matthewmarkey's profile - activity

Kinetic Ubuntu 16.04

I have used the MSA to get all the appropriate files for Rviz motion planning simulation. It works perfectly with my custom 4DOF arm as well as will my custom move group python interface.

I now would like to take the next step and send these plans to gazebo. My first question is: is the demo_gazebo.launch that the MSA has written for me the correct launch file to preform motion planning in Gazebo? I have been attempting to figure out how the controllers work for several days now with no success.

After reading the material I have read, I am thoroughly confused on what controller <.yaml> file am supposed to utilize. My second question is, how am I supposed to use the appropriate launch files and .yaml files to get my model moving in gazebo? There are tutorials that use this type of file :

moveit_sim_hw_interface:
  joint_model_group: arm
  joint_model_group_pose: Home
# Settings for ros_control_boilerplate control loop
generic_hw_control_loop:
  loop_hz: 300
  cycle_time_error_threshold: 0.01
# Settings for ros_control hardware interface
hardware_interface:
  joints:
    - plat_joint
    - shoulder_joint
    - forearm_joint
    - wrist_joint
  sim_control_mode: 1  # 0: position, 1: velocity
# Publish all joint states
# Creates the /joint_states topic necessary in ROS
joint_state_controller:
  type: joint_state_controller/JointStateController
  publish_rate: 50
controller_list:
  []
arm:
  type: effort_controllers/JointPositionController
  joints:
    - plat_joint
    - shoulder_joint
    - forearm_joint
    - wrist_joint
  gains:
    plat_joint:
      p: 100
      d: 1
      i: 1
      i_clamp: 1
    shoulder_joint:
      p: 100
      d: 1
      i: 1
      i_clamp: 1
    forearm_joint:
      p: 100
      d: 1
      i: 1
      i_clamp: 1
    wrist_joint:
      p: 100
      d: 1
      i: 1
      i_clamp: 1

I have seen these files in this form:

controller_list:
  - name: arm
    action_ns: follow_joint_trajectory
    type: FollowJointTrajectory
    default: true
    joints:
      - plat_joint
      - shoulder_joint
      - forearm_joint
      - wrist_joint

as well as this way:

arm:
  # Publish all joint states -----------------------------------
    joint_state_controller:
      type: joint_state_controller/JointStateController
      publish_rate: 50
    # Position Controllers ---------------------------------------
    joint1_position_controller:
      type: effort_controllers/JointPositionController
      joint: plat_joint
      pid: {p: 0, i: 0.0, d: 0}
    joint2_position_controller:
      type: effort_controllers/JointPositionController
      joint: shoulder_joint
      pid: {p: 0, i: 0.0, d: 0}
    joint3_position_controller:
      type: effort_controllers/JointPositionController
      joint: forearm_joint
      pid: {p: 0, i: 0.0, d: 0}
    joint4_position_controller:
      type: effort_controllers/JointPositionController
      joint: wrist_joint
      pid: {p: 0, i: 0.0, d: 0}

When I run roslaunch arm_moveit_config demo_gazebo.launch:

-rviz simulation and motion planning spawns and works correctly

-gazebo spawn my robot model *not in the same position as the rviz model, the gazebo model looks collapsed as if affected by gravity with no controllers enabled and the model is slowly moving away from the origin.

-when I try to plan and execute the motion plan in rviz, the following following error appears in the window that roslaunch arm_moveit_config demo_gazebo.launch was run in:

[ INFO] [1589045034.162329986, 56.619000000]: SimpleSetup: Path simplification took 0.005122 seconds and changed from 3 to 2 states
[ INFO] [1589045034.165551729, 56.621000000]: Returned 0 controllers in list
[ERROR] [1589045034.165727411, 56.622000000]: Unable to identify any set of controllers that can actuate the specified joints: [ forearm_joint plat_joint shoulder_joint wrist_joint ]
[ERROR] [1589045034.166596511, 56.622000000]: Known controllers and their joints:

[ERROR] [1589045034.167526138, 56.622000000]: Apparently trajectory initialization failed
[ INFO] [1589045034.176038782, 56.632000000 ...

Hey friends,

I have a custom 4DOF arm I have whipped up and have been slogging through the tutorials but I feel like I am getting turned around easily now.

I am running Kinetic on Ubuntu 16.04 and have my Rviz and Moveit! setup working nicely. It can take plans and execute them as well as work quite nicely with my move group python interface. I have used the MSA to setup my Moveit files, and now would like to simulate my movements in gazebo and eventually tie in the custom arm.

My issue pops up when trying to run the files that were created by the MSA. Running demo_gazebo.launch from /arm_moveit_config yields this error:

[ERROR] [1588933219.280616367]: Failed to build tree: child link [base_link] of joint [dummy_joint] not found
[ERROR] [1588933219.518289973]: Failed to build tree: child link [base_link] of joint [dummy_joint] not found
[ERROR] [1588933219.520045115]: Unable to parse URDF from parameter '/robot_description'
[robot_state_publisher-7] process has died [pid 17994, exit code 255, cmd /opt/ros/kinetic/lib/robot_state_publisher/robot_state_publisher __name:=robot_state_publisher __log:=/home/homefolder/.ros/log/83c0a11e-9115-11ea-ad2a-001c429fcd02/robot_state_publisher-7.log].
log file: /home/homefolder/.ros/log/83c0a11e-9115-11ea-ad2a-001c429fcd02/robot_state_publisher-7*.log
[robot_state_publisher-7] restarting process
process[robot_state_publisher-7]: started with pid [18108]

Which continues to repeat until the program is killed. The Rviz and Gazebo windows pop up, but the model does not appear and they both show signs of error. After killing the program, there is also a warning that pops up before it dies:

Which I am unsure is a contributing factor to the first errors, or a product of them.

I have included my arm.xacro file below as well the launch file I am attempting to call.

Any suggestions or help is greatly appreciated.

m

arm.xacro

<?xml version="1.0"?>

<robot name="arm" xmlns:xacro="http://www.ros.org/wiki/xacro">

   <xacro:include filename="$(find version1_desc)/urdf/links_joints.xacro" />
   <xacro:include filename="$(find version1_desc)/urdf/arm.gazebo" />
   <create/>
   <gazebo>
     <plugin name="gazebo_ros_control" filename="libgazebo_ros_control.so">
       <robotNamespace>/arm</robotNamespace>
     </plugin>
   </gazebo>

<!--Dummy Link-->
    <link name="dummy_link"/>

<!-- Dummy End Effector -->
    <joint name="dummy_joint" type="fixed">
        <parent link="dummy_link"/>
        <child link="base_link"/>
      </joint>

<!--Base Link-->

    <m_link_mesh_c name = "base_link"
                     origin_rpy = "0 0 0" origin_xyz = "0 0 0" mass = "1.0"
                     meshfile = "package://version1_desc/meshes/base_link.dae"
                     meshscale  = "1 1 1"
                     ixx = "0.00153508333333" ixy = "0" ixz = "0" iyz = "0"
                     iyy = "0.00153508333333"
                     izz = "0.00245"
                     radius = "0.07" length= "0.061"/>

<!--Plat Joint-->

    <joint name="plat_joint" type="revolute">
        <parent link="base_link"/>
        <child link="plat_link"/>
        <origin rpy="0 0 0" xyz="0 0 0.0305"/>
        <limit lower="-1.5" upper="1.5" effort="1000" velocity="0.5"/>
        <axis xyz="0 0 1"/>
    </joint>

    <transmission name = "trans_plat">
        <type> transmission_interface/SimpleTransmission</type>
        <joint name= "plat_joint">
            <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
        </joint>
        <actuator name = "motor_plat">
            <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
            <mechanicalReduction>1</mechanicalReduction>
        </actuator>
    </transmission>

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