Determining tread depth using data from tire mounting sensors

Abstract

Methods, apparatus, systems, and computer program products for determining tread depth using data from a tire mounting sensor (TMS). In a specific embodiment, determining tread depth using data from the TMS includes: determining tire deformation of the tire based on data collected by the tire mounting sensor; determining the effective rolling radius of the tire based on the tire deformation; and determining an estimated tread depth of the tire based at least on the effective rolling radius of the tire.

Description

Technical Field Background Technology

[0001] The load on the tires can be estimated by measuring various characteristics of the vehicle. For example, the load carried by the vehicle can be estimated using a vehicle-based height sensor. However, these methods require vehicle-specific sensors that must be calibrated for the specific springs and components of the vehicle. Furthermore, load measurements taken using these vehicle-specific sensors, and subsequent calculations based on these measurements, are prone to inaccuracies. Summary of the Invention

[0002] In some embodiments, a method for determining tread depth using data from a tire mounted sensor (TMS) includes: determining tire deformation of the tire based on data collected by the TMS; determining the effective rolling radius of the tire based on the tire deformation; and determining an estimated tread depth of the tire based at least on the effective rolling radius of the tire.

[0003] In some embodiments, the method further includes: determining the rolling radius of the tire based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel. In some embodiments, the method further includes: receiving data indicating the linear velocity and angular velocity. In some embodiments, the linear velocity is based on Global Positioning System (GPS) Doppler velocity. In some embodiments, the angular velocity is based on wheel speed sensor data. In some embodiments, determining the tire deformation includes: determining the contact patch length based on radial acceleration data. In some embodiments, the method further includes: receiving one or more parameters; wherein determining the estimated tread depth is also based on one or more parameters. In some embodiments, one or more parameters include: tire pressure or one or more tire stiffness parameters. In some embodiments, the method further includes: transmitting data indicating the estimated tread depth. In some embodiments, transmitting data indicating the estimated tread depth includes: transmitting the data indicating the estimated tread depth to the vehicle control system (VCS) via a transceiver of the TMS.

[0004] In some embodiments, an apparatus for determining tread depth using data from a tire mount sensor (TMS) is configured to perform steps including: determining tire deformation of a tire based on data collected by the tire mount sensor; determining the effective rolling radius of the tire based on the tire deformation; and determining an estimated tread depth of the tire based at least on the effective rolling radius of the tire.

[0005] In some embodiments, the step further includes: determining the rolling radius of the tire based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel. In some embodiments, the step further includes: receiving data indicating the linear velocity and angular velocity. In some embodiments, the linear velocity is based on Global Positioning System (GPS) Doppler velocity. In some embodiments, the angular velocity is based on wheel speed sensor data. In some embodiments, determining the tire deformation includes: determining the contact patch length based on radial acceleration data. In some embodiments, the step further includes: receiving one or more parameters; wherein determining the estimated tread depth is also based on one or more parameters. In some embodiments, one or more parameters include: tire pressure or one or more tire stiffness parameters. In some embodiments, the step further includes: transmitting data indicating the estimated tread depth. In some embodiments, transmitting data indicating the estimated tread depth includes: transmitting the data indicating the estimated tread depth to the vehicle control system (VCS) via a transceiver of the TMS.

[0006] The foregoing and other objects, features, and advantages of the invention will become apparent from the following more specific description of exemplary embodiments of the invention as illustrated in the accompanying drawings, wherein like reference numerals generally denote like parts of exemplary embodiments of the invention. Attached Figure Description

[0007] Figure 1 A block diagram of a system for determining tread depth using data from a tire-mounted sensor (TMS) is illustrated according to this disclosure.

[0008] Figure 2 A block diagram of a tire having a TMS configured to determine tread depth is shown according to the present disclosure;

[0009] Figure 3 A reference diagram of a tire according to this disclosure is shown;

[0010] Figure 4 A block diagram of an exemplary vehicle control system according to the present disclosure is shown;

[0011] Figure 5 Another block diagram of an exemplary Telematics Control Unit (TCU) according to this disclosure is shown;

[0012] Figure 6 A block diagram of an exemplary TMS according to this disclosure is shown;

[0013] Figure 7 This is a flowchart of an example method for determining tire tread depth using data from TMS, according to this disclosure;

[0014] Figure 8 This is a flowchart of an example method for determining tire tread depth using data from TMS, according to this disclosure; and

[0015] Figure 9 This is a flowchart of an example method for determining tire tread depth using data from TMS, according to this disclosure. Detailed Implementation

[0016] For the purpose of describing specific examples, the terminology used herein is not intended to limit other examples. Whenever the use of singular forms such as “a,” “an,” and “the,” and the use of only a single element is neither explicitly nor implicitly defined as mandatory, other examples may also use multiple elements to achieve the same functionality. Similarly, when a function is subsequently described as being implemented using multiple elements, further examples may use a single element or processing entity to achieve the same functionality. It will be further understood that the terms “comprising,” “including,” “encompassing,” and / or “having,” when used, specify the presence of the stated feature, integral, step, operation, process, action, element, and / or component, but do not preclude the presence or addition of one or more other features, integrals, steps, operations, processes, actions, elements, components, and / or any group thereof.

[0017] It will be understood that when one element is referred to as "connected" or "coupled" to another element, these elements can be directly connected or coupled, or connected or coupled via one or more intermediate elements. If two elements A and B are combined using "or," it should be understood that all possible combinations are disclosed, namely, only A, only B, and A and B. An alternative wording for the same combination is "at least one of A and B." The same applies to combinations of more than two elements.

[0018] Therefore, although various modifications and alternative forms are possible with the other examples, certain specific examples are shown in the accompanying drawings and will be described in detail thereafter. However, this detailed description does not limit the other examples to the specific forms described. The other examples may cover all modifications, equivalents, and alternatives falling within the scope of this disclosure. The same reference numerals throughout the description of the drawings denote the same or similar elements that can be implemented equivalently or in modified form when compared with each other, while providing the same or similar function.

[0019] from Figure 1 Beginning with reference to the accompanying drawings, exemplary methods, apparatus, and computer program products for determining tread depth using data from a tire-mounted sensor (TMS) are described according to this disclosure. Figure 1A diagram illustrating a system (100) for determining tread depth using data from a tire-mounted sensor (TMS) according to an embodiment of the present disclosure is provided. Figure 1 The system includes: a vehicle (101) equipped with tires (103), the tires (103) including tire-mounted sensors (TMS) (105). Although Figure 1 The embodiment shows two tires, each equipped with a TMS (105), but it should be understood that as few as one and as many as all of the tires (103) of the vehicle (101) may include a TMS (105). Figure 1 The vehicle also includes a vehicle control system (VCS) (107) that controls various components and systems within the vehicle. In a particular embodiment, the VCS (107) includes multiple electronic control units (ECUs) configured to control one or more vehicle subsystems. Often referred to as the vehicle's "computer," an ECU may be a central control unit or may collectively refer to one or more vehicle subsystem control units, such as an Engine Control Module (ECM), Powertrain Control Module (PCM), Transmission Control Module (TCM), Brake Control Module (BCM), Central Timing Module (CTM), General Electronic Module (GEM), or Suspension Control Module (SCM). In embodiments according to this disclosure, the VCS (107) includes a BCM that includes an Antilock Braking System (ABS) and an Electronic Stability Program (ESP). Alternatively, the VCS (107) may include a telematics control unit (TCU) independent of vehicle-based sensors (e.g., aftermarket systems).

[0020] Each TMS (105) is equipped with a wireless transceiver for bidirectional wireless communication with the VCS (107), as described in more detail below. Similarly, the VCS is equipped with a wireless transceiver for bidirectional wireless communication with each of the TMS (105), as described in more detail below. Bidirectional wireless communication can be implemented using low-power communication technologies (such as Bluetooth Low Energy) or other low-power bidirectional communication technologies designed to conserve energy. Alternatively, each TMS (105) may include a unidirectional transmitter configured to send signals to the VCS (107).

[0021] Each vehicle system may include sensors (113) for measuring and communicating vehicle operating conditions. For example, ABS may include wheel speed sensors on the wheelbase for measuring wheel speed. The ESP subsystem may include a yaw rate sensor configured to measure the acceleration caused by yaw of the vehicle while it is turning. Readings from these sensors (113) may be provided to the VCS (107), which may provide parameters to the TMS (105) based on these readings.

[0022] The vehicle (101) may further include a transceiver (109) communicatively coupled to the VCS (107) for use in cellular terrestrial communications, satellite communications, or both.

[0023] constitute Figure 1 The arrangement of devices in the exemplary system shown is for illustrative purposes and not for limitation. As those skilled in the art will appreciate, useful data processing systems according to various embodiments of this disclosure may include: (not in...) Figure 1 The diagram illustrates additional servers, routers, other devices, and a peer-to-peer architecture. The network in this data processing system can support many data communication protocols, including, for example, TCP (Transmission Control Protocol), IP (Internet Protocol), Bluetooth, Near Field Communication, Controller Area Network (CAN) protocol, and other protocols that those skilled in the art would recognize. In addition... Figure 1 The embodiments shown herein, and the various embodiments of this disclosure, can be implemented on various hardware platforms.

[0024] Figure 2A block diagram of a tire with a TMS (105) is shown. Typically, the TMS (105) is mounted on or otherwise coupled to the inner surface of the tire (103), particularly on the tire liner above the tread. As the tire (103) rotates, the portion engaging with the road surface at any given time is flattened. This flattened portion is referred to as the tire mark, or interchangeably as the contact patch. One or more features of the tire (103), particularly the length of the contact patch (typically measured in the vehicle's direction of travel), can be used, for example, as an indication of the load on the tire (103). The electrical signal generated by the TMS (105) can be used to measure the contact patch, particularly its length, as will be described in more detail below. It will be understood that one or more of the tires (103) of a vehicle (101) may each include a TMS (105) for providing one or more target signals for which pulse width measurements are performed.

[0025] Figure 3 A reference diagram of a tire (103) according to this disclosure is shown. As used herein, the z-axis of the tire (103) is the direction of the radial force during rotation, the y-axis of the tire is the direction of the lateral force during rotation, and the x-axis of the tire (103) is the direction of the tangential force during rotation. The rotational angular velocity, in radians, is denoted by ω, and is also referred to herein as wheel speed.

[0026] To further explain, Figure 4 A diagram illustrating an exemplary vehicle control system (VCS) (400) according to embodiments of the present disclosure for determining tread depth using data from a tire-mounted sensor (TMS). The VCS (400) includes a controller (401) coupled to a memory (403). The controller (401) is configured to acquire sensor readings related to vehicle operating conditions and data from external sources, and to provide configuration parameters to the TMS (such as TMS (600)) (see...). Figure 6The controller may include or implement a microcontroller, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic array (PLA) such as a field-programmable gate array (FPGA), or other data computing units according to this disclosure. Sensor readings and data, as well as tire feature data received from the TMS, may be stored in a memory (403). The memory (403) may be a non-volatile memory, such as flash memory. For example, the VCS (400) may acquire vehicle operating condition data, such as sensor readings from onboard sensors.

[0027] For bidirectional wireless communication with the TMS, the VCS (400) includes a TMS transceiver (405) coupled to the controller (401). In one embodiment, the TMS transceiver (405) is a Bluetooth Low Energy transmitter-receiver. In other embodiments, the TMS transceiver (405) may be other types of low-power bidirectional communication technologies designed to save energy consumption in the TMS. The VCS (400) may also include a transceiver (407) for cellular terrestrial communication, satellite communication, or both.

[0028] The VCS (400) may further include a Controller Area Network (CAN) interface (409) for communicatively coupling vehicle sensors and devices to the controller (401). Particularly relevant to this disclosure, the CAN interface (409) couples wheel speed sensors (411), yaw rate sensors (413), tilt sensors (415), and other sensors (417) to the controller (401). The wheel speed sensor (411) measures, for example, the angular velocity of rotation of the wheel in radians per second. The yaw rate sensor (413) can be used to measure the acceleration caused by yaw of the vehicle (e.g., when the vehicle is turning), which affects the magnitude of the load on each tire. The yaw rate sensor (413) can also provide information about the shear force on the tire at the point of contact with the road surface. The tilt sensor (415) can detect the longitudinal and / or lateral tilt of the vehicle. Wheel speed sensor (411), yaw rate sensor (413) and tilt sensor (415) send their respective readings to controller 401.

[0029] The controller (401) is configured to receive tire characteristic data from the TMS, such as contact patch length (CPL) or peak radial displacement (PRD) as described above. Based on the tire characteristic data, the processor is configured to calculate tire loads or compensate for loads derived from vehicle dynamics / conditions by the TMS. In some embodiments, the controller (401) may be configured to calculate tread depth based on data retrieved from the TMS during driving. For example, the controller (401) may receive data indicating the tire's CPL from the TMS via a TMS transceiver (405). The controller (401) can then determine the tire load using a stored characteristic equation for determining the load based on CPL and other factors such as tire pressure, tire speed, tire temperature, etc. For example, the controller (401) may receive data indicating these other factors from the TMS or from other sensors (e.g., tire pressure sensors, etc.) via the TMS transceiver (405).

[0030] After the load on the tire has been determined using the stored characteristic equations used to determine the load based on PRD, tire deformation, or CPL, the controller (401) can then determine the estimated tread depth of the tire based on the modified rolling radius of the tire. The rolling radius of the tire can be expressed as a function of the load on the tire, tire pressure, tire stiffness, tread depth, and tire speed. Therefore, the tread depth of the tire can be determined based on the load on the tire (the load on the tire itself can be based on factors including tire pressure, tire stiffness, and / or speed) and the rolling radius of the tire. Tire stiffness can be expressed as one or more tire stiffness parameters. For example, one or more tire stiffness parameters can include one or more tire stiffness coefficients in a polynomial function for tire stiffness. For example, one or more tire stiffness coefficients can be determined for a given tire model under varying loads and pressures using a drum testing machine, a flat-rail test, or tire simulation. One or more tire stiffness coefficients can then be stored in the tire's TMS at manufacturing time or at another time. The controller (401) then receives the tire stiffness coefficient from the TMS (e.g., via a TMS transceiver (405)). The controller 401 may receive data indicating tire pressure from the TMS, from a pressure sensor mounted on the valve, or from another sensor.

[0031] The rolling radius of a tire can be calculated as the ratio of the linear velocity of the wheel center to the angular velocity of the wheel. The linear velocity of the wheel center can be based on GPS Doppler data. The angular velocity of the wheel can be based on data from a wheel speed sensor (411) or a TMS. For example, the wheel speed sensor (411) can be a component of an anti-lock braking system (ABS). The controller (401) then calculates the rolling radius of the tire based on the data indicating the linear velocity and angular velocity of the wheel.

[0032] The controller (401) can then use a stored characteristic equation to calculate the tire tread depth, which takes (as determined by the CPL) the load on the tire, tire pressure, tire stiffness, speed, and tire rolling radius as input. The controller (401) can be configured to calculate the tread depth in response to the tire reaching a stable temperature state. For example, when a vehicle begins driving from a cold start, the tire will warm up until it reaches a stable state (e.g., constant temperature, where the temperature changes to a level below a threshold). The TMS can provide temperature readings to the controller (401) to allow the controller (401) to determine that a stable temperature state has been reached. The TMS can also determine that a stable temperature state has been reached and send a signal to the controller (401). Those skilled in the art will recognize that temperature data can be received from other temperature sensors, such as an external air temperature sensor mounted on the vehicle.

[0033] Although the calculation of tread depth using the tire's CPL is discussed as being determined by the controller (401), it should be understood that the calculations and determinations described above can be performed at least in part by the TMS and provided to the controller (401). Furthermore, it should be understood that peak radial displacement or another tire deformation can also be calculated and used to determine the tire load, and thus the tread depth. When determining the tire load based on tire-specific CPL (or other deformation) measurements, tread depth calculations are more accurate than other methods using vehicle height sensors or other vehicle-related measurements.

[0034] To further explain, Figure 5 A diagram illustrating an embodiment of a remote information control unit (TCU) (500) (e.g., an aftermarket system not directly coupled to vehicle-based sensors) is provided. The TCU (500) includes a controller (501), a memory (503), and a TMS transceiver (505), which perform the functions described above. Figure 4Similar functionality to that described in the VCS (400). The TCU (500) also includes a Global Positioning System (GPS) receiver (557) configured to communicate with one or more GPS satellites to determine the vehicle's position, speed, direction of movement, etc. The TCU (500) also includes an Inertial Measurement Unit (IMU) (559) configured to measure the vehicle's specific force, angular rate, and / or orientation using a combination of accelerometers, gyroscopes, and / or magnetometers. The TCU (500) also includes an on-board diagnostics (OBD) interface (561) for coupling the TCU (500) to one or more on-board diagnostic devices in the vehicle. The TCU (500) can receive power via a power interface (563) that can be coupled to the vehicle's power bus.

[0035] In a specific embodiment, the controller (401) of the TCU (500) can be configured to determine the tire deformation of the tire based on data collected by the TMS. The controller (501) can also be configured to: determine the effective rolling radius of the tire based on the tire deformation; and determine an estimated tread depth of the tire based on the effective rolling radius of at least one tire.

[0036] To further explain, Figure 6 A diagram illustrating an exemplary TMS (600) for determining tread depth according to an embodiment of the present disclosure is provided. The TMS (600) includes a processor (601). The processor may include or implement a microcontroller, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic array (PLA) such as a field-programmable gate array (FPGA), or other data computing units according to the present disclosure.

[0037] Figure 6The TMS (600) also includes a memory (603) coupled to the processor (601). The memory may store signal acquisition configuration parameters (621) and other data received from the VCS (400). The memory (603) may store a sampling rate table (622) of sampling rates, each sampling rate corresponding to a specific parameter value (e.g., wheel speed or tire rotation period). The memory (603) may also store a window function table (623) of window functions, each window function corresponding to a specific parameter value (e.g., wheel speed or tire rotation period). The memory (603) may also store a filter table (624) of filter bands, each filter band corresponding to a specific parameter value (e.g., wheel speed or tire rotation period). The memory (603) may also store acceleration data (625), which includes: the raw digital signal sampled by the ADC (611) from the accelerometer (607) and the processed acceleration waveform processed by the processor (601). The memory (603) may also store tire feature data (626) (such as CPL or PRD extracted by the processor (601)). The memory (603) may also store FFT or Goertzel algorithm configurations (627).

[0038] For bidirectional wireless communication with VCS(400), Figure 6 The TMS (600) includes a transceiver (605) coupled to a processor (601). In one embodiment, the transceiver (605) is a Bluetooth Low Energy transmitter-receiver. In other embodiments, the transceiver (605) may be other types of low-energy bidirectional communication technologies designed to save energy consumption in the TMS (600). The TMS (600) transmits extracted tire feature data (such as acceleration profiles, PRD, and CPL) to the VCS (400) via the transceiver (605). In an alternative embodiment, the TMS (600) includes a unidirectional transmitter configured to transmit data to the VCS (400).

[0039] Figure 6The accelerometer (607) can also be an acceleration sensor, accelerometer device, vibration sensor, force sensor, microelectromechanical system (MEM) sensor, or other similar devices that respond to acceleration amplitude and / or acceleration changes. For example, the accelerometer senses acceleration in a radial plane (z-plane) and outputs an electrical pulse signal in response to the sensed acceleration. In embodiments, the accelerometer (607) can be configured with an accelerometer range, wheel speed parameters, or other vehicle parameters provided by the VCS (400). For example, g-offset can be determined via a wheel speed sensor or another vehicle parameter and used to capture and process signals more quickly. Accelerometers can have a selectable range of force values ​​that they can measure. These ranges can vary from ±1g to ±700g. An example range for an accelerometer is ±200g. The accelerometer range can be configured based on wheel speed, for example, ±150g at low speeds, ±250g at medium speeds, and ±500g at high speeds. Typically, the smaller the range, the more sensitive the accelerometer readings will be.

[0040] Figure 6 The TMS (600) also includes an analog-to-digital converter (ADC) (611), which receives electrical pulse signals from the accelerometer (607) and samples them according to a sampling rate. The ADC (611) converts the raw analog signals received from the accelerometer (607) into raw digital signals suitable for digital signal processing. The sampling rate of the ADC (611) can be configured via wheel speed from a wheel speed sensor or parameters provided by another vehicle from a vehicle sensor.

[0041] Figure 6 The TMS (600) also includes a battery (609) connected to a power bus (not shown) to power the transceiver (605), processor (601), ADC (611), accelerometer (607), and memory (603). Those skilled in the art will recognize that the TMS (600) can be powered by other sources, such as energy harvesters or other power sources, that replace or supplement the battery (609).

[0042] In some embodiments, the TMS (600) can be configured to calculate tread depth while driving. For example, the TMS (600) can determine the tire's CPL based on data from an accelerometer (607). In this example, the CPL can be estimated by measuring the time it takes for the radial acceleration to return to zero g and remain at zero g. This time is then expressed as a quotient / ratio for the full rotation time, and the CPL is derived from the ratio of the CPL to the known tire circumference. The processor (601) can then determine the tire load using a stored characteristic equation for determining the load based on the CPL and other factors such as tire pressure, tire speed, tire temperature, etc. For example, the controller (601) can calculate these other factors based on sensors in the TMS, or receive data indicating these factors from the VCS (400), such as measurements by other sensors (417) of the VCS (400), or data indicating these factors from other sensors (e.g., tire pressure sensors mounted on the valves, etc.).

[0043] After determining the tire load using the stored characteristic equation for determining the load based on CPL, the processor (601) can then use the characteristic equation to determine the estimated tread depth, which takes the load on the tire, tire pressure, tire stiffness, speed, and tire rolling radius as input. Tire stiffness can be represented as tire stiffness parameters stored in memory (603) (e.g., represented as tire characteristic data (626)). Data indicating tire pressure can be received from a pressure sensor mounted on the valve or determined by the TMS (600).

[0044] The rolling radius of a tire can be calculated as the ratio of the linear velocity of the wheel center to the angular velocity of the wheel. The TMS (600) can receive data indicating the linear velocity of the wheel (e.g., based on GPS Doppler data) and data indicating the angular velocity of the wheel (e.g., based on data from a wheel speed sensor (411) of the VCS (400) from the VCS (400). The processor (601) then calculates the rolling radius of the tire based on the data indicating the linear velocity and angular velocity of the wheel.

[0045] The processor (601) can then use the stored characteristic equation to calculate the tread depth of the tire, which takes (as determined by the CPL) the load on the tire, tire pressure, tire stiffness, speed, and tire rolling radius as input. The processor (601) can be configured to calculate the tread depth in response to the tire reaching a stable temperature state. The TMS (600) can then transmit the estimated tread depth (e.g., via transceiver (605)) to the VCS (400).

[0046] Although the calculation of tread depth using the tire's CPL is discussed as being determined by the processor (601) of the TMS (600), it should be understood that the calculations and determinations described above can be performed at least in part by the VCS (400) and provided to the TMS (600). Furthermore, it should be understood that peak radial displacement or another tire deformation can also be calculated and used to determine the tire load, and thus the tread depth. Additionally, although the interaction between the TMS (600) and the VCS (400) is discussed, it should be understood that similar functionality can be achieved through communication with the TCU (500).

[0047] To further explain, Figure 7 A flowchart illustrates an exemplary method for determining tread depth using data from a tire mounting sensor (TMS) according to embodiments of the present disclosure. The method includes determining (702) tire deformation of the tire based on data collected by the tire mounting sensor (TMS) (600), e.g., via the TMS (600), via a controller (401) of a VCS (400), or via a controller (501) of a TCU (500). Tire deformation may include: contact patch length (CPL), peak radial deformation, or another conceivable deformation. The TMS (600) may determine tire deformation based on data from an accelerometer (607). For example, CPL can be estimated by measuring the time it takes for radial acceleration to return to zero g and remain at zero g. This time is then expressed as a quotient / ratio for the full rotation time, and CPL is derived from a ratio of CPL to a known tire circumference. Determining (702) the tire deformation based on data collected by the tire-mounted sensor (TMS) (600) can be performed by the controller of the VCS or the controller of the TCU receiving data collected from the TMS or receiving tire deformation from the TMS. Optionally, determining (702) the tire deformation based on data collected by the tire-mounted sensor (TMS) (600) can be performed by the TMS calculating the tire deformation based on the data collected by the TMS.

[0048] Figure 7 The method further includes: determining (704) the effective rolling radius of the tire based on tire deformation (e.g., by a controller (401) of the TMS (600), a controller (401) of the VCS (400), or a controller (501) of the TCU (500). The rolling radius of the unloaded tire is derived from the tire's circumference. The effective rolling radius of the tire (e.g., the current rolling radius of the tire under load) is determined based on the unloaded tire's rolling radius and CPL (or another tire deformation factor such as peak radial deformation).

[0049] Figure 7The method also includes determining (706) an estimated tread depth of the tire based on the tire's effective rolling radius (e.g., via a TMS (600), a controller (401) of a VCS (400), or a controller (501) of a TCU (500). For example, a characteristic equation can be used to calculate the tread depth based on the tire load and the tire's effective rolling radius. The tire load can be determined based on one or more other factors, including tire pressure, tire speed, tire temperature, etc. For example, the tire speed can be determined by a TMS (600), by a wheel speed sensor, or otherwise. Therefore, using tire-specific deformation (e.g., CPL) and the effective rolling radius to calculate the determined tread depth provides a more accurate determination of both load and tread depth.

[0050] To further explain, Figure 8 This is a flowchart illustrating an exemplary method for determining tread depth using data from a tire mounting sensor (TMS) according to embodiments of the present disclosure, the method comprising: determining (702) tire deformation of a tire based on data collected by the tire mounting sensor (TMS) (600); determining (704) the effective rolling radius of the tire based on the tire deformation; and determining (706) an estimated tread depth of the tire based at least on the effective rolling radius of the tire.

[0051] Figure 8 Methods and Figure 7 The difference is that, Figure 8 The method further includes determining (802) the tire's rolling radius based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel (e.g., via a TMS (600), a controller (401) of a VCS (400), or a controller (501) of a TCU (500). The tire's rolling radius can be calculated as the ratio of the linear velocity of the wheel center to the angular velocity of the wheel. The linear velocity of the wheel center can be based on Global Positioning System (GPS) Doppler data. The angular velocity of the wheel can be based on data from a wheel speed sensor (411) of the (VCS). The TMS (600) and / or the controller (401, 501) can receive data indicating the linear velocity and angular velocity of the wheel and calculate the tire's rolling radius. The calculated tire rolling radius can then be used to determine the effective rolling radius of the tire.

[0052] To further explain, Figure 9A flowchart illustrating an exemplary method for determining tread depth using data from a tire mounting sensor (TMS) according to embodiments of the present disclosure is provided. The method includes: determining (702) tire deformation of a tire based on data collected by the tire mounting sensor (TMS) (600); determining (704) the effective rolling radius of the tire based on the tire deformation; and determining (706) an estimated tread depth of the tire based at least on the effective rolling radius of the tire.

[0053] Figure 9 Methods and Figure 7 The difference is that, Figure 9 The method also includes receiving (902) one or more tire parameters (e.g., via a TMS (600), a controller (401) of a VCS (400), or a controller (501) of a TCU (500). As described above, the effective rolling radius of the tire can be expressed as a function of the load on the tire and the tread depth of the tire, as well as other tire parameters. Such other parameters may include tire pressure, tire stiffness, and / or speed. Tire stiffness can be expressed as one or more tire stiffness parameters. For example, one or more tire stiffness parameters may include one or more tire stiffness coefficients as a polynomial function of tire stiffness. For example, one or more tire stiffness coefficients can be determined for a given tire model under varying loads and pressures using a drum testing machine, a flat-rail test, or tire simulation. One or more tire stiffness coefficients can then be stored in the memory (603) of the tire's TMS (600) at the time of manufacture or at another time. Tire pressure can be determined (600) by the TMS. Tire pressure can also be determined by a pressure sensor installed on the valve and the tire pressure is provided to the controller (401) of the TMS (600) and / or VCS (400) or the controller (501) of the TCU (500).

[0054] The received (902) one or more parameters (e.g., tire pressure, tire stiffness, and / or speed) can then be used to determine (706) the estimated tread depth of the tire. For example, in addition to the estimated tire load and the tire's rolling radius, the characteristic equation used to calculate the tire's tread depth can also accept tire pressure, tire stiffness, and / or speed as inputs.

[0055] In light of the foregoing explanation, the reader will recognize that the benefits of using data from a tire-mounted sensor (TMS) to determine tread depth according to embodiments of this disclosure include, but are not limited to:

[0056] • By comparing the tire-specific deformation measured by tire-mounted sensors with vehicle-specific measurements, the estimated load on the tire is calculated, providing a more accurate tire load estimate.

[0057] • Compared to other methods that rely on load sensors that calibrate vehicle-specific springs, using tire-mounted sensors to calculate tire load and tread depth makes proximity to the vehicle unknown.

[0058] • Uses more accurate tire-specific estimates of tire deformation to calculate tread depth, thus providing a more accurate estimate of tread depth.

[0059] Exemplary embodiments of the present invention are described primarily within the context of a fully functional computer system for determining tread depth using data from a tire mounting sensor (TMS). However, those skilled in the art will recognize that the invention can also be embodied in a computer program product set on a computer-readable storage medium for use with any suitable data processing system. Such a computer-readable storage medium can be any storage medium for machine-readable information, including magnetic, optical, or other suitable media. Examples of such media include disks in hard disk drives or floppy disks, compressed disks for optical drives, magnetic tape, and other media that will be apparent to those skilled in the art. Those skilled in the art will readily recognize that any computer system with suitable programming means will be able to perform the steps of the methods of the invention embodied in the computer program product. Those skilled in the art will also recognize that while some exemplary embodiments described herein are oriented toward software installed on and executed on computer hardware, alternative embodiments as firmware or hardware implementations are fully within the scope of the invention.

[0060] This invention can be a system, apparatus, method, and / or computer program product. A computer program product may include a computer-readable storage medium (or medium) having computer-readable program instructions thereon for causing a processor to perform aspects of the invention.

[0061] A computer-readable storage medium can be a tangible device capable of retaining and storing instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable optical disc read-only memory (CD-ROM), digital versatile disk (DVD), memory sticks, floppy disks, mechanical encoding devices (such as punched cards or raised structures in slots containing recorded instructions), and any suitable combination of the foregoing. As used herein, a computer-readable storage medium should not be construed as being itself a transient signal, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses passing through fiber optic cables), or electrical signals transmitted through wires.

[0062] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a suitable computing / processing device, or downloaded via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network) to an external computer or external storage device. This network may include copper transmission cables, optical fiber transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to a computer-readable storage medium within the respective computing / processing device.

[0063] Computer-readable program instructions for performing the operations of this invention may be assembly instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in one or more programming languages, including object-oriented programming languages ​​(e.g., Smalltalk, C++, etc.) and conventional procedural programming languages ​​(e.g., "C" programming language or similar programming languages)). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs) can execute computer-readable program instructions by personalizing the electronic circuitry using state information from the computer-readable program instructions, thereby performing aspects of the invention.

[0064] This document describes aspects of the invention with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0065] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that can instruct a computer, programmable data processing apparatus, and / or other device to operate in a particular manner, such that the computer-readable storage medium storing the instructions includes an article of writing comprising instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0066] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the instructions, which execute on the computer, other programmable apparatus or other device, implement the function / action specified in one or more blocks of a flowchart and / or block diagram.

[0067] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, apparatuses, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or part of an instruction, comprising one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may not occur in the order indicated in the figures. For example, depending on the functions involved, two blocks shown consecutively may actually be executed substantially simultaneously, or these blocks may sometimes be executed in reverse order. It should also be noted that each block shown in the block diagrams and / or flowcharts, and combinations of blocks shown in the block diagrams and / or flowcharts, may be implemented by a hardware-based dedicated system that performs the specified function or action or executes a combination of dedicated hardware and computer instructions.

[0068] The advantages and features of this disclosure can be further described by the following statements:

[0069] 1. A method for determining tread depth using data from a tire mount sensor (TMS), the method comprising: determining tire deformation of a tire based on data collected by the tire mount sensor; determining the effective rolling radius of the tire based on the tire deformation; and determining an estimated tread depth of the tire based at least on the effective rolling radius of the tire.

[0070] 2. According to the method in statement 1, the method further includes: determining the rolling radius of the tire based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel.

[0071] 3. According to the method stated in statement 1 or 2, it further includes: receiving data indicating linear velocity and angular velocity.

[0072] 4. The method according to any one of statements 1-3, wherein the linear velocity is based on the Global Positioning System (GPS) Doppler velocity.

[0073] 5. The method according to any one of statements 1-4, wherein the angular velocity is based on wheel speed sensor data.

[0074] 6. The method according to any one of statements 1-5, wherein determining the tire deformation includes: determining the contact patch length based on radial acceleration data.

[0075] 7. The method according to any one of statements 1-6 further includes: receiving one or more parameters; wherein determining the estimated tread depth is also based on one or more parameters.

[0076] 8. The method according to any one of statements 1-7, wherein the one or more parameters include: tire pressure or one or more tire stiffness parameters.

[0077] 9. The method according to any one of statements 1-8 further includes: sending data indicating the estimated tread depth.

[0078] 10. The method according to any one of statements 1-9, wherein the transmission comprises: transmitting data indicating the estimated tread depth via a transceiver of the TMS to the vehicle control system (VCS), the data indicating the estimated tread depth.

[0079] 11. An apparatus for determining tread depth using data from a tire-mounted sensor (TMS), the apparatus being configured to perform a step comprising:

[0080] The tire deformation is determined based on data collected by tire-mounted sensors;

[0081] Determining the effective rolling radius of a tire based on tire deformation; and

[0082] The estimated tread depth of the tire is determined based at least on the tire's effective rolling radius.

[0083] 12. The apparatus according to statement 11, wherein the step further includes: determining the rolling radius of the tire based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel.

[0084] 13. The apparatus according to statement 11 or 12, wherein the step further includes: receiving data indicating linear velocity and angular velocity.

[0085] 14. The apparatus according to any one of statements 11-13, wherein the linear velocity is based on the Global Positioning System (GPS) Doppler velocity.

[0086] 15. The apparatus according to any one of statements 11-14, wherein the angular velocity is based on wheel speed sensor data.

[0087] 16. The apparatus according to any one of statements 11-15, wherein determining the tire deformation of the tire includes: determining the contact patch length based on radial acceleration data.

[0088] 17. The apparatus according to any one of statements 11-16, wherein the step further comprises: receiving one or more parameters; wherein determining the estimated tread depth is also based on one or more parameters.

[0089] 18. The apparatus according to any one of statements 11-17, wherein one or more parameters include: tire pressure or one or more tire stiffness parameters.

[0090] 19. The apparatus according to any one of statements 11-18, wherein the step further includes: transmitting data indicating the estimated tread depth.

[0091] 20. The apparatus according to any one of statements 11-19, wherein transmitting data indicating the estimated tread depth comprises: transmitting data indicating the estimated tread depth to the vehicle control system (VCS) via a transceiver of the TMS.

[0092] One or more embodiments may be described herein by means of method steps that illustrate the performance of specific functions and their relationships. For ease of description, the boundaries and order of these functional building blocks and method steps have been arbitrarily defined herein. Alternative boundaries and orders may be defined as long as the specified functions and relationships are properly performed. Therefore, any such alternative boundaries or orders are within the scope and spirit of the claims. Furthermore, for ease of description, the boundaries of these functional building blocks have been arbitrarily defined. Alternative boundaries may be defined as long as certain important functions are properly performed. Similarly, flowchart blocks may also be arbitrarily defined herein to illustrate certain important functions.

[0093] Within the scope of use, flowchart block boundaries and sequences can be defined in other ways while still performing certain important functions. Therefore, this substitution of functional building blocks and flowchart blocks and sequences is limited within the scope and spirit of the claims. Those skilled in the art will also recognize that the functional building blocks, as well as other illustrative blocks, modules, and components herein, can be implemented as shown in the figures or by discrete components, application-specific integrated circuits, processors executing appropriate software, or any combination thereof.

[0094] While specific combinations of various functions and features of one or more embodiments are explicitly described herein, other combinations of these features and functions are equally possible. This disclosure is not limited to the specific examples disclosed herein and explicitly incorporates these other combinations.

Claims

1. A method for determining tread depth using data from tire-mounted sensors, the method comprising: The tire deformation is determined by the tire-mounted sensor based on the data collected by the tire-mounted sensor. The tire-mounted sensor receives first data and second data from the vehicle control system of the vehicle on which the tire is mounted, the first data indicating the linear velocity of the wheel center of the tire and the second data indicating the angular velocity of the wheel of the tire. The rolling radius of the tire is determined by a sensor mounted on the tire based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel. Based on the tire deformation, the effective rolling radius of the tire is determined by the tire-mounted sensor; and The estimated tread depth of the tire is determined by the tire-mounted sensor, based at least on the effective rolling radius of the tire.

2. The method according to claim 1, wherein, The first data indicating the linear velocity of the tire's center of gravity is based on Doppler velocity data from the Global Positioning System.

3. The method according to claim 1, wherein, The second data indicating the angular velocity of the wheel of the tire is based on wheel speed sensor data, which is included in the data received from the vehicle control system.

4. The method according to claim 1, wherein, Determining the tire deformation includes: determining the contact patch length using sensors mounted on the tire based on radial acceleration data.

5. The method according to claim 1, further comprising: The tire-mounted sensor receives one or more parameters, including tire pressure or one or more tire stiffness parameters. The estimated tread depth is determined based on one or more of the parameters.

6. The method according to claim 1, further comprising: The transceiver of the tire-mounted sensor transmits data indicating the estimated tread depth to the vehicle control system.

7. An apparatus for determining tread depth using data from a tire-mounted sensor, the apparatus being configured to perform a step comprising: The tire deformation is determined by the tire-mounted sensor based on the data collected by the tire-mounted sensor. The tire-mounted sensor receives first data and second data from the vehicle control system of the vehicle on which the tire is mounted, the first data indicating the linear velocity of the wheel center of the tire and the second data indicating the angular velocity of the wheel of the tire. The rolling radius of the tire is determined by a sensor mounted on the tire based on the linear velocity of the tire's wheel center and the angular velocity of the tire's wheel. Based on the tire deformation, the effective rolling radius of the tire is determined by the tire-mounted sensor; and The estimated tread depth of the tire is determined by the tire-mounted sensor, based at least on the effective rolling radius of the tire.

8. The apparatus according to claim 7, wherein, The first data indicating the linear velocity of the tire's center of gravity is based on Doppler velocity data from the Global Positioning System.

9. The apparatus according to claim 7, wherein, The second data indicating the angular velocity of the wheel of the tire is based on wheel speed sensor data, which is included in the data received from the vehicle control system.

10. The apparatus according to claim 7, wherein, Determining the tire deformation includes: determining the contact patch length using sensors mounted on the tire based on radial acceleration data.

11. The apparatus according to claim 7, wherein, The steps also include: The tire-mounted sensor receives one or more parameters, including tire pressure or one or more tire stiffness parameters. The estimated tread depth is determined based on one or more of the parameters.

12. The apparatus according to claim 7, wherein, The step further includes: transmitting data indicating the estimated tread depth to the vehicle control system via a transceiver of the tire-mounted sensor.

Images