sdlUtility.tirread

Import TIR file to Tire (Magic Formula) block

Since R2022b

Syntax

tireParameters = sdlUtility.tirread(fileName)

sdlUtility.tirread(block,tireParameters)

Description

tireParameters = sdlUtility.tirread(fileName) returns the tire parameters for the TIR file, fileName. The function saves only the information required to parameterize the Tire (Magic Formula) block.

sdlUtility.tirread(block,tireParameters) applies the tire parameters from tireParameters to the specified Tire (Magic Formula) block.

Examples

Generate Tire Parameters from TIR File

This example shows how to import a TIR file called sample_tire_245_60_R16.tir and save the relevant tire parameters as a workspace variable called STire. Once you have the parameters saved to the workspace, you can apply the tire parameters to a Tire (Magic Formula) block.

Suppose you have a file named sample_tire_245_60_R16.tir. To generate the tire parameters for the file, enter:

STire = sdlUtility.tirread('sample_tire_245_60_R16.tir')

STire = 

  struct with fields:

                        UNITS: [1×1 struct]
                        MODEL: [1×1 struct]
                    DIMENSION: [1×1 struct]
         OPERATING_CONDITIONS: [1×1 struct]
                      INERTIA: [1×1 struct]
         ROLLING_COEFFICIENTS: [1×1 struct]
                     VERTICAL: [1×1 struct]
                   STRUCTURAL: [1×1 struct]
    LONGITUDINAL_COEFFICIENTS: [1×1 struct]
              LONG_SLIP_RANGE: [1×1 struct]
         SCALING_COEFFICIENTS: [1×1 struct]

Apply Tire Parameters to Block

This example shows how to apply tire parameters in a TIR file to the left tire in the VehicleWithFourSpeedTransmission model.

Suppose you have a file named sample_tire_245_60_R16.tir. To generate the tire parameters for the file, enter:

STire = sdlUtility.tirread('sample_tire_245_60_R16.tir')

STire = 

  struct with fields:

                        UNITS: [1×1 struct]
                        MODEL: [1×1 struct]
                    DIMENSION: [1×1 struct]
         OPERATING_CONDITIONS: [1×1 struct]
                      INERTIA: [1×1 struct]
         ROLLING_COEFFICIENTS: [1×1 struct]
                     VERTICAL: [1×1 struct]
                   STRUCTURAL: [1×1 struct]
    LONGITUDINAL_COEFFICIENTS: [1×1 struct]
              LONG_SLIP_RANGE: [1×1 struct]
         SCALING_COEFFICIENTS: [1×1 struct]

Determine the path of the tire. The tires are part of the Vehicle Body subsystem. To parameterize the left tire using the workspace variable STire, enter:

sdlUtility.tirread('VehicleWithFourSpeedTransmission/Vehicle Body/Tire Left', STire);

Open the Tire Left block. The block uses the parameters in the STire structure array.

Input Arguments

fileName — TIR file name

character vector | string scalar

TIR file name, specified as a character vector or string scalar.

Data Types: char | string

block — Tire (Magic Formula) block to parameterize

character vector | string scalar

Tire (Magic Formula) block to parameterize, specified as a character vector or string scalar. You can specify the block path or use the block handle.

Data Types: char | string

tireParameters — Structure array that contains tire parameters

string scalar

Structure array that contains the tire parameters, specified as a string scalar. The function reduces the parameters to only what the Tire (Magic Formula) block requires.

Data Types: struct

Output Arguments

tireParameters — Structure array that contains tire parameters

structure

Structure array variable that contains the tire parameters, specified as a structure. The structure contains only the parameters needed to parameterize the Tire (Magic Formula) block.

Data Types: struct

Limitations

• The TIR file must be in the standard format.

• The TIR file must list the units in meters, Newtons, kilograms, and seconds.

• The TIR file must contain all the data needed to parameterize the block.

References

[1] Besselink, I. J.M., A. J.C. Schmeitz, and H. B. Pacejka. “An Improved Magic Formula/Swift Tyre Model That Can Handle Inflation Pressure Changes.” Vehicle System Dynamics 48, no. sup1 (December 2010): 337–52. https://doi.org/10.1080/00423111003748088.

[2] Pacejka, Hans Bastiaan, and Igo Besselink. Tire and Vehicle Dynamics. 3rd edition. Oxford Waltham: Butterworth-Heinemann Elsevier, 2012.

Version History

Introduced in R2022b

R2023a: Tire (Magic Formula) Block Updates

Due to updates to the Tire (Magic Formula) block, the sdlUtility.tirread function now fully supports Magic Formula version 6.2 for effective rolling radius, rolling resistance, scaling, and slip saturation.

The function still supports Magic Formula version 6.2 for the tire-road friction interaction.

R2023a: Function Behavior Change

The sdlUtility.tirread function no longer updates the setting of the Compliance and Inertia parameters. The function does update parameters that may be hidden depending on the Compliance and Inertia parameter settings. The function indicates which hidden parameters it updates in the MATLAB^® command window.