Implement a trajectory follow controller

[cxt]

Hi,

I want to implement a trajectory follow controller. For example, I want the end effector to draw a 3D curve in workspace with fixed orientation. I think generateIKpath can only use to perform straight lines, while ompl planner seems too much for this task (I don't need collision checking) and I don't know how to set the projection constraint to the planner to reach the desired trajectory and whether it's possible to find such constraint. My idea is to create a simple jacobian-based controller to let the arm always stay on the curve and use null-space projection to try best to satisfy constraints while moving. Does that sound a plan? Thanks in advance!

Xiaotong

[coppelia]

Hello,

you will have to build an ik task first to constrain your end-effector to follow another object (e.g. a target dummy) in position and/or orientation. Once you have that, you can programmatically move the target dummy in position/orientation, solve the manipulator angles via IK, and repeat.

Take for instance the demo model models/robots/non-mobile/IRB4600.ttm that does exactly that.

Cheers

[cxt]

Thanks so much for your response! I never got the idea ik can do this. I will see through the demo you provided.

[cxt]

Hi,

I am trying to find the demo model you posted (IRB4600) but cannot find it though. I have version 4.1.0 rev.1. I searched through scene files and found 10-applyingIkToDynamicallyEnabledModels.ttt in scenes/ik_fk_simple_examples and find this seems include the same as you mentioned. I will try this out instead

[cxt]

Oh I see it, it has prefix 'ABB'. never mind