Misalignment of the l_sole and r_sole frames in ergoCubSN001 and ergoCubGazeboV1_1 models

[GiulioRomualdi]

Task description

Upon examining the l_sole and r_sole frames in both ergoCubSN001 and ergoCubGazeboV1_1, we have observed that they are not properly located on the robot's sole.

In this visualization, I am plotting the r_sole and l_sole frames. On the left, we have ergoCubSN000, and on the right, we have ergoCubSN001. The frames appear to be centered in different positions, with the frames for ergoCubSN001 appearing higher.

Definition of Done

Our expectation was that l_sole and r_sole would be positioned in the same manner as in ergoCubSN000.

---

cc @isorrentino @DanielePucci

[GiulioRomualdi]

Applying this patch to the robot model the frames are placed as expected

diff --git a/urdf/ergoCub/robots/ergoCubGazeboV1_1/model.urdf b/urdf/ergoCub/robots/ergoCubGazeboV1_1/model.urdf
index 3430d58..b7826c9 100644
--- a/urdf/ergoCub/robots/ergoCubGazeboV1_1/model.urdf
+++ b/urdf/ergoCub/robots/ergoCubGazeboV1_1/model.urdf
@@ -2508,7 +2508,7 @@
   </joint>
   <link name="l_sole"/>
   <joint name="l_sole_fixed_joint" type="fixed">
-    <origin xyz="0.059629999999999996 0 1.1102230246251565e-16" rpy="0 1.5094274020956558e-31 0"/>
+    <origin xyz="0.059629999999999996 0 -0.022299999999999986" rpy="0 1.5094274020956558e-31 0"/>^M
     <parent link="l_foot_rear"/>
     <child link="l_sole"/>
   </joint>
@@ -2874,7 +2874,7 @@
   </joint>
   <link name="r_sole"/>
   <joint name="r_sole_fixed_joint" type="fixed">
-    <origin xyz="0.05963 -1.3877787807814457e-17 7.771561172376096e-16" rpy="0 3.1371750050201436e-30 0"/>
+    <origin xyz="0.05963 -1.3877787807814457e-17 -0.022299999999999986" rpy="0 3.1371750050201436e-30 0"/>^M
     <parent link="r_foot_rear"/>
     <child link="r_sole"/>
   </joint>

[GiulioRomualdi]

To be more specific the definition of done is to be compliant with https://www.ros.org/reps/rep-0120.html#l-sole-and-r-sole

l_sole and r_sole
The coordinate frame called l_sole defines the position and orientation of the left leg support body. The (X,Y) plane of this frame must be coplanar with the support body contact surface. It is recommended to choose the origin as the projection of the support body origin on the contact surface. The Z coordinate of this frame should be on the ground level when standing.

The coordinate frame called r_sole defines the equivalent frame for the right leg.

@traversaro

[Nicogene]

To give a context here, for this issue:

• l_foot_rear_ft, l_foot_front_ft,, r_foot_rear_ft, and r_foot_front_ft, FT sensor frame have a ~2cm offset in Z direction w.r.t. to the corresponding link frame #146

We moved up the frames of the parts in order to be coincident w/ the ones of the ft sensor. Probably l/r_sole has been moved up by mistake

I will add also a check in the unit test

[Mick3Lozzo]

Yes, L_SOLE and R_SOLE were defined following the L/R_FOOT frames' placement. I am going to correct them.

@Nicogene @GiulioRomualdi

[Mick3Lozzo]

@GiulioRomualdi as per your comment I verified that L_SOLE and R_SOLE are 2 mm higher than the contact surface, that happens on the rubber soles.

Do you mean that they should be located on the lower part of the rubber soles, that is the effective contact surface?

cc @Nicogene

[Mick3Lozzo]

Updated ergoCub 1.1 CAD and SIM shrinkwrapped model.

@Nicogene @GiulioRomualdi

[Nicogene]

Fix shipped here:

• ergoCubV1*: move down the l/r_sole frames #187