[ODE] Simulating a bobsleigh

[Megan Fox]

The common demo passed around for car sim is carworld
(http://www.mindcontrol.org/~hplus/carworld.html)

Now this doesn't apply directly in your case, but a problem every
single car sim comes to is rolling - this demo applies anti-sway
(torque force) to combat it, in a fashion that can be tweaked to
control the amount of roll you want.

There might be some other parts that are handy too; Worth a look in any case.

-Megan Fox

On 8/4/05, David Ramos <dramos at cyanide-studio.com> wrote:
> Good advices,
> 
> Michael, Megan, Jon,
> Got what I wanted :)
> dContactApprox1 , mu2 and slip2 are the key, thanks guys.
> No more wheels or traction force.
> 
>  Jon,
> You are right, I experiment some strange behavior with boxes, some
>  inexpected "jumps" etc.. despite a good global sensation.
> What's exactly the problem ? Any fix expected ?
> 
> Using cylinders for the skates tends to make the bobsleigh rolling
> despite my effort to lower the Center of Mass, the mass of the bob and
> to increase the mass of the skates.
> 
> Using rays seems to give exactly the opposite...very hard to roll :)
> 
> I need a compromise because both behaviors are expected in bobsleigh.
> 
>  thanks for your help,
> David
> 
> > ----- Original Message -----
> > From: "Jon Watte (ODE)" <hplus-ode at mindcontrol.org>
> > To: "David Ramos" <dramos at cyanide-studio.com>
> > Cc: <ode at q12.org>
> > Sent: Monday, August 01, 2005 6:43 PM
> > Subject: Re: [ODE] Simulating a bobsleigh
> >
> >
> >>
> >> Did you turn on dContactApprox1 for the contacts? If not, then "mu" is
> >> really a force limit, which is usually not what you want.
> >>
> >> Also, I'm not sure that you want boxes, because those will have nasty
> >> behavior when running over rough terrain, along the edges. I'd probably
> >> use ccylinders, or possibly just a ray per skate, and doctor the contacts
> >> to use fDir, and have a high friction sideways, and low friction
> >> lengthways.
> >>
> >> Cheers,
> >>
> >>           / h+
> >>
> >>
> >>
> >> David Ramos wrote:
> >>> Hi,
> >>>  I'm trying to setup a bobsleigh :
> >>> a box for the chassis, and 4 hinged-boxes for the skates.
> >>>  The problem is that this configuration makes the bob to behave a little
> >>> like an hovercraft. I don't have much control.
> >>>  mu is set to a low value (0.0015f) to make the bob sliding but the
> >>> skates don't have
> >>> any grip. Playing with slip values doesn't give me better results.
> >>>  On the other side, setting mu to a higher friction asks me to add some
> >>> traction force simulated with hinge2 joints and spheres for the wheels.
> >>> So I end up with a car :) Not the result expected....
> >>>  an hybrid approach with traction for the rear wheels and skates for the
> >>> front wheels is not better...
> >>>  Some ideas on how to model that kind of behavior ?
> >>>  Thanks,
> >>> David
> >>>
> >>>
> >>> ------------------------------------------------------------------------
> >>>
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> >>
> >
> 
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