[Gzz-commits] manuscripts/Control1 poster.rst

[Tuomas J. Lukka]

CVSROOT:        /cvsroot/gzz
Module name:    manuscripts
Changes by:     Tuomas J. Lukka <address@hidden>        03/05/05 09:00:02

Modified files:
        Control1       : poster.rst 

Log message:
        tips

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/Control1/poster.rst.diff?tr1=1.18&tr2=1.19&r1=text&r2=text

Patches:
Index: manuscripts/Control1/poster.rst
diff -u manuscripts/Control1/poster.rst:1.18 
manuscripts/Control1/poster.rst:1.19
--- manuscripts/Control1/poster.rst:1.18        Mon May  5 08:54:03 2003
+++ manuscripts/Control1/poster.rst     Mon May  5 09:00:02 2003
@@ -143,12 +143,47 @@
 While interrelated, the second problem is more relevant
 to robotics and has therefore been dealt with in that context 
 due to the popularity of the LEGO Mindstorms.
+See e.g. REF!!
 
 Mechanical looseness is a different matter; it suggests
 the following design rules:
 
 - No frictionless pins.  For controllers, the frictionless pins are next to 
useless
   except in special circumstances due to their looseness.
+
+- A high gear ratio at the very beginning of the gearing is vital 
+  to alleviate the looseness in the next gears.
+
+- Axles used in gears must be attached at several points, far enough
+  from each other.
+
+- All joints where there is significant force should be designed
+  symmetrically, using e.g. 3-long pins with friction. The symmetry
+  makes the looseness in one direction much less. (This is similar
+  to taking the numerical derivative of a function 
+
+.. raw latex
+
+    $f(x)$
+
+  at
+
+.. raw latex
+
+    $x$
+  
+  as
+
+.. raw latex
+
+    $(f(x+\epsilon/2) - f(x-\epsilon/2)) / \epsilon$
+
+   instead of
+
+.. raw latex
+
+    $(f(x+\epsilon) - f(x)) / \epsilon$
+  
 
 Conclusion
 ==========