add flag to ignore Coulomb friction

petercorke · petercorke · commit 1f7a55312aea · 2020-10-12T08:56:10.000+10:00
diff --git a/roboticstoolbox/robot/DHLink.py b/roboticstoolbox/robot/DHLink.py
@@ -573,7 +573,7 @@ def nofriction(self, coulomb=True, viscous=False):
 
         return link
 
-    def friction(self, qd):
+    def friction(self, qd, coulomb=True):
         """
         ``tau = friction(qd)`` Calculates the joint friction force/torque (n)
         for joint velocity qd (n). The friction model includes:
@@ -607,10 +607,11 @@ def friction(self, qd):
 
         tau = self.B * np.abs(self.G) * qd
 
-        if qd > 0:
-            tau += self.Tc[0]
-        elif qd < 0:
-            tau += self.Tc[1]
+        if coulomb:
+            if qd > 0:
+                tau += self.Tc[0]
+            elif qd < 0:
+                tau += self.Tc[1]
 
         # Scale up by gear ratio
         tau = -np.abs(self.G) * tau
