[Solved] Using bullet to simulate a loop structure
Posted: Thu Mar 12, 2015 6:18 am
Hello,
I'm currently useing Bullet engine (BulletSharp version) to build a simulator.
And I'm try to build a loop struct (a 4 bar linkage) as shown in this picture: (Cube: ridigBody; Cylinder: HingeConstraint )
However, the structure always blow up after the simulation begins...
If those joints are free to rotate, the structure can exist for a relatively long time, but somehow distort and reassemble and blows up.
If one joint is motorized (the others are free), then the structure blows up right after 1~2 seconds.
The parameters used are:
simulation freguency interpoleTime@1000Hz, internalTime@60Hz using stepSimulation(interpoleTime);
MLCP Dantzig solver
Joint movable range = -20~20 degree
Joint overrideIteration = 120
RigidBody mass = 2.0kg
Note: The blue cube in the picture is a 6DOF constraint locking two rigidBodies.
I tried remove them, but it has no effect.
Does the solver have limitation on loop sturcture? Or some parameters must be specified?
I've built other articulated structures(no loop inside), and they works fine using this solver.
Any ideas? Thanks~
-------------------------------------------------------------------------------------------------------
Update:
The problem is solved using double precision version of BulletPhysics~
I'm currently useing Bullet engine (BulletSharp version) to build a simulator.
And I'm try to build a loop struct (a 4 bar linkage) as shown in this picture: (Cube: ridigBody; Cylinder: HingeConstraint )
However, the structure always blow up after the simulation begins...
If those joints are free to rotate, the structure can exist for a relatively long time, but somehow distort and reassemble and blows up.
If one joint is motorized (the others are free), then the structure blows up right after 1~2 seconds.
The parameters used are:
simulation freguency interpoleTime@1000Hz, internalTime@60Hz using stepSimulation(interpoleTime);
MLCP Dantzig solver
Joint movable range = -20~20 degree
Joint overrideIteration = 120
RigidBody mass = 2.0kg
Note: The blue cube in the picture is a 6DOF constraint locking two rigidBodies.
I tried remove them, but it has no effect.
Does the solver have limitation on loop sturcture? Or some parameters must be specified?
I've built other articulated structures(no loop inside), and they works fine using this solver.
Any ideas? Thanks~
-------------------------------------------------------------------------------------------------------
Update:
The problem is solved using double precision version of BulletPhysics~