Wheel slippery, wrong direction and not straight
Hi,
created a differential drive robot with a ball caster. Tried to set mu1 and mu2 values of the wheels to values >1 and <1 for the caster. But the robot stands still and the wheels are slipping. Sometimes it moves slowly around the caster.
You may find the xacro files here: Robot definition
Thanks for your help and any ideas.
UPDATE: Tried to add a fixed joint with a link of a box with mass of 10. (idea was to get more weight on the wheels - just a stupid idea because of frustration :) ) -> nothing changed. Bot seems to be fixed around the caster and the wheels spin around and are slipping.
Anybody any advise?
UPDATE 2: I just recognized that the wheels are turning backwards when i use the i key in teleop. I changed the wheel separation parameter in the differencial drive plugin for gazebo. Robot now moves a little bit but really strange, it not moves straight forward ihr backward. It slips sidewise. See video. video
BR Marco
Update: Added content of xacro files:
hallrover_v2.xacro
<?xml version="1" ?>
<robot name="hallrover_v2" xmlns:xacro="http://www.ros.org/wiki/xacro">
<xacro:property name="hallrover_body_width" value="0.20"/>
<xacro:property name="hallrover_body_length" value="1.50"/>
<xacro:property name="hallrover_body_heigth" value="0.10"/>
<xacro:property name="hallrover_frame_heigth" value="0.05"/>
<xacro:property name="hallrover_frame_width" value="1.34"/>
<!-- - roller_length*2 + roller_body_space*2 + hallrover_body_width + hallrover_frame_thick*2 -->
<xacro:property name="hallrover_frame_length" value="1.50"/>
<xacro:property name="hallrover_frame_thick" value="0.05"/>
<!-- hallrover_frame_height -->
<xacro:property name="roller_length" value="0.50"/>
<xacro:property name="roller_diam" value="0.25"/>
<xacro:property name="roller_body_space" value="0.02"/>
<!-- Import all Gazebo-customization elements, including Gazebo colors -->
<xacro:include filename="$(find hallrover_v2)/urdf/hallrover_v2.gazebo"/>
<xacro:include filename="$(find hallrover_v2)/urdf/makros.xacro"/>
<gazebo>
<material>Gazebo/White</material>
</gazebo>
<link name="base_footprint">
<visual>
<origin xyz="0 0 0" rpy="0 0 0" />
<geometry>
<box size="0.001 0.001 0.001" />
</geometry>
</visual>
</link>
<joint name="base_joint" type="fixed">
<parent link="base_footprint"/>
<child link="base_link"/>
<origin xyz="0 0 ${roller_diam}" rpy="0 0 0" />
</joint>
<gazebo reference="base_footprint">
<mu1 value="0.01"/>
<mu2 value="0.01"/>
<fdir1 value="1 1 0"/>
<material>Gazebo/White</material>
</gazebo>
<link name="base_link">
<visual>
<geometry>
<box size="${hallrover_body_width} ${hallrover_body_length} ${hallrover_body_heigth}"/>
</geometry>
<origin xyz="0 0 0"/>
<material name="white">
<color rgba="1 1 1 1"/>
</material>
</visual>
<collision>
<geometry>
<box size="${hallrover_body_width} ${hallrover_body_length} ${hallrover_body_heigth}"/>
<!-- TODO change size to hallrover frame -->
</geometry>
</collision>
<!-- <xacro:box_inertia m="10" x="${hallrover_body_width}" y="${hallrover_body_length}" z="${hallrover_body_heigth}"/>-->
<xacro:box_inertial mass="2" x="${hallrover_body_width}" y="${hallrover_body_length}" z="${hallrover_body_heigth}"/>
</link>
<gazebo reference="base_link">
<mu1 value="0.01"/>
<mu2 value="0.01"/>
<fdir1 value="1 1 0"/>
<material>Gazebo/White</material>
</gazebo>
<xacro:include filename="$(find hallrover_v2)/urdf/hallrover_rollers_v2.xacro"/>
hallrover_rollers_v2.xacro
<?xml version="1" ?>
<robot xmlns:xacro="http://www.ros.org/wiki/xacro">
<link name="roller_left">
<visual>
<geometry>
<cylinder length="${roller_length}" radius="${roller_diam /2}"/>
</geometry>
<origin rpy="0 ${pi/2} 0" xyz="0 0 0"/>
<material name="black">
<color rgba ...
Could you please update your question with the contents of the
xacro
files? That way the question will be self-contained (should your files disappear from your Dropbox) and currently we have to download your files to view them.Sure, thanks for advise. File content was added. BR Marco
@jayess@Boregard Did you find the fix for the robot moving backward rather than forward on "i" key press of teleop_twist_keyboard ?