01032016, 05:33 PM,


vdriftz
Junior Member

Posts: 3
Threads: 1
Joined: Jan 2016


Request for additional car data.
Hi,
I downloaded the car data files of the Modena 360
and of the 2002 Formula One racing car, containing
extensive information about these vehicles.
I would be very grateful if anybody can provide the
following data on the above cars, or on any other
suitable vehicles:
(1) Wheel data (wheel = tyre + rim):
The mass of each wheel m_w.
The radius and width of each wheel, r_w and w_w.
The moment of inertia of each wheel about an axis through
its center of mass and perpendicular to the plane of the
wheel, I_w_zz.
The moment of inertia of each wheel about an axis through
its center of mass and perpendicular to the ground plane,
I_w_xx.
(2) Car body data (car body = car without the four wheels)
The mass of the car body m_b.
The dimensions of a rectangular box (length, width and height)
bounding the car body.
The widths of the front and rear axles.
The length of the wheelbase.
The position of the center of mass of the car body relative
to the wheelbase.
The moment of inertia of the car body about an axis through
its center of mass and perpendicular to the ground plane,
I_b_zz.
(3) Drive train data (drive train = engine + gearbox +
drive shaft + differential gearbox + side shafts)
Equivalent inertia of the drive train defined as follows.
Approximate the rotational inertia of the drive train, with
an equivalent inertia rotating about the axis of rotation
of the engine crank shaft.
Thanks very much.
Constantine Frangos.


01112016, 12:14 PM,
(This post was last modified: 01112016, 02:16 PM by arturo.)


arturo
Junior Member

Posts: 30
Threads: 7
Joined: Nov 2015


RE: Request for additional car data.
For the Modena:
 The radius and width of each wheel, r_w and w_w.
Rear wheels are 275/40/18. This makes w_w = 275 and r_w = 325
Front wheels are 215/45/18. This makes w_w = 215 and r_w = 312
 The widths of the front and rear axles.
1669 / 1617
 The length of the wheelbase.
2600
 The position of the center of mass of the car body relative to the wheelbase.
1482 from the front axle / 1118 from the rear axle
43/57 % ( http://www.zeperfs.com/en/fiche146ferra...modena.htm)
These were of course the easy ones. For all the other data, I wish you luck. Please let us know if and where you can find them.


01132016, 05:21 PM,


vdriftz
Junior Member

Posts: 3
Threads: 1
Joined: Jan 2016


RE: Request for additional car data.
(01112016, 12:14 PM)arturo Wrote: For the Modena:
 The radius and width of each wheel, r_w and w_w.
Rear wheels are 275/40/18. This makes w_w = 275 and r_w = 325
Front wheels are 215/45/18. This makes w_w = 215 and r_w = 312
 The widths of the front and rear axles.
1669 / 1617
 The length of the wheelbase.
2600
 The position of the center of mass of the car body relative to the wheelbase.
1482 from the front axle / 1118 from the rear axle
43/57 % (http://www.zeperfs.com/en/fiche146ferra...modena.htm)
These were of course the easy ones. For all the other data, I wish you luck. Please let us know if and where you can find them.
Thanks for the data. This is a good start and hopefully
other users will be able to supply the rest of the
requested values.
It seems that if vdrift is accurately simulating the
motion of the vehicle body, and the motion of the wheels,
and other moving parts like the engine, steering system,
etc then the data I requested should be somewhere inside
the vdrift software. Is this correct ?


01132016, 10:10 PM,


arturo
Junior Member

Posts: 30
Threads: 7
Joined: Nov 2015


RE: Request for additional car data.
All the physics is in the .car files that you can find under vdrift/data/cars.
You may start by looking at the description of VDrift car parameters here: https://github.com/VDrift/vdrift/blob/ma...ameters.md, but please be aware that some of the data you want are not directly available. For instance, the moment of inertia of the car body is calculated from several "mass particules", including even the driver and her corresponding balancing ballast.
Personally, I would take some of these data as an approximation as best, contrary to the ones that I provided you first, which are based on realworld measurements.
As a aside, in the car I am developing I've put no polar inertia at all, but a single mass particle located (by definition) at the center of mass. This means that the simulation is realistic as long as all wheels have grip, but does not accurately represent what happens as soon as you start drifting. In a way, this makes keeping the car on the racing line a bit easier  but life is already hard enough, don't you think?


01142016, 04:47 AM,


vdriftz
Junior Member

Posts: 3
Threads: 1
Joined: Jan 2016


RE: Request for additional car data.
(01132016, 10:10 PM)arturo Wrote: All the physics is in the .car files that you can find under vdrift/data/cars.
You may start by looking at the description of VDrift car parameters here: https://github.com/VDrift/vdrift/blob/ma...ameters.md, but please be aware that some of the data you want are not directly available. For instance, the moment of inertia of the car body is calculated from several "mass particules", including even the driver and her corresponding balancing ballast.
Personally, I would take some of these data as an approximation as best, contrary to the ones that I provided you first, which are based on realworld measurements.
As a aside, in the car I am developing I've put no polar inertia at all, but a single mass particle located (by definition) at the center of mass. This means that the simulation is realistic as long as all wheels have grip, but does not accurately represent what happens as soon as you start drifting. In a way, this makes keeping the car on the racing line a bit easier  but life is already hard enough, don't you think?
Thanks for the fast response and interesting information.
You mention that the moments of inertia of the vehicle is calculated internally
in vdrift by using various point masses placed in the volume of the vehicle.
If possible please provide these calculated moments of inertia for the vehicle body,
for the wheels, and for any other moving vehicle parts for which calculated moments
of inertia are available  thanks.


01142016, 05:48 AM,


arturo
Junior Member

Posts: 30
Threads: 7
Joined: Nov 2015


RE: Request for additional car data.
Quote:If possible please provide these calculated moments of inertia for the vehicle body, for the wheels, and for any other moving vehicle parts for which calculated moments of inertia are available  thanks.
I don't think any moment of inertia is calculated for the wheels, but I am sure that someone more knowledgeable than me could point to you where to find the calculation for the car body.


