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I am having trouble with my NAO robot sinking into the webots floor. For the floor material, I have tried a plane, a box, a regular floor, etc. In all cases, once the NAO's selfCollision is set to TRUE, the robot stinks into the floor when I start the simulation.

Can anyone provide me with some insight into what the problem is?

Here is a link to my world file.

Other things that I have tried (but did not help): - lower basicTimeStep to a value in range [1, 8) - increase ERP from 0.6 to 1 - lower CFM (although this doesn't seem to hold because when I save the world file, it resets to 1e-05) - changed world contact material from 'NAO material' to 'NAO foot material' but this caused the robot to be lost in the world (completely disappeared from view)

Sheila
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1 Answers1

3

This is due to a bug in the Nao.proto definition in the Webots resources. The boundingObjects (defining the collisions) of the touch sensors overlap the feet bodies. This cause strong internal forces and so weird collisions with floors.

I created a fix here: https://github.com/cyberbotics/webots/pull/1117

You can apply these modifications directly in your WEBOTS_HOME/projects/robots/softbank/nao/protos/Nao.proto file:

diff --git a/projects/robots/softbank/nao/protos/Nao.proto b/projects/robots/softbank/nao/protos/Nao.proto
index 22e75abe0..23c87c55f 100644
--- a/projects/robots/softbank/nao/protos/Nao.proto
+++ b/projects/robots/softbank/nao/protos/Nao.proto
@@ -4058,8 +4058,13 @@ PROTO Nao [
                                                 }
                                               }
                                             }
-                                            boundingObject DEF BUMPER_BO Box {
-                                              size 0.02 0.025 0.01
+                                            boundingObject DEF BUMPER_BO Transform {
+                                              translation 0.0075 0 0
+                                              children [
+                                                Box {
+                                                  size 0.005 0.025 0.01
+                                                }
+                                              ]
                                             }
                                             lookupTable [
                                             ]

.. or wait on the patch to be merged in Webots; it will be for sure included in the revision nightly build of tomorrow or in the next Webots release (> R2019b.rev1): https://github.com/cyberbotics/webots/releases)

FabienRohrer
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