Your browser was unable to load all of the resources. They may have been blocked by your firewall, proxy or browser configuration.
Press Ctrl+F5 or Ctrl+Shift+R to have your browser try again.

capability for closed chains? #24

Hello,

Is there any way to make a robot with a closed kinematic chain in klampt? If so, are examples available, e.g. a simple loop-type system?

My system of interest is a floating base, closed chain which 'opens' over time - that is, joints disappear on command, and links are removed. The kinematics & dynamics during the opening procedure are of great interest. Thus far, I've simulated a simplified version of the system using an open chain, but now need to reach a higher level of fidelity.

Alternatively, perhaps there is another viable approach to model this system in klampt?

Thanks in advance!

  • replies 1
  • views 1.6K
  • likes 0
#2

There is support for closed-chain kinematics, but it's not (yet?) in the dynamics API. This is not automatic, however, and getting closed-chain kinematics requires setting up one or more link-to-link inverse kinematics constraints and solving them as you move the robot's active DOFs.

Although it is not in the Klamp't API, there is a workaround to getting closed chain dynamics to work if you are using C++. You can get access to the Open Dynamics Engine bodies inside the ODERobot class and add additional hinge / prismatic joints to produce closed-chain constraints.