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I follow the ABB IRB 360.ttt and Quattro.ttt model .The joints will break when I don't set dependent joint in simulation. If I add dependent joint, The link will tremble in simulation ,then I drag the ik_target, link will break and run in a mass,My model is https://pan.baidu.com/s/17nhXgSPXGMbXIef0GKtiLA, The password is 7w81.
Hi,I reupload it from google drive. https://drive.google.com/open?id=162mgw ... D4gI58QZpa.Thank you for your replay.
Ok, there are several things that appear wrong. Here a few suggestions:
- Make sure you do not use any damped resolution method for your IK chains. If your construction is correct with enough degrees of freedom, then it should be stable with an undamped resolution method.
- Try to go step-by-step. Typically, create first two IK branches: Branch A: starting at the base of arm 1, ending at the base of arm 2. Branch B: starting at the base of arm 1, ending at the base of arm 3. Once that is stable and looks right, add the 3 branches for the parallel rods of the secondary arms. Those can actually also end at the extremity of the primary arms. This gives you 5 IK elkements of the main task (inside one IK group)
- Then you need to add a 6th IK element into that IK group for the case when you want to control the arm in IK mode. You'll have to programmatically enable/disable that 6th IK element to switch between IK and FK mode (you'll also have to switch the mode of the 3 base joints in that case: from Ik mode to passive mode.
- In your scene, if you delete all IK groups except for the main, and set the resolution method to pseudo inverse, then it is stable. But you'll see some small initial movement due to the fact that you joints are not positioned/oriented precisely. Also, it is important to have the exact same pose for linked dummies.
- My suggestion: make the FK mode first work. To that end, temporarily disable the last IK element. And set the 3 base joints into passive mode. Then you can test things with a sinusoid movement on them