Systems and methods for in-tire wheel force transducers

Abstract

A sensor module for estimating one or more parameters of a tire includes a detection patch having a contact patch and a sidewall patch, each of the contact patch and the sidewall patch having one or more extensible capacitors with capacitance that is variable with at least deformation of the contact patch and the sidewall patch, respectively; a power source; and an electronics unit electronically connected to the power source and the detection patch and configured to control the sensor module, wherein the detection patch is configured to be attached to an inside of the tire such that the contact patch contacts an inside of a tread portion and the sidewall patch contacts an inside of a sidewall portion, and the electronics unit is configured to estimate at least one of the parameters of the tire using the capacitance of the one or more extensible capacitors.

Description

[Technical Field]

[0001] The present disclosure relates generally to wheel force transducers (WFTs) for vehicles. More particularly, the present disclosure relates to compliance sensor systems and methods for in-tire sensors configured to detect tire forces and moments. [Background technology]

[0002] Flexible sensors are known, for example, in U.S. Patent Nos. 8,941,392, 9,222,764, 9,476,692, 9,612,102, 9,874,431, 10,551,917, 10,823,546, 10,959,644, and U.S. Patent Application Publication No. 2022 / 0034692, the contents of which are incorporated herein by reference.

[0003] In-tire sensors are also known. For example, WO2021168286A1 discloses an in-tire sensor, the contents of which are incorporated herein by reference.

[0004] Additionally, commercially available WFTs are known for measuring real-time forces and moments at a vehicle's wheel hub. These forces and moments can be used as inputs to a vehicle's electronic control unit (ECU) to control, for example, an anti-lock brake system (ABS) and electronic stability control (ESC), thereby improving driving safety and vehicle handling. For example, the publication "Improving the active safety of road vehicles by sensing forces and moments at the wheels" (Massimiliano Gobbi, Juan C. Botero, Giampiero Mastinu (2008) Vehicle System Dynamics, 46:S1, 957-968) shows that using tire forces and moments as inputs to an ABS can reduce stopping distances by 10% and enable smoother braking.

[0005] However, existing WFTs are typically expensive and heavy. For example, one Kistler-branded WFT costs over $100,000, more than most vehicles. The cost of four such sensors (e.g., one per wheel) is impractical. Additionally, a set of four such WFTs weighs approximately 20-40 kg, reducing fuel efficiency, among other things. Current systems and methods also have other drawbacks, inconveniences, inefficiencies, and challenges. Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, the disclosed embodiments address these and other drawbacks, inconveniences, inefficiencies, and problems that exist in current systems and methods. The disclosed systems and methods also offer other advantages and efficiencies. [Means for solving the problem]

[0007] As used herein, "flexible," "extensible," "compliant," "deformable," etc. are used somewhat interchangeably and all mean that there is some degree of bending, extension, compression, twisting, curvature, etc. to the embodiment being described. As used herein, "extensible" is used generally to refer to all of the above collectively.

[0008] Disclosed exemplary embodiments include an in-tire sensor system consisting of a contact patch (CP) sensor and a sidewall (SW) sensor, each bonded to the interior of the tire to directly sense tire deformation. The CP and SW sensor embodiments may also include one or more capacitors, each having a capacitance that is variable at least with the deformation of the respective capacitor. The sensor system embodiments may also include an electronics unit connected to each capacitor and configured to control the sensors. The electronics unit may be configured to estimate at least one of the tire parameters based on the capacitance of each capacitor.

[0009] Exemplary methods are also disclosed for calculating tire forces, tire moments, and slip angles using the CP and SW sensor signals. Method embodiments may also extract macro-features from the CP and SW sensor signals. Method embodiments may also select the most relevant macro-features to calculate tire physical quantities of interest. Other embodiments exist. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a portion of a tire including an exemplary sensor module for estimating one or more parameters of the tire, according to an embodiment of the disclosure. [Figure 2A] FIG. 10 is a schematic diagram of another exemplary sensor module, according to an embodiment of the disclosure. [Figure 2B] FIG. 10 is a schematic diagram of another exemplary sensor module, according to an embodiment of the disclosure. [Figure 3] FIG. 2C is a schematic diagram of an exemplary energy generation circuit that may be included in the sensor module of FIGS. 2A and 2B, according to an embodiment of the disclosure. [Figure 4A] FIG. 1 illustrates another exemplary sensor module according to an embodiment of the disclosure. [Figure 4B] FIG. 1 illustrates another exemplary sensor module according to an embodiment of the disclosure. [Figure 5A] 1 illustrates an embodiment of a tire sensor module located inside a tire according to an embodiment of the disclosure. FIG. [Figure 5B] 1 illustrates an embodiment of a tire sensor module located inside a tire according to an embodiment of the disclosure. FIG. [Figure 6] FIG. 10 illustrates the microscopic signals of the sensor module components (CP and SW) according to an embodiment of the disclosure. [Figure 7] FIG. 10 illustrates the macroscopic signals of the sensor module components (CP and SW) according to an embodiment of the disclosure. [Figure 8] FIG. 1 illustrates an experimental setup including a force-moment machine and an in-tire sensor module, according to an embodiment of the disclosure. [Figure 9] FIG. 9 shows the CP, SW, and WFT signals obtained from the experimental setup of FIG. 8. [Figure 10] FIG. 10 is a diagram illustrating the notation of forces and moments in FIG. 9. [Figure 11] FIG. 1 illustrates an example workflow for using CP and SW signals to extract macroscopic features from each, according to an embodiment of the disclosure. [Figure 12] 10A-10C illustrate calculation of lateral force Fy using only SW signals and both SW and CP signals according to a disclosed embodiment. [Figure 13] 10A-10C illustrate calculation of slip angle (SA) using only the SW signal and both CP and SW according to a disclosed embodiment; [Figure 14] FIG. 10 illustrates the calculation of the x-axis moment (Mx) using only the SW signal and both the CP and SW signals, according to an embodiment of the disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are herein described in detail. It is to be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0012] 1 is a cross-sectional view of a portion of a tire 100 including an example sensor module 102 for estimating one or more parameters of the tire 100, configured in accordance with at least one embodiment described herein. In some embodiments, the tire 100 is a tubeless tire having a tire carcass 104 with an inner surface 106 that forms an airtight seal with a wheel 108 to define a reservoir 110 for receiving a gas (typically air) therein. The tire carcass 104 may have tire beads 112 that interact with the wheel 108 to form an airtight seal. In some embodiments, the tire 100 employs an inner tube disposed within the reservoir 110 to hold a gas, such as air, without the tire 100 needing to form an airtight seal with the wheel 108. The tire carcass 104 may include a tread portion 114, a shoulder portion 116, and a sidewall portion 118.

[0013] The sensor module 102 may be disposed on an inner surface 106 of the tire 100, or, if the tire 100 is implemented as an inner tube, on the outer surface of the inner tube disposed within the reservoir 110, or in any other suitable location. The sensor module 102 may generally include a detection patch 120 and an electronics unit 122 connected to the detection patch 120. The sensor module 102 may also include or be coupled to a power source 124. For example, the electronics unit 122 may be coupled to the power source 124 to obtain power for operation.

[0014] The sensing patch 120 may include one or more sensor regions 126A, 126B, and / or 126C (hereinafter collectively or collectively referred to as "sensor regions 126"). Each of the sensor regions 126 may include one or more capacitors. The sensing patch 120 may be applied to or coupled to the inner surface 106 such that one or more of the sensor regions 126 are disposed on, near, and / or next to the tread portion 114, the shoulder portion 116, and / or the sidewall portion 118. For example, as shown in FIG. 1 , the sensor region 126A is disposed on, near, or next to the tread portion 114, the sensor region 126B is disposed on, near, or next to the shoulder portion 116, and the sensor region 126C is disposed on, near, or next to the sidewall portion 118. In some embodiments, the proximity can be within 1 millimeter (mm), 5 mm, 10 mm, 25 mm, or 100 mm of the tread portion 114, shoulder portion 116, or sidewall portion 118 of the tire 100. Alternatively or additionally, the detection patch 120 may be attached to the inside of the tread portion 114 (e.g., inner surface 106), the inside of the shoulder portion 116 (e.g., inner surface 106), and / or the inside of the sidewall portion 118 (e.g., inner surface 106).

[0015] 1 shows each sensor region 126 as being located inside one of the tread region 114, shoulder region 116, or sidewall region 118. Alternatively or additionally, one or more of the sensor regions 126 may be located inside two or more of the tread region 114, shoulder region 116, or sidewall region 118. For example, at least one of the sensor regions 126 may be elongated and extend across the inside of at least two of the tread region 114, shoulder region 116, or sidewall region 118.

[0016] 1, the electronics unit 122 is shown inside the tread 114, but more generally may be located on or coupled to the tire 100, wheel 108, detection patch 120, and / or power source 124. In some embodiments, the electronics unit 122 includes one or more of a printed circuit board (PCB), one or more voltage and / or current measurement circuits, a transmitter, a receiver, a transceiver, or other components. The electronics unit 122 may be configured to measure one or more parameters of the sensor area 122 or a capacitor therein, estimate one or more tire parameters based on the measurements, transmit the estimated tire parameters to another system or device, and / or transmit the measurements to another system or device to perform estimation of the one or more tire parameters.

[0017] Power source 124 may include one or more batteries, energy generating circuitry, a receiver coil and circuitry of an inductive charging unit, or other power source.

[0018] 1 includes arbitrarily defined X, Y, and Z coordinate axes, with the X axis aligned longitudinally (e.g., the direction that tire 100 moves as it rolls back and forth without skidding), the Y axis aligned laterally (e.g., perpendicular to the longitudinal and horizontal directions), and the Z axis aligned vertically perpendicular to the longitudinal and lateral directions. The X, Y, and Z coordinate axes are sometimes also referred to as the roll, pitch, and yaw axes, respectively.

[0019] A vehicle equipped with one or more tires, such as tire 100, tends to roll (e.g., rotate about an X-axis or roll axis) when making a turn. For example, when the vehicle is making a turn, the tire 100 of the vehicle on the inside of the turn (hereinafter, "inner tire 100"), more specifically, the center of gravity of the inner tire 100, tends to rise through the turn, while the tire 100 of the vehicle on the outside of the turn (hereinafter, "outer tire 100"), more specifically, the center of gravity of the outer tire 100, tends to descend. As a result, the centers of gravity of the inner tire 100 and the outer tire may move in the XZ plane of FIG. 1.

[0020] When a vehicle accelerates or decelerates, it tends to rotate about the Y axis or pitch axis. For example, when a rear-wheel drive vehicle accelerates forward, the front of the vehicle, and therefore the front tire 100, and more specifically, the center of gravity of the front tire, tends to lift. When the vehicle decelerates or brakes while moving forward, the front of the vehicle, and therefore the front tire 100, and more specifically, the center of gravity of the front tire, tends to be pushed down. As a result, the center of gravity of the front tire 100 may move in the YZ plane of FIG. 1. Furthermore, for example, when the vehicle accelerates or decelerates, the vertical force acting on the tire 100 may change. For example, compared to moving forward at a constant speed, the vertical downward force acting on the front tire 100 may be smaller when accelerating and larger when decelerating.

[0021] When another vehicle collides sideways with the vehicle in front of or behind the center of gravity, the vehicle tends to rotate around the Z axis or yaw axis. For example, when another vehicle collides sideways with the vehicle behind the center of gravity, the rear tire 100 tends to move laterally in the negative Y direction, and the front tire 100 tends to move laterally in the positive Y direction, assuming the positive X direction in FIG. 1 is the direction the vehicle is facing. As a result, the front tire 100 may move in the XY plane in FIG. 1.

[0022] The vertical, longitudinal, and / or lateral forces exerted on a vehicle's tire 100, and / or other parameters of the tire 100, such as strain, flexion, curvature, etc., may vary in these and other situations. In the embodiments described herein, one or more sensor modules 102 in one or more tires 100 of a vehicle may be used to estimate such tire parameters. In combination, these measured tire parameters may comprise a set of leading indicators of pitch, roll, and yaw felt by the vehicle suspension system. Employing leading indicators should reduce response delay of the active or semi-active suspension system.

[0023] In some embodiments, one or more of the capacitors included in the sensor region 126 of the sensor module 102 may be layered and / or laminated. Alternatively or additionally, one or more of the capacitors may be flexible, stretchable, expandable, and / or deformable. The flexibility, stretchability, expansion, and / or deformability of one or more of the capacitors may be at least partially elastic. For example, a capacitor is considered elastically deformable if it changes shape under stress or force and the change in shape is reversible after the stress or force is removed.

[0024] In some embodiments, one or more of the capacitors may include a unidirectional or multidirectionally expandable or extensible capacitor. As used herein, multidirectionally expandable or extensible means that the capacitor is expandable or extensible in multiple directions relative to its initial position on the inner surface 106 of the tire 100. In some embodiments, the capacitor may be expandable or extensible in response to a longitudinal, lateral, or vertical force, or a combination thereof. The capacitor may be disposed at a first location on the inner surface 106 and adapted to move or expand from the first location to a second relative position due to inflation of the tire 100 under an applied force relative to the first location.

[0025] In some embodiments, one or more capacitors and / or the sensing patch 120 may be constrained to stretch only in certain dimensions by appropriate addition and / or placement of elements in the sensor module 102. For example, an anisotropic member may be added to the sensing patch 120 that constrains deformation along the Y-axis but not along the X-axis. This may amplify the X-axis deformation signal from the sensing patch 120 and attenuate the Y-axis deformation signal. The anisotropic member may be any layer (including an adhesive) in the stack of the sensing patch 120. As another example, the additional member may continue to allow bending but restrict stretching. This may be the case if the additional member itself is flexible but has limited stretchability.

[0026] One or more of the capacitors included in the sensor region 126 of the sensor module 102 may be elongated. That is, the length of one or more of the capacitors may exceed its width. In some embodiments in which the detection patch 120 includes multiple capacitors, including a first capacitor and a second capacitor, and / or multiple sensor regions 126, the first and second capacitors or first and second sensor regions 126 may be arranged such that the length of the second capacitor or second sensor region 126 is aligned within ±5°, 10°, 15°, 20°, or 30° of the length of the first capacitor or first sensor region 126 or within ±5°, 10°, 15°, 20°, or 30° in a direction perpendicular to the length of the first capacitor or first sensor region 126. In some embodiments, the first and second capacitors and / or first and second sensor regions 126 are alignable in a straight line. In some embodiments, multiple capacitors and / or sensor areas 126 of sensing patch 120 can be arranged in a plane parallel to the radial direction (eg, the XY plane in FIG. 1).

[0027] 2A and 2B are schematic diagrams of another exemplary sensor module 200 configured in accordance with at least one embodiment described herein. The sensor module 200 may include, be included in, or correspond to the sensor module 102 of FIG. 1. For example, the sensor module 102 of FIG. 1 may have the same, similar, or different organization and / or configuration as the sensor module 200 of FIG. 2A and 2B.

[0028] As shown in FIGS. 2A and 2B, the sensor module 200 may generally include a detection patch 202 and an electronics unit 204, and optionally a power source 206, where the electronics unit 204 may be connected to the detection patch 202 and the power source 206.

[0029] Detection patch 202, electronics unit 204, and power source 206 may respectively include detection patch 120, electronics unit 122, and power source 124 of FIG. 1, or may be included in detection patch 120, electronics unit 122, and power source 124 of FIG. 1, or may correspond to detection patch 120, electronics unit 122, and power source 124 of FIG. 1.

[0030] The detection patch 202 may include a mounting surface 208 ( FIG. 2B ) and one or more sensor regions 210 ( FIG. 2B ). The mounting surface 208 may be configured to be attached to the surface of an object, such as a tire, and / or may include a lower or bottom surface ( FIG. 2B ) of the detection patch 202. Alternatively or additionally, the mounting surface 208 may include an adhesive 212 ( FIG. 2B ) disposed thereon to adhere the detection patch 202 to a desired location within the tire cavity of the tire or on the exterior of the inner tube. The adhesive 212 may include a thermoplastic adhesive or other suitable adhesive.

[0031] The sensor region 210 may generally include a capacitor. In some embodiments, the capacitor and / or the sensor region 210 may be flexible, stretchable, expandable, deformable, layered, and / or laminated. Alternatively or additionally, the sensor region 210 may be at least partially covered, bonded to, and / or surrounded by one or more protective layers 214 as part of the detection patch 202. The protective layers 214 may include an elastomeric material, such as silicone.

[0032] The power source 206 may include a battery, an energy generating circuit, an energy harvesting system (EHS) module, a dielectric elastomer power generating material, a piezoelectric power generating material, and / or a receiver coil and circuitry of an inductive charging unit.

[0033] The electronics unit 204 may be electrically connected to the detection patch 202 and the power source 206, respectively, via one or more corresponding electrical connectors 216 (FIG. 2B). Alternatively or additionally, the electronics unit 204 and the power source 206 may be mechanically bonded together with epoxy and / or disposed within a housing or encapsulant 218 (FIG. 2B) that is mechanically coupled to the detection patch 202. The housing or encapsulant 218 may be an electrical, thermal, and / or mechanical insulator. For example, the housing or encapsulant 218 may include a vibration-damping material such as platinum silicone flexible foam, an example of which is SOMA FOAMA 25. In another embodiment, the housing 218 may be supported by vibration isolators mounted to the mounting surface 208. The vibration isolators may be or include spring mechanisms, patterned grids of vibration dampers, microlattices, etc. The vibration isolators may be constructed of molded rubber, metal, or a composite thereof. In another embodiment, the cyclic deformation of the vibration isolator may actuate a power generating element (eg, a dielectric elastomer power generating material and / or a piezoelectric power generating material).

[0034] 2A , the electronics unit 204 may include a controller 220, a memory 222, and / or a communications module 224. The controller 220 may be operatively coupled to the memory 222 and the communications module 224, respectively, and may generally be configured to control the operation of the sensor module 200. For example, the electronics unit 204 may generally include the controller 220 specifically configured to perform or control the performance of operations including charging each capacitor of the sensor module 200, calculating a change in capacitance of each capacitor relative to the amount of charge discharged when each capacitor is discharged, and / or estimating at least one tire parameter based on the capacitance and / or the change in capacitance. In some embodiments, the controller 220 may estimate, compare, and / or analyze one or more tire parameters. The tire parameters may include one or more of internal tire pressure, distortion, angular displacement, temperature, under- and over-inflation, friction, hydroplaning of the contact patch, road surface classification, uneven tire load, camber imbalance, vehicle load, individual tire balance, suspension anomalies, tire anomalies (cracks, delamination, punctures), tread wear and tire thickness, tire distortion, hard acceleration, hard turns, hard braking, slip angle, slip ratio, effect of camber angle, longitudinal force, longitudinal acceleration, longitudinal velocity, lateral force, lateral acceleration, lateral velocity, torque about a longitudinal axis, torque about a lateral axis, torque about a vertical axis, and / or tire rotational speed. In some embodiments, controller 220 estimates tire rotational speed and road surface classification and uses them to modulate the sampling frequency. This may save energy in some situations while providing sufficient data for calculation of safety parameters such as road surface classification, including hydroplaning at high speeds. For example, the controller 220 may increase the sampling rate when it detects a wet road surface, allowing a human driver or automated vehicle to respond faster.

[0035] In some embodiments in which the sensor module 200 includes multiple sensor regions 210, the controller 220 may selectively receive data from any and all sensor regions 210, or portions thereof. This may facilitate tire parameter analysis during tire motion and / or under turning stress. Alternatively or additionally, self-testing of the sensor module 200 may identify when to replace one or more sensor regions 210, the entire sensor module 200, or portions thereof. The memory 222 may store data generated by the sensor regions 210 (e.g., raw measurement data or signals), data generated by the controller 220 (e.g., calculated capacitance, change in capacitance, or estimated tire parameters), and / or other data.

[0036] The incorporation of an in-sensor computing element (e.g., controller 220) reduces the amount of raw data, such as strain data and angular displacement data, that can be sent to external or remote devices. This reduces memory and energy consumption for wireless transmission to external or remote devices and may reduce feedback latency. In some embodiments, each tire on a vehicle includes one or more sensor modules 200, each of which can transmit its data to the vehicle's onboard computer. The onboard computer is a remote device relative to each of the sensor modules 200, even though they are on the same vehicle. Based on the data received from the sensor modules 200, the onboard computer can generate a notification, such as an alarm, to the vehicle driver, store the data, perform further processing on the data, report the data to a fleet or vehicle management system, or perform some other operation on, by, or based on the data. In some embodiments, each sensor module 200 may be connected (e.g., networked) to external or remote systems or devices over a local area network (LAN), an intranet, an extranet, or the Internet. The external or remote system or device may operate as a server or client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. Each sensor module 200 may include or be in communication with a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), mobile phone, web appliance, server, network router, switch or bridge, vehicle circuitry, on-board computer, or any machine capable of executing a set of instructions (sequential or otherwise) that specify operations to be performed by the sensor module 200. The controller 220 and communications module 224 may include asset-side active tracking circuitry used for asset tracking.

[0037] In some embodiments, the controller 220 can selectively decrease the sampling frequency of at least one sensor region 210 when the sensor module 200 rotates out of contact with or outward from the tire tread of the tire to which it is attached. In some embodiments, the sampling frequency can increase proportionally to the tire rotational speed. In some embodiments, the controller 220 can selectively utilize the capacitive output from sensor regions 210 at specific locations to facilitate determining or estimating spatial displacement, angular displacement, or other tire parameters of selected tire portions.

[0038] Controller 220 may comprise any suitable special-purpose or general-purpose computer, computing entity, or processing device, including various computer hardware or software modules, and may be configured to execute instructions stored on any applicable computer-readable storage medium. For example, controller 220 may include a processor, microprocessor, microcontroller, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or any other digital or analog circuit configured to interpret and / or execute computer-executable instructions and / or process data. While controller 220 is shown as a single controller 220, it may include any number of controllers configured to individually, jointly, or directly perform any number of operations described in this disclosure. In some embodiments, controller 220 may include a separate AI or integrated AI chip that may function as a sensor fusion center.

[0039] In some embodiments, controller 220 may be configured to interpret and / or execute computer-executable instructions and / or process data stored in memory 222 and / or other data storage. In some embodiments, controller 220 may fetch computer-executable instructions from persistent data storage and load them into non-persistent storage, such as memory 222. After the computer-executable instructions are loaded into memory 222, controller 220 may execute the computer-executable instructions.

[0040] Memory 222 may include computer-readable storage media for retaining or storing computer-executable instructions or data structures. Such computer-readable storage media may include any available media that can be accessed by a general-purpose or special-purpose computer, such as controller 220. By way of example, such computer-readable storage media may include tangible or non-transitory computer-readable storage media including random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory devices (e.g., solid-state memory devices), or any other storage medium usable to retain or store specific program code in the form of computer-executable instructions or data structures or that can be accessed by a general-purpose or special-purpose computer. Combinations of the above may also be included within the scope of computer-readable storage media. Computer-executable instructions may include, for example, instructions and data configured to cause controller 220 to perform or control the execution of a particular operation or group of operations.

[0041] The communications module 224 may include one or more circuits or devices configured to facilitate communication between the sensor module 200 and one or more external or remote devices. In some embodiments, such circuits or devices may include a transmitter, a receiver, a transceiver, and / or an antenna. For example, the communications module 224 may include one or more wireless chips for wireless communication using any proprietary or standards-based wireless protocol, including, by way of example, the IEEE 802.11 standard (e.g., WiFi), Bluetooth, Zigbee, etc.

[0042] In some embodiments, the sensor module 200 further comprises a microphone. The microphone may be included, for example, on a semiconductor chip that may also include the controller 220. In some embodiments, the microphone may determine pressure. In some embodiments, the processor's pressure estimate may be dynamically refined by comparing tire strain measurements determined by the sensor area 210 with pressure measurements from the microphone. In some embodiments, possible suspension problems may be detected by comparing outputs from at least one wheel and / or each and every wheel of the vehicle to one another. In some embodiments, the accuracy of the road surface classification algorithm may be improved by fusing input from the microphone with input from the detection patch 202.

[0043] In some embodiments, the final results of the sensor module 200 calculations can be transmitted to an end-user receiver. In some embodiments, the end-user receiver can be a smartphone. In some embodiments, the end-user receiver can be a cloud server. In some embodiments, the end-user receiver can be the vehicle itself. In some embodiments, the output can be sent to a processing unit on the vehicle, which can modify the vehicle's motion (e.g., slowing the vehicle if the overall tire distortion level reaches a certain threshold). In some embodiments, the output can be sent to a data logger in the vehicle. In some embodiments, the data logger can be part of an on-board computer that compares outputs from the tires and extracts parameters for a fleet of tires (e.g., comparing tire wear patterns and recommending a specific tire rotation pattern). In some embodiments, the on-board computer can instruct a particular controller unit 220 of a corresponding sensor module 200 to reduce the sampling rate and / or data transmission rate from the sensor module 200 if the battery or charge level of the power source 206 is below a threshold. To compensate, the on-board computer can use data from adjacent tires to extrapolate the ensemble information. In some embodiments, an output can be sent to an indicator light that indicates achievement of a given threshold parameter.

[0044] Figure 3 is a schematic diagram of an exemplary energy generation circuit 300 configured in accordance with at least one embodiment described herein. The energy generation circuit 300 may include, be included in, or correspond to the power supply 206 of Figures 2A and 2B. For example, the power supply 206 of Figures 2A and 2B may include some or all of the energy generation circuit 300 of Figure 3.

[0045] The energy generation circuit 300 may include a power generation element 302, an EHS module 304, an energy storage circuit 306, and / or a battery 308. The EHS module 304 may be electrically coupled to the power generation element 302, the energy storage circuit 306, and / or the battery 308.

[0046] The power generating element 302 may include a dielectric power generating material, a piezoelectric power generating material, or other material, system, or device that generates electricity when subjected to motion, mechanical stress, or other input, or a combination thereof. In some embodiments, bending of the power generating element 302, for example, implemented as a piezoelectric bending film and / or a portion of a detection patch having such materials, can generate an electric charge on the surface of the power generating element 302. Suitable materials for the power generating element 302 include, for example, silicone polymers and charge generating materials (e.g., lead zirconate titanate). In some embodiments, the charge generating material may comprise 50-90% silicone polymer by weight. In some embodiments, the power generating element 302 may be disposed in proximity to the tread, shoulder, and / or sidewall of a tire.

[0047] In some embodiments, the EHS module 304 collects the capacitive discharge and / or current generated by the power generation element 302. The EHS module 304 may include a bridge rectifier, a voltage regulator, and / or an energy buffer capacitor to collect the power generation element 302 output and generate an electrical output compatible with a corresponding sensor module and / or vehicle electronics. After accumulating an output above a threshold level, the EHS module 304 may discharge the stored output and send it to the energy storage circuit 306. In some embodiments, not all of the energy stored by the energy buffer capacitor is sent to the energy storage circuit 306, but instead, some of the energy can be returned to the electronics unit 204 for use.

[0048] In some embodiments, the energy storage circuitry 306 includes a battery charging integrated circuit (IC) and / or a direct electrical connection to a storage source (e.g., a rechargeable battery 308). Additionally, an electronics unit, such as the electronics unit 204 of FIGS. 2A and 2B, may draw operating power from the battery 308.

[0049] 4A and 4B illustrate another exemplary sensor module 400 configured in accordance with at least one embodiment described herein. In particular, FIG. 4A is an overhead view of the sensor module 400, and FIG. 4B is a cross-sectional view of the sensor module 400 taken along section 4B-4B of FIG. 4A. The sensor module 400 may include, be included in, or correspond to other sensor modules described herein. For example, the sensor module 102 of FIG. 1 and / or the sensor module 200 of FIGS. 2A and 2B may have the same, similar, or different configuration as the sensor module 400 of FIGS. 4A and 4B.

[0050] 4A and 4B, sensor module 400 may generally include detection patch 402 and electronics unit 404, and optionally, power source 406, with electronics unit 404 connected to detection patch 402 and power source 406. Detection patch 402, electronics unit 404, and power source 406 may each include, be included in, or correspond to other detection patches, electronics units, and power sources described herein.

[0051] 4A, the sensing patch 402 may include two sensor areas 408, 410, each electrically coupled to the electronics unit 404 by corresponding electrical traces 412, 414. The sensor areas 408, 410 may each include a capacitor having a capacitance that is variable with deformation.

[0052] 4B, the electronics unit 204 and power supply 206 can be disposed within a housing or encapsulant 416 that is mechanically bonded together with epoxy and / or mechanically coupled to the sensing patch 402. The housing or encapsulant 416 can be an electrical, thermal, and / or mechanical insulator. For example, the housing or encapsulant 416 can include a vibration damping material such as platinum silicone flexible foam, an example of which is SOMA FOAMA 25.

[0053] 4B , the electronics unit 404 may include a PCB 418 having one or more circuits formed thereon or coupled thereto. Alternatively or additionally, the PCB 418 may have one or more voltage and / or current measurement circuits, transmitters, receivers, transceivers, or other components mounted thereon or coupled thereto. Similar to the other electronics units described herein, the electronics unit 404 may be configured to measure one or more parameters of the sensor areas 408, 410 or capacitors therein, estimate one or more tire parameters based on the measurements, transmit the estimated tire parameters to another system or device, and / or transmit the measurements to another system or device to perform estimation of one or more tire parameters.

[0054] 5A and 5B illustrate an embodiment of a tire sensor module (e.g., module 200, 400) disposed inside a tire, according to embodiments of the disclosure. The tire sensor module consists of a contact patch (CP) sensor 408 and a sidewall (SW) sensor 410. As shown in FIG. 5A, an embodiment may have the SW sensor 410 generally aligned along the tire's axis of rotation (e.g., the x-axis in FIG. 1) and the CP sensor 408 generally aligned along the horizontal axis (e.g., the y-axis in FIG. 1). As shown in FIG. 5B, a reverse alignment is also possible, with the SW sensor 410 generally aligned along the y-axis and the CP sensor 408 generally aligned along the x-axis. Other orientations are also possible. The sensor components CP 408 and SW 410 generate different signals. Microscopically (as shown in FIG. 6), the waveforms for each signal are different. Furthermore, macroscopically (as shown in FIG. 7), the signals for CP 408 and SW 410 are different. The micro- and macro-signals shown in Figures 6 and 7 were generated as the tire slip angle varied from -6° to +6° on a force-moment machine 800 (WFT) shown in Figure 8. The force-moment tester 800 shown in Figure 8 is equipped with a wheel force transducer 802, and the tire is equipped with an in-tire sensor module (e.g., 400) (located within the tire as shown schematically in Figure 8).

[0055] The slip angle obtained and the force (F x , F y , F z ) and moment (M x , M y , M z ) and are shown in Figure 9, with the CP408, SW410, and WFT802 signals substantially aligned. The notation of forces and moments follows the ISO tire coordinate system shown in Figure 10.

[0056] FIG. 11 shows an example workflow using the CP408 and SW410 signals to extract macroscopic features from each. These features are then used in multiple machine learning algorithms to (1) determine the most relevant macroscopic features and (2) calculate tire force, tire moment, and slip angle. As will be apparent to those skilled in the art having the benefit of this disclosure, the selection of features is important, as results will vary depending on the features used by the machine learning model. For example, as shown in FIG. 12, the lateral force F that changes tire slip angle can be calculated. y When calculating , in some embodiments, using only the SW signal is more accurate than using both the SW and CP signals.

[0057] As another example, as shown in Figure 13, calculating the slip angle (SA) using only the SW signal is more accurate than including both CP 408 and SW 410. This is because F y 14. As will be appreciated by those skilled in the art having the benefit of this disclosure, for some physical quantities, using both CP 408 and SW 410 will result in a more accurate model than using only one of these signals. For example, as shown in FIG. 14, when both CP 408 and SW 410 signals are used, the calculated M x M x Other embodiments are also possible.

[0058] While various embodiments have been shown and described above, it is understood that the disclosure is not limited thereto, but includes all such modifications and variations as would become apparent to one skilled in the art.

Claims

1. A tire, A tread portion; A sidewall portion; a sensor module for estimating one or more parameters of the tire; a sensing patch comprising a ground patch and a sidewall patch, the ground patch and the sidewall patch each comprising one or more extensible capacitors having capacitances that are variable with at least a deformation of the ground patch and the sidewall patch, respectively; Power supply and an electronics unit electronically connected to the power source and the sensing patch and configured to control the sensor module; a sensor module comprising: Equipped with the sensing patch is affixed to an inside of the tire such that the contact patch contacts an inside of the tread portion and the sidewall patch contacts an inside of the sidewall portion, and the electronics unit is configured to use the capacitance of the one or more tensile capacitors to estimate at least one of the parameters of the tire.

2. 10. The tire of claim 1, wherein each of the one or more tensile capacitors is charged with a direct current, and the change in capacitance is calculated based at least in part on the amount of charge discharged.

3. The tire of claim 1 , wherein the contact patch has a length and a width, the length being greater than the width.

4. The tire of claim 1 wherein said sidewall patch has a length and a width, said length being greater than said width.

5. 10. The tire of claim 1, wherein said contact patch has a length and a width, said length being at least twice said width.

6. 10. The tire of claim 1, wherein said sidewall patch has a length and a width, said length being at least twice said width.

7. 10. The tire of claim 1, wherein the detection patch has a length and a width, the length being at least twice the width.

8. The tire of claim 1 wherein the axis of said contact patch is oriented in a different direction than the axis of said sidewall patch.

9. The tire of claim 1 wherein the axis of said contact patch is oriented substantially perpendicular to the axis of said sidewall patch.

10. 10. The tire of claim 9, wherein the axis of the contact patch is oriented substantially parallel to the direction of travel of the tire.

11. 10. The tire of claim 9, wherein the axis of the contact patch is oriented substantially perpendicular to the direction of travel of the tire.

12. 1. A sensor module for estimating one or more parameters of a tire, comprising: a sensing patch comprising a ground patch and a sidewall patch, the ground patch and the sidewall patch each comprising one or more extensible capacitors having capacitances that are variable with at least a deformation of the ground patch and the sidewall patch, respectively; Power supply and an electronics unit electronically connected to the power source and the sensing patch and configured to control the sensor module; Equipped with the sensing patch is configured to adhere to an inside of a tire such that the contact patch contacts an inside of a tread portion and the sidewall patch contacts an inside of a sidewall portion, and the electronics unit is configured to estimate at least one of the parameters of the tire using the capacitance of the one or more tensile capacitors.

13. The sensor module of claim 12 , wherein each of the one or more extensional capacitors is charged with a direct current, and the change in capacitance is calculated based at least in part on the amount of discharged charge.

14. The sensor module of claim 12 , wherein the ground patch has a length and a width, the length being greater than the width.

15. The sensor module of claim 12 , wherein the sidewall patch has a length and a width, the length being greater than the width.

16. The sensor module of claim 12 , wherein the ground patch has a length and a width, the length being at least twice the width.

17. The sensor module of claim 12 , wherein the sidewall patch has a length and a width, the length being at least twice the width.

18. The sensor module of claim 12 , wherein the sensing patch has a length and a width, and the length is at least twice the width.

19. The sensor module of claim 12 , wherein an axis of the ground patch is oriented in a different direction than an axis of the sidewall patch.

20. The sensor module of claim 12 , wherein an axis of the ground patch is oriented substantially perpendicular to an axis of the sidewall patch.

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