choosing frictional parameters of a cube for sliding [closed]

asked 2022-05-29 07:06:08 -0500

shameer gravatar image

I am trying to slide a cube using a robotic finger. I have a pre-computed joint-trajectory for the finger, that will execute a sliding motion once a contact is made is with the object. I expected the cube to slide when the motion is executed. However, I get a rolling kind of motion that prevent sliding, and the edge of cube seem to be sticky. Have I missed adding any parameters to the cube model? I use same value for mu and mu2 of the cube. Here is a gif of the simulation.

image description

My observation:

mu, mu2: 0.7-0.75 --> cube slides very quickly as soon as contact is made (without requiring sliding motion)

mu, mu2: 0.76-0.79 --> cube slides quickly as soon as contact is made (without requiring sliding motion)

mu, mu2: > 0.8 --> cube tries to roll instead of sliding (with sliding motion (shown in the figure))

I saved the world after spawning the hand from xacro file. I removed some elements in the world file as they are repetitive for other fingers. The world file is:

    <sdf version='1.6'>
  <world name='default'>
          <physics type="ode">
      <gravity>0.000000 0.000000 -9.810000</gravity>
    <model name='r_shadow_motor_right'>
    <link name='rh_ffdistal'>
        <pose frame=''>0.033 -0.01 0.412 0 -0 0</pose>
          <pose frame=''>0 0 0.013077 0 -0 0</pose>
        <collision name='rh_ffdistal_collision'>
          <pose frame=''>0 0 0 0 -0 0</pose>
              <scale>0.001 0.001 0.001</scale>
        <visual name='rh_ffdistal_visual'>
          <pose frame=''>0 0 0 0 -0 0</pose>
              <scale>0.001 0.001 0.001</scale>

cube model file is:

<?xml version="1.0"?>
<robot xmlns:xacro="" name="color_cube">

<xacro:property name="dx" value="0.06" /> <!-- length -->
<xacro:property name="dy" value="0.06" /> <!-- width -->
<xacro:property name="dz" value="0.06" /> <!-- height -->
<xacro:property name="mass" value="0.015" />

<gazebo reference="color_cube_link">
    <xacro:property name="object_mu" default="0.78" />
        <box size="${dx} ${dy} ${dz}"/>
</gazebo ...
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Closed for the following reason too localized by shameer
close date 2022-06-01 03:23:19.632563