Refine V1 gripper geometry and V1/V2 motor dynamics

dev/README.md

@@ -2,11 +2,15 @@
 
 ## Mirrored collision meshes
 
-V2 uses 16 pre-mirrored collision meshes as a temporary
+V1 uses six pre-mirrored arm collision meshes, and V2 uses 16 pre-mirrored
+arm and gripper collision meshes, as a temporary
 workaround for [MuJoCo #3604](https://github.com/google-deepmind/mujoco/issues/3604).
 Negative mesh scale can produce inward convex polygon normals and incorrect
-contacts. The V2 arm and gripper collision assets load with positive scale.
-Visual mesh definitions retain their original files and scales.
+contacts. All V1/V2 collision assets load with positive scale.
+Arm visual mesh definitions retain their original files and scales.
+
+V1 fingers share `finger.stl`; the opposing finger geometry is rotated 180
+degrees around Z instead of using a mirrored mesh.
 
 Regenerate the `_left` assets after updating their original meshes:
 

dev/mirror_meshes.py

@@ -12,15 +12,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Generate the pre-mirrored V2 collision meshes across Y=0."""
+"""Generate the pre-mirrored V1/V2 collision meshes across Y=0."""
 
 from pathlib import Path
 import struct
 
 
 _TRIANGLE = struct.Struct("<12fH")
-_COLLISION = Path(__file__).resolve().parents[1] / "v2" / "assets" / "collision"
-_MESHES = (
+_ROOT = Path(__file__).resolve().parents[1]
+_V1_COLLISION = _ROOT / "v1" / "meshes" / "collision" / "arm"
+_V1_MESHES = [f"link{i}.stl" for i in (0, 1, 2, 5, 6, 7)]
+_V2_COLLISION = _ROOT / "v2" / "assets" / "collision"
+_V2_MESHES = (
     ["base_link.stl", "ee_base_link.stl"]
     + [f"link{i}.stl" for i in (1, 2, 6)]
     + [f"link5_part_{i:02d}.stl" for i in range(3)]
@@ -52,10 +55,14 @@ def mirror_stl(source: Path, destination: Path) -> None:
 
 
 def main() -> None:
-    """Regenerate the 16 mirrored V2 collision assets from their originals."""
-    for name in _MESHES:
-        source = _COLLISION / name
-        mirror_stl(source, source.with_stem(f"{source.stem}_left"))
+    """Regenerate six V1 and 16 V2 mirrored collision assets."""
+    for directory, names in (
+        (_V1_COLLISION, _V1_MESHES),
+        (_V2_COLLISION, _V2_MESHES),
+    ):
+        for name in names:
+            source = directory / name
+            mirror_stl(source, source.with_stem(f"{source.stem}_left"))
 
 
 if __name__ == "__main__":

v2/cell/cell.xml

@@ -26,7 +26,7 @@ limitations under the License.
     </default>
     <default class="lifter">
       <joint limited="true" type="slide" damping="50" />
-      <position kp="8000" kv="4000" forcelimited="true" forcerange="-3000 3000" ctrllimited="true" />
+      <position forcelimited="true" forcerange="-3000 3000" ctrllimited="true" />
     </default>
   </default>
 

v2/openarm_bimanual.xml

@@ -19,17 +19,21 @@ limitations under the License.
   <default>
     <joint stiffness="0" ref="0.0" />
     <default class="robot">
+      <!-- Armatures approximate motor rotor readouts * gear ratio squared (kg*m^2).
+           Damping references from motor readouts, assuming the same conversion (N*m*s/rad):
+           DM8009P ~0.13, DM4340 ~0.33, DM4310 ~0.03. Reference only; gearbox contributions
+           are unconfirmed. Applied damping is unchanged. -->
       <default class="motor_DM8009">
-        <joint frictionloss="0.2" damping="1.0" armature="0.0081" limited="true" type="hinge" />
-        <position kp="200" kv="150" forcelimited="true" forcerange="-40 40" ctrllimited="true" />
+        <joint frictionloss="0.2" damping="1.0" armature="0.016" limited="true" type="hinge" />
+        <position forcelimited="true" forcerange="-40 40" ctrllimited="true" />
       </default>
       <default class="motor_DM4340">
-        <joint frictionloss="0.1" damping="0.9" armature="0.1600" limited="true" type="hinge" />
-        <position kp="100" kv="30" forcelimited="true" forcerange="-27 27" ctrllimited="true" />
+        <joint frictionloss="0.1" damping="0.9" armature="0.030" limited="true" type="hinge" />
+        <position forcelimited="true" forcerange="-27 27" ctrllimited="true" />
       </default>
       <default class="motor_DM4310">
-        <joint frictionloss="0.04" damping="0.9" armature="0.0100" limited="true" type="hinge" />
-        <position kp="200" kv="5" forcelimited="true" forcerange="-7 7" ctrllimited="true" />
+        <joint frictionloss="0.04" damping="0.9" armature="0.002" limited="true" type="hinge" />
+        <position forcelimited="true" forcerange="-7 7" ctrllimited="true" />
         <!-- Keep gripper-specific friction and damping; inherit DM4310 inertia and limits. -->
         <default class="motor_finger">
           <joint frictionloss="0" damping="0.6"/>