Single Tire Entity Editor

The Tire Entity Editor is shown in the following image.

Tire - Property File

The Properties section has two file browsers: one for the tire property file and another for the road property file. For the tire interface, the tire parameters and the properties are set by a Tire Property File with the extension (.tir/.tpf/.fxt), while the road interface is described by a Road Property File with the extension (.rdf/.crg/.rgr). Both of these property files are in the TeimOrbit file format. The parameters of the Tire Properties section and their significance is explained below:

Tire Property File

Parameter

Description

Tire Property File

Browse and select the required file.

Edit File

Edit the file and save the edited file.

Tire Graphic Radius

Distance between the WC and the contact point of tire in unloaded conditions.

Tire Graphic Width

Section width of the tire.

Tire Graphic Aspect Ratio

Describes the sidewall height as a percentage of the tire section width.

Tire Side

Defines the left or right side of the tire.

Wheel Mass

The meaning of wheel mass changes with a tire model.


Fiala, Simplified durability tire	Mass of rim + Mass of Tire
MF-Tyre, MF-SWIFT	Mass of the rim + Mass of tire	‘Mass of tire’ should include the tire belt mass which can be read from Tire property file (INERTIA block) or it can be read from MotionSolve log file.
FTire	Mass of the rim + Mass of ‘rim-fixed’ tire parts Or Mass of the rim + Mass of the tire – Mass of the ‘free’ tire parts	rim-fixed tire parts are not accounted in FTire model, only ‘free’ tire mass is accounted. These masses can be read from the tire property file or can be read from the MotionSolve log file.
CDTire	Mass of the rim + Mass of ‘rim-fixed’ tire parts Or Mass of the rim + Mass of the tire – Mass of the ‘free’ tire parts	rim-fixed tire parts are not accounted in the CDTire model, only ‘free’ tire mass is accounted. These masses can be read from the tire property file or can be read from the CDTire log file.

Inpl.Iner.Ixx, Inpl.Iner.Iyy

Moment of Inertia of the wheel in the wheel plane.

Adjust the wheel inertia per the tire model by including the inertias of tire fixed parts that are not accounted for in the tire models.

Rot.Iner.Izz

Moment of inertia of the wheel about the spin axis.

Adjust the wheel inertia by including or excluding the inertias of tire parts that are accounted for or not accounted for in the tire models.

Hub Offset

Defines the offset of Hub graphic center from the wheel center.

Wheel CM offset

Defines the wheel part CM offset from the wheel center.

Tire Role

Defines tire function: front or rear.

VARSUB Switch

Activates the solver variables that contains the tire’s states. This option can be used for control prototyping.

PIN Mode

(For CD Tire only)

Defines the options in which inflation pressure is provided to CDTire.

File Extension: Retrieve the inflation pressure from the extension of the file (example: 21MPa if the file name is tire_50.21).
Tire Prop File: Retrieve the inflation pressure from the data within the tire property file.
Variable: Retrieve the inflation pressure from the specified SolverVariable. This option is useful if you wish to have the inflation pressure varying as a function of another variable in the model, such as TIME for example.

PIN [MPa]

(For CD Tire only)

Shows the inflation pressure when it is a constant value specified using either the “File Extension” or “Tire Property File”.

Units: MPa

PIN [MPa] Collector

(For CD Tire only)

Activates only when the "Variable" option is chosen for PIN Mode.

Use this selector to specify the SolverVariable in the model that contains the pressure variation during the simulation.

Note: You need to create this SolverVariable and specify the pressure function on it.

Units: MPa

Road Property File


Parameter	Description
Road Property File	Property File option is used to browse and select the required road property file.
Edit File	Edit file button is used to edit the road property file and save the edited file.
Method	Defines the road model type.
Road Type	Defines the type of road.
Function Name	Name of the function being called by Solver.

Tire - Connectivity Section

Use the Hub Body, Wheel Center, Tire Marker and Road Marker collector buttons in the Connectivity section to define the tire interface.


Connection	Significance
Hub Body	The wheel body on which the tire forces act.
Wheel Center	The point corresponding to the wheel center.
Tire Marker	The tire marker determines the direction in which the tire forces act.
Road Marker	The road marker, is the marker with respect to which the road is positioned and oriented for the simulation.

Tire – Subroutines Definition

Force Subroutine Input Parameters

The Tire force subroutine is defined in the cdtire.dll (.so) for the CD Tire case, and in mbdtire.dll (.so) for other Tire types. The function name is cdtire and mbdtire, respectively.

TNO, USER or CTI tire:

usrsub_param_str="USER(P₁,P₂,P₃)"


Parameter	Description
`P₁`	Branch ID: 908 (TNO, USER), 408 (CTI)
`P₂`	Tire force ID
`P₃`	Tire input array ID

Force definition block in the xml:

<!-- MODEL.tire_0.gf_tire_force -->
  <Force_Vector_TwoBody
     id                  = "30301"
     label               = "Tire force"
     type                = "ForceAndTorque"
     i_marker_id         = "30301031"
     j_floating_marker_id= "30301034"
     ref_marker_id       = "30101040"
     usrsub_param_string = "USER(908,30301,30300100)"
     usrsub_dll_name     = "mbdtire"
     usrsub_fnc_name     = "mbdtire"
  />

CD Tire:

usrsub_param_str="USER(P₁,P₂,P₃, P₄,P₅,P₆,P₇,P₈,P₉,P₁₀,P₁₁,P₁₂,P₁₃,P₁₄,P₁₅,P₁₆)"


Parameter	Description
`P₁`	Branch ID: 838 or 839
`P₂`	Tire force I Marker ID
`P₃`	Rim X Marker ID
`P₄`	Rim Y Marker ID
`P₅`	Rim Z Marker ID
`P₆`	Road Reference Marker ID
`P₇`	CDTire control file solver string ID
`P₈`	Tire property file solver string ID
`P₉`	Road property file solver string ID
`P₁₀`	Tire input array ID
`P₁₁`	CDTire user road solver string ID / 0
`P₁₂`	CDTire Pin Mode solver string ID
`P₁₃`	CDTire Pin Value solver string ID
`P₁₄`	CDTire Pin Mode value
`P₁₅`	All solver variables array ID
`P₁₆`	CDTire type

Force definition block in the xml:

<!-- MODEL.tire_0.gf_tire_force -->
  <Force_Vector_TwoBody
     id                  = "30301"
     label               = "Tire force"
     type                = "ForceAndTorque"
     i_marker_id         = "30301031"
     j_floating_marker_id= "30301034"
     ref_marker_id       = "30101040"
     usrsub_param_string = "USER(839,30301031,30301020,30301030,30301040,30101040,303007,303001,303002,30300100,0,303008,303009,0,30300400,303010)"
     usrsub_dll_name     = "cdtire"
     usrsub_fnc_name     = "cdtire"
  />

GSE Subroutine Input Parameters

The Tire subroutine is defined only for TNO or USER tires in the mbdtire.dll (.so). The function name is GSESUB.

GSE subroutine input user string:

usrsub_param_str="USER(P₁,P₂,P₃)"


Parameter	Description
`P₁`	Branch ID: 908
`P₂`	Tire force ID
`P₃`	Tire input array ID

CSE definition block in the xml:

<Control_StateEqn
     id                  = "305001"
     type                = "USERSUB"
     x_solver_array_id   = "30500200"
     y_solver_array_id   = "30500300"
     u_solver_array_id   = "30500100"
     ic_solver_array_id  = "0"
     num_state           = "5"
     num_output          = "0"
     usrsub_param_string = "USER(908,30301,30300100)"
     usrsub_dll_name     = "mbdtire"
     usrsub_fnc_name     = "GSESUB"
     usrsub_der1_name    = "GSEXX"
     usrsub_der2_name    = "GSEXU"
     usrsub_der3_name    = "GSEYX"
     usrsub_der4_name    = "GSEYU"
     is_static_hold      = "FALSE"
  />

Variables Subroutine Input Parameters

The Variable subroutine is defined in both mbdtire and msautoutils (.dll/.so). The function name for both variable subroutines is VARSUB.

VARSUB definition in msautoutils:

usrsub_param_str="USER(P₁,P₂,P₃,
                    P₄, P₅, P₆)"


Parameter	Description
`P₁`	Branch ID: 907 (Calculate the direction cosines of the component vector (X, Y, Z) of marker I in the coordinate system of marker J)
`P₂`	Marker I ID
`P₃`	Marker J ID
`P₄`	Marker J ID
`P₅`	Vector component (1: X, 2: Y, 3: Z)
`P₆`	Projected component of the direction cosines result (1,2,3)

Variable definition block in the xml:

<!-- MODEL.tire_0.sys_tire_states.sv_u_rim_x_dot_x -->
  <Reference_Variable
     id                  = "30500500"
     label               = "X Disp - u_rim_x_dot_x"
     full_label          = "Model-Tire 0-Tire States-X Disp - u_rim_x_dot_x"
     type                = "USERSUB"
     usrsub_param_string = "USER(907,30301031,30101040,30101040,1,1)"
     usrsub_dll_name     = "msautoutils"
     usrsub_fnc_name     = "VARSUB"
  />

VARSUB definition in mbdtire:

Branch 906:

usrsub_param_str="USER(P₁,P₂,P₃,
                    P₄, P₅)"


Parameter	Description
`P₁`	Branch ID: 906 (Calculate the velocity of marker I with respect to marker J resolved in the coordinate system of marker K in the requested component.)
`P₂`	Component (1: VX, 2: VY, 3: VZ, 4: WX, 5: WY, 6: WZ)
`P₃`	Marker J ID
`P₄`	Marker J ID
`P₅`	Marker K ID

Variable definition block in the xml:

<!-- MODEL.tire_0.sys_tire_states.sv_u_rim_vx -->
  <Reference_Variable
     id                  = "30501100"
     label               = "X Vel - u_rim_vx"
     full_label          = "Model-Tire 0-Tire States-X Vel - u_rim_vx"
     type                = "USERSUB"
     usrsub_param_string = "USER(906,1,30301031,30101040,30101040)"
     usrsub_dll_name     = "mbdtire"
     usrsub_fnc_name     = "VARSUB"
  />

Branch 167:

usrsub_param_str="USER(P₁,P₂,P₃)"


Parameter	Description
`P₁`	Branch ID: 167 (Get the requested element from the tire force ID.)
`P₂`	Tire force ID
`P₃`	Requested element 0: Longitudinal slip 1: Lateral slip 2: Camber 3: Contact Patch Force -X 4: Contact Patch Force -Y 5: Contact Patch Force -Z 6: Contact Patch Moments -X 7: Contact Patch Moments -Y 8: Contact Patch Moments -Z 9: Rim Angular Velocity 10: Rim Longitudinal Velocity 11: Rim Vertical Velocity 12: Dynamic Rolling radius 13: Contact Patch Location -X 14: Contact Patch Location -Y 15: Contact Patch Location -Z 16: Wheel center location -X 17: Wheel center location -Y 18: Wheel center location -Z 19: Loaded radius 20: Tydex W origin - x 21: Tydex W origin - y 22: Tydex W origin - z 23: Tydex W to Global/road tramat 24: Tire Deflection

Variable definition block in the xml:

<!-- MODEL.tire_0.sys_varsub.sv_long_slip -->
  <Reference_Variable
     id                  = "30400100"
     label               = "Longitudinal Slip"
     full_label          = "Model-Tire 0-VARSUB-Longitudinal Slip"
     type                = "USERSUB"
     usrsub_param_string = "USER(167,30301,1)"
     usrsub_dll_name     = "mbdtire"
     usrsub_fnc_name     = "VARSUB"
  />

Request Subroutine Input Parameters

The request subroutine is defined in the cdtire.dll (.so) for CD Tire case and in mbdtire.dll (.so) for the rest Tire types. The function name is reqsub for both cases.

usrsub_param_str="USER(P₁,P₂,P₃)"


Parameter	Description
`P₁`	Branch ID: 902 (TNO, USER or CTI), 839 (CD)
`P₂`	Requested element See Coordinate Systems and Output Requests for additional information.
`P₃`	Tire force ID

Request definition block in the xml:

<!-- MODEL.tire_0.o_rolling_states -->
  <Post_Request
     id                  = "70000007"
     label               = "Tire 0 - Radius OmegaActual OmegaFree"
     comment             = "Tire 0 - Radius OmegaActual OmegaFree"
     type                = "USERSUB"
     usrsub_param_string = "USER(902,1,30301)"
     usrsub_dll_name     = "mbdtire"
     usrsub_fnc_name     = "reqsub"
     cname2              = "Radius"
     cname3              = "Omega-actual"
     cname4              = "Omega-free"
  />