[ODE] AddForce vs. SetPosition

[Klaus Kesseler]

Hello!

I'm creating a (tool-)machine simulation and ODE is used to simulate the 
machine's kinematic,
e.g. all possible moves of a special marked point (the tool center point 
TCP). As an example
see this one (to be viewed in fixed width fonts):


                               ?   TCP
                               |
                           o-------o
                          /         \
                         /           \
                        /             \
                       x               x
                      /                 \
    Min ---------    /                   \          y
                    /                     \         |
                   O                       O        |__x
                                                    /
                                                   z


where
'?'  is the TCP,
'o'  are hinges (without any constraints)
'x'  are sliders
'O'  are spatial hinges

Well, if I apply a force to the TCP, the machine behaves as expected, 
i.e. I can move the center
Point in x and y direction. But if I move the TCP via 
dSetPosition(body[TCP], ... ) then

 > the bodies begin to flicker
 > if I move the TCP towards the negative y-axis, there are forces, 
which prevent the TCP to move
below the Min-line. This does not happen, if I move the TCP by applying 
a force.

Here is the big question:
Is there a possibility to move (exact) one body of the simulation, and 
the other bodies behave as
if the first one has been accelerated by a force?

Best Regards,
Klaus