I have already turned the torque way down and experimented with changing the masses. I added the additional parameters you suggested as well. Unfortunately it didn't really change much. The best that I have been able to do so far is to keep the velocity low. In my particular case it would be better if I could turn some of the physics off for just the robot's wheels and have it behave more like it does in Stage. I have done some experimentation with Microsoft Robotics Developer Studio as well. When I modeled the same robot there, they recommended that the wheels should just be set to a given velocity instead of having the physics engine try to compute their behavior.
On Thu, 2010-04-01 at 12:58 -0700, Nate Koenig wrote: > Hello, > > You can reduce the torque parameter, and play with the masses. > > You can also modify the friction of the wheels. To do this add a the > following parameters to a geom: > > <geom ...> > <kp>100000000</kp> > <kd>1.0</kd> <!-- Damping constraint --> > <bounce>0.0</bounce> <!-- How bouncy the surface is --> > <bounceVel>10</bounceVel> <!-- MAx velocity before bounce is applied --> > <mu1> BIG NUMBER </mu1> > <mu2> BIG NUMBER </mu2> > <slip1> small number (0.01) </slip1> > <slip2> small number (0.01)</slip2> > </geom> > > The ODE manual has descriptions of all these parameters. > > -nate > > On Sun, Mar 28, 2010 at 9:41 PM, David Michal <[email protected]> > wrote: > > I have modeled a differential drive robot in Gazebo. The problem is > > that when I driver the robot from Player it seems to have quite a bit of > > inertia. When turning to the left or the right it overshoots the target > > quite a bit. The real robot uses stepper motors so that once you tell > > it to stop turning it does. Is there a way to get Gazebo to better > > model a stepper motor? I am using Player 3.0.1, Gazebo 0.9.0, and ODE > > 0.11.1. > > > > Here is what I have in the model file. > > > > <body:cylinder name="left_wheel_body"> > > <xyz>0.0 0.1325 -0.2032</xyz> > > <rpy>0 90 90</rpy> > > <geom:cylinder name="left_wheel_geom"> > > <size>.0635 .032</size> > > <mass>0.5</mass> > > <visual> > > <rpy>0 0 90</rpy> > > <size>0.127 0.127 0.032</size> > > <mesh>drivewheel.mesh</mesh> > > <material>Gazebo/Black</material> > > </visual> > > </geom:cylinder> > > </body:cylinder> > > > > <body:cylinder name="right_wheel_body"> > > <xyz>0.0 -0.1325 -0.2032</xyz> > > <rpy>0 90 90</rpy> > > <geom:cylinder name="right_wheel_geom"> > > <size>.0635 .032</size> > > <mass>0.5</mass> > > <visual> > > <rpy>0 0 90</rpy> > > <size>0.127 0.127 0.032</size> > > <mesh>drivewheel.mesh</mesh> > > <material>Gazebo/Black</material> > > </visual> > > </geom:cylinder> > > </body:cylinder> > > > > <joint:hinge name="left_wheel_joint"> > > <body1>left_wheel_body</body1> > > <body2>chassis_body</body2> > > <anchor>left_wheel_body</anchor> > > <anchorOffset>0 0 0</anchorOffset> > > <axis>0 1 0</axis> > > <erp>0.8</erp> > > <cfm>10e-5</cfm> > > </joint:hinge> > > > > <joint:hinge name="right_wheel_joint"> > > <body1>right_wheel_body</body1> > > <body2>chassis_body</body2> > > <anchor>right_wheel_body</anchor> > > <anchorOffset>0 0 0</anchorOffset> > > <axis>0 1 0</axis> > > <erp>0.8</erp> > > <cfm>10e-5</cfm> > > </joint:hinge> > > > > <controller:differential_position2d name="controller1"> > > <leftJoint>right_wheel_joint</leftJoint> > > <rightJoint>left_wheel_joint</rightJoint> > > <wheelSeparation>0.265</wheelSeparation> > > <wheelDiameter>0.127</wheelDiameter> > > <torque>1</torque> > > <interface:position name="position_iface_0"/> > > </controller:differential_position2d> > > > > > > > > ------------------------------------------------------------------------------ > > Download Intel® Parallel Studio Eval > > Try the new software tools for yourself. Speed compiling, find bugs > > proactively, and fine-tune applications for parallel performance. > > See why Intel Parallel Studio got high marks during beta. > > http://p.sf.net/sfu/intel-sw-dev > > _______________________________________________ > > Playerstage-gazebo mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > > > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Playerstage-gazebo mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Playerstage-gazebo mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/playerstage-gazebo
