What's the units of vehicle parameters' default values?

[dytiantian]

We could not find the unit information about vehicle parameters’ default values.

 

For example, we could just get to know the default value of ‘Max Steer Speed’’ is 50, but we could not find the unit is km/h or m/s.

 

But the unit information is necessary for us since we need to change some default values of vehicle parameters.Would you mind telling us all the units of the vehicle parameters’ default values in the attached picture?

[silent]

Hi,

 

Vehicle speed is in km/h. However, Max Steer Speed is the maximum wheel steering speed (degree / sec). It's used when car speed is not so big and you can easily do a u-turn. Maximum car speed is mostly depends on gearbox switching ratio and engine's RPM / torque parameters.

 

Maximum car speed can be only limited for AI cars.

 

Thanks!

[dytiantian]

Thank you very much for replying to me.

Actually we need to know all the parameters in the attached picture I posted before, not just the vehicle speed's unit.

So would you mind telling me where I can find all the units information, or just sending the file what describes all the units if you happen to have this kind of file.

It will be a big help to me.

Thank you again!

[silent]

Hi,

 

Unfortunately, most of the parameters doesn't have any units, since they are just coefficients for physics calculations.

 

Gear ratios variables are being taken from real vehicle. For (almost) every car you can find this numbers in its specification (for exampe, transmission gear ratios for ford focus).

 

Number Gears - the number of gears in gearbox;

Drive efficency - drive gear efficiency (0.7 = 70%, 30% loss of the efficiency);

Max controllable velocity  - maximum car speed in km/h when steering speed is decreased to its minimum;

Max/Min RPM - engine spec. can also be found in car specs (rotation per minute);

Max Torque - Nm; unfortunately it is not a real value (can be calculated like (simulated_car_mass (kg) * real_car_torque (Nm) / real car mass (kg);

 

Following parameters are affecting simulated physical car behavior:

Joins iteration - number of joints iteration. Affects on overall suspension behavior and physics performance;

Angular damping (max / handbrake) - angular wheel resistance while pressing the brake / handbrake;

Angular damping (min) - constant angular resistance of the wheels;

Max steer angle - max angle for wheel rotations (in degrees);

Max steer speed / Min Steer speed - speed in degrees/sec of wheels rotation;

Suspension Limit From / To - the wheel suspension limits in meters (default values is -0.3 / 0; they means that wheels can only go up to 30cm from its center);

Wheel Threshold - coefficient that affects on car behavior on hitting the curb (we recommend to not change it);

 

Suspension Spring - coefficient that set suspension stifness

Suspension Damping - coefficient that set up suspension linear damping

Suspension Target Height - unused, will be removed

 

Wheel Tangent Friction - max coefficient of wheels friction;

Wheel Tangent Angle - coefficient that sets up how fast wheel tangent friction will be reached (you can control the acceleration speed by those two parameters)

Wheel Binormal Friction / Angle - the same that wheel tangent but, for the side friction;

 

Wheel Radius - in meters;

Wheel Mass - unused, will be removed;

 

Speed Max Fov - speed when camera fov is maximum (in km/h);

Fov Max / Fov Min - Camera field of view in degrees;

 

Automatic transmission - enable automatic transmission;

Gear Shifting Schedule - xml file with gear shifting schedule for automatic transmission; Also, you can find sample of this xml file in our documentation.

 

Thanks!