Robot elements are hanging down due to gravity
Posted: Sun Aug 21, 2016 8:44 pm
Hi,
I have a robot modelled in bullet with btHingeConstraint joints.
If I run the robot in real time mode (around 10ms per cycle), the elements are not at their place, especially in the other axes of the hinge joint. They are hanging down a little bit. If I decrease the gravity, they dont hang down anymore.
The masses of the elements are realistic ones from a real robot.
If I do 1ms steps the problem is not present. But then it is not real time, so not an option.
I found the solver parameter btContactSolverInfoData.m_erp, which kinda solves it if I increase to 1.0f. But then the joints start to oscillating, when moved once. Increasing damping additionally does not help.
Isnt btContactSolverInfoData the wrong place to tune since there are no contacts involved?
What would be the correct parameters to fix this?
thanks!
cheers
veio
I have a robot modelled in bullet with btHingeConstraint joints.
If I run the robot in real time mode (around 10ms per cycle), the elements are not at their place, especially in the other axes of the hinge joint. They are hanging down a little bit. If I decrease the gravity, they dont hang down anymore.
The masses of the elements are realistic ones from a real robot.
If I do 1ms steps the problem is not present. But then it is not real time, so not an option.
I found the solver parameter btContactSolverInfoData.m_erp, which kinda solves it if I increase to 1.0f. But then the joints start to oscillating, when moved once. Increasing damping additionally does not help.
Isnt btContactSolverInfoData the wrong place to tune since there are no contacts involved?
What would be the correct parameters to fix this?
thanks!
cheers
veio