The rotors don't spin

[sunnyshi0310]

Hi, after installing the BebopS, I run the command roslaunch bebop_simulator bebop_without_controller.launch. The quadrotor shows successfully, while when I run rostopic pub /gazebo/command/motor_speed mav_msgs/Actuators '{angular_velocities: [1000, 1000, 1000, 1000]}', the terminal shows publishing and latching message while the rotors of the aerial-robot don't spin.

Then I tried the roslaunch bebop_simulator task1_world.launch it shows the error Invalid <tag> tag: arg 'enable_imu' has already been declared. Arg xml is <arg default="true" name="enable_imu"/>

It will be very kind of you if anyone can help me with that. Thanks!!!

[welcome[bot]]

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[gsilano]

I suggest starting from #26, #25, #23, #19, and #4. If the problem still persists, please let me know.

[sunnyshi0310]

Hi, thanks for your reply. I have checked those issues but unfortunately they didn't help. I attached the screenshots when I tried to run roslaunch bebop_simulator bebop_without_controller.launch Everything seems work well but the rotors don't spin. btw, I work with Ubuntu 16.04 and Gazebo 7. Thanks in advance.

[gsilano]

As you can see, the gazebo/command/motor_speed topic does not have a connection with Gazebo. For this reason, the motors do not spin. Try to publish the same command on the bebop/command/motors or /command/motor_speed topic, and let me know. Also, could you send me the list of the available topics? I think there may be a typo in the README or in the launch file.

[sunnyshi0310]

Hi, thanks for your reply. I got three issues.

• When I try the roslaunch bebop_simulator bebop_without_controller.launch I publish the command on the bebop/command/motors topic and the quadrotor starts to run, but it runs randomly and dropped soon. So I decrease the angular velocity from 1000 to 100 and it stays at the origin with spinning rotors. So I think the problem is solved. :) That's its rqt_graph and rostopic list.I also tried it on the /command/motor_speed topic and the rotors don't spin.

• I try the roslaunch bebop_simulator task1_world.launch. It shows the error

• I run the roslaunch bebop_simulator task2_world.launch. The rotors don't spin and the robot stays in the origin. Its rqt_graph and rostopic list are shown as follows

Thanks again for your work.!!

[gsilano]

So, great. This means it works. I mean, we found the motor spin issue. Obviously, automatic control feedback is needed to control system behavior.

I just removed the typo. Please, try it again. Try to replace this line <remap from="/command/motor_speed" to="/gazebo/command/motor_speed" /> with this <!-- <remap from="/command/motor_speed" to="/gazebo/command/motor_speed" /> --> (simply comment it), and let me know.

[sunnyshi0310]

Hi, I comment the line <arg name="enable_imu" default="true"/> and run the roslaunch bebop_simulator task1_world.launch , while errors occur as follows:

[gsilano]

Replace the content of the file with this

<?xml version="1.0"?>
<launch>
    <arg name="name" default="bebop"/>
    <arg name="x" default="0.0" />
    <arg name="y" default="0.0" />
    <arg name="z" default="0.02" />
    <arg name="use_sim_time" default="true"/>
    <arg name="world_name" default="basic"/>
    <arg name="wind_force" default="0.5"/>
    <arg name="wind_start" default="15.0"/>
    <arg name="wind_duration" default="10.0"/>
    <arg name="wind_direction_x" default="0.0"/>
    <arg name="wind_direction_y" default="0.0"/>
    <arg name="wind_direction_z" default="1.0"/>
    <arg name="csvFilesStoring" default="false"/>
    <arg name="csvFilesStoringTime" default="15.0"/> <!-- seconds -->
    <arg name="user_account" default="giuseppe"/>
    <arg name="waypoint_filter" default="true"/>
    <arg name="EKFActive" default="false"/>
    <arg name="enable_imu" default="true"/>
    <arg name="enable_odometry_sensor_with_noise" default="false"/>
    <!-- The "disable_odometry_sensor_with_noise" variable values is equal to true if "enable_odometry_sensor_with_noise"
    is false, and viceversa -->
    <arg name="disable_odometry_sensor_with_noise" value="true" unless="$(arg enable_odometry_sensor_with_noise)"/>
    <arg name="disable_odometry_sensor_with_noise" value="false" if="$(arg enable_odometry_sensor_with_noise)"/>
    <arg name="enable_ground_truth_sensor" default="false"/>
    <arg name="enable_wind_plugin" default="false"/>
    <arg name="enable_laser1D" default="false"/>

  <env name="GAZEBO_MODEL_PATH" value="${GAZEBO_MODEL_PATH}:$(find bebop_simulator)/models"/>
  <env name="GAZEBO_RESOURCE_PATH" value="${GAZEBO_RESOURCE_PATH}:$(find bebop_simulator)/models"/>
  <include file="$(find gazebo_ros)/launch/empty_world.launch">
    <arg name="world_name" value="$(find bebop_simulator)/worlds/$(arg world_name).world" />
  </include>

    <!-- Launch UAV -->
    <include file="$(find bebop_simulator)/launch/spawn_bebop.launch">
       <arg name="name" value="$(arg name)" />
       <arg name="x" value="$(arg x)"/>
       <arg name="y" value="$(arg y)"/>
       <arg name="z" value="$(arg z)"/>
       <arg name="wind_force" value="$(arg wind_force)"/>
       <arg name="wind_start" value="$(arg wind_start)"/>
       <arg name="wind_duration" value="$(arg wind_duration)"/>
       <arg name="wind_direction_x" value="$(arg wind_direction_x)"/>
       <arg name="wind_direction_y" value="$(arg wind_direction_y)"/>
       <arg name="wind_direction_z" value="$(arg wind_direction_z)"/>
      <!-- The disable_odometry_sensor_with_noise will only become true if enable_odometry_sensor_with_noise will is false.
       In this way, only one odometry sensor will be simulated: with or without noise. -->
       <arg name="enable_odometry_sensor_with_noise" value="$(arg enable_odometry_sensor_with_noise)"/>
       <arg name="disable_odometry_sensor_with_noise" value="$(arg disable_odometry_sensor_with_noise)" /> 
       <arg name="enable_ground_truth_sensor" value="$(arg enable_ground_truth_sensor)"/>
       <arg name="enable_wind_plugin" value="$(arg enable_wind_plugin)"/>
       <arg name="enable_laser1D" value="$(arg enable_laser1D)"/>
       <arg name="enable_imu" value="$(arg enable_imu)"/>
    </include>

    <!-- Launch the controller  -->
    <node name="position_controller_node" pkg="bebop_simulator" type="position_controller_node" output="screen"> 
      <rosparam command="load" file="$(find bebop_simulator)/resource/controller_bebop.yaml" />
      <rosparam command="load" file="$(find bebop_simulator)/resource/bebop.yaml" />
      <rosparam command="load" file="$(find bebop_simulator)/resource/EKF_matrix.yaml" />
      <rosparam command="load" file="$(find bebop_simulator)/resource/waypoint_filter.yaml" />
      <param name="use_sim_time" value="$(arg use_sim_time)" />
      <param name="csvFilesStoring" value="$(arg csvFilesStoring)"/>
      <param name="csvFilesStoringTime" value="$(arg csvFilesStoringTime)"/>
      <param name="user_account" value="$(arg user_account)"/>
      <param name="waypoint_filter" value="$(arg waypoint_filter)"/>
      <param name="EKFActive" value="$(arg EKFActive)"/>
      <remap from="/odometry" to="/bebop/odometry" />
      <remap from="/odometry_gt" to="/bebop/odometry_gt" />
      <remap from="/referenceAngles" to="/bebop/referenceAngles" />
      <remap from="/filteredOutput" to="/bebop/filteredOutput" />
      <remap from="/stateErrors" to="/bebop/stateErrors" />
      <remap from="/smoothedTrajectory" to="/bebop/smoothedTrajectory" />
      <remap from="/command/trajectory" to="/bebop/command/trajectory" />
    </node>

    <!-- Launch the trajectory generator -->
   <group ns="$(arg name)">
       <node name="hovering_example" pkg="bebop_simulator" type="hovering_example" output="screen"/>   
    </group>

</launch>

[sunnyshi0310]

Hi, everything works well now in terms of the terminal. But the robot don't move when I run roslaunch bebop_simulator task1_world.launch or roslaunch bebop_simulator task2_world.launch. Should I do sth after run the launch file? Its topics and rqt_graph are listed here. I am really appreciated for your work and feel so sorry to bother you so much. :)

[gsilano]

Run the task1.launch file, and then publish a message on gazebo/command/motor_speed. Let me know if this fix the issue. If so, I will update the launch file in the repository.

rostopic pub /gazebo/command/motor_speed mav_msgs/Actuators '{angular_velocities: [1000, 1000, 1000, 1000]}'

[sunnyshi0310]

Hi, it performs same as I run roslaunch bebop_simulator bebop_without_controller.launch.

• When I run roslaunch bebop_simulator task1_world.launch and then rostopic pub /gabebop/command/motors mav_msgs/Actuators '{angular_velocities: [1000, 1000, 1000, 1000]}, nothing happens.

• Then I publish the commend on topic /bebop/command/motors , the robot starts to move (spins its rotors) but not achieve the objective of task 1 (Parrot Bebop takes off from the ground and keeps indefinitely the hovering position subjected to wind gusts (up to 0.5 N) for a minute. )

[gsilano]

Please, pull my last change and try again.

[sunnyshi0310]

Everything works now! Thanksssss!!!! btw, where is the code for landing? (or are there any command for landing?)

[gsilano]

There is no command for landing.