HTire Parameters Common to all MF Variants
Section [COSIN_HEADER]
The [COSIN HEADER] section is the place to specify a comment and a file version number. If the section is not found, all tire models of the FTire Tire Model Family assume the file is specified in the newest ASCII format version.Section [UNIT]
Name in input file | Unit | Required | Default value | Explanation |
---|---|---|---|---|
force | - | No | N | Force unit, defined by case-insensitive character string. Supported units
are:
|
mass | - | No | kg | Mass unit, defined by case-insensitive character string. Supported units
are:
|
length | - | No | m | Length unit, defined by case-insensitive character string. Supported units
are:
|
time | - | No | s | Time unit, defined by case-insensitive character string. Supported units
are:
|
angle | - | No | rad | Angle unit, defined by case-insensitive character string. Supported units
are:
|
Section [MODEL]
Name in input file | Unit | Required | Default value | Explanation |
---|---|---|---|---|
property_file_format | - | Yes | - | Tire model selection. The string is case-insensitive. Supported models
are:
Note: The models may be locked due to license restrictions.
|
tyreside | - | No | asis | If necessary, mirrors or zeros side-dependent data. Possible values are:
Note: By default, no data are modified (asis).
|
use_mode | - | No | -1 | Activation of model features are:
The right-most digit selects the forces to be computed:
Note: By default, the most complex use mode (24) is
used.
|
separate_animation | - | No | 0 |
Requests and specifies properties of an extra animation window for all tire model instances which are called by CTI. The value of separate_animation consists of up to 8 decimal digits. The definition of each mode is defined below. Select animation mode:
Note: Not all animation modes are available for all tire model
types.
Select contour plot type (only FTire):
Select running diagram type:
Show interactive sliders, if available:
Select camera setting:
Select tire structure visualization (only FTire):
Select road visualization:
Select sound (if available):
|
cosingl_path | - | No | working directory and more |
Path to the COSIN/gl animation program cosingl (optional). By default, CTI searchs for this program in a certain predefined list of directories. This list includes the working directory, the home directory, the root directory, and the directory specified by the environmental variable COSINGLPATH. If COSIN/gl cannot be found, CTI runs anyway, but does not display the on-line animation. This does not affect any simulation results. |
road_grid_size | length | No | 600x300 mm | Approximate width and length (same value for both) of road visualization grid in animation window. |
road_grid_line_dis | length | No | 5x50 mm | Approximate grid line distance (same value for x and y direction) of road visualization in animation window. |
animation_time_step | time | No | same as simulation time step | Approximate time step for on-line animation, to be specified in the time unit of the data file. If zero or not specified, an approximate animation time step of 1 ms is used. |
animation_start | time | No | 0.0 | Approximate simulation time to begin animation. If not specified, animation (if requested) begins with simulation. |
animation_end | time | No | unlimited | Approximate simulation time to end animation. If not specified, animation ends with simulation. |
force_scaling | - | No | 1.0 | Factor that scales all kinds of force display in the animation window (sliders, forces in running diagrams, contact force vectors, etc.). Default value is 1.0. |
Section [DIMENSION]
Name in input file | Unit | Required | Default value | Explanation |
---|---|---|---|---|
unloaded_radius | length | Yes, in case of 2002 variant | estimated | Maximum radius of unloaded tire. By default, estimated on basis of tire dimension. |
width | length | Yes | - | Maximum width of unloaded tire. |
aspect_ratio | - | Yes | - | Tire aspect ratio. Note: This value is not specified in %, but in a value
between 0 and 1.
|
rim_radius | length | Yes | - | Rim (bead seat) radius. |
rim_width | length | Yes, in case of 2002 variant | estimated | Rim (bead seat) width. By default, estimated on basis of tire dimension. |
rolling_circumference | length | No | estimated | Rolling circumference. By default, estimated on basis of tire dimension. |
Section [PARAMETER] or [VERTICAL]
Name in input file | Unit | Required | Default value | Explanation |
---|---|---|---|---|
vertical_stiffness | force /length |
(Yes) | - | Mean radial stiffness (required if no section [DEFLECTION_LOAD_CURVE] is specified). |
vertical_damping | force /time /length |
No | 0 | Mean radial damping coefficient. |
step_size_contact_plane_calc | length | No | 50 mm | Numerical step-size to approximate the road normal vector by numerical differentiation. Should be roughly half the contact patch width. |
Fnomin | N | Yes, in case of 2002 variant | LI load | Nominal wheel load. |
breff | - | Yes, in case of 2002 variant | 9 | Parameter Breff in determination of effective rolling radius (eq. (A3.7), p. 617 in [PAC]). |
dreff | - | Yes, in case of 2002 variant | 0.23 | Parameter Dreff in determination of effective rolling radius (eq. (A3.7), p. 617 in [PAC]). |
freff | - | Yes, in case of 2002 variant | 0.01 | Parameter Freff in determination of effective rolling radius (eq. (A3.7), p. 617 in [PAC]). |
lateral_stiffness | force /length |
No | infinity | Lateral stiffness of the non-rolling tire; used for contact patch shift estimation due to tire forces. |
longitudinal_stiffness | force /length |
No | infinity | Longitudinal stiffness of the non-rolling tire; used for contact patch shift estimation due to tire forces and for the influence of wheel load on overturning torque. |
rolling_resistance | - | No | 0.012 | Dimensionless rolling resistance coefficient. |
relaxation_length_Fx | length | No | 0 | Relaxation length of longitudinal force. |
max_time_constant_Fx | time | No | 0.3 s | Time constant upper bound for longitudinal force lag. |
relaxation_length_reduction_Fx | - | No | 0.7 | Relaxation length reduction of longitudinal force decrease relative to force increase. |
relaxation_length_Fy | length | No | 0 | Relaxation length of side force. |
max_time_constant_Fy | time | No | 0.3s | Time constant upper bound for side force lag. |
relaxation_length_reduction_Fy | - | No | 0.7 | Relaxation length reduction of side force decrease relative to force increase. |
relaxation_length_Mz | length | No | 0 | Relaxation length of aligning torque. |
max_time_constant_Mz | time | No | 0.3 s | Time constant upper bound for aligning torque lag. |
relaxation_length_reduction_Mz | - | No | 0.7 | Relaxation length reduction of aligning torque decrease relative to torque increase. |
model_switch_ref_speed | length /time |
No | 0.2 | Forward speed at which model is smoothly switched from ‘slip-based’ to ‘displacement-based’. The latter mode is a simplified approach for the standing tire. The reference speed is used if the calling integrator time-step is 1ms; shorter or longer time-steps decrease or increase the switching velocity, respectively. |
Section [DEFLECTION_LOAD_CURVE]
This section provides an alternative to vertical_stiffness. If specified, the x and y data in this section define a smooth spline, representing the non-linear deflection/load characteristic of the tire. Arbitrarily, many x and y data of tire deflection (length) and radial load (force) can be specified, one or more in a line. Deflection values must be monotonously increasing. TeimOrbit compatible comment lines are allowed between the data lines.
[DEFLECTION_LOAD_CURVE]
0 0.0
5 400.0
10 1250.0
20 4000.0
30 8500.0