Changeset 520 for Modelica/branches/maintenance/2.2.1/Modelica/Mechanics/MultiBody/parts.mo

Timestamp:

07/29/2007 09:01:22 PM (18 months ago)

Author:

otter

Message:

Bug in MultiBody.Parts.FixedRotation corrected:
The torque balance was wrong in the following case:
- frame_b is in the spanning tree closer to the root

(usually this is frame_a).

- vector r from frame_a to frame_b is not zero

Files:

• Modelica/branches/maintenance/2.2.1/Modelica/Mechanics/MultiBody/parts.mo (modified) (1 diff)

Modelica/branches/maintenance/2.2.1/Modelica/Mechanics/MultiBody/parts.mo

@@ -573 +573 @@
       frame_b.R = Frames.absoluteRotation(frame_a.R, R_rel);
       zeros(3) = frame_a.f + Frames.resolve1(R_rel, frame_b.f);
-      zeros(3) = frame_a.t + Frames.resolve1(R_rel, frame_b.t) - cross(r,
-        frame_a.f);
+      zeros(3) = frame_a.t + Frames.resolve1(R_rel, frame_b.t) - cross(r, frame_a.f);
     else
       frame_a.R = Frames.absoluteRotation(frame_b.R, R_rel_inv);
       zeros(3) = frame_b.f + Frames.resolve1(R_rel_inv, frame_a.f);
-      zeros(3) = frame_b.t + Frames.resolve1(R_rel_inv, frame_a.t) + cross(r,
-        frame_b.f);
+      zeros(3) = frame_b.t + Frames.resolve1(R_rel_inv, frame_a.t) + cross(Frames.resolve1(R_rel_inv,r), frame_b.f);
     end if;
   end FixedRotation;