circumferential sequence to be resilient to debris by ensuring that the structure strongly reflects millimeter wave radiation. Additionally, or in the alternative, it can be desirable for the differential reflective structure and circumferential sequence to be resilient to errors that can result from foreign objects or debris that become lodged in the grooves, such as in Figure 5 , Figure 6 and Figures 6A to 6C are schematically represented by reference character FBJ. Further, or as another alternative, it can be desirable for the tire sensing system 126 to be operable to decode and / or disambiguate signals from the differential reflective structure and / or circumferential sequence along adjacent grooves. As previously discussed, Figure 8 depicts a sample tire tread pattern and corresponding ISAR image, where the surface plot depicts P(r, φ, z) where φ and r represent the x and y axes, respectively, and the pixel intensity represents the value P(r, φ, z). Again, it is noted that the circumferential sequence of the differential reflective structure is closely aligned with the corresponding ISAR image. As a result, the tire sensing system 126 can effectively identify points on the surface of the tire by correlating the ISAR image with known patterns and / or data applied to the differential reflective structure and / or circumferential sequence of the tire.

[0065] As discussed above, any suitable configuration and / or arrangement of the differential reflective structure and circumferential sequence can be used. In a preferred arrangement, such differential reflective structure and circumferential sequence can utilize a modulation of mapped zeros (0) and ones (1). In some cases, it can be desirable to include as many bits as possible within the available surface area of the groove. The tire sensing system 126 is preferably resilient to bit errors as well as collisions between the differential reflective structure and / or circumferential sequence from adjacent grooves. In some cases, the differential reflective structure and / or circumferential sequence can be encoded by thin segments of different widths of material for pulse width modulation. In other words, the differential reflective structure and / or circumferential sequence can be encoded in the relative amplitude of the signal reflected from the differential reflective structure, rather than the phase or sign.

[0066] In some cases, the differential reflective structure and / or circumferential sequence can utilize coded bits of different lengths that are designed to have high autocorrelation and poor cross-correlation. Such an approach is compatible with pulse width modulation, considering that it effectively results in a significant difference in the total amplitude reflected from zero and one bits. While optional, such a configuration can beneficially provide poor cross-correlation and thus can have increased resilience to collisions when the code across adjacent grooves needs to be disambiguated. Additionally, such a configuration is inherently resilient to bit flips, thereby exhibiting high robustness to erroneous bits.

[0067] The foregoing arrangement can relate the differential reflection structure and / or circumferential sequence to different possible known sequences in order to detect the presence of a particular groove, such as can be associated with a given brand, model, and size of tire. Additionally, such an arrangement can also be used directly as an encoder. Given the known differential reflection structure and / or circumferential sequence present, the tire sensing system 126 is effective in measuring the precise depth of a groove of a tire, but such structure and / or sequence can in some cases experience distortion (e.g., smoothing) due to the limited resolution of the millimeter wave radar and the dynamics of tire rotation.

[0068] As the tire sensing system 126 moves along the trajectory (r, f(t), z), it can calibrate or otherwise adjust for such distortion by utilizing a model M (r,φ(t),z) (C) that captures the expected wireless channel from such sequence or code C taking into account the expected distortion. Then, a relationship to the true depth of the groove given by r can be determined by correlating this model with the received channel. In particular, the coordinates of the groove can be estimated as:

[0069] r g = argmax corr(M (r,φ(t),z) (C), h(t))

[0070] r g The value of r can be subtracted from the previous measured value of r s of the tire outer surface to calculate the tread depth.

[0071] The tire sensing system 126 can also optionally be robust to detect and locate foreign objects that can be lodged on or in the tire. The tire sensing system 126 can be operable to determine the location of the foreign object, and optionally, for example, such as to provide a notification of the presence of such foreign object to an operator and / or a remote data storage device or computer system. The tire sensing system 126 can process the output of the ISAR algorithm, which can appear similar to an X-ray image showing components lodged within the tire. Multiple such images can be captured as the tire rotates over time. These images can then be stitched together to generate a continuous image of the tire, and the known pattern of differential reflection structure and circumferential sequence used to determine an approximate location of the foreign object. In some cases, a machine learning algorithm can optionally be used to distinguish between different types and / or kinds of objects lodged in the tire.

[0072] In some cases, the accumulation of foreign objects on the surface of the tire and / or within its grooves can lead to undesirable bias in the range estimation and / or the determination of the tread depth. Accordingly, in some cases, a foreign object detection routine or module can operate as a precursor to the determination of the tread depth. In such cases, the tread depth determination routine or module can in some cases only be executed in the presence of a tire that is substantially free of foreign objects. The foreign object detection module can classify into one of a plurality of predefined categories based on extracting features from the reflected signature and inferring from a trained machine learning model, for example. That is, anomalies in the ISAR image that arise due to the presence of a foreign object can be detected and localized. The shape, intensity, and phase corresponding to these anomalies can be used to classify the type of foreign object, such as by the size of the foreign object FBJ, the location of the foreign object FBJ on or along the tire 156, and / or by the material that at least partially forms the foreign object FBJ.

[0073] The tire sensing system 126 can optionally utilize background subtraction to localize foreign objects on the tire by monitoring any new reflectors that arise in the ISAR image. The tire sensing system 126 can then localize the (r, f(t), z) position of objects that arise in the ISAR image and persist when averaged across multiple frames. Given its high spatial resolution, the ISAR image can capture foreign objects FBJ as small as approximately 3 mm on the surface of the tire or along the surface of the tire and / or within any grooves of the tire. It has been recognized that foreign objects located deep within the tire grooves can not reflect as strongly as foreign objects located along the outer surface of the tire. Accordingly, the tire sensing system 126 can utilize the presence of known differential reflection structures and circumferential sequences on the tire to identify deviations from such known differential reflection structures and circumferential sequences as regions that represent potential foreign objects. The tire sensing system 126 can then utilize such deviations to localize and classify foreign objects.

[0074] The tire sensing system 126 can classify the object type by relying on the amplitude and phase of the signal received at a particular (r, f(t), z) location. In some cases, any one or more of three particular characteristics corresponding to the effect of a foreign object on the sensed signal can be used. Such characteristics can include (1) the reflection amplitude (stronger for metallic objects); (2) the phase that captures the reflectivity of the object; and / or (3) the shape and size of the object that appears on the ISAR image. As one non-limiting example, a simple linear binary class classifier utilizing a Gaussian mixture model can be used. The tire sensing system 126 can generate an indication to an operator and / or a remote data storage and / or computer system that a foreign object has been detected and the location of the tire in which the foreign object is located and / or the tread depth.

[0075] Reference is now made to Figure 2 and Figure 9The controller 132 is shown as communicatively coupled to various means and components of the tire sensing system 126, such as being adapted to send, receive, and / or otherwise transmit signals, data, values, and / or information to, from, and / or between the means and / or components of the controller and system. It should be understood that the controller 132 may include any suitable hardware, software, and / or combinations thereof for the configuration and operation of the tire sensing system according to the subject matter of this disclosure. For example, the controller 132 may include a processing means, which may be of any suitable type, kind, and / or configuration, such as a microprocessor, for example, to process data, execute software routines / programs, and other functions related to the performance and / or operation of the tire sensing system 126. Additionally, the controller may include any suitable type, kind, and / or configuration of memory that may be used to store software, parameters, settings, inputs, data, values, and / or other information used in connection with the performance and / or operation of the tire sensing system 126. Figure 9 In the arrangement shown, controller 132 includes microprocessor 218 and memory 220, which is represented by blocks 220A and 220B.

[0076] like Figure 9 As shown, controller 132 may optionally include tire recognition module 222, which is capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications, and / or otherwise transferring data, values, information, signals, and / or communications to and / or outside of tire sensing system 126, such as relating to or otherwise associated with the type, type, configuration, and / or construction of one or more tires of vehicle 100 (e.g., tire 156). In some cases, tire recognition module 222 may request, receive, process, and / or store data, values, information, signals, and / or communications input by a user, such as via visual communication device 144 and / or tactile input device 148. In other cases, tire recognition module 222 may receive or otherwise transfer data, values, information, signals, and / or communications, for example, via interface 140 from, for example, a remote data storage device and / or a remote computer. Non-limiting examples of inputs and selections that may involve data, values, information, signals, and / or communications may include tire manufacturer, tire model, tire size, installation location on the vehicle, and installation date. Data, values, information, signals, and / or communications that are requested, received, processed, or otherwise transferred to the tire sensing system 126 may be stored in memory 220, such as by means of [other storage methods]. Figure 9 Box 222D in the text represents this.

[0077] The controller 132 can also optionally include a calibration module 224 that is capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications and / or otherwise transferring data, values, information, signals, and / or communications to and / or from the tire sensing system 126, for example such as can be related to or otherwise associated with the identification of one or more tires (e.g., the tires 156) of the vehicle 100 such as by imaging a plurality of differential reflective structures and / or circumferential sequences. As another non-limiting example, the calibration module 224 can be capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications and / or otherwise transferring data, values, information, signals, and / or communications to and / or from the tire sensing system 126, for example such as can be related to or otherwise associated with the rotational dynamics of one or more tires (e.g., the tires 156) of the vehicle 100 such as by adjusting spatial distortions, skewing, and / or other variables associated with the dynamic rotation of the tires. Data, values, information, signals, and / or communications requested, received, processed, or otherwise transferred to the tire sensing system 126 can be stored in the memory 220, for example such as by the calibration module 224 as represented by block 224D in FIG. 22. Figure 9

[0078] Further, the controller 132 can optionally include a tread imaging module 226 that is capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications and / or otherwise transferring data, values, information, signals, and / or communications to and / or from the tire sensing system 126, for example such as can be related to or otherwise associated with imaging an outer surface of one or more tires (e.g., the tires 156) of the vehicle 100 such as by operating the sensing device 128 to generate a 3D depth image of at least a portion of the outer surface of the tire, applying adjustment data from the calibration module 224, performing background subtraction and / or other such functions, as discussed above. Data, values, information, signals, and / or communications requested, received, processed, or otherwise transferred to the tire sensing system 126 can be stored in the memory 220, for example such as by the tread imaging module 226 as represented by block 226D in FIG. 22. Figure 9

[0079] ​​Further, the controller 132 can optionally include a distance determination module 228 capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications and / or otherwise transferring data, values, information, signals, and / or communications to and / or from the tire sensing system 126, such as for example, as can relate to or otherwise be associated with evaluating image data from the tread imaging module 226 related to an outer surface of one or more tires (e.g., the tire 156) of the vehicle 100, such as for example, by determining one or more distances from a corresponding origin point or other reference point to a surface portion of the tire. Data, values, information, signals, and / or communications requested, received, processed, or otherwise transferred to the tire sensing system 126 can be stored in the memory 220, such as for example, by the Figure 9 distance determination module 228, as represented by block 228D in FIG. 12.

[0080] Additionally, the controller 132 can optionally include a tread depth determination module 230 capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications and / or otherwise transferring data, values, information, signals, and / or communications to and / or from the tire sensing system 126, such as for example, as can relate to or otherwise be associated with a distance, depth, or other metric of remaining tread of one or more tires (e.g., the tire 156) of the vehicle 100, such as for example, by subtracting or otherwise determining a difference between a surface portion of an outer surface of the tire and a root surface portion of a corresponding tread groove. Data, values, information, signals, and / or communications requested, received, processed, or otherwise transferred to the tire sensing system 126 can be stored in the memory 220, such as for example, by the Figure 9 tread depth determination module 230, as represented by block 230D in FIG. 12.

[0081] Further, the controller 132 can optionally include a foreign object identification module 232 capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications and / or otherwise transferring data, values, information, signals, and / or communications to and / or from the tire sensing system 126, such as for example, as can relate to or otherwise be associated with identification, localization, and / or classification of extraneous materials, debris, and / or objects disposed on, arranged along, and / or embedded within one or more tires (e.g., the tire 156) of the vehicle 100, such as for example, by employing a simple linear binary class classifier and / or a machine learning model. Data, values, information, signals, and / or communications requested, received, processed, or otherwise transferred to the tire sensing system 126 can be stored in the memory 220, such as for example, by the Figure 9 foreign object identification module 232, as represented by block 232D in FIG. 12.

[0082] As Figure 9As shown in FIG. 1, the controller 132 can also optionally include a communication module 234 that is capable of requesting, receiving, processing, storing data, values, information, signals, and / or communications to and / or from the tire sensing system 126, for example, that can be related to or otherwise associated with communicating characteristics related to one or more tires (e.g., the tire 156) of the vehicle 100 to an operator, a remote data storage device, and / or a remote computer system. The communication module 234 can request, receive, transmit, process, and / or store data, values, information, signals, and / or communications, for example, such as from user inputs and / or transmissions to a user, such as through the visual communication device 144, the haptic input device 148, and / or the audible output device 152. In other instances, for example, the communication module 234 can be operable to send, receive data, values, information, signals, and / or communications to, from, or otherwise transfer data, values, information, signals, and / or communications between a remote data storage device and / or a remote computer system, such as through the interface 140. Data, values, information, signals, and / or communications requested, received, processed, or otherwise transferred into the tire sensing system 126 can be stored in the memory 220, for example, such as by the Figure 9 represented in block 234D in FIG. 2.

[0083] It should be appreciated that one or more modules of the controller 132 (shown and described herein as modules 222-234) can be provided in any suitable manner, such as software, hardware, and / or a combination of hardware and software. In some instances, the modules 222-234 can take the form of algorithms, routines, and / or programs. If provided in whole or in part as software, the configuration and operation modules of the controller 132 can be provided and stored in any suitable manner or arrangement. For example, all of the algorithms, routines, and / or programs can be integrated into a single software program in which separate sections or portions of software code will perform the various actions and / or activities of the system. In another embodiment, two or more separate modules (e.g., algorithms, routines, and / or programs) can be used to perform the various actions and / or activities of the system.

[0084] Further, the memory 220 can store or otherwise retain any suitable data, values, settings, software, algorithms, routines, programs, and / or any other information in any suitable manner or form. Also, in the preferred arrangement, the microprocessor 218 can be in communication with the memory 220 and can be operable to selectively access and / or process one or more of the data, values, information, algorithms, routines, and / or programs, such as those held in the memory storage locations 222-234 and / or 222D-234D, individually or in combination, for example. For example, the microprocessor 218 can execute or otherwise process an algorithm, routine, or program, such as from one or more of the memory locations 222-234 that are operable to access, analyze, or otherwise utilize data and / or information, such as can be stored in one or more of the memory locations 222D-234D.

[0085] Figure 10 is a graphical representation of one example of a method 300 of sensing a physical property of an associated tire, such as a depth of a tire tread and / or a presence of a foreign object or substance, for example. The method 300 can include transmitting millimeter waves toward the associated tire, such as in Figure 10 is represented by block 302. The method can also include receiving millimeter waves reflected from the associated tire, such as represented by block 304 in Figure 10 . The method 300 can further include imaging a first radial extent and a second radial extent of the associated tire using the reflected millimeter waves, such as represented by block 306 in Figure 10 . In some cases, the first radial extent and the second radial extent of the associated tire can correspond to an outer surface and a groove bottom surface of the associated tire, respectively. Additionally, in some cases, imaging the first radial extent and the second radial extent can include using an inverse synthetic aperture radar (ISAR) algorithm. The method can also include determining a dimensional difference between the first radial extent and the second radial extent of the associated tire, such as represented by block 308 in Figure 10 .

[0086] As used herein with reference to certain features, elements, components and / or structures, numerical ordinals (e.g., first, second, third, fourth, etc.) can be used to denote different singles of a plurality or otherwise identify certain features, elements, components and / or structures, and do not imply any order or sequence unless specifically so stated by the claim language. In addition, the term "lateral" and the like is to be interpreted broadly. As such, the term "lateral" and the like can encompass a wide range of angular orientations, including but not limited to an approximately perpendicular angular orientation. In addition, the terms "circumferential", "circumferentially", and the like are to be interpreted broadly, and they can include but are not limited to circular shapes and / or configurations. In this regard, the terms "circumferential", "circumferentially", and the like can be synonymous with terms such as "peripheral", "peripherally", and the like.

[0087] It should be appreciated that many differing features and / or components are illustrated in the embodiments shown and described herein, and no one embodiment is specifically illustrated and described as including all such features and components. Thus, it should be understood that the disclosed subject matter is intended to encompass any and all combinations of different features and components shown and described herein, and that the features and components can be used in any suitable arrangement without limitation. Accordingly, it should be clearly understood that the claims, whether recited herein or not, are intended to embrace any and all combinations of features and / or components, whether specifically embodied herein or not. To aid the Patent Office and any readers of this application and any resulting patents in interpreting the claims, Applicant does not intend any claim element to be limited by the mere recital of a listing of claim elements. None will be introduced by the mere use of the phrases "means for" or "step for" unless a claim element is specifically recited as "means for" or "step for". No limitation will be introduced by the mere use of the phrase "means for" or "step for" unless a claim element is specifically recited as "means for" or "step for".

[0088] Thus, while the disclosed subject matter has been described with reference to the above embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the principles of the application. In addition, many modifications can be made to the embodiments described in the preceding specific disclosure, other than those described, which form the subject of this application. Accordingly, the disclosed subject matter is intended to embrace all such alterations, permutations, and combinations. It will thus be appreciated that those skilled in the art will be able to devise numerous alternative methods and embodiments that, although not explicitly described or shown herein, embody the principles of the application and are intended to be within the spirit and scope of the application. Accordingly, the disclosed subject matter is to be considered as illustrative and not restrictive, and the scope of the application is to be determined not with reference to the above description, but with reference to the appended claims, along with their full scope of equivalents.

Claims

1. A tire sensing system (126) operable to determine one or more physical characteristics of an associated tire (156) of an associated wheel assembly (108, 118), the tire sensing system (126) comprising: a sensing device (128) supported on an associated vehicle (100) proximate an associated wheel assembly (108, 118), the sensing device (128) comprising: one or more antennas (206) facing toward an associated tire (156) such that the sensing device (128) has a field of view (FVW) of an associated tire tread (192) along an associated outer surface (184) of an associated tire (154); a millimeter wave transmitting device (128T); a millimeter wave receiving device (128R); and, a processor (218) communicatively coupled with a memory (220) comprising instructions to: transmit millimeter waves (TXs; TXg) toward the associated tire (156) using the millimeter wave transmitting device (128T); receive millimeter waves (RXs; RXg) reflected from the associated tire (156) at the millimeter wave receiving device (128R); image a first radial extent and a second radial extent (rs; rg) of the associated tire (156) based on the received millimeter waves (RXs; RXg) using an associated given point of traversal (GPT) on the associated surface (184) that travels into and through the field of view (FVW) of the sensing device (128) as the associated tire (156) angularly displaces about an axis of rotation (AXR); and, determine a dimensional difference between the first radial extent and the second radial extent (rs; rg) of the associated tire (156).

2. The tire sensing system (126) of claim 1, wherein the first radial extent (rs) corresponds to an outer surface (184) of the associated tire (156), the second radial extent (rg) corresponds to a groove (190) of the associated tire (156) at least partially defining an associated tire tread (192), and the instructions to determine the dimensional difference comprise instructions to determine a radial difference corresponding to a depth of the associated tire tread (192).

3. The tire sensing system (126) of any one of claims 1 and 2, wherein the millimeter waves have a predetermined bandwidth and a corresponding bandwidth extent resolution, and the memory (220) comprises instructions to process the received millimeter waves (RXs; RXg) to resolve extent resolution differences less than five percent (5) of the bandwidth extent resolution.

4. The tire sensing system (126) of claim 3, wherein the bandwidth extent resolution is approximately 37-1 / 2 millimeters, and the instructions to process the reflected millimeter waves resolve extent resolution differences less than one (1) millimeter.

5. The tire sensing system (126) according to any one of claims 1 to 4, wherein the instructions for imaging the first and second radial extents (rs; rg) comprise an inverse synthetic aperture radar algorithm.

6. The tire sensing system (126) according to any one of claims 1 to 5, wherein the millimeter wave transmitting device (128T) comprises a frequency modulated continuous wave generator.

7. The tire sensing system (126) according to any one of claims 1 to 6, wherein the memory (220) comprises instructions for determining a presence of a relevant foreign body (FBJ) having at least a predetermined minimum size along the first and / or second radial extent (rs; rg) of the relevant tire (156).

8. The tire sensing system (126) according to claim 7, wherein the memory (220) comprises instructions for classifying the relevant foreign body (FBJ) as belonging to one or more predetermined classes of foreign bodies.

9. The tire sensing system (126) according to any one of claims 7 and 8, wherein the instructions for determining the presence of the relevant foreign body (FBJ) comprise instructions for determining an approximate radial size (r) and an approximate angular position (phi) of the relevant foreign body (FBJ) on the relevant tire (156) with respect to a cylindrical coordinate system (r, phi, z) with an origin at a center of the relevant tire (156).

10. The tire sensing system (126) according to any one of claims 1 to 9, wherein the instructions for imaging the first and second radial extents (rs; rg) of the relevant tire (156) comprise instructions for measuring a deflection of a z-axis with respect to a cylindrical coordinate system (r, phi, z) along the relevant tire (156) and instructions for estimating a corresponding z-offset as a function of time, with an origin at the center of the relevant tire (156).

11. The tire sensing system (126) according to any one of claims 1 to 10, wherein the memory (220) comprises instructions for comparing the imaged first and second radial extents (rs; rg) of the relevant tire (156) with stored image data of a tire tread pattern (192).

12. The tire sensing system (126) according to any one of claims 1 to 11, wherein the memory (220) comprises instructions for identifying a circumferential sequence (208) of a plurality of reflective differential structures (210; 212) applied to and / or embedded within the relevant tire (156).

13. A non-transitory machine-readable storage medium (220) having machine- readable instructions stored thereon, the machine-readable instructions causing a processor (218) to: emit millimeter waves (TXs; TXg) with one or more antennas (206) of a sensing device (128) toward a relevant tire (156) using a millimeter wave transmitting device (128T); receiving, using one or more antennas (206) of the sensing device (128), millimeter waves (RXs; RXg) reflected from the associated tire (156) at a millimeter wave receiving device (128R); imaging, based on the received millimeter waves (RXs; RXg), a first radial extent and a second radial extent (rs; rg) of the associated tire (156) using an associated given hypothetical point (GPT) on an associated surface (184) of the associated tire (156) that travels into and through a field of view (FVW) of the sensing device (128) as the associated tire (156) is angularly displaced about an axis of rotation (AXR); and, determining a dimensional difference between the first radial extent and the second radial extent (rs; rg) of the associated tire (156).

14. The non-transitory machine-readable storage medium (220) of claim 13, wherein the first radial extent (rs) corresponds to an outer surface (184) of the associated tire (156), the second radial extent (rg) corresponds to a groove (190) of the associated tire (156) at least partially defining an associated tire tread (192), and the instructions to determine the dimensional difference include instructions to determine a radial difference corresponding to a depth of the associated tire tread (192).

15. The non-transitory machine-readable storage medium (220) of any one of claims 13 and 14, wherein the millimeter waves have a predetermined bandwidth and a corresponding bandwidth extent resolution, and the non-transitory machine-readable storage medium (220) includes instructions to process the received millimeter waves (RXs; RXg) to resolve extent resolution differences less than five percent (5) of the bandwidth extent resolution.

16. The non-transitory machine-readable storage medium (220) of claim 15, wherein the bandwidth extent resolution is approximately 37-1 / 2 millimeters, and the instructions to process the reflected millimeter waves (RXs; RXg) resolve extent resolution differences less than one (1) millimeter.

17. The non-transitory machine-readable storage medium (220) of any one of claims 13 to 16, wherein the instructions to image the first radial extent and the second radial extent (rs; rg) include inverse synthetic aperture radar algorithms.

18. The non-transitory machine-readable storage medium (220) of any one of claims 13 to 17, wherein the instructions to transmit millimeter waves (TXs; TXg) include instructions to transmit frequency modulated continuous waves.

19. The non-transitory machine-readable storage medium (220) of any one of claims 13 to 18, wherein the non-transitory machine-readable storage medium (220) includes instructions to determine presence of an associated foreign body (FBJ) having at least a predetermined minimum dimension along the first radial extent (rs) and / or the second radial extent (rg) of the associated tire (156).

20. The non-transitory machine readable storage medium (220) according to claim 19, wherein the non-transitory machine readable storage medium (220) comprises instructions for classifying the relevant foreign body (FBJ) as belonging to one or more predetermined classes of foreign bodies.

21. The non-transitory machine readable storage medium (220) according to any one of claims 19 and 20, wherein the instructions for determining the presence of the relevant foreign body (FBJ) comprise instructions for determining an approximate radial dimension (r) and an approximate angular position (phi) of the relevant foreign body (FBJ) on the relevant tire (156) with respect to a cylindrical coordinate system (r, phi, z), wherein the origin is at the center of the relevant tire (156).

22. The non-transitory machine readable storage medium (220) according to any one of claims 13 to 21, wherein the instructions for imaging the first and second radial extent (rs; rg) of the relevant tire (156) comprise instructions for measuring a deflection with respect to a cylindrical coordinate system (r, phi, z) along the z-axis of the relevant tire (156), and instructions for estimating a respective z-offset as a function of time, wherein the origin is at the center of the relevant tire (156).

23. The non-transitory machine readable storage medium (220) according to any one of claims 13 to 22, wherein the non-transitory machine readable storage medium (220) comprises instructions for comparing the imaged first and second radial extent (rs; rg) of the relevant tire (156) with stored image data of a tire tread pattern (192).

24. The non-transitory machine readable storage medium (220) according to any one of claims 13 to 23, wherein the non-transitory machine readable storage medium (220) comprises instructions for identifying a circumferential sequence (208) of a plurality of reflective differential structures (210; 212) applied to and / or embedded within the relevant tire (156).

25. A method (300) of sensing physical properties of a relevant tire (156), the method (300) comprising: emitting millimeter waves (TXs; TXg) using one or more antennas (206) of a sensing device (128) toward the relevant tire (156); receiving millimeter waves (RXs; RXg) reflected from the relevant tire (156) using one or more antennas (206) of the sensing device (128); imaging a first and a second radial extent (rs; rg) of the relevant tire (156) using the received millimeter waves (RXs; RXg) while the relevant tire (156) is angularly displaced about an axis of rotation (AXR) using a relevant given point of tangency (GPT) on a relevant surface (184) of the relevant tire (156) that travels into and through a field of view (FVW) of the sensing device (128); and, ​ determining a dimensional difference between the first and second radial extents (rs; rg) of the relevant tire (156).

26. The method (300) of claim 25, wherein the first radial extent (rs) corresponds to an outer surface (184) of the relevant tire (156), the second radial extent (rg) corresponds to a groove (190) of the relevant tire (156) at least partially defining a relevant tire tread (192), and the act of determining the dimensional difference comprises determining a radial difference corresponding to a depth of the relevant tire tread (156).

27. The method (300) of any one of claims 25 and 26, wherein the millimeter waves have a predetermined bandwidth and a corresponding bandwidth range resolution, and the method (300) further comprises processing the transmitted and reflected millimeter waves (TXs; TXg, RXs; RXg) to resolve a range resolution difference of less than five percent (5) of the bandwidth range resolution.

28. The method (300) of claim 27, wherein the bandwidth range resolution is about 37-1 / 2 millimeters, and processing the transmitted and reflected millimeter waves (TXs; TXg, RXs; RXg) to resolve a range resolution difference of less than one millimeter.

29. The method (300) of any one of claims 25 to 28, wherein the act of imaging the first and second radial extents (rs; rg) of the relevant tire (156) is based on an inverse synthetic aperture radar algorithm.

30. The method (300) of any one of claims 25 to 29, wherein the act of transmitting the millimeter waves (TXs; TXg) comprises transmitting frequency modulated continuous wave pulses.

31. The method (300) of any one of claims 25 to 30, further comprising determining a presence of a relevant foreign body (FBJ) having at least a predetermined minimum dimension along the first radial extent (rs) and / or the second radial extent (rg) of the relevant tire (156).

32. The method (300) of claim 31, further comprising classifying the relevant foreign body (FBJ) as belonging to one or more predetermined classes of foreign bodies.

33. The method (300) of any one of claims 31 and 32, wherein the act of determining the presence of the relevant foreign body (FBJ) comprises determining an approximate radial dimension (r) and an approximate angular position (phi) of the relevant foreign body (FBJ) on the relevant tire (156) relative to a cylindrical coordinate system (r, phi, z) with an origin at a center of the relevant tire (156).

34. The method (300) of any one of claims 25 to 33, wherein the act of imaging the first and second radial extents (rs; rg) of the relevant tire (156) comprises measuring a deflection along a z-axis of the relevant tire (156) based on a cylindrical coordinate system (r, phi, z) with an origin at the center of the relevant tire (156) and estimating a corresponding z-offset as a function of time.

35. The method (300) of any one of claims 25 to 34, further comprising comparing the imaged first and second radial extents (rs; rg) of the relevant tire (156) to a stored tire tread pattern (192).

36. The method (300) according to any one of claims 25 to 35, further comprising identifying a circumferential sequence (208) of a plurality of reflective differential structures (210; 212) applied to and / or embedded within the relevant tire (156).

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