Baxter Robot Co-ordinate Frame

asked 2018-07-26 16:56:07 -0600

flightlesskite gravatar image

updated 2018-07-27 09:19:08 -0600

I'm trying to map HTC Vive controllers to Baxter's arms through ROS.

So I've got scripts working for getting controller data & have successfully mapped position (x, y, z) to control the robot's arms according the the R-H rule I found through: http://www.ros.org/reps/rep-0103.html

However, I'm having lots of trouble with orientation. Specifically, I am not sure how orientation of Baxter's co-ordinate frame is relative to the HTC controller's. Right now I've got it mapped as follow: rot.z, rot.y, rot.x= rot.y, -rot.x, -rot.z

It seemed to be 'correct' mapping of orientation- e.g. when I tilt up or pan left/right, the tf shows correct movement. I noticed that Baxter's end effectors co-ordinate system appears to be different to that of ROS. So now, whenever I hold the controller upright, Baxter's end-effector points backwards, rather than forwards. Any idea on how to correct this?

Here are some pictures to explain my issue.: image description

The tf in Rviz shows Baxter's end effector pointing in the direction the blue axis (Z), whereas my controller would be pointing in the red axis (X)... so I'm not sure if this is the problem. If anyone has successfully mapped HTC controllers to a Baxter machine before, I'd be very appreciative of some feedback! Thanks

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Comments

Could you please attach your imaged directly to the question? I've given you sufficient karma for that.

gvdhoorn gravatar imagegvdhoorn ( 2018-07-27 03:09:54 -0600 )edit

If you convert the transformation into a 4x4 HD matrix then you can use the same translation for position and orientation.

PeteBlackerThe3rd gravatar imagePeteBlackerThe3rd ( 2018-07-27 10:04:56 -0600 )edit