Tire behavior modeling

Abstract

A method for determining a set of temperature-dependent scaling factors to correct for calculated forces or moments acting on the tread surface of a tire during driving, A step of measuring the value of the actual force or moment acting on the tread surface within the tire's contact patch during driving; A step of measuring a value of a temperature associated with a tire, or estimating a value of a temperature associated with a tire based on the value of one or more measured parameters associated with a tire; A step of calculating the value of the theoretical force or moment acting on the tread surface of the tire during driving using a mathematical model; and The method includes the step of determining a set of temperature-dependent scaling factors for correcting the calculated theoretical force or moment by comparing the calculated theoretical force or moment value with the measured actual force or moment value or a value derived from the measured actual force or moment value, and determining the relationship between the comparison result and the measured or estimated temperature value.

Description

Technology Field

[0001] The present invention relates to tire behavior modeling, and more particularly to a thermo-mechanical model for predicting tire behavior by considering the effect of temperature on tire behavior during rolling conditions.

[0002] Although various different methods for modeling tire behavior during driving have been used over the years, some of the most widely used models are the Pacejka "Magic Formula" tire models. These models allow forces or moments at the contact patch, such as lateral forces, longitudinal forces, and alignment moments, to be calculated. These forces are typically plotted against various slip angles or slip ratios of the tire.

[0003] However, tire models used until now have not taken into account many real-world conditions that affect tire performance.

[0004] The present invention aims to alleviate at least one problem associated with the prior art.

[0005] A first aspect of the present invention provides a method for determining a set of temperature-dependent scaling factors for correcting a calculated force or moment acting on the tread surface of a tire during driving, the method comprising:

[0006] A step of measuring the value of the actual force or moment acting on the tread surface within the tire's contact patch during driving;

[0007] A step of measuring a value of a temperature associated with a tire, or estimating a value of a temperature associated with a tire based on the value of one or more measured parameters associated with a tire;

[0008] A step of calculating the value of the theoretical force or moment acting on the tread surface of the tire during driving using a mathematical model; and

[0009] The method includes the step of determining a set of temperature-dependent scaling factors for correcting the calculated theoretical force or moment by comparing the calculated theoretical force or moment value with the measured actual force or moment value or a value derived from the measured actual force or moment value, and determining the relationship between the comparison result and the measured or estimated temperature value.

[0010] In this way, the force or moment acting perpendicular to the tire radius within the contact patch can be corrected to take into account the tire temperature and obtain a tire model with higher accuracy than a conventional tire model.

[0011] The tread surface tire temperature can be measured on the outer radius of the tread element on the tread surface, and the internal temperature can be measured at different points on the inner liner.

[0012] Alternatively, instead of a method for determining a set of temperature-dependent scaling factors, the method may be a method for determining a set of wear-dependent scaling factors. In such a method, instead of the step of measuring or estimating the temperature associated with the tire, the method may include the step of measuring the value of the tire tread depth reduction (tread loss) or estimating the value of the tire tread loss based on the value of one or more measured parameters associated with the tire. Additionally, instead of the step of determining a set of temperature-dependent scaling factors, the method may include the step of determining a set of wear-dependent scaling factors to correct the calculated theoretical force or moment by comparing the calculated theoretical force or moment value with the measured actual force or moment value or a value derived from the measured actual force or moment value, and the step of determining the relationship between the comparison result and the measured or estimated tread loss value.

[0013] Preferably, in the method, the comparison is performed by calculating the ratio between the calculated theoretical force or moment value and the measured actual force or moment value, and determining the relationship between the calculated ratio and the measured or estimated temperature value.

[0014] Preferably, in the force or moment measurement step and the temperature measurement or estimation step, the actual force or moment and the temperature associated with the tire or one or more parameters are measured on the force and moment tire test rig, but other measurement or estimation methods may be possible. For example, it may be possible to measure or estimate these values ​​during the road test step.

[0015] Preferably, the method further includes a road test step of measuring a temperature value associated with the tire while the tire is installed on a vehicle running on a road, for example, on a test track. Preferably, in the temperature measurement or estimation step, at least one temperature value identical to the temperature value obtained in the road test step is measured or estimated. In this way, it can be ensured that a scaling factor is determined at the temperature the tire will experience during road use.

[0016] Preferably:

[0017] During the road test phase, the values ​​of other parameters associated with the tire are measured, and

[0018] While the tire is installed on the tire test rig, the temperature value associated with the tire is measured, and the values ​​of other parameters associated with the tire are measured,

[0019] The method further includes the step of determining the relationship between the temperature measured during the road test phase and other parameters measured during the road test phase using the temperature value measured on the tire test rig and other parameters measured on the tire test rig, and the step of determining a set of temperature-dependent scaling factors using the result. In this way, the scaling factor may depend on the temperature during the road test phase, which is estimated from the other parameters measured during the road test phase. Therefore, when using the scaling factor, it may not be necessary to measure the temperature directly. The other parameters may be, for example, road speed or vertical load on the tire.

[0020] The method may include a step of determining the relationship between a measured temperature associated with the tire and other measured parameters associated with the tire. In this way, the temperature associated with the tire can be estimated based on other measured parameters.

[0021] The temperature associated with the tire can be estimated based on at least one of the following parameters: measured road speed, measured lateral force on the tire, measured longitudinal force on the tire, slip angle, brake temperature, and tire ambient air temperature.

[0022] Preferably, the method further comprises the step of measuring the value of the tread loss of a tire or estimating the value of the tread loss of a tire based on the value of one or more measured parameters associated with the tire, and the step of determining a set of temperature-dependent scaling factors comprises the step of comparing a calculated theoretical force or moment value with a measured actual force or moment value or a value derived from a measured actual force or moment value, and the step of determining a relationship between the comparison result and the measured or estimated tread loss value.

[0023] The tread loss of a tire can be estimated based on at least one of the following parameters: a measured lateral force on the tire, a measured longitudinal force on the tire, the amount or angle of slip, and the tire's usage history. Based on the tire's usage history, there may be a starting point of tread loss (which may be zero tread loss) where additional wear (reduction in tread depth) is added based on the measured time history of force and slip.

[0024] In the step of estimating tire tread loss, tread loss can be estimated based on the tire compound.

[0025] A second aspect of the present invention provides a computer-implemented method for calculating a force or moment acting on the tread surface of a tire during driving, wherein the computer-implemented method comprises:

[0026] A step of calculating the force or moment acting on the tread surface of the tire using a mathematical tire model during driving;

[0027] A step of calculating a set of scaling factors based on at least one temperature associated with the tire; and

[0028] It includes a step of correcting the calculated force or moment using a set of scaling factors.

[0029] The desirable features of the first embodiment are equally applicable to the second embodiment, and vice versa.

[0030] The step of calculating the set of scaling factors can be performed before the step of calculating the force or moment.

[0031] Alternatively, instead of calculating a set of scaling factors based on at least one temperature associated with the tire, the method may include a step of calculating a set of scaling factors based on the amount of tire wear (tread loss).

[0032] This method can be performed in the ECU of a vehicle equipped with tires or in a vehicle simulator. Alternatively, the method can be performed in the cloud, and the corrected calculated force or moment can be transmitted back to the vehicle equipped with tires.

[0033] A set of scaling factors indicates how the force or moment acting on the tire changes with temperature, and allows the calculated force or moment to be corrected according to the tire temperature.

[0034] Preferably, the force or moment acting on the tire is a lateral force, a longitudinal force, or an alignment moment. The longitudinal force may be a braking force or a traction force. The lateral force, longitudinal force, or alignment moment acting on the tread surface of the tire can be calculated in terms of a force such as a vertical load.

[0035] Lateral force can be calculated based on the vertical load on the tire, slip angle, and camber angle.

[0036] The longitudinal force can be calculated based on the vertical load and slip ratio on the tire.

[0037] The alignment moment can be calculated based on the vertical load and slip angle on the tire, and optionally the tire camber angle.

[0038] The method may include the step of estimating the vertical load on the tires based on the output of the vehicle body accelerometer and the vehicle static payload distribution on the four wheels.

[0039] The method may include a step of estimating the slip angle of the tire based on the outputs of an inertial measurement unit and a lateral velocity unit. The inertial measurement unit may measure the yaw angle, while the vehicle velocity unit may measure the longitudinal body velocity and / or lateral body velocity.

[0040] The method may include a step of estimating the tire slip ratio based on the output of a wheel angular velocity unit. The wheel angular velocity unit can measure the wheel angular velocity.

[0041] Preferably, the force or moment acting on the tire is calculated using the Pajeka Magic Formula tire model.

[0042] Preferably, at least one temperature includes the outer surface temperature of the tire.

[0043] Preferably, the outer surface temperature of the tire is the tread surface temperature of the tire.

[0044] Preferably, the outer surface temperature of the tire is estimated based on at least one of road speed, lateral force on the tire, longitudinal force on the tire, slip angle, brake temperature, and air temperature around the tire.

[0045] Force and slip (slip angle, slip ratio) allow the friction force to be calculated, which ultimately indicates the tire temperature.

[0046] Alternatively, the external surface temperature of the tire can be measured using a thermal sensor that can be installed on the vehicle body.

[0047] Preferably, at least one temperature includes the inner liner temperature of the tire, and preferably at least one temperature includes at least one of the brake temperature and the air temperature around the tire.

[0048] Preferably, at least one of the tire inner liner temperature, brake temperature, and tire ambient air temperature is measured using a thermal sensor that can be installed on the vehicle body.

[0049] Preferably, the set of scaling factors is calculated based on tire wear.

[0050] Tire wear may be the tire tread loss (amount of wear). Tread loss can be calculated based on the wear energy and / or wearability of the tire tread compound. Wear energy can be calculated from the value obtained by multiplying the amount of slip (e.g., slip angle × vehicle speed) by the shear stress or total force (e.g., lateral force) within the contact patch.

[0051] Tire wear can be estimated based on the tire's usage history. For example, the usage history may include at least one of the following: the distance traveled by the tire, and the wear energy experienced by the tire over time.

[0052] The tread depth of a tire can be measured using an optical sensor. From this, the tread loss of the tire can be calculated.

[0053] Tire wear can be estimated based on the tire compound.

[0054] A third aspect of the present invention may provide a device configured to perform the method of the first or second aspect.

[0055] The device may include memory. The memory may store information for calculating a set of scaling factors based on at least one temperature associated with the tire. The memory may be configured to store information regarding the tire's usage history. Alternatively, information regarding the usage history may be stored in the memory of a cloud server.

[0056] A fourth aspect of the present invention provides a system comprising the device of the third aspect and at least one sensor configured to measure body acceleration, body speed, road speed, brake temperature, or ambient air temperature.

[0057] At least one sensor may be an accelerometer that can be installed on the vehicle body, or a thermal sensor that can be installed on the vehicle body.

[0058] At least one sensor may be provided within the inertial measurement unit.

[0059] Preferably, at least one temperature associated with the tire is calculated based on the output of at least one sensor, and preferably, a force or moment acting on the tire is calculated based on the output of at least one sensor.

[0060] For example, the vertical load, slip angle and / or slip ratio can be calculated based on the output of at least one sensor, and the force or moment acting on the tire can be calculated based thereon.

[0061] A fifth aspect of the present invention provides a method for calculating a force or moment acting on the tread surface of a tire during driving, the method comprising:

[0062] A step of determining a set of scaling factors using the method of the first embodiment, and

[0063] It includes the step of calculating the force or moment acting on the tread surface of the tire using the method of the second embodiment during driving.

[0064] The method can preferably be performed in the vehicle's ECU or in a vehicle simulator.

[0065] A sixth aspect of the present invention provides a computer program comprising instructions that cause the computer to perform the method of the first or second aspect when the program is executed by the computer.

[0066] A seventh aspect of the present invention provides a computer-readable storage medium comprising instructions that, when executed by a computer, cause the computer to perform a step of the method of a first or second aspect.

[0067] A preferred feature of any of the first and seventh embodiments may be equally applied to any other embodiment among the first to seventh embodiments.

[0068] A preferred embodiment of the present invention will now be described purely by example with reference to the drawings.

[0069] Figure 1 is a diagram showing the lateral force (slewing force) plotted against the slip angle.

[0070] FIG. 2 is a flowchart showing a procedure for determining a set of scaling factors according to one embodiment of the present invention.

[0071] Figure 3 is a block diagram illustrating the technical architecture of Server X.

[0072] FIG. 4 is a block diagram illustrating the technical architecture of a communication device (1).

[0073] An example of the Pajeka Magic Formula tire model ("MF tire model") for lateral force or turning force is provided below as Equation 1.

[0074]

[0075] Among the foods:

[0076] F is the lateral force of N;

[0077] B, C, D, and E are dimensionless coefficients, some of which depend on normal force in kN, camber angle in degrees, and / or slip angle in degrees;

[0078] α depends on the slip angle in degrees;

[0079] S is a vertical shift.

[0080] Using this equation, the lateral force can be predicted and plotted, for example, for various slip angles. However, under actual conditions, when the tire temperature increases and the tire becomes hot, the lateral force curve changes and the maximum lateral force achievable by the tire becomes lower.

[0081] Figure 1 is a diagram illustrating lateral force (slewing force) plotted against slip angle. Figure 1 shows the upper curve when the tire is under nominal conditions and the lower curve when the tire is under damped conditions with increased temperature. Data for both curves were obtained from an indoor test stand, and the lower curve for damped conditions is obtained by increasing the temperature of the tread compound. In the figure, arrows indicate the direction in which the curve slope, or peak force slip angle, shifts as the temperature increases. Specifically, the arrow on the left shows that the curve slope decreases at high slip angles. The middle arrow shows how the peak force slip angle shifts from approximately -6 or -7 degrees for the nominal condition curve to approximately -5 degrees for the damped condition curve. The arrow on the right shows the direction in which the curve slope shifts as the temperature increases at low slip angles.

[0082] Using a conventional MF tire model will provide a curve that is close to the upper (nominal condition) curve. However, the curve of a conventional MF tire model will not be close to the lower (damped condition) curve (at least for slip angles greater than -5 degrees). On the other hand, a temperature-compensated MF tire model can provide a curve that is closer to the lower (damped condition) curve for a specific increased temperature. Because the curve of the temperature-compensated MF tire model takes into account the temperature change of the tire under actual conditions, it will be a model closer to the actual behavior of the tire.

[0083] FIG. 2 is a flowchart showing the entire procedure for determining a set of scaling factors to correct for calculated forces or moments (in this case, lateral forces) acting on the tread surface of a tire during driving. However, the procedure is illustrative, and not all steps of the procedure are essential. The procedure includes outdoor track testing, indoor testing on a tire test machine, and data processing of data obtained during the outdoor and indoor tests. Data processing generates a set of scaling factors that depend on temperature (e.g., various temperatures associated with the tire), which can be used to calibrate the Pajeka Magic Formula tire model to obtain a more accurate representation of the tire's behavior under actual conditions.

[0084] Referring to FIG. 2, 101 refers to the outdoor test portion of the procedure. During the outdoor test, various temperatures associated with the tires are measured as the vehicle (passenger car) travels on a test track or road. Data on how the temperature changes over time is recorded. The measured temperatures include the tire tread surface temperature, the tire inner liner temperature, the brake temperature, and the ambient air temperature (respectively, T surf , T inner , T brakes , T amb It is. Tire wear level and appearance are also evaluated. In addition, tire vertical load (F ZVe ) Slip angle, slip ratio, and road speed (V XVe The value of the tire input, such as ), is estimated.

[0085] Next, at 102, an indoor test is performed on a tire testing machine or rig. The following are measured, and how they change over time is recorded: tire tread surface temperature, tire inner liner temperature ( T surf , T inner ), and vertical force or load (F ZFT ), lateral force( F Y ), end power( F X ), and road speed( V XFT Tire inputs such as ). During indoor testing, specific procedures are implemented to reproduce tire temperature and wear levels that match those experienced during outdoor testing.

[0086] It should be noted that, in principle, it would be possible to perform the procedure without the outdoor test portion (101) and obtain sufficient data to generate a set of temperature-dependent scaling factors based solely on the indoor test. However, it is desirable to include some outdoor test, as the temperature in the indoor test environment does not necessarily accurately represent actual outdoor operating conditions. Therefore, in this embodiment, both the outdoor test and the indoor test are performed, and a transfer function is generated to convert the indoor data into an outdoor prediction, as described below.

[0087] Next, in 103, processing of the data obtained from 101 and 102 is performed to obtain the transfer function. Assuming the thermal equivalence of the temperatures measured during the outdoor and indoor tests, F ZVe and F ZFT and V XVe and V XFT When comparing data for, an algorithm is used to obtain the transfer function.

[0088] Next, at 104, a thermal model is obtained. The thermal model is not essential, but, for example, the tire tread surface temperature ( T surf It is useful when ) cannot be measured. The thermal model allows this temperature to be estimated from other parameters that are easier to measure. To obtain a thermal model,T surf Is F ZVe , V XVe , F Y , F X , T brakes , T amb It is taken as a function of tire input such as, T surf The relationship between and these other variables is determined to obtain a heat model.

[0089] Next, in 105, a force model is obtained. In this embodiment, this is a lateral force model, but instead, it may be a longitudinal force model or an alignment moment model. First, theoretical F Y The value of is calculated using a conventional MF model. Subsequently, the theoretical F Y The value of was measured at 102 F Y Divided by the value of to obtain a set of raw scaling factors. This involves multiple theoretical F Y Multiple measured values ​​for the same slip angle F Y It includes dividing by each value. (Alternatively, the measured F Y Instead of using the value directly, F Y (It can be estimated from measurements at 102, for example, by interpolation.) Subsequently, the set of raw scaling factors is T surf , T inner , T brakes , and T amb Assuming it is a function of, the relationship between the set of raw scaling factors and these other variables is determined, and the set of temperature-dependent scaling factors l KY , l MUY Obtain [the value] and, accordingly, complete a force model with higher accuracy than a conventional MF model.

[0090] The implementation example described above is T brakes and T amb It is provided that a model is considered to account for external heat generation; it should be noted that while this may provide a more accurate model, it is not essential. The model, for example, T surf Only, or T surf and T inner It can be based on.

[0091] Once the set of temperature-dependent scaling factors is determined, the force model uses i) a conventional MF model F Y Step of calculating, ii) T surf and calculated using a set of temperature-dependent scaling factors F Y A step of calculating a set of actual scaling factors to correct , and iii) the calculated F Y Multiply by F Y This can be used by the step of obtaining a correction value for. If desired, a number of correction values ​​can be obtained and plotted, for example, against the slip angle to provide a plot of the kind shown in FIG. 1. Here, for example, it can be easily seen that the maximum lateral force for the nominal curve is about 8500 N at about -6 or -7 degrees, whereas the maximum lateral force for the damped curve when temperature effects are taken into account is about 8000 N at about -5 degrees.

[0092] When a vehicle is driven aggressively on the test track during a track test, the damped condition curve for each completed wheel is expected to become lower as the tire temperature rises.

[0093] The force model can be improved by considering tire wear. In this regard, during indoor testing in 102, while the corresponding tire input is being measured by a tire testing machine, tire wear can be measured at various points during the test procedure (e.g., by hand). The test can be performed so that forces are acquired at different wear levels while the tire temperature is maintained constant. Subsequently, when acquiring the force model in 105, the set of raw scaling factors is T surf , T inner , T brakes , and T amb In addition, assuming that it is a function of wear, the relationship between the set of raw scaling factors and these other variables is determined, and a set of scaling factors that depend on wear as well as temperature is obtained.

[0094] Enhanced accuracy force models have various potential applications. They can be used, for example, in tire design; in vehicle ECUs to inform or warn the driver about how the tires are behaving; or in vehicle simulations to more accurately simulate how tires behave under real-world conditions.

[0095] Taking its use in a vehicle's ECU as an example, the ECU may include software that performs a method of calculating the force acting on the tread surface of the tire during driving using an enhanced accuracy force model. Here, the ECU calculates the force acting on the tire using the MF equation. Subsequently, instead of directly measuring the outer surface temperature of the tire, the ECU will typically estimate the outer surface temperature of the tire based on road speed, lateral force on the tire, longitudinal force on the tire, slip angle, brake temperature, and the air temperature around the tire. These parameters are measured or estimated on their own. Then, based on the estimated outer surface temperature of the tire, a set of scaling factors for that specific temperature will be calculated from a set of temperature-dependent scaling factors. Next, the ECU will correct the calculated force acting on the tire using the set of scaling factors to obtain a corrected force for the estimated temperature. The ECU may then be configured to warn the driver, for example, if the tires provide significantly less lateral force than normal due to higher temperatures, or if the vehicle is driven in a manner where the lateral force required for cornering is likely to exceed the force the tires can generate at current or predicted future temperatures.

[0096] If the model is improved to account for tire wear, tire wear can be estimated using the wear energy and wearability of the tire compound. Wear energy can be calculated from the amount of slip and shear stress of the contact patch, and shear stress is calculated from the force acting on the tread surface within the contact patch.

[0097] The ECU includes memory in which information for calculating a set of scaling factors is stored. In this embodiment, an expression defining the relationship between a set of scaling factors and a temperature is stored in memory, which enables the processor of the ECU to calculate a set of scaling factors for any possible temperature. Additionally, an uncorrected MF model or expression is stored in memory, and an expression defining the relationship between the uncorrected MF model and the corrected model using a set of scaling factors is stored in memory.

[0098] As used in this application, terms such as “component,” “module,” “engine,” “system,” “device,” “interface,” etc. are intended to refer to computer-related entities that are generally hardware, a combination of hardware and software, software, or running software. For example, a component may be, but is not limited to, a process, processor, object, executable file, execution thread, program, and / or computer running on a processor. As an example, both an application running on a controller and the controller may be components. One or more components may reside within a process and / or thread of execution, and components may be localized on a single computer and / or distributed across two or more computers.

[0099] Additionally, the claimed subject may be implemented by a method, device, or manufactured article using standard programming and / or engineering techniques to generate software, firmware, hardware, or any combination thereof to control a computer to implement the disclosed subject. For example, the claimed subject may be implemented by a computer-readable medium containing a computer executable program that includes a computer program accessible from any computer-readable storage device or storage medium. For example, the computer-readable medium may include, but is not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical discs (e.g., compact discs (CDs), digital multi-purpose discs (DVDs)), smart cards, and flash memory devices (e.g., cards, sticks, key drives).

[0100] Figure 3 is a block diagram illustrating the technical architecture of Server X.

[0101] The technical architecture includes a processor (222) (which may be referred to as a central processor unit or CPU) communicating with memory devices including secondary storage (224) (e.g., a disk drive), read-only memory (ROM) (226), and random access memory (RAM) (228). The processor (222) may be implemented with one or more CPU chips. The technical architecture may further include an input / output (I / O) device (230) and a network connectivity device (232).

[0102] The secondary storage (224) is typically composed of one or more disk drives or tape drives and is used for non-volatile storage of data and as an overflow data storage device when RAM (228) is not large enough to hold all work data. The secondary storage (224) may be used to store programs that are loaded into RAM (228) when these programs are selected for execution.

[0103] In this embodiment, the secondary storage (224) has an order processing component (224a) containing non-transient instructions operated by the processor (222) to perform various operations of the method of the present invention. The ROM (226) is used to store instructions and possibly data that are read during program execution. The secondary storage (224), RAM (228), and / or ROM (226) may be referred to as computer-readable media and / or non-transient computer-readable media in some contexts.

[0104] The I / O device (230) may include a printer, a video monitor, a liquid crystal display (LCD), a plasma display, a touch screen display, a keyboard, a keypad, a switch, a dial, a mouse, a trackball, a voice recognizer, a card reader, a paper tape reader, or other well-known input devices.

[0105] The network connectivity device (232) may take the form of a modem, a modem bank, an Ethernet card, a Universal Serial Bus (USB) interface card, a serial interface, a Token Ring card, a Fiber Distributed Data Interface (FDDI) card, a Wireless Local Area Network (WLAN) card, a wireless transceiver card that facilitates wireless communication using protocols such as Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Long Term Evolution (LTE), World Wide Interoperability for Microwave Access (WiMAX), Near Field Communication (NFC), Radio Frequency Identification (RFID), and / or other air interface protocol wireless transceiver cards, and other well-known network devices. These network connectivity devices (232) enable the processor (222) to communicate with the Internet or one or more intranets. It is considered that through such network connectivity, the processor (222) can receive information from the network or output information to the network while performing the method operation described above. This information, often expressed as a sequence of instructions to be executed using a processor (222), can be received from a network and output thereto, for example, in the form of a computer data signal implemented as a carrier wave.

[0106] The processor (222) executes instructions, code, computer programs, and scripts accessed from a hard disk, floppy disk, optical disk (all these various disk-based systems can be considered as secondary storage (224)), flash drive, ROM (226), RAM (228), or network connectivity device (232). Although only one processor (222) is shown, multiple processors may exist. Thus, instructions may be discussed as being executed by a processor, but instructions may be executed simultaneously, serially, or otherwise by one or more processors.

[0107] Although the technical architecture is described with reference to a computer, it should be recognized that the technical architecture may be formed by two or more communicating computers that cooperate to perform a task. For example, but not limited to, an application may be partitioned in such a way that instructions of the application can be processed concurrently and / or in parallel. Alternatively, data processed by the application may be partitioned in such a way that different parts of the data set can be processed concurrently and / or in parallel by two or more computers. In one embodiment, virtualization software may be utilized by the technical architecture (220) to provide the functionality of multiple servers that are not directly limited to the number of computers within the technical architecture (220). In one embodiment, the functionality disclosed above may be provided by running the application and / or applications in a cloud computing environment. Cloud computing may include providing computing services over a network connection using dynamically scalable computing resources. The cloud computing environment may be established by an enterprise and / or may be leased from a third-party provider as needed.

[0108] It is understood that by programming and / or loading executable instructions onto a technical architecture, at least one of the CPU (222), RAM (228), and ROM (226) is modified so that the technical architecture is partially converted into a machine or device for a specific purpose having novel functionality taught by the present invention. It is a fundamental principle in the fields of electrical engineering and software engineering that functionality that can be implemented by loading executable software into a computer can be converted into a hardware implementation by well-known design rules.

[0109] FIG. 4 is a block diagram illustrating the technical architecture of a communication device (1). In an embodiment, the communication device (1) is expected to be a smartphone or a tablet device.

[0110] The technical architecture includes a processor (322) (which may be referred to as a central processor unit or CPU) that communicates with memory devices including secondary storage (324) (e.g., a disk drive or memory card), read-only memory (ROM) (326), and random access memory (RAM) (328). The processor (322) may be implemented with one or more CPU chips. The technical architecture further includes an input / output (I / O) device (330) and a network connectivity device (332).

[0111] The I / O device includes a user interface (UI) (330a), a camera (330b), and a geolocation module (330c). The UI (330a) may include a touch screen, a keyboard, a keypad, or other known input device. The camera (330b) enables the user to capture images and store the captured images in electronic form. The geolocation module (330c) may operate to determine the geolocation of the communication device, for example, using signals from Global Positioning System (GPS) satellites.

[0112] The secondary storage (324) is typically composed of a memory card or other storage device and is used for non-volatile storage of data and as an overflow data storage device when RAM (328) is not large enough to hold all work data. The secondary storage (324) may be used to store a program that is loaded into RAM (328) when such a program is selected for execution.

[0113] In this embodiment, the secondary storage (324) has a sequence generating component (324a) containing non-transient instructions operated by the processor (322) to perform various operations of the method of the present invention. The ROM (326) is used to store instructions and possibly data that are read during program execution. The secondary storage (324), RAM (328), and / or ROM (326) may be referred to as computer-readable media and / or non-transient computer-readable media in some contexts.

[0114] The network connectivity device (332) may take the form of a modem, a modem bank, an Ethernet card, a Universal Serial Bus (USB) interface card, a serial interface, a Token Ring card, a Fiber Distributed Data Interface (FDDI) card, a Wireless Local Area Network (WLAN) card, a wireless transceiver card that facilitates wireless communication using protocols such as Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Long Term Evolution (LTE), World Wide Interoperability for Microwave Access (WiMAX), Near Field Communication (NFC), Radio Frequency Identification (RFID), and / or other air interface protocol wireless transceiver cards, and other well-known network devices. These network connectivity devices (332) enable the processor (322) to communicate with the Internet or one or more intranets. It is considered that through such network connectivity, the processor (322) can receive information from the network or output information to the network while performing the method operation described above. This information, often expressed as a sequence of instructions to be executed using a processor (322), can be received from a network and output thereto, for example, in the form of a computer data signal implemented as a carrier wave.

[0115] The processor (322) executes instructions, code, computer programs, and scripts accessed from a hard disk, floppy disk, optical disk (all these various disk-based systems can be considered as secondary storage (324)), flash drive, ROM (326), RAM (328), or network connectivity device (332). Although only one processor (322) is shown, multiple processors may exist. Thus, instructions may be discussed as being executed by a processor, but instructions may be executed simultaneously, serially, or otherwise by one or more processors.

[0116] Preferred embodiments of the present invention have been described purely by way of example, and various modifications, additions, and / or omissions will be presented to those skilled in the art, all of which form part of the present invention.

Claims

Claim 1 A method for determining a set of temperature-dependent scaling factors for correcting a calculated force or moment acting on a tread surface of a tire during driving, comprising: a step of measuring a value of an actual force or moment acting on said tread surface within a contact patch of the tire during driving; a step of measuring a value of a temperature associated with said tire or estimating a value of a temperature associated with said tire based on the value of one or more measured parameters associated with said tire; a step of calculating a value of a theoretical force or moment acting on a tread surface of said tire during driving using a mathematical model; and a step of determining a set of temperature-dependent scaling factors for correcting said theoretical force or moment by comparing said calculated theoretical force or moment value with said measured actual force or moment value or a value derived from said measured actual force or moment value, and determining a relationship between said comparison result and said measured or estimated temperature value. Claim 2 A method according to claim 1, wherein in the force or moment measurement step and the temperature measurement or estimation step, the actual force or moment and the temperature or one or more parameters associated with the tire are measured on a force and moment tire test rig. Claim 3 A method according to claim 1 or 2, further comprising a road test step of measuring the value of the temperature associated with the tire while the tire is installed on a vehicle traveling on a road. Claim 4 A method according to claim 3, which is dependent on claim 2, wherein during the road test phase, the value of another parameter associated with the tire is measured, and while the tire is installed on the tire test rig, the value of the temperature associated with the tire is measured and the value of the other parameter associated with the tire is measured, and the method further comprises the step of determining the relationship between the temperature measured during the road test phase and the other parameter measured during the road test phase using the value of the temperature measured on the tire test rig and the other parameter measured on the tire test rig, and the step of determining a set of temperature-dependent scaling factors using the result. Claim 5 A method according to any one of claims 1 to 4, further comprising the step of measuring the value of the tread loss of the tire or estimating the value of the tread loss of the tire based on the value of one or more measured parameters associated with the tire, wherein the step of determining the set of temperature-dependent scaling factors comprises the step of comparing the calculated theoretical force or moment value with the measured actual force or moment value or a value derived from the measured actual force or moment value, and the step of determining the relationship between the comparison result and the measured or estimated tread loss value. Claim 6 A computer-implemented method for calculating a force or moment acting on a tread surface of a tire during driving, comprising: a step of calculating the force or moment acting on the tread surface of a tire using a mathematical tire model during driving; a step of calculating a set of scaling factors based on at least one temperature associated with the tire; and a step of correcting the calculated force or moment using the set of scaling factors. Claim 7 A method in which, in any one of claims 1 to 6, the force or moment acting on the tire is calculated using the Pajeka Magic Formula tire model. Claim 8 A method according to claim 6 or 7, wherein at least one temperature includes the outer surface temperature of the tire. Claim 9 A method according to claim 8, wherein the outer surface temperature of the tire is estimated based on at least one of road speed, lateral force on the tire, longitudinal force on the tire, slip angle, brake temperature, and air temperature around the tire. Claim 10 A method according to any one of claims 6 to 9, wherein the at least one temperature includes the inner liner temperature of the tire, and preferably the at least one temperature includes at least one of the brake temperature and the tire ambient air temperature. Claim 11 A method according to any one of claims 6 to 10, wherein the set of scaling factors is calculated based on the wear of the tire. Claim 12 A device configured to perform the method of any one of paragraphs 6 through 11. Claim 13 A system comprising the device of claim 12 and at least one sensor configured to measure body acceleration, body speed, road speed, brake temperature, or ambient air temperature. Claim 14 A system according to claim 13, wherein the at least one temperature associated with the tire is calculated based on the output of the at least one sensor, and preferably the force or moment acting on the tire is calculated based on the output of the at least one sensor. Claim 15 A method for calculating a force or moment acting on the tread surface of a tire during driving, comprising the steps of determining a set of scaling factors using the method of any one of claims 1 to 5, and calculating said force or moment acting on the tread surface of a tire using the method of any one of claims 6 to 14 during driving.

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