JP2007290694A - Calculation method for excessive response data of tire, data processing method, design method for tire and vehicle motion forecasting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calculate excessive response data of a tire during cornering (braking/driving) using tire dynamics model and to determine a parameter value for determining excessive response used for a tire model. <P>SOLUTION: A value of a tire dynamics element parameter constituting a tire dynamics model is obtained and a response function of a primary delaying response for specifying deformation response of a tread part during cornering (braking/driving) and a time variation amount of time series data of a slip angle (slip ratio) given to the tire dynamics model are folding-integrated to calculate the time series data of the excessive response of the slip angle (slip ratio) of the tread part relative to a road surface in the tire dynamics model. Output data of lateral force and self-aligning torque (forward/rearward force) are calculated as the cornering (braking/driving) excessive response based on the time series data of the excessive response. Further, the value of the parameter for determining the excessive response is determined by correcting a delay time constant such that the output data are approximately coincident with the actual measurement data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of calculating transient response data for calculating transient response data during cornering or braking / driving of a tire based on a tire dynamic model configured using a plurality of tire dynamic element parameters, and The present invention also relates to a data processing method for calculating a value of a transient response parameter of a response function that defines a behavior, and further relates to a tire design method and a vehicle motion prediction method performed using the transient response calculation method.

  Currently, in the automobile industry, advanced vehicle control for safe driving of vehicles and avoidance of danger is required. Since the tire is interposed between the vehicle and the road surface and transmits the force from the road surface to the vehicle only, the role of the tire is important. Therefore, it is necessary to analyze the cornering characteristics of the tire.

  Patent Document 1 below discloses calculating cornering characteristics of a steady-state tire when a slip angle is given as time series data based on a tire dynamic model configured using a plurality of tire dynamic element parameters. Has been. Thereby, it is supposed that it becomes possible to design a tire efficiently.

  However, although the tire dynamic model can provide a steady-state cornering characteristic by giving a slip angle, it cannot reproduce a transient response during cornering that changes every moment by giving the slip angle in time series. Especially under the condition of an urgently high steering speed in order to avoid danger, the lateral force and self-aligning torque generated in the tire show characteristics of a transient state different from the steady state. Therefore, the cornering characteristic in the steady state is used. The motion analysis cannot proceed.

  Further, in today's vehicles, braking using an anti-lock braking system (ABS) is normally performed. In ABS, the slip ratio is controlled at several Hz so that the braking force during braking is always maximized. For this reason, the generated braking force is based on characteristics of a transient state different from the steady state. This characteristic is different from the characteristic when the braking force is applied in a steady state. Therefore, even if the longitudinal force in the steady state is calculated using the tire dynamic model, the motion analysis of the vehicle including the ABS cannot be advanced using the longitudinal force.

JP 2005-88832 A

  Therefore, the present invention is to solve the above conventional problems. Provided is a method for calculating tire transient response data during tire cornering and braking / driving using a tire dynamic model to determine the transient response of the tire, and for determining the parameter values defining the transient response used in the tire model. It is another object of the present invention to provide a data processing method, and further, a tire design method and a vehicle motion prediction method performed using the transient response data calculation method.

  The present invention relates to tire transient response data for calculating tire transient response data during cornering when a slip angle is given as time-series data based on a tire dynamic model configured using a plurality of tire dynamic element parameters. The tire dynamic element parameter values constituting the tire dynamic model are acquired and given to the response function of the first-order lag response defining the deformation response of the tread portion during cornering and the tire dynamic model The time series data of the transient response of the slip angle is calculated by calculating the time series data of the transient response of the slip angle to the road surface in the tread portion of the tire dynamic model by performing convolution integration with the time change amount of the time series data of the slip angle. At least one of lateral force and self-aligning torque calculated by the tire dynamic model based on The output data, which provides a method for calculating the transient response data of the tire and calculating a cornering transient response.

At that time, the time-series data of the slip angle given to the tire dynamic model is corrected by the torsional deformation of the tire generated according to the self-aligning torque, and the corrected time-series data is converted to the slip angle transient. It is preferably used when calculating time series data of responses. In particular, the torsional deformation of the tire that occurs in response to the self-aligning torque includes the response function of the first-order lag response that defines the deformation response of the side portion during cornering and the past time-series data of the self-aligning torque. It is preferable that the convolution integral with the time change amount is divided by the torsional rigidity value in the tire dynamic model.
Further, it is preferable that the output data calculated using the tire dynamic model is data of lateral force corrected by bending deformation of the belt portion generated according to lateral force. In particular, the bending deformation of the belt portion that occurs in response to the lateral force includes a time-dependent amount of change in the past time-series data of the generated lateral force and a response function of a first-order lag response that defines the deformation response of the belt portion during cornering. It is preferable that it is expressed by performing convolution integration with.

  Furthermore, the present invention relates to a tire transient that calculates tire transient response data during cornering when a slip angle is given as time-series data based on a tire dynamic model configured using a plurality of tire dynamic element parameters. A method for calculating response data, wherein time series data of a slip angle changing including a range between at least 0 degrees and a predetermined angle is given to a tire as a steady-state slip angle, and by actually measuring the tire, The values of the lateral force and the self-aligning torque in the steady state are acquired in advance, and the response function of the first-order lag response that defines the deformation response of the tread portion during cornering and the time-series data of the slip angle applied to the tire Transient response of slip angle at the tread to the road surface in a tire dynamic model by performing convolution integration with time variation By calculating time-series data and obtaining the steady-state side force or self-aligning torque value corresponding to the calculated time-series data of the transient response of the slip angle, the transient side force or self-alignment value is obtained. Provided is a tire transient response calculation method characterized in that time series data of lining torque is calculated as transient response data during cornering.

  Further, according to the present invention, a deformation response of a tread portion that defines a transient response during cornering in a tire dynamic model configured using a plurality of tire dynamic element parameters is defined as a first-order lag response, and a transient that defines the first-order lag response is defined. A data processing method for calculating a value of a response parameter, wherein the time series data of a slip angle is given to a tire as a measurement condition, and measurement data of a transient response during tire cornering is acquired in advance, and the transient response parameter A value is initially set, a response function of the first-order lag response is determined, and a response function of the determined first-order lag response and a time change amount of time series data of a slip angle given as a measurement condition to the tire By performing convolution integration, time series data of the transient response of the slip angle to the road surface in the tread portion of the tire dynamic model is obtained. Based on the time series data of the transient response of the slip angle, the side force or the cell aligning torque value is calculated from the tire dynamic model, and the time series data of the transient side force or the self aligning torque during cornering is calculated. Is calculated until the squared residual sum of the time series data of the calculated lateral force or self-aligning torque and the measured data of the tire is obtained, and the setting is made until the squared residual sum is minimized. The value of the transient response parameter is corrected, the reproduction calculation is repeated, and the value of the transient response parameter when the sum of squared residuals is minimized is set as the value of the transient response parameter that determines the first-order lag response. A data processing method characterized by determining is provided.

  Further, in the present invention, a deformation response of a tread portion that defines a transient response during cornering in a tire dynamic model configured using a transient response parameter is defined as a first-order lag response, and a transient response parameter that defines the first-order lag response is used. A data processing method for calculating a value, wherein time series data of a slip angle in which a slip angle reciprocates including a range between at least 0 degrees and a predetermined angle is given to the tire as a measurement condition, and the tire Measurement data of the transient response during cornering is acquired in advance, the value of the transient response parameter is initialized, the response function of the first-order lag response is determined, and the response function of the first-order lag and the tire are measured. The tread with respect to the road surface in the tire dynamic model is obtained by performing convolution integration with the time change amount of the time series data of the slip angle given as a condition. The time series data of the slip angle transient response at the time is obtained, and the characteristic curve representing the value of the lateral force or self-aligning torque with respect to the value of the time series data of the transient response of the slip angle obtained is smoothed using a curve function. The least square regression is performed on one of the curves, and the regression calculation is performed to obtain the square residual sum of the least square regression curve obtained by the least square regression and the characteristic curve, and the calculated square residual sum is minimized. Until the value of the set transient response parameter is corrected and the regression calculation is repeated, and the value of the transient response parameter when the sum of squared residuals is minimized is determined as the transient response parameter defining the first-order lag response. The data processing method is characterized in that it is determined as a value of.

  Further, according to the present invention, transient response data of a tire during braking / driving when a slip ratio is given as time series data in a tire longitudinal direction based on a tire dynamic model configured using a plurality of tire dynamic element parameters. A method of calculating tire transient response data to be calculated, wherein the value of the tire dynamic element parameter constituting the tire dynamic model is acquired, and a response of a first-order lag response that defines a deformation response of a tread portion during braking / driving The time series data of the transient response of the slip ratio to the road surface in the tread part of the tire dynamic model is calculated by performing convolution integration of the function and the time change amount of the time series data of the slip ratio given to the tire dynamic model. The longitudinal force output data calculated by the tire dynamic model based on the time series data of the transient response of the rate is It provides a method for calculating the transient response data of the tire, characterized in that calculated as transient response data.

  The present invention calculates transient response data of a tire during braking / driving when a slip ratio in the longitudinal direction of the tire is given as time series data based on a tire dynamic model configured using a plurality of tire dynamic element parameters. A method for calculating tire transient response data, in which steady-state slip rate time-series data including a range between at least 0 degrees and a predetermined slip ratio is given as a steady-state slip ratio. The value of the longitudinal force in the tire is obtained in advance by actual measurement of the tire, and the response function of the first-order lag response that defines the deformation response of the tread portion during braking / driving is convoluted with the time variation of the time series data of the slip ratio. Integration is performed to calculate time series data of the transient response of the slip ratio in the tread portion with respect to the road surface in the tire dynamic model, and the calculated slip By calculating the steady state longitudinal force value corresponding to the transient response time series data value, the transient longitudinal force time series data is calculated as transient response data during braking / driving. A method for calculating the transient response data of the tire is provided.

  Further, in the present invention, a deformation response of a tread portion that defines a transient response during braking / driving of a tire in a tire dynamic model configured using a plurality of tire dynamic element parameters is set as a first-order lag response, and this first-order lag response. Is a data processing method for calculating a value of a transient response parameter that determines the slip rate time-series data in which the slip rate reciprocates and includes a range between at least 0 degrees and a predetermined slip rate. The measurement data of the transient response during braking / driving of the tire is obtained in advance, the transient response parameter value is initialized, the response function of the first-order lag response is determined, and the first-order lag is determined. Is applied to the road surface in the tire dynamic model by performing convolution integration between the response function of the tire and the time variation of the time series data of the slip ratio given as a measurement condition to the tire. The time series data of the transient response of the slip ratio in the tread portion is obtained, and a characteristic curve representing the value of the longitudinal force with respect to the value of the obtained time series data of the transient response of the slip angle is obtained using a curve function. Perform a regression calculation to obtain the squared residual sum of the least squares regression curve and the characteristic curve after performing least square regression on the curve, and set until the calculated squared residual sum is minimized The value of the transient response parameter is corrected, the regression calculation is repeated, and the value of the transient response parameter when the sum of squared residuals is minimized is set as the value of the transient response parameter that defines the first-order lag response. A data processing method characterized by determining is provided.

  Further, according to the present invention, a deformation response of a tread portion that defines a transient response during braking / driving in a tire dynamic model configured using a transient response parameter is defined as a first-order lag response, and the transient response parameter that defines the first-order lag response. Is a data processing method for calculating the value of the tire, the time series data of the slip ratio in the longitudinal direction of the tire is given to the tire as a measurement condition, and the measurement data of the transient response during the braking operation of the tire is acquired in advance, and the transient A response parameter value is initialized, a response function of the first-order lag response is determined, the determined response function of the first-order lag, and a time change amount of time series data of a slip ratio given as a measurement condition to the tire, The time series data of the transient response of the slip ratio in the tread portion with respect to the road surface in the tire dynamic model is obtained by performing the convolution integral of the tire dynamic model, Based on the value of the time series data of the transient response of the lip ratio, the longitudinal force is calculated from the tire dynamic model, and the reproduction calculation is performed to calculate the time series data of the longitudinal force in the transient state during braking / driving. The sum of squared residuals of the time series data of the longitudinal force and the measurement data of the tire is obtained, and the value of the set transient response parameter is corrected until the sum of squared residuals is minimized, and the reproduction calculation is repeated. The data processing method is characterized in that the value of the transient response parameter when the sum of squared residuals is minimized is determined as the value of the transient response parameter defining the first-order lag response.

  Further, the present invention calculates and outputs tire transient response data using the tire transient response data calculation method, until the output tire transient response data satisfies a set target condition. By adjusting the tire structural element that defines the tire dynamic element parameter or the first-order lag response, the value of the tire dynamic element parameter and the value of the transient response parameter that defines the first-order lag response are corrected. Provided is a tire design method characterized by repeatedly calculating output data and determining the tire constituent member at this time as a target tire constituent member when the output data satisfies a target condition.

  Further, according to the present invention, the tire transient response data is calculated and output using the tire transient response data calculation method, and the output tire transient response data is given to the axle portion of the vehicle model to A vehicle motion prediction method for predicting vehicle motion by a model is provided.

  In the tire transient response data calculation method according to the present invention, in the tire dynamic model, the time-series data of the transient response of the slip angle or the slip ratio of the tread with respect to the road surface is used as the first order delay that defines the deformation response of the tread during cornering. Calculated by convolution integration of the response function of the response and the time variation of the time series data of the slip angle given to the tire dynamic model, lateral force and self-aligning based on the time series data of the transient response of this slip angle Calculate time series data of torque or longitudinal force. For this reason, the time-series data in the transient state can be easily calculated using the tire dynamic model.

  Further, the deformation response of the tread portion that defines the transient response during cornering or braking / driving in the tire dynamic model is defined as a first-order lag response, and when calculating the value of the transient response parameter that defines the first-order lag response, the transient response parameter The initial value is set to determine the response function of the first-order lag response, the convolution integration of the response function of the first-order lag response and the time change amount of the time series data of the slip angle or the slip ratio is performed, and the tire dynamics Since the time series data of the transient response of the slip angle to the road surface in the tread part of the model is obtained, the time series data of the transient lateral force, self-aligning torque or longitudinal force during cornering or braking / driving can be easily calculated. It is possible to search and determine the value of the transient response parameter relatively easily.

  Further, the time series data of the lateral force, the self-aligning torque, or the longitudinal force can be obtained as desired target conditions by associating the types of tire constituent members with the values of the dynamic element parameters of the tire dynamic model and the values of the transient response parameters. Tires that achieve can be designed. Also, predicting the motion of the vehicle during cornering or braking / driving by inputting the time series data of the lateral force, self-aligning torque or longitudinal force calculated by the tire transient response calculation method to the vehicle model You can also.

  Hereinafter, based on an embodiment shown in the accompanying drawings, a tire transient response data calculation method, a data processing method, and a tire design method performed using the tire transient response data calculation method according to the present invention, and The vehicle motion prediction method will be described in detail.

FIG. 1 is a block diagram of a computing device 10 that implements the tire transient response data calculation method and data processing method of the present invention.
The arithmetic device 10 measures the lateral force F _y , the self-aligning torque (hereinafter simply referred to as torque) M _z , and the longitudinal force F _x in a transient state when the slip angle and the slip ratio are given as time series data. Is input to calculate a delay time constant (transient response parameter) that characterizes the transient response characteristics of the tire based on a tire dynamic model, which will be described later, and this delay time constant and the tire dynamic elements constituting the tire dynamic model This is a device that calculates time series data of the lateral force F _y , torque M _z , and longitudinal force F _{x in} the transient state using each parameter value. Here, the transient response characteristics are output characteristics of the lateral force F _y , torque M _z , and longitudinal force F _x that change with time in accordance with the time change of the slip angle and slip ratio during cornering. The transient response data refers to data of the lateral force F _y , torque M _z , and longitudinal force F _x in a transient state that changes with time according to the time change of the slip angle and slip ratio during cornering.

  The arithmetic unit 10 represents a data input unit 12 that accepts various data such as measurement data and parameters, and a tire dynamic model described later by an analytical expression, and uses the set parameter values to calculate lateral force and torque, and longitudinal force. By calculating the tire dynamic model calculation unit 14 and the tire dynamic model calculation unit 14 in a predetermined sequence, values of various parameters such as a tire dynamic element parameter and a delay time constant (transient response parameter) to be described later are determined. Alternatively, the processing unit 16 that calculates the time series data of the lateral force and torque or the longitudinal force in a transient state in the tire dynamic model, and the value of the determined delay time constant or the time series data of the calculated lateral force and torque Or an output unit 18 that collects time-series data of longitudinal force and outputs it as output data to a monitor or printer (not shown). Configured to have a.

Examples of tire dynamic element parameters calculated based on a tire dynamic model (see FIG. 2, FIG. 3, and FIG. 10) described below are exemplified.
(A) the lateral stiffness K _y0 defined by the lateral shear stiffness of the tire,
(B) the coefficient of sliding friction between the road surface and the tire μ _d ,
(C) lateral stiffness coefficient (K _y0 / μ _s ) obtained by dividing lateral stiffness K _y0 by an adhesion friction coefficient μ _s between the road surface and the tire,
(D) the lateral bending coefficient ε of the belt member,
(E) Torsional compliance (1 / G _mz ), which is the reciprocal of torsional rigidity around the tire central axis of the tire,
(F) Coefficient n that defines the contact pressure distribution on the contact surface during the generation of lateral force
(G) a coefficient C _q representing the degree of deflection of the ground pressure distribution,
(H) a movement coefficient C _xc indicating the degree of movement of the tire center position in the front-rear direction on the ground contact surface;
(I) Effective ground contact length l _e when lateral force is generated,
(J) The longitudinal rigidity A _x in the contact surface (a parameter that determines the longitudinal force torque component), and the like.
Examples of the transient response parameters that characterize the transient response characteristics include the following.
(K) a delay time constant t _s of a first-order lag response that defines a deformation response due to shear deformation of the tread portion,
(L) the delay time constant t _r deformation defining a response first-order lag response by the side portion of the torsion deformation,
(M) a delay time constant t _d of a first-order lag response that defines a deformation response due to bending deformation of the belt portion,

Here, the lateral stiffness K _y0 , the lateral bending coefficient ε, and the torsional compliance (1 / G _mz ) G _mz are the stiffness parameter for the lateral shear deformation of the tire, the stiffness parameter for the lateral bending deformation, and the twist of the tire, respectively. This is a stiffness parameter for deformation. Each of the delay time constants (k) to (m) represents a time constant in the response function of each first-order lag response. Further, the lateral direction in which the lateral force is generated means the axial direction of the tire rotation axis. Therefore, the lateral direction when the tire rolls in a straight line state is the left-right direction with respect to the rolling direction, and the direction coincides. However, when the slip angle is added, the lateral direction is the slip angle with respect to the rolling direction of the tire. I can't tell. The front-rear direction refers to a direction that is parallel to the road surface on which the tire contacts and that is orthogonal to the axial direction of the rotation axis of the tire. The tire central axis (referred to as the axis CL in FIGS. 5A and 5B) is perpendicular to the road surface perpendicular to the rotational axis of the tire and passing through the central plane in the tire width direction. Is the axis.

The data input unit 12 is a part that accepts various data such as lateral force and torque measurement data or longitudinal force measurement data and the above parameters, and rewrites these data into a predetermined format and supplies them to the processing unit 16. At the same time, various input data are stored in the memory 21.
The processing unit 16 determines the values of various parameters by causing the tire dynamic model calculation unit 14 to calculate the lateral force and torque according to a sequence described later, or the lateral force, torque, This is the part that calculates the longitudinal force data.

The processing unit 16 has four different types of sequences, and corresponding to each of the sequences, a cornering parameter calculation unit 20 that determines the value of the delay time constant from lateral force and torque measurement data, and longitudinal force measurement A braking / driving parameter calculation unit 22 that determines the value of the delay time constant from the data, a F _y / M _z data calculation unit 24 that obtains time series data of lateral force and torque in a transient state using a tire dynamic model, And an F _x data calculation unit 26 that obtains time series data of longitudinal force in a transient state using a tire dynamic model.
The functions of the cornering parameter calculation unit 20, the braking / driving parameter calculation unit 22, the F _y / M _z parameter calculation unit 24, and the F _x data calculation unit 26 will be described later.

The tire dynamic model calculation unit 14 is a calculation unit that calculates the lateral force and torque calculation results based on the tire dynamic model using various data supplied from the processing unit 16 and returns the calculated calculation results to the processing unit 16. is there.
2, 3, 4 (a) to (c), FIGS. 5 (a) to (d), and FIGS. 6 (a) to (c) are diagrams illustrating a tire dynamic model.

  As shown in FIG. 2, the tire dynamic model includes a sidewall model composed of a plurality of spring elements representing the spring characteristics of the sidewalls on a rigid cylindrical member, and a belt model composed of an elastic ring body connected to these spring elements. And a tread model composed of an elastic element representing a tread model connected to the surface of the elastic ring body.

The tire dynamic model included in the tire dynamic element calculation unit 14 is in accordance with instructions from the cornering parameter calculation unit 20, the braking / driving parameter calculation unit 22, the F _y / M _z parameter calculation unit 24, and the F _x data calculation unit 26. The lateral force and torque in the transient state during cornering are calculated, and the longitudinal force in the transient state during braking and driving is calculated.
First, a case where the lateral force and torque in a transient state during cornering are calculated will be described. As shown in FIG. 3, numerical values of tire dynamic element parameters composed of various linear parameters and non-linear parameters configured by combining various spring elements of the tire are set, and time series data α of slip angles given as input data 3, the lateral force F _y (t) and torque M _z (which are time series data in the equations (6) and (7) are processed according to the equations (1) to (8) in FIG. t) is calculated as data.
The linear parameter means a parameter expressed in a linear form in the equations (6) and (7), and the nonlinear parameter means a positively or implicitly nonlinear form in the equations (6) and (7). Refers to the parameters represented by
[1-exp (− (t−t ′) / t _r )] in the equation (1) in FIG. 3 is a response of the first-order lag response of the torsional deformation of the side portion caused by the torque M _z (t). Represents a function. [1-exp (− (t−t ′) / t _s )] in the equation (4) is a response function of the first order lag response of the shear deformation of the tread portion caused by the given slip angle α (t). To express. [1-exp (− (t−t ′) / t _d )] in the equation (8) represents a response function of the first-order lag response of the lateral bending deformation caused by the lateral force of the belt portion.

The tire dynamic model calculation unit 14 calculates the torque M _z (t) and the torque M _z (t) according to the equation (1) expressed using the response function [1-exp (− (t−t ′) / t _r )] of the first order lag response. By calculating the torsion return angle obtained using torsional compliance (1 / G _mz ) and subtracting this torsion return angle from the applied slip angle α (t), the effective slip angle α _e (T) is calculated. The torsion return angle caused by the torque M _z (t) is due to the first order lag response of the torsional deformation of the side portion, and this torsion return angle is the first order lag that defines the deformation at this time. The result of convolution integration of the response function of the response and the time variation of the past time series data of the torque M _z (t) is multiplied by the torsional compliance (1 / G _mz ), that is, divided by the torsional rigidity. is there. Thus, the effective slip angle α _e (t) is calculated because the torque M _z (t) generated when the slip angle is applied acts on the tire itself so as to reduce the applied slip angle. This is because it acts to twist back. Therefore, when the slip angle is applied and the torque M _z (t) is generated, the effective slip angle α _e (t) is compared with the actually applied slip angle α (t) as shown in FIG. ) And the value of the deformation slip angle α _f (t) described later becomes smaller. The torque M _z (t) in the equation (1) uses the data of the torque M _z (t) in the equation (7) obtained in the previous time step.

Further, the deflection coefficient q that defines the shape of the contact pressure distribution is calculated from the torque _Mz by the equation (2). The deflection coefficient q means that the ground pressure distribution in the straight traveling state with the slip angle α = 0 (see FIG. 5A) is generated, and the lateral force F _y is generated as shown in FIG. This is a parameter representing the shape of the contact pressure distribution deflected toward the front in the direction (the stepping end on the contact surface). This contact pressure distribution is represented by p (x) (x is a coordinate position normalized by the contact length when the x axis is taken in the backward direction of travel in FIGS. 5A and 5B). Then, the shape of the contact pressure distribution p (x) is defined by the function D _gsp (x; n, q) represented by the equation (9) in FIG.
Here, the coefficient n in the function D _gsp (x; n, q) defines the contact pressure distribution of the contact surface during the generation of the lateral force. As shown in FIG. It is a coefficient that defines the contact pressure distribution so that it is angular (the curvature increases) near the kicking end. Further, as shown in FIG. 5D, the peak position of the contact pressure distribution is set so as to move toward the stepping-end side as the coefficient q is changed from 0 to 1. Thus, the coefficient q and the coefficient n are shape defining coefficients that define the shape of the contact pressure distribution.

Furthermore, a value (x _c / l) representing the degree to which the tire center position moves to the depression end side when the lateral force F _y is generated is calculated in association with the torque M _z by the expression (3). The value (x _c / l) is used in equation (7). Here, l is the contact length. Contacting define the movement of the tire center position O in such a formula (3), as shown in FIG. 5 (b), a tire center position O serving as a rotational center of the torque M _z due to the generation of the lateral force F _y This is to move to the stepping side of the ground.

Further, according to the equation (4), the transient slip angle is defined with respect to the effective slip angle α _e (t) in consideration of the first-order lag response of the shear deformation of the tread portion. That is, the followability at the time of deformation of the tread portion with respect to the road surface is based on the first-order lag response, and the response function of the first-order lag response that defines the deformation of the tread portion and the amount of time change of the effective slip angle α _e (t) The result of performing the convolution integral is defined as the deformation slip angle α _f (t) in the transient state. In equations (5) to (7), the modified slip angle α _f (t) is used for all.

Further, the boundary position (l _h / l) between the sliding friction and the adhesion friction within the contact surface that occurs when the deformation slip angle α _f (t) is large is calculated from the equation (5). The boundary position (l _h / l) is defined as follows.
The maximum friction curves shown in FIGS. 6A to 6C are obtained by multiplying the adhesion friction coefficient _μs by the contact pressure distribution p (x). The tire tread member that is in contact with the road surface at the stepping end is gradually sheared from the road surface by the deformation slip angle α _f (t) as it moves to the kicking end, and shear force (adhesion friction force) is generated on the tire tread member. To do. The shear force reaches the maximum friction curve gradually increases, tire tread elements which have adhesion to the road surface Suberidashi accordance sliding friction curve obtained by multiplying the ground contact pressure distribution p (x) to the sliding friction coefficient mu _d Sliding friction force is generated. In FIG. 6 (a), the region at the stepping end side from the boundary position (l _h / l) is an adhesion region where the tire tread member adheres to the road surface, and the region at the kick-out side is the tire tread member relative to the road surface. It becomes the slipping area of the sliding tire. FIG. 6 (b) shows a state in which the deformation slip angle α _f (t) is greater than the deformation slip angle α _f (t) shown in Figure 6 (a). The boundary position (l _h / l) has moved to the stepping end side as compared with FIG. Further, when the deformation slip angle α _f (t) increases, as shown in FIG. 6C, a sliding friction is generated from the position of the stepping end of the contact surface.

As can be seen from FIGS. 6 (a) to 6 (c), the ratio between the adhesion region and the slip region varies greatly according to the deformation slip angle α _f (t). The lateral force F _y (t) can be calculated by integrating the frictional force in the adhesion region and the sliding region, that is, the lateral force component along the tire width direction, and the moment around the tire center O can be calculated. By calculating, torque M _z (t) can be calculated.
In equations (6) and (7), the lateral force F _y (t) and the torque M _z (t) are calculated using the deformation slip angle α _f (t) separately for the above-mentioned adhesion region and slip region. .

In equation (6), the lateral force F _y (t) is calculated by the sum of two terms (two lateral force components). The first term is an integral having an integration range of 0 to (l _h / l), and represents an adhesion lateral force component generated in the adhesion region. The second term is an integral having an integration range of (l _h / l) to 1, and represents a slip lateral force component generated in the slip region.

The adhesion lateral force component of the first term in equation (6) is the lateral force in the adhesion region. In equation (6), the lateral displacement of the tread member caused by the deformation slip angle α _f (t) The adhesion lateral force component is calculated by expressing the state delayed by the lateral bending deformation. The sliding lateral force component of the second term is a lateral force in the sliding region. In the equation (5), the shape of the contact pressure distribution p (x) generated by the deformation slip angle α _f (t) is expressed by the function D _gsp (x; n , Q) to calculate the sliding lateral force component.

In the equation (7), the first term is an integral having an integration range of 0 to (l _h / l), and represents the torque component generated by the adhesion lateral force component generated in the adhesion region. Is an integral with an integration range of (l _h / l) to 1 and represents a torque component generated by a slip lateral force component generated in the slip region. In equation (7), in addition to the above two torque components, another torque component, that is, a third term is provided. The third term, A _x · (l _h / l) · tan α _f (t), indicates that the ground contact surface of the tire moves laterally due to the slip angle α as will be described later. The torque component around the tire center O generated by the force is expressed. That is, the torque M _z (t) is calculated by the sum of three components: a torque component generated by the adhesion lateral force, a torque component generated by the sliding lateral force, and a torque component generated by the longitudinal force.

Equation (8) is an expression for determining the _{F ye (t), F ye} (t) represents the lateral force that has been modified by the belt portion is subjected to lateral bending deformation by the lateral force F _y (t). The correction of the lateral force in the equation (8) is performed by convolution integration of the response function of the first-order lag response of the lateral bending deformation of the belt portion and the time variation of the past time series data of the lateral force F _y (t). Done.
Note that the tire dynamic model calculation unit 14 sets time series data of the lateral force F _y (t) and the torque M _z (t) from t = 0 to a minute time Δt according to the above formulas (1) to (8). Is sequentially calculated so that F _ye (t) obtained by the equation (8) at the time step of the time t is the F in the equations (5) and (6) at the next time step, that is, the time (t + Δt). Used for _ye (t). Similarly, _{M z} (t) which is obtained by the formula (7) at time t, the equation at the next time step (time t + Δt) (1), (2), (3), M z (t in (4) ).

4A to 4C schematically show the relationship between the deformation slip angle α _f (t), the delayed adhesion lateral force component caused by the deformation of the belt, the longitudinal force component, and the torque component, and the contact surface. This is shown in the figure.
FIG. 4A shows that when time series data of the slip angle α (t) is given, the slip angle α (t) is reduced by the torque generated by the slip angle α (t). 2 shows a state in which the tire acts on the tire itself and is in a transitional deformation slip angle α _f (t) due to the first-order lag deformation. FIG. 4B shows the relationship between the lateral displacement caused by the deformed slip angle α _f (t) and the lateral displacement caused by the lateral bending deformation of the belt. FIG. 4C shows a mechanism in which the longitudinal force distribution caused by the lateral contact force of the tire moving in the lateral direction contributes to the torque M _z (t). In FIG. 4C, M _z1 and M _z2 indicate a torque component due to the adhesion lateral force component and a torque component due to the sliding lateral force component, and M _z3 indicates a torque component due to the longitudinal force acting on the contact surface.

本発明中のモデル中の他の式に関しても、上記と類似の記述形式の変換（ｔ_x→σ_x）により表すことができる。 FIG. 7 is a processing block diagram until the lateral force F _y (t) and the torque M _z (t) are calculated based on the tire dynamic model when the slip angle α (t) is given. As can be seen from FIG. 7, in the tire dynamic model according to the present invention, when calculating the lateral force F _y (t) and the torque M _z (t), the lateral bending deformation of the belt portion, the shape change of the contact pressure distribution, and the side portion The torsional deformation is applied, and the lateral force F _y (t) and the torque M _z (t) are calculated based on the equations (6) and (7). Moreover, the lateral bending deformation of the belt portion, the torsional deformation of the side portion, and the shear deformation of the tread portion are expressed by a first order lag response. Here, G ₁ (s), G ₂ (s), and G ₃ (s) in FIG. 7 are expressed by Laplace transform of the transfer function of the first-order lag response, and s is Laplace calculation. Represents a child.
In general, when the delay time constant related to the transient response of the tire is t _x , the delay time constant t _x is often handled in the form of a relaxation length σ _x in consideration of the dependency on the running speed V. The relaxation length σ _x is “a travel distance necessary for the tire to output a steady lateral force with respect to a step input such as a slip angle”, and a transient response at a travel speed V. The delay time constant t _x is expressed by the following equation.
t _x = σ _x (relaxation length) / V (travel speed)
Relaxation lengths σ _s , σ _d , and σ _r are also defined for the delay time constants t _s , t _r , and t _d described above. When the relaxation length and the distance frequency s _v = s / V are used, the transfer function in the block diagram of FIG. 7 can be expressed in the following format excluding the speed dependency.

Other formulas in the model in the present invention can also be expressed by conversion (t _x → σ _x ) in a description format similar to the above.

Note that the lateral force F _ye (t) calculated by the tire dynamic model calculation unit 14 does not necessarily match the lateral force F _y (t). However, since the lateral force F _ye (t) and the lateral force F _y (t) differ only by one time step (difference by a minute time Δt), the difference between them is small and has substantially the same value. I can say that.
In the present embodiment, each of shear deformation of the tread portion, lateral bending deformation of the belt portion, and torsional deformation of the side portion is used as a first-order lag response. However, in the present invention, at least shear deformation of the tread portion is 1 What is necessary is just to use as a next delay response. This is because the delay time constant in the shear deformation of the tread portion is longer than the delay time constant of the lateral bending deformation of the belt portion and the torsional deformation of the side portion, and is a main factor of the cornering transient response of the tire.
Note that linear and nonlinear parameter values including dynamic element parameters used in the tire dynamic model are stored in the memory 21 in advance. The values of these parameters are obtained, for example, using a parameter value derivation method disclosed in JP-A-2005-88832.

FIG. 8 shows a comparison between the lateral force F _y (t) and torque M _z (t) obtained by actual measurement of the tire, and the lateral force F _y (t) and torque M _z (t) calculated by the tire dynamic model. ing. In the example shown in FIGS. 8A to 8C, the slip angle α (t) is applied to the tire (tire size 205 / 55R16 89V) under the conditions of a traveling speed of 80 (km / hour) and a load of 3.9 (kN). Given as time series data, measured data of lateral force F _y (t) and torque M _z (t) as shown in FIGS. 8B and 8C were obtained. The time series data of the lateral force F _y (t) and the torque M _z (t) calculated using the corresponding tire dynamic model are shown in FIGS. 8 (e) and 8 (f). FIG. 8D shows time series data of the slip angle α (t) given to the tire dynamic model.
FIGS. 9A and 9B are graphs representing the measurement data of FIGS. 8A to 8C with the slip angle α (t) taken on the horizontal axis. In the tire dynamic model, only the delay time constant t _s in the shear deformation of the tread portion is used as a transient response (t _s = 0.03 seconds), and the delay time constant of the lateral bending deformation of the belt portion and the torsional deformation of the side portion is used. Was not used. The graphs of the lateral force F _y (t) and torque M _z (t) calculated using the tire dynamic model corresponding to this are shown in FIGS.

Comparing the corresponding graphs of FIGS. 8A to 8F and FIGS. 9A to 9D, the lateral force F _y (t) and torque M _z (t) calculated using the tire dynamic model are compared. Is very close to the actual measurement data, and the time series data of the lateral force F _y (t) and torque M _z (t) of the transient response during cornering are calculated to fit the actual measurement using a tire dynamic model. You can see that you can. In the examples of FIGS. 8D to 8F and FIGS. 9C and 9D, the values of the dynamic element parameters are obtained in advance from the measurement data of the lateral force F _y and the torque M _{z in} the steady state. A thing was used. The value of each dynamic element parameter was obtained using the parameter value derivation method disclosed in JP-A-2005-88832.

Next, a tire dynamic model for calculating the longitudinal force in a transient state during braking / driving will be described.
As shown in FIG. 10, the values of the tire dynamic element parameters including various linear parameters and non-linear parameters configured by combining various spring elements of the tire are set, and the time-series data S of the slip ratio given as input data Using (t), the longitudinal force F _x (t), which is time series data in the equation (14), is calculated according to the equations (10) to (14) in FIG. Yes.
The time series data of the longitudinal force is sequentially calculated by increasing the time by a minute time Δt from t = 0. Here, [1-exp (− (t−t ′) / t _r )] in the equation (11) represents the first order lag response of the shear deformation of the tread portion caused by the given slip rate S (t). Represents a response function to represent.
In addition, the linear parameter in FIG. 10 means the parameter represented by the linear form in Formula (14), and the non-linear parameter is expressed explicitly or implicitly in the non-linear form in Formula (14). Parameter.

The tire dynamic model calculation unit 14 is based on the equation (11) expressed using the response function [1-exp (− (t−t ′) / t _s ) of the first-order lag response, and the deformation slip ratio S _f ( t) is calculated.
In other words, the first-order lag response is due to the first-order lag of the shear deformation in the front-rear direction of the tread portion, and the response function of the first-order lag response that defines the deformation response at this time and the past slip rate S (t). The result of convolution integration with the time variation of the time-series data is defined as a deformation slip ratio S _f (t). This deformation slip ratio S _f (t) acts on the belt portion.

Further, the deflection coefficient q that defines the shape of the ground pressure distribution is calculated from the torque _Mz by the equation (10). As in the tire dynamic model at the time of cornering shown in FIG. 3, the deflection coefficient q is such that the contact pressure distribution in the straight traveling state with the slip ratio S = 0 (see FIG. 5A) is as shown in FIG. 5B. is a parameter representing the shape of the contact pressure distribution of the contact pressure distribution longitudinal force F _x is generated is deflected towards the direction of travel (the leading edge of the ground plane). This contact pressure distribution is represented by p (x) (x is a coordinate position normalized by the contact length when the x axis is taken backward in the traveling direction in FIGS. 5 (a) and 5 (b)). Then, the shape of the ground pressure distribution p (x) is defined by the function D _gsp (x; n, q) represented by the equation (9) in FIG.
Here, the coefficient n in the function D _gsp (x; n, q) defines the contact pressure distribution of the contact surface during the generation of the lateral force. As shown in FIG. It is a coefficient that defines the contact pressure distribution so that it is angular (the curvature increases) near the kicking end. Further, as shown in FIG. 5D, the peak position of the contact pressure distribution is set so as to move toward the stepping-end side as the coefficient q is changed from 0 to 1. Thus, the coefficient q and the coefficient n are shape defining coefficients that define the shape of the contact pressure distribution.

Further, the boundary position (l _h / l) between the sliding friction and the adhesion friction within the contact surface that occurs when the deformation slip ratio S _f (t) is large is calculated from the equation (12). The boundary position (l _h / l) is defined as follows.
FIGS. 11A and 11B are diagrams illustrating the longitudinal force generated in the tire.
As shown in FIG. 11 (a), first, the road surface has a tread portion in contact with the road surface in the ground plane front moves to the ground plane behind the tread speed V _t, which is in contact with the tire during braking, the tread rotational speed in the running speed V _p of the faster tire than the V _t to move to the rear. Tread speed V _t, so speed is slower than the tire running speed V _p, the difference in speed V _p -V _t, the tread portion is subjected to shearing force in the traveling direction rearward toward the rear from the ground plane front. When this shear force is smaller than the adhesion force between the tread and the ground, there is no relative movement between the tread and the ground, and there is a state of adhesion friction, but the shear force exceeds the maximum adhesion friction force. Then, the tread portion starts to move relative to the ground and enters a sliding friction state. The braking force is represented by a friction force obtained by adding the frictional force generated in the contact surface and the frictional force in the sliding region. Further, the braking force coefficient μ is obtained by dividing the total braking force totaled by the tire load.
The maximum adhesion frictional force defines the boundary between adhesion friction and sliding friction and is an important factor characterizing the μ-S curve. As shown in FIG. It can be roughly represented by the product of the contact pressure distribution p (x), which is the distribution of contact pressure in the direction of receiving the braking / driving force, and the adhesion friction coefficient μ _s . The ground pressure distribution p (x) is the same as the ground pressure distribution p (x) shown in FIG.

Thus, the shear forces acting on the tread portion reaches the maximum friction curve gradually increases, the tread portion Suberidashi which was adhesion to the road surface, the coefficient of sliding friction mu _d in contact pressure distribution p (x) The sliding friction force is generated according to the sliding friction curve multiplied by. In FIG. 11 (b), the region on the stepping end side from the boundary position (l _h / l) is an adhesion region where the tire tread member adheres to the road surface, and the region on the kicking side slides the tread portion with respect to the road surface. It becomes a sliding area.

As can be seen from FIG. 11 (b), the ratio between the adhesion area and the slip area varies greatly according to the deformation slip ratio S _f (t). The longitudinal force F _x (t) can be calculated by integrating the frictional force in the adhesion region and the slip region, that is, the longitudinal force component along the tire longitudinal direction.
In Expression (14), the longitudinal force F _x (t) is calculated using the deformation slip ratio S _f (t) separately for the above-mentioned adhesion region and slip region.

Equation (12) calculates the boundary position (l _h / l) between the sliding frictional force and the adhesion frictional force in the contact surface that occurs when the deformation slip ratio S _f (t) is large.
Equation (13) defines the sliding friction coefficient μ _d and is defined to depend on the traveling speed V _p .
In Formula (14), the longitudinal force F _x (t) is represented by the sum of the adhesion friction force and the sliding friction force.
Note that linear and nonlinear parameter values including dynamic element parameters used in the tire dynamic model are stored in the memory 21 in advance. The values of these parameters are obtained, for example, using a parameter value derivation method disclosed in Japanese Patent Application Laid-Open No. 2003-57134.

The calculation results of the longitudinal force F _x (t) calculated by such a tire dynamic model are shown in FIGS. In the example of FIGS. 12A to 12C, the slip rate S (t) is applied to the tire (tire size 205 / 55R16 94V) under the conditions of a traveling speed of 80 (km / hour) and a load of 3.9 (kN). Given as series data, the longitudinal force F _x (t) as shown in FIGS. 12B and 12C is calculated. Delay time constant t _s at this time, it was 0.035 seconds.
FIG. 12A shows the slip ratio S (t) given to the tire dynamic model. The slip rate S (t) shows two types, one based on a sine wave of 0.5 Hz and one based on a sine wave of 2 Hz. FIG. 12B shows a locus when the longitudinal force F _x (t) for 1.5 cycles of the slip rate S (t) by a sine wave of 0.5 Hz is divided by the load F _z (= 3.9 kN). It is a graph showing. FIG. 12B simultaneously shows the longitudinal force F _x in the steady state for comparison. From this, it can be seen that at the slip rate S (t) of 0.5 Hz, the longitudinal force F _x (t) changes from the steady state longitudinal force F _x . FIG. 12C shows a locus when the longitudinal force F _x (t) for 1.5 cycles of the slip rate S (t) by the 2 Hz sine wave is divided by the load F _z (= 3.9 kN). It is a graph. The FIG. 12 (c), the represents the simultaneous longitudinal force F _x in the steady state for comparison. Thus, at a slip rate S (t) of 2 Hz, the longitudinal force F _x (t) changes from the steady state longitudinal force F _x , compared to the longitudinal force at the slip rate S (t) of 0.5 Hz. The change is growing. Thus, it can be seen that in the tire dynamic model, the longitudinal force F _x (t) also changes according to the frequency at which the slip ratio S (t) varies. For each value of each dynamic element parameter of the tire dynamic model, the parameter value deriving method disclosed in Japanese Patent Laid-Open No. 2003-57134 was used.

In this way, as shown in FIG. 3, the tire dynamic model calculation unit 14 gives time series data of the slip angle α (t), whereby the lateral force F _y (t) and the torque M _z (t) are obtained. While calculating the series data, as shown in FIG. 10, the time series data of the longitudinal force F _x (t) is calculated by giving the time series data of the slip ratio S (t). Such time series data of the lateral force F _y (t) and the torque M _z (t) or the time series data of the longitudinal force F _x (t) is obtained from the above-described cornering parameter calculation unit 20 and braking / driving parameter calculation unit 22. , F _y / M _z data calculation unit 24 and F _x data calculation unit 26, and the respective processes are performed.

Next, functions of the cornering parameter calculation unit 20, the braking / driving parameter calculation unit 22, the _Fy / _Mz data calculation unit 24, and the _Fx data calculation unit 26 will be described.
The cornering parameter calculation unit 20 supplies the time-series data of the given slip angle α (t) and the initially set values of the delay time constants t _s , t _r , t _d to the tire dynamic model calculation unit 14. The tire dynamic model calculation unit 14 uses the supplied slip angle α (t), the initial set values of the delay time constants t _s , t _r , and t _d and the values of the parameters called from the memory 21. Then, the time series data of the lateral force F _y (t) and the torque M _z (t) is calculated according to the equations (1) to (8) shown in FIG. 3, and this time series data is returned to the cornering parameter calculation unit 20. The cornering parameter calculation unit 20 measures the lateral force F _y (t) and torque M _z (t) time series data calculated by the tire dynamic model calculation unit 14 separately and stores the lateral force F _y in the memory 21 separately. (t), compared with measured data of torque M _z (t), that is, calculated lateral force F _y (t), torque M _z (t), measured lateral force F _y (t), torque M _z When the square residual sum of (t) is obtained and this square residual sum is not smaller than a predetermined value, the initial set values of the delay time constants t _s , t _r , t _d are corrected, and the corrected values are The slip angle α (t) is supplied to the tire dynamic model calculation unit 14, and the calculation of the lateral force F _y (t) and the torque M _z (t) is repeated. Thus, the values of the delay time constants t _s , t _r , and t _d are corrected until the sum of squared residuals becomes smaller than the predetermined value and becomes the minimum. Then, the value of the delay time constant when the sum of squared residuals is minimized is determined as the value of the delay time constant that determines the first-order lag response.
In this way, the cornering parameter calculation unit 20 determines the value of the delay time constant.
The square residual sum calculated for the value of the delay time constant may be calculated using only the lateral force F _y (t) or may be calculated using only the torque M _z (t). It may be calculated using the lateral force F _y (t) and the torque M _z (t).

Braking drive parameter calculation section 22 supplies the initial value set as the index given slip S (t) and the delayed time constant t _s to the tire dynamic model computing section 14. In the tire dynamic model computing section 14, by using the values of the parameters invoked from the supplied slip ratio S (t) and delay time (t _s) and the memory 21, the formula (10) shown in FIGS. 10 to (14 ) To calculate the time series data of the longitudinal force F _x (t), and this time series data is returned to the braking / driving parameter calculation unit 22. Braking-driving parameter calculating section 22, tire dynamic time-series data of the model calculation unit 14 longitudinal force calculated in F _x (t) is the longitudinal force stored in the memory 21 obtained by separately measured tire F _x (t ), That is, a square residual sum of the calculated longitudinal force F _x (t) and the actually measured longitudinal force F _x (t) is obtained, and this square residual sum is smaller than a predetermined value. If not, modify the initial setting value of the delay time constant t _s, again, the calculation of the longitudinal force and the values obtained by correcting the tire dynamic model computing section 14 and the slip ratio S (t) is supplied F _x (t) is repeated It is. Thus, the value of the delay time constant t _s is corrected until the sum of squared residuals becomes smaller than the predetermined value and becomes the minimum. Then, the value of the delay time constant t _s when the sum of squared residuals becomes minimum is determined as the value of primary delay of the delay time constant defining the response.
In this way, the braking / driving parameter calculation unit 22 determines the value of the delay time constant.

Note that the cornering parameter calculation unit 20 and the braking / driving parameter calculation unit 22 both use the lateral force F _y (t), the values of the known steady-state linear parameters and nonlinear parameters in the tire dynamic model. The value of the delay time constant is determined by calculating the torque M _z (t) and the longitudinal force F _x (t). In the present invention, at least some values of the linear parameter or the nonlinear parameter are unknown, The value may be determined together with the value of the delay time constant.

The F _y / M _z data calculation unit 24 supplies time series data of the slip angle α (t) to the tire dynamic model calculation unit 14, whereby each tire dynamic model calculation unit 14 stores each memory 21. The lateral force F _y (t) and torque M _z (t) are calculated using the values of the parameters and the delay time constants t _s , t _r , t _d , and this data is used for the transient side force during cornering. This is a portion of time series data of F _y (t) and torque M _z (t).
The F _x data calculation unit 26 supplies the time series data of the slip ratio S (t) to the tire dynamic model calculation unit 14, whereby the parameter values stored in the memory 21 are stored in the tire dynamic model calculation unit 14. And the value of the delay time constant t _s are used to calculate the longitudinal force F _x (t), and this data is used as time-series data of the transient longitudinal force F _x (t) during braking / driving. .
The above description is the description of the configuration of the arithmetic device 10.

FIG. 13 shows a calculation method of tire transient response data, that is, the time series data of the lateral force F _y (t) and torque M _z (t) during cornering, or the longitudinal force F _x (t) during braking / driving. It is a flowchart which shows the flow which calculates time series data. Hereinafter, the calculation of the time series data of the lateral force F _y (t) and the torque M _z (t) during cornering will be mainly described, and the calculation of the time series data of the longitudinal force F _x (t) during braking / driving will be described. , ().

First, the slip angle α (t) (slip rate S (t)) is set by the F _y / M _z data calculation unit 24 (F _x data calculation unit 26) (step S10). The setting of the slip angle α (t) (slip rate S (t)) may be input by an input operation system such as a mouse or a keyboard connected to the arithmetic device 10, or may be created by the arithmetic device 10. . It may also be input from a connected external device. For example, time series data of the slip angle α (t) as shown in FIG. 8D is set. The time series data is supplied to the tire dynamic model calculation unit 14.

In the tire dynamic model calculation unit 14, the values of the nonlinear parameters including the values of the linear parameters used for the tire dynamic model and the values of the delay time constant stored in the memory 21 are called up as the parameter values of the tire dynamic model. Obtained (step S20).
Further, the tire dynamic model calculation unit 14 uses the values of these parameters together with the supplied slip angle α (t) (slip rate S (t)) to obtain equations (1) to (8) (equation (10 ) To (14)), time series data of the lateral force F _y (t) and the torque M _z (t) (front / rear force F _x (t)) are calculated (step S30). The time series data of the lateral force F _y (t) and the torque M _z (t) (front / rear force F _x (t)) calculated by the tire dynamic model calculation unit 14 is F _y / M _z data calculation unit 24 ( The data is returned to the F _x data calculation unit 26) and is made time-series data during cornering (braking / braking).

In the present invention, the response function of the first-order lag response used in the tire dynamic model is [1-exp (− (t−t ′) / t _r )], [1-exp (− (t−t ′) / t]. _s )], [1-exp (− (t−t ′) / t _d )], and these response functions are expressed as torque M _z (t), effective slip angle α _e (t), and lateral force F. It is characterized in that it is used in a tire dynamic model by convolution integration with the time variation of time series data of _y (t). By this convolution integration, a slip angle (slip ratio) during cornering (braking / braking) forms a gently changing curve, and as shown in FIG. 8, time-series data that substantially matches actual measurement data can be calculated. it can. FIG. 14A shows an example in which the effective slip angle α _e (t) is a step function. At this time, a deformed slip angle α _f (t) representing a gently changing curve as shown in FIG. 14B is generated by convolution integration of the time variation of the response function and the time series data.

  FIG. 15 is a flowchart showing an example of the data processing method of the present invention. This data processing method determines the value of the delay time constant of the response function that defines the transient response during cornering or braking / driving. Hereinafter, the determination of the delay time constant in the first-order lag response during cornering will be mainly described, and the determination of the delay time constant in the first-order lag response during braking / driving will be described in parentheses.

First, the time-series data of the slip angle α (t) (slip rate S (t)) is set by the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22) (step S110). The setting of the slip angle α (t) (slip rate S (t)) may be input by an input operation system such as a mouse or a keyboard connected to the arithmetic device 10, or may be created by the arithmetic device 10. . It may also be input from a connected external device. For example, time series data of the slip angle α (t) as shown in FIG. 8D is set. The time series data is supplied to the tire dynamic model calculation unit 14.
The time-series data of the set slip angle α (t) (slip rate S (t)) is supplied to a tire dynamic characteristic tester (not shown), and the supplied slip angle α (t) (slip rate S (t) )) Tires are tested based on time series data. Accordingly, the tire is actually measured, and measurement data of the lateral force F _y (t) and the torque M _z (t) (front / rear force F _x (t)) in the transient state is acquired (step S120). The acquired measurement data is supplied to the arithmetic unit 10 and stored in the memory 21.

Next, in the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22), the values of the linear parameter and the non-linear parameter stored in the memory 21 are called up and acquired as parameters used for the tire dynamic model (step). S130).
Next, in the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22), delay time constants t _r , t _s , t _d (delay time constant t _s ) that define the response function of the first-order lag response of the tire are obtained. Initially set to a predetermined value, for example, 0.02 seconds (step S140). In FIG. 15, the delay time constant is indicated as a relaxation time constant.
Thereafter, the initial set values of the delay time constants t _r , t _s , t _d (delay time constant t _s ) set by the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22), and the set slip angle Time series data of α (t) (slip rate S (t)) is supplied to the tire dynamic model calculation unit 14.

In the tire dynamic model calculation unit 14, the values of nonlinear parameters excluding the linear parameters and the delay time constant stored in the memory 21 are called, and the values of these parameters and the delay time constant are supplied as the supplied slip angle α ( t) Used along with time-series data of (slip rate S (t)), according to the equations (1) to (8) (equations (10) to (14)), the lateral force F _y (t) and the torque M _z (t) Time-series data of (front / rear force F _x (t)) is calculated (step S150).

The calculated lateral force F _y (t) and torque M _z (t) (front / rear force F _x (t)) are returned to the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22) and measured in step S120. Then, the measurement data of the lateral force F _y (t) and the torque M _z (t) (longitudinal force F _x (t)) stored in the memory 21 is called and the calculated lateral force F _y (t) and the torque M _z are calculated. (t) The sum of squared residuals is calculated with respect to the time series data of (front / rear force F _x (t)) (step S160). The sum of squared residuals is obtained by calculating the difference of the lateral force F _y (t) and the difference of the torque M _z (t) at the same time of the time series data, and adding the squared difference. Therefore, when the sum of squared residuals becomes smaller than a predetermined value close to 0, it can be said that the calculated time series data of the lateral force F _y (t) and the torque M _z (t) substantially coincide with the actually measured measurement data.

Therefore, it is determined whether or not the square residual sum is smaller than a predetermined value and the square residual sum is minimum (step S170).
If the result of the determination is negative, the set values of the delay time constants t _r , t _s and t _d (delay time constant t _s ) are corrected (step S180). If the result of determination is affirmative, the set value of the delay time constant is determined as the delay time constant of the response function representing the first-order delay response (step S190). The method of minimizing the sum of squared residuals is not particularly limited, and can be performed using, for example, a Newton-Raphson method nonlinear least square regression algorithm.
As described above, the time series data of the slip angle (slip rate) is given to the tire as a measurement condition, and the measurement data of the transient state during cornering (braking / braking) of the tire is acquired in advance, while the delay time constant is initialized. Thereafter, calculation is performed to calculate the lateral force F _y (t) and the torque M _z (t) (the longitudinal force F _x (t)) using the tire dynamic model. Then, the square residual sum of the measured data of the previous tire and the calculated time series data is obtained, and the above calculation is repeated by correcting the value of the delay time constant until the square residual sum is minimized. The set value of the delay time constant when the sum is minimized is determined as the value of the delay time constant that determines the first-order delay response. At this time, the values of the linear parameters used in the tire dynamic model and the values of the nonlinear parameters excluding the delay time constant are calculated using the steady-state lateral force F _y and torque M _z (longitudinal force F _x ). Since the delay time constant in the transient response can be determined using the value of the tire dynamic element parameter in the steady state, the delay time constant can be determined efficiently.

In the present invention, the value of the delay time constant can be determined by the following method in addition to the flow shown in FIG. FIG. 16 is a flowchart when the value of the delay time constant is determined by a method different from the method shown in FIG. FIGS. 17A to 17D are graphs for explaining the data processing method.
The following explanation explains the transient response data during cornering when the time series data of the slip angle is given to the tire dynamic model, but also the transient response during braking / driving when the time series data of the slip ratio is given. The same can be explained. In the following, the transient response during cornering will be mainly described, and the transient response during braking / driving will be described in parentheses. That is, in the data processing method described below, the deformation response of the tread portion that defines a transient response during cornering (braking / braking) in a tire dynamic model configured using a plurality of tire dynamic element parameters is defined as a first-order lag response. Then, the value of the transient response parameter that determines this first-order lag response is calculated.

First, the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22) reciprocates the slip angle (slip rate) including a range between at least 0 degrees and a predetermined angle (0 and a predetermined slip rate). The time-series data of the slip angle (slip rate) that changes in step S210 is set. For example, as shown in FIG. 17A, the time series data of the slip angle in which the slip angle reciprocates between −20 degrees and +20 degrees is set.
Next, the time series data of the set slip angle α (t) (slip rate S (t)) is given to the tire as measurement conditions to measure transient response data during tire cornering (braking / braking). Measurement data of the lateral force F _y (t) or torque M _z (t) (front / rear force F _x (t)) is acquired in advance (step S220). For example, measurement data of actual lateral force F _y (t) as shown in FIG. 17B is acquired. The actual measurement of the tire was performed on tires having a tire size of 205 / 55R16 89V under measurement conditions of a load of 3.9 (kN) and a traveling speed of 80 (km / hour).

While measuring transient response data during cornering (braking / braking), the initial value of the delay time constant of the first-order delay deformation response (hereinafter, this constant is referred to as t ₁ ) used in the tire dynamic model is used. The response function of the first order lag response is set (step S240). In FIG. 16, the delay time constant is referred to as a relaxation time constant.

Next, the tire dynamic model calculation unit 14 performs a convolution integral of the determined first-order lag response function and the time variation of the time-series data of the slip angle (slip ratio) given to the tire as a measurement condition, to thereby calculate the tire dynamics. The deformation slip angle α ′ (t) (deformation slip ratio S ′ (t)), which is time series data of the transient response of the slip angle (slip ratio) in the tread portion with respect to the road surface in the model, is expressed by the following equation (20) (−C = It is calculated according to t ₁₎ (step S250).
The value of the time series data of the transient response of the calculated deformation slip angle α ′ (t) (deformation slip ratio S ′ (t)) is returned to the cornering parameter calculation unit 20 (braking / driving parameter calculation unit 22). The value of the time series data of the transient response, the value of the time series data of the transient response of the deformation slip angle α ′ (t) (the deformation slip ratio S ′ (t)), and the measured lateral force F _y acquired in step S120. A characteristic curve represented by (t) or torque M _z (t) (longitudinal force F _x (t)) is created. The characteristic curve is a curve when the horizontal axis represents the slip angle (slip rate) and the vertical axis represents the lateral force or torque (front / rear force). The graph shown in FIG. 17C is created using the measured data value of the measured lateral force F _y (t) shown in FIG. 17B and the time-series data value of the transient response of the slip angle. It is a characteristic curve. Here, C in the equation (20) is a delay time constant t ₁ of the first-order delay deformation response in the entire tire described above.

Next, the characteristic curve is subjected to least square regression to one smooth curve using a smooth curve function, for example, a spline function, and the least squares regression curve obtained by least square regression at that time and the squared residual sum of the characteristic curve Is calculated (step S260).
Next, it is determined whether or not the calculated square residual sum is smaller than a predetermined value and minimized (step S270). If the calculated square residual sum is not the smallest, the set delay time constant t _{1 is determined.} The first order lag response function is corrected (step S280), and steps S250 and 260 are repeated. Then, the value of the delay time constant t ₁ when the sum of squared residuals is minimized is determined as the value of the delay time constant t ₁ that determines the first-order lag response (step S290).

Thus, the reason for determining the value of the delay time constant t ₁ so that the sum of squared residuals is minimized is as follows. As shown in FIG. 17C, in the transient state, the value of the lateral force differs depending on whether the slip angle increases or decreases. This is because, for the given slip angle (slip rate), the first-order lag deformation of the tread part, belt part and side part according to the past history of the slip angle (slip ratio) causes an actual transient response. This is because the slip angle (slip rate) is different. Therefore, if a characteristic curve is created by replacing the given slip angle (slip rate) with the slip angle (slip rate) at the time of transient response, the same lateral force (front-rear force) is obtained when the slip angle increases and decreases. That is, a characteristic curve such as a lateral force (front / rear force) with respect to a slip angle in a steady state. Therefore, the delay time constant is set so that the sum of squared residuals is minimized when a transient characteristic curve with different values as the slip angle (slip rate) increases or decreases is represented by one smooth curve. Search while correcting the value of t ₁ . The value of the delay time constant t ₁ at this time can be corrected using, for example, a Newton-Raphson method nonlinear least square regression algorithm. FIG. 17D shows an example of a smooth characteristic curve created using the determined delay time constant value. This characteristic curve corresponds to a lateral force characteristic curve in a steady state.
In this way, it is possible to search and determine the delay time constant that minimizes the residual sum of squares.

Further, in the present invention, the time series data of the lateral force F _y (t) and the torque M _z (t) during cornering or the time series data of the longitudinal force F _x (t) during braking / driving is calculated in FIG. Instead of the calculation method of the transient response data of the tire shown, the lateral force F _y (t) during cornering, the time series data of torque M _z (t), or the longitudinal force F _x (t ) Time-series data can also be calculated.
FIG. 18 is a flowchart showing a flow of a method for calculating transient response data of a tire different from the method shown in FIG. That is, FIG. 18 shows a tire transient during cornering (braking / braking) when a slip angle (slip rate) is given as time series data based on a tire dynamic model configured using a plurality of tire dynamic element parameters. It is a flowchart which shows the flow which calculates response data.

First, the time series data of the slip angle α (t) (slip rate S (t)) at which the slip angle changes including at least a range between 0 degrees and a predetermined angle is set (step S310). Next, the lateral force F _y or torque M in the steady state when the set slip angle α (t) (slip rate S (t)) is given to the tire as the steady state slip angle α (slip rate S). The value of _z (front / rear force F _x ) is acquired in advance by actual measurement of the tire (step S320). Measurement data obtained by this actual measurement is stored in the memory 21 of the arithmetic unit 10 via the data input unit 12.

Next, the value of the delay time constant is called from the memory 21, and a response function of a first-order lag response that defines the deformation response of the tread portion during cornering (braking / braking) is set. The value of the delay time constant called from the memory 21 includes a delay time constant t ₁ of a response function that defines a first-order delay deformation response in the entire tire. The above equation (20), where the convolution integral of the set response function and the time variation of the time series data of the set slip angle α (t) (slip rate S (t)) is the delay time constant C = t ₁ ), The time series data of the transient response of the deformation slip angle α ′ (t) (deformation slip ratio S ′ (t)) in the tread portion with respect to the road surface is calculated (step 330).

Next, the time-series data of the steady-state lateral force or self-aligning torque corresponding to the value of the time-series data of the transient state of the calculated deformation slip angle α ′ (t) (deformation slip ratio S ′ (t)). By calculating the value, the lateral force or torque (front / rear force) in the transient state is calculated (step S340).
In the method for calculating the transient response, the values of the lateral force and torque (front / rear force) in the transient state are corrected not by the actually applied slip angle (slip rate) but by the deformation of the primary delay of the tread portion. This is because it is considered to be based on the deformation slip angle (deformation slip ratio). By using this method, the lateral force and torque (front / rear force) of the side force and torque (front / rear force) can be simply and in a short time using the data of steady state lateral force and torque (front / rear force) and the deformation slip angle (deformation slip ratio). Transient time series data can be calculated.

As described above, the linear parameter value and the nonlinear parameter value including the delay time constant in the tire dynamic model are calculated, and these values are associated with each type of tire component, that is, the type of tire component Accordingly, a table can be prepared in advance so that a linear parameter value and a nonlinear parameter value including a delay time constant can be derived, and a tire design method as described below can be performed.
That is, the tire transient response data (lateral force, torque, longitudinal force data) is output using the tire transient response data calculation method described above, and the output data at this time achieves the set target condition. When not, for example, when the target data does not match within the allowable error, the type of the tire constituent member that determines the value of the linear parameter and the value of the nonlinear parameter including the delay time constant is changed. In this way, the linear parameter value and the nonlinear parameter value including the delay time constant are changed according to the changed type of the tire component, and the tire transient response data is repeatedly calculated and output. When the output data achieves the target condition, the type of the tire constituent member at this time is determined as the target tire constituent member. Thereby, the tire which achieves a desired target condition can be designed.

  Further, by using the tire transient response data calculation method described above, tire transient response data is calculated and output. The tire transient response data is given to the vehicle model on which the tire is mounted, and the vehicle model vehicle By predicting the motion, a simulation calculation of the motion behavior of the vehicle can be performed.

In the above data processing method, the delay time constant of the first-order lag at the time of cornering and the delay time constant of the first-order lag at the time of braking / driving are determined separately. in addition capable of simultaneously determining the delay time constant of the primary delay, cornering, distinguished without delay time constant t _r during braking and driving, t _s, it is possible to determine the value of t _d.
Similarly, the time series data of the lateral force, torque and longitudinal force when the slip angle and the slip ratio are given at the same time can be calculated simultaneously.
Further, in the above data processing method, the value of the delay time constant of the first-order lag at the time of cornering or the value of the delay time constant of the first-order lag at the time of braking / driving is determined using the measurement data in the tire transient state. The target to be expanded may be expanded and the values of some of the linear parameters or nonlinear parameters shown in FIG. 3 and FIG. 10 may be determined together with the delay time constant.

  As described above, the tire transient response data calculation method, data processing method, tire design method, and vehicle motion prediction method of the present invention have been described in detail. However, the present invention is not limited to the above embodiment, and the gist of the present invention is described. Of course, various improvements and modifications may be made without departing from the scope. For example, in the above description, the behavior of the transient response during cornering and the behavior of the transient response during braking / driving are described as separate models, but these behaviors are integrated, that is, braking / driving during cornering is integrated. Lateral force, torque, and longitudinal force can be calculated using a model that reproduces the behavior of the vehicle and the behavior caused by steering during braking / driving, and the value of the delay time constant can also be calculated.

It is a block diagram of the arithmetic unit of one Example which implements the calculation method of the transient response data of the tire of this invention, and a data processing method. It is a figure explaining the tire dynamic model used in the calculation method of the transient response data of the tire of the present invention, and the data processing method. It is a figure explaining the tire dynamic model in cornering used in the calculation method of the transient response data of the tire of the present invention, and the data processing method. (A)-(c) is a figure explaining the tire dynamic model used in the calculation method of the transient response data of the tire of this invention, and a data processing method. (A)-(d) is a figure explaining the tire dynamic model used in the calculation method of the transient response data of the tire of this invention, and a data processing method. (A)-(c) is a figure explaining the tire dynamic model used in the calculation method of the transient response data of the tire of this invention, and a data processing method. It is a figure explaining the relationship between the deformation | transformation of each tire part, lateral force, and torque in the tire dynamic model used in the calculation method of the transient response data of the tire of this invention, and a data processing method. (A) to (c) are examples of time-series data obtained by actual measurement of tires, and (d) to (f) are obtained by the tire transient response data calculation method of the present invention. It is a figure which shows the time series data corresponding to each of ()-(c). (A), (b) is an example of measurement data obtained by actual measurement of a tire, and (c), (d) are obtained by the method for calculating transient response data of a tire according to the present invention, (a) , (B) is a figure which shows the data corresponding to each. It is a figure explaining the tire dynamic model under braking / driving used in the calculation method and the data processing method of the transient response data of the tire of the present invention. (A), (b) is a figure explaining generation | occurrence | production of the longitudinal force during the braking / driving of a tire. (A)-(c) is a figure which shows the result obtained by the calculation method of the transient response data of a tire. It is a flowchart which shows the flow of an example of the calculation method of the transient response data of the tire of this invention. (A), (b) is a figure explaining the transient response of the slip angle used in the calculation method of the transient response data of the tire of this invention. It is a flowchart which shows the flow of an example of the data processing method of this invention. It is a flowchart which shows the flow of the other example of the data processing method of this invention. (A)-(d) is a figure which shows the graph obtained by the method shown in FIG. It is a flowchart which shows the flow of the other example of the calculation method of the transient response data of the tire of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Calculation apparatus 12 Data input part 14 Tire dynamic model calculation part 16 Processing part 18 Output part 20 Cornering parameter calculation part 21 Memory 22 _Braking / driving parameter calculation part 24 _Fy / _Mz data calculation part 26 _Fx data calculation part

Claims (14)

A tire transient response data calculation method for calculating tire transient response data during cornering when a slip angle is given as time-series data based on a tire dynamic model composed of a plurality of tire dynamic element parameters. There,
Obtaining a value of the tire dynamic element parameter constituting the tire dynamic model;
The convolution integration of the response function of the first-order lag response that defines the deformation response of the tread part during cornering and the time variation of the time series data of the slip angle given to the tire dynamic model is performed, and the tread part of the tire dynamic model is Calculate the time series data of the transient response of the slip angle to the road surface,
Output data of at least one of lateral force and self-aligning torque calculated by the tire dynamic model based on time series data of the transient response of the slip angle is calculated as transient response data during cornering. Calculation method of tire transient response data.   The time-series data of the slip angle given to the tire dynamic model is corrected by the torsional deformation of the tire generated according to the self-aligning torque, and the corrected time-series data is converted into the time of the transient response of the slip angle. The tire transient response data calculation method according to claim 1, which is used when calculating the series data.   The torsional deformation of the tire that occurs in response to the self-aligning torque includes the response function of the first-order lag response that defines the deformation response of the side portion during cornering and the time of past time-series data of the self-aligning torque. The method of calculating tire transient response data according to claim 2, wherein the convolution integral with the amount of change is expressed by dividing by a value of torsional rigidity in the tire dynamic model.   The output data calculated using the tire dynamic model is data of lateral force corrected by lateral bending deformation of a belt portion generated according to lateral force. To calculate transient response data for tires in Japan.   The lateral bending deformation of the belt portion that occurs in response to the lateral force includes a response function of a first-order lag response that defines the deformation response of the belt portion during cornering, and a temporal change amount of past time-series data of the generated lateral force. The method for calculating tire transient response data according to claim 4, which is expressed by performing convolution integration of the tire. A tire transient response data calculation method for calculating tire transient response data during cornering when a slip angle is given as time-series data based on a tire dynamic model composed of a plurality of tire dynamic element parameters. There,
Slip angle time-series data that changes over a range between at least 0 degrees and a predetermined angle is given to the tire as a steady-state slip angle, and the lateral force and self-alignment in the steady state are measured by measuring the tire. Obtain the torque value in advance,
The convolution integration of the response function of the first-order lag response that defines the deformation response of the tread part during cornering and the time variation of the time series data of the slip angle applied to the tire is performed, and the tread part with respect to the road surface in the tire dynamic model Calculate the time series data of the transient response of the slip angle at
By obtaining the value of the steady-state side force or self-aligning torque corresponding to the calculated value of the time-series data of the transient response of the slip angle, the time-series data of the transient side force or self-aligning torque is obtained. A method for calculating tire transient response data, characterized by calculating as transient response data during cornering. The deformation response of the tread that defines the transient response during cornering in a tire dynamic model composed of a plurality of tire dynamic element parameters is defined as a first-order lag response, and the value of the transient response parameter that defines this first-order lag response is calculated. A data processing method for
The time series data of the slip angle is given to the tire as a measurement condition to obtain in advance the measurement data of the transient response during the cornering of the tire,
Initializing the value of the transient response parameter to determine a response function of the first order lag response;
A slip angle with respect to the road surface in the tread portion of the tire dynamic model is obtained by performing convolution integration between the determined response function of the first-order lag response and the time change amount of the time series data of the slip angle given as a measurement condition to the tire. The time series data of the transient response is obtained, and the value of the lateral force or the cell aligning torque is calculated from the tire dynamic model based on the time series data of the transient response of the slip angle thus obtained, and the transient state during cornering is calculated. Reproduction calculation to calculate the time series data of lateral force or self-aligning torque of
Obtain the squared residual sum of the time series data of the calculated lateral force or self-aligning torque and the measured data of the tire, and set the value of the set transient response parameter until the squared residual sum is minimized. The correction calculation is repeated, and the value of the transient response parameter when the sum of squared residuals is minimized is determined as the value of the transient response parameter that determines the first-order lag response. Processing method. Data processing for calculating a value of a transient response parameter that defines the first order lag response as a deformation response of a tread portion that defines a transient response during cornering in a tire dynamic model configured using the transient response parameter A method,
Preliminary measurement data of transient response during tire cornering is given to tires as time-series data of slip angles that change by reciprocating slip angles including a range between at least 0 degrees and a predetermined angle. Aside,
Initializing the value of the transient response parameter to determine a response function of the first order lag response;
The convolution integration of the response function of the first-order lag and the time change amount of the time series data of the slip angle given as the measurement condition to the tire is performed, and the transient response of the slip angle in the tread portion with respect to the road surface in the tire dynamic model is obtained. Time-series data is obtained, and a characteristic curve representing the value of the lateral force or self-aligning torque with respect to the value of the time-series data of the transient response of the obtained slip angle is obtained by using a curve function to form a least square in a smooth curve. Regression is performed, and a regression calculation is performed to find the sum of squared residuals of the least-squares regression curve and the characteristic curve obtained by least-squares regression.
Until the calculated residual sum of squares is minimized, the value of the set transient response parameter is corrected and the regression calculation is repeated, and the value of the transient response parameter when the sum of squared residuals is minimized Is determined as a value of a transient response parameter that determines the first-order lag response. Based on a tire dynamic model composed of multiple tire dynamic element parameters, tire transient response is calculated by calculating the transient response data of the braking / driving tire when the slip ratio is given as time series data in the tire longitudinal direction A method for calculating data,
Obtaining a value of the tire dynamic element parameter constituting the tire dynamic model;
The tread part of the tire dynamic model is obtained by convolving the response function of the first-order lag response that defines the deformation response of the tread during braking and the time variation of the time series data of the slip ratio given to the tire dynamic model. Calculate the time series data of the transient response of the slip ratio to the road surface at
Output data of longitudinal force calculated by the tire dynamic model based on time series data of the transient response of the slip ratio is calculated as transient response data during the braking / driving operation. Calculation method. Based on a tire dynamic model composed of multiple tire dynamic element parameters, tire transient response is calculated by calculating the tire transient response data during braking / driving when the tire longitudinal slip ratio is given as time series data. A method for calculating data,
The value of the longitudinal force in the steady state when the time series data of the slip ratio changing including the range between at least 0 degree and the predetermined slip ratio is given as the steady state slip ratio is obtained in advance by actual measurement of the tire. Aside,
The convolution of the response function of the first-order lag response that defines the deformation response of the tread part during braking and the time variation of the time series data of the slip ratio is performed, and the slip ratio in the tread part with respect to the road surface in the tire dynamic model Calculate the time series data of the transient response of
By calculating the steady state longitudinal force value corresponding to the calculated transient response time series data value of the slip ratio, the transient longitudinal force time series data is used as transient response data during braking / driving. A calculation method of transient response data of a tire, characterized by calculating. The deformation response of the tread that defines the transient response during braking / driving of the tire in the tire dynamic model configured using the transient response parameter is defined as the first-order lag response, and the value of the transient response parameter that defines this first-order lag response is calculated. A data processing method for
Measurement data of the transient response during braking / driving of the tire is given to the tire as time series data of the slip ratio in which the slip ratio reciprocates and includes a range between at least 0 degrees and a predetermined slip ratio. Obtain in advance,
Initializing the value of the transient response parameter to determine a response function of the first order lag response;
The convolution integration of the response function of the first-order lag and the time change amount of the time series data of the slip ratio given to the tire as a measurement condition is performed, and the transient response of the slip ratio in the tread portion with respect to the road surface in the tire dynamic model Time series data is obtained, and a characteristic curve representing the value of the longitudinal force with respect to the value of the time series data of the transient response of the obtained slip angle is subjected to least square regression to one smooth curve using a curve function, Perform a regression calculation to find the squared residual sum of the least squares regression curve and the characteristic curve
Until the calculated residual sum of squares is minimized, the value of the set transient response parameter is corrected and the regression calculation is repeated, and the value of the transient response parameter when the sum of squared residuals is minimized Is determined as a value of a transient response parameter that determines the first-order lag response. The deformation response of the tread that defines the transient response during braking / driving in a tire dynamic model configured using a plurality of tire dynamic element parameters is defined as a first-order lag response, and the value of the transient response parameter that defines this first-order lag response is A data processing method to calculate,
The measurement data of the transient response during the braking drive of the tire is obtained in advance by giving the tire the time series data of the slip ratio in the tire longitudinal direction as a measurement condition,
Initializing the value of the transient response parameter to determine a response function of the first order lag response;
A transient response of the slip ratio in the tread portion with respect to the road surface in the tire dynamic model is performed by performing convolution integration between the determined first-order delay response function and the time change amount of the time series data of the slip ratio given as a measurement condition to the tire. Time series data is calculated, and the longitudinal force is calculated from the tire dynamic model based on the value of the time series data of the transient response of the obtained slip ratio, and the time series data of the longitudinal force in the transient state during braking / driving Perform a reproduction calculation to calculate
The square residual sum of the calculated time series data of the longitudinal force and the measurement data of the tire is obtained, and the value of the set transient response parameter is corrected until the square residual sum is minimized, and the reproduction is performed. A data processing method, characterized in that the calculation is repeated and the value of the transient response parameter when the sum of squared residuals is minimized is determined as the value of the transient response parameter that determines the first-order lag response. Using the tire transient response data calculation method according to any one of claims 1 to 6, claim 9, and claim 10, the tire transient response data is calculated and output,
The tire dynamic element parameter value and the first order lag response are adjusted by adjusting the tire structural element parameter or the tire constituent member that defines the first order lag response until the output transient response data satisfies the set target condition. The value of the transient response parameter that determines the
When the output data satisfies a target condition, the tire constituent member at this time is determined as the target tire constituent member. Using the tire transient response data calculation method according to any one of claims 1 to 6, claim 9, and claim 10, the tire transient response data is calculated and output,
A vehicle motion prediction method for predicting vehicle motion by a vehicle model by providing the output transient response data to an axle portion of the vehicle model.

Images