Why car model continuing jump After load controller_manage？

[Joeylllshen]

Hello,

Recently , I was working on smart car project . Use gazebo simulate smart car .

where I just load one joint controller " right_back_wheel_velocity_controller". ( If I load all controller , model parts rapid and no rules move, then the car will split into parts , stop at zeros.)

when I start ROS launch (see roslaunch mycar.launch), and pressed down start in gazebo. my car fall down , then car continual jump? The rqt_graph figure see figure.1 .

Then check topic /mycar/joint_states , find that acting a effort on joint, this is limit value in xacro. See figure.2.

After that, I use rqt_controller_mananger manual load "right_back_wheel_velocity_controller" or other controller , the problem also like above . Stop controller, car stop.

I think the problem is with the controller, or my parameters? Or something?

But Why would my car continuing jump after I load controller_manage ? and Why does load controller then would have a effort acting on joint ?

• roslaunch mycar.launch

  <?xml version="1.0"?>
  <launch>
  <arg name="world_name" default="mycar" />
  <arg name="gui" default="true" />
  <arg name="run_camera" default="false"/>
  
  <arg name="x_pos" default="0.0"/>
  <arg name="y_pos" default="0.0"/>
  <arg name="z_pos" default="-0.01"/>
  
  <include file="$(find gazebo_ros)/launch/empty_world.launch">
    <arg name="world_name" value="$(find mycar_gazebo)/worlds/$(arg world_name).world"/>
    <arg name="paused" value="true" />
    <arg name="gui" value="$(arg gui)"/>
  </include>
  
  <!-- urdf xml robot description loaded on the Parameter Server, converting the xacro into a proper urdf file-->
  <param name="robot_description" command="$(find xacro)/xacro '$(find mycar_description)/urdf/mycar.xacro'" />
  
  <!-- push robot_description to factory and spawn robot in gazebo -->
  <node name="mycar_spawn" pkg="gazebo_ros" type="spawn_model" output="screen" args="-urdf -param robot_description -model mycar -x $(arg x_pos) -y $(arg y_pos) -z $(arg z_pos)" />
  
  <!-- ros_control racecar launch file -->
  <include file="$(find mycar_control)/launch/mycar_control2.launch" ns="/"/>
  
  <!-- Spawn the MUXs -->
  <!--
  <arg name="racecar_version" default="racecar-v2" />
  <include file="$(find racecar)/launch/mux.launch" ns="vesc" />
  -->
  <!-- Publish "better odom" topic that is normally generated by the particle filter -->
  <!--
  <node name="better_odom" pkg="topic_tools" type="relay"
        args="/vesc/odom /pf/pose/odom" />
  --> 
  <!--Launch the simulation joystick control-->
  <!--
  <rosparam command="load" file="$(find mycar_gazebo)/config/keyboard_teleop.yaml" />
  <node pkg="mycar_gazebo" type="keyboard_teleop.py" name="keyboard_teleop" />
  -->
  </launch>

• mycar_control2.launch

  
  <?xml version='1.0'?>

* mycar.xacro part
```xml 
  <joint
    name="right_back_wheel_joint"
    type="continuous">
    <origin
      xyz="-0.013597 0.034853 0.060173"
      rpy="-3.1416 0.40836 -1.5746" />
    <parent
      link="base_link" />
    <child
      link="right_back_wheel" />
    <axis
      xyz="0 1 0" />
    <limit
      effort="10"
      velocity="1000" /> 
  </joint>

  <transmission name="right_back_wheel_transmission">
      <type>transmission_interface/SimpleTransmission</type>
      <joint name="right_back_wheel_joint">
          <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
      </joint>
      <actuator name ="right_back_wheel_motor">
          <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
          <mechanicalReduction>1</mechanicalReduction>
      </actuator>
  </transmission>

  <link
    name="left_back_wheel">

• fig.1 rqt_graph

• fig.2 gazebo model and joint topic

[Joeylllshen]

I may find a problem. It seems that the quality of the parts is too light. The mass is too light after I export it with SOLIDWORK tool?