now0930 일지

Let’s go!

  • sdf? urdf?

    urdf로 모델을 그리려면 각 좌표값를 모두 알아야 한다. 수치를 넣어야 되는데 시간 많이 걸린다. 다행히도 gazebo가 제공하는 model 에디터로 사각형, 바퀴 등 을 쉽게 그릴 수 있다. 원하는 그림이 없다면 무료 프로그램인 blender로 스케치한 다음 stl, dae 파일로 export 후 gazebo에서 import하면 만족도가 높아진다.

    그런데 ros가 urdf를 정식으로 지원하고, sdf는 지원하지 않는 듯 하다. sdf만으로는 joint_state_publisher, robot_state_publisher를 제대로 이용할 수 없다. sdf와 urdf는 사용 분야가 다르고, 한 형식이 확장하는 개념은 아니다. ros에서 모델을 불러 제어하기 위해서는 어떻게든 sdf를 urdf로 바꿔야 한다고 결론을 냈다. 다행히 관련 스크립트를 찾을 수 있었다.

    https://ik-test.readthedocs.io/en/latest/pysdf/

    실행하면 sdf 1.7은 지원하지 않지만, parse.py의 supported_sdf_versions에 1.7을 추가하면 큰 무리없이 사용할 수 있다.(오픈소스의 위대함!!)

     22 mesh_path_env_name='MESH_WORKSPACE_PATH'
 23 if mesh_path_env_name in os.environ:
 24   catkin_ws_path = os.environ[mesh_path_env_name]
 25 else:
 26   catkin_ws_path = os.path.expanduser('~') + '/catkin_ws/src/'
 27 supported_sdf_versions = [1.4, 1.5, 1.6, 1.7]

    mesh 파일 부분을 넣는 부분이 잘 안되는데, stl 위치를 export로 넣어주면 된다. 찾은 stl, dae 모두 OR로 넣어주는데, 해당 부분을 찾아 정확하게 수정해야 한다.

    now0930@amd2004:~/ros_test/workspace/src/battery_agv$ tree
.
├── CMakeLists.txt
├── include
│   └── battery_agv
├── launch
│   ├── robot_description.launch
│   └── staion.launch
├── meshes
│   ├── axis_gear.stl
│   ├── stepperMotor.stl
│   └── stepperMotor3.stl
├── models
│   └── AGV
│       ├── axis_gear.stl
│       ├── model.config
│       ├── model.sdf
│       ├── stepperMotor.stl
│       └── stepperMotor3.stl
├── package.xml
├── src
│   └── red_green_light.py
├── urdf
│   ├── agv.urdf
│   └── agv.xacro
└── worlds
    └── testbed2

9 directories, 16 files
    <?xml version="1.0"?>
<robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="AGV">
  <joint name="AGV__link_bottomplate_JOINT_0" type="fixed">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_topplate"/>
    <origin xyz="0      -0.00667  1.86611" rpy="1.5708 0     0.01"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_bottomplate_JOINT_2" type="fixed">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_leftplate"/>
    <origin xyz="-8.80000e-04 -4.18110e-01  1.42999e+00" rpy="0.e+00  0.e+00 -2.e-05"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_bottomplate_JOINT_3" type="fixed">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_rightplate"/>
    <origin xyz="8.80000e-04 4.12490e-01 1.42998e+00" rpy="-3.14159  0       0"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_bottomplate_JOINT_4" type="revolute">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_leftwheel"/>
    <origin xyz="0.73669 -0.27702  1.05254" rpy="1.5708 0     0"/>
    <axis xyz="0 0 1"/>
    <limit lower="-1.79769e+308" upper="1.79769e+308" effort="-1.0" velocity="-1.0"/>
  </joint>
  <joint name="AGV__link_bottomplate_JOINT_5" type="revolute">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_rightwheel"/>
    <origin xyz="0.73669 0.27702 1.05434" rpy="1.5708 0     0"/>
    <axis xyz="0 0 1"/>
    <limit lower="-1.79769e+308" upper="1.79769e+308" effort="-1.0" velocity="-1.0"/>
  </joint>
  <joint name="AGV__link_bottomplate_JOINT_6" type="fixed">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_rightwheel0"/>
    <origin xyz="-0.73669  0.27702  1.05254" rpy="1.5708 0     0"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_bottomplate_JOINT_7" type="fixed">
    <parent link="AGV__link_bottomplate"/>
    <child link="AGV__link_leftwheel0"/>
    <origin xyz="-0.73669 -0.27702  1.05254" rpy="1.5708 0     0"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_loadingplate_JOINT_2" type="fixed">
    <parent link="AGV__link_loadingplate"/>
    <child link="AGV__link_rightgear"/>
    <origin xyz="0.87839 -0.40904 -0.19812" rpy="-1.57395e+00 -3.18700e-02  1.20000e-04"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_loadingplate_JOINT_3" type="fixed">
    <parent link="AGV__link_loadingplate"/>
    <child link="AGV__link_leftgear"/>
    <origin xyz="0.86434 -0.40766  0.24228" rpy="-1.57395e+00 -3.18700e-02  1.20000e-04"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_loadingplate_JOINT_4" type="fixed">
    <parent link="AGV__link_loadingplate"/>
    <child link="AGV__link_rightgear2"/>
    <origin xyz="-0.86391 -0.40925 -0.25368" rpy="-1.57395e+00 -3.18700e-02  1.20000e-04"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_loadingplate_JOINT_5" type="fixed">
    <parent link="AGV__link_loadingplate"/>
    <child link="AGV__link_leftgear2"/>
    <origin xyz="-0.87795 -0.40787  0.18672" rpy="-1.57395e+00 -3.18700e-02  1.20000e-04"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_topplate_JOINT_0" type="fixed">
    <parent link="AGV__link_topplate"/>
    <child link="AGV__link_motor"/>
    <origin xyz="-0.01114  0.04217 -0.43284" rpy="-1.00e-05  2.08e-03  0.00e+00"/>
    <axis xyz="0 0 0"/>
    <limit lower="0" upper="0" effort="0" velocity="0"/>
  </joint>
  <joint name="AGV__link_topplate_JOINT_6" type="prismatic">
    <parent link="AGV__link_topplate"/>
    <child link="AGV__link_loadingplate"/>
    <origin xyz="0.0000e+00 4.0032e-01 3.1000e-04" rpy="3.150e-03  2.187e-02 -2.000e-05"/>
    <axis xyz="0 0 1"/>
    <limit lower="0.0" upper="0.3" effort="-1.0" velocity="-1.0"/>
  </joint>
  <link name="AGV__link_leftplate">
    <inertial>
      <mass value="432.31"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="26.0634" ixy="0" ixz="0" iyy="184.903" iyz="0" izz="158.909"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_bottomplate">
    <inertial>
      <mass value="432.31"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="26.0634" ixy="0" ixz="0" iyy="184.903" iyz="0" izz="158.909"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 1" rpy="1.5708 0     0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 1" rpy="1.5708 0     0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_leftgear">
    <inertial>
      <mass value="20"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_leftgear2">
    <inertial>
      <mass value="20"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_leftwheel">
    <inertial>
      <mass value="10.3358"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0.107579" ixy="0" ixz="0" iyy="0.107579" iyz="0" izz="0.206717"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_leftwheel0">
    <inertial>
      <mass value="10.3358"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0.107579" ixy="0" ixz="0" iyy="0.107579" iyz="0" izz="0.206717"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_loadingplate">
    <inertial>
      <mass value="432.31"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="26.0634" ixy="0" ixz="0" iyy="184.903" iyz="0" izz="158.909"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_motor">
    <inertial>
      <mass value="1"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0.166667" ixy="0" ixz="0" iyy="0.166667" iyz="0" izz="0.166667"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/stepperMotor3.stl" scale="1 1 1"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/stepperMotor3.stl" scale="1 1 1"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_rightgear">
    <inertial>
      <mass value="20"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_rightgear2">
    <inertial>
      <mass value="20"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0" ixy="0" ixz="0" iyy="0" iyz="0" izz="0"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://battery_agv/meshes/axis_gear.stl" scale="1 1 1"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_rightplate">
    <inertial>
      <mass value="432.31"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="26.0634" ixy="0" ixz="0" iyy="184.903" iyz="0" izz="158.909"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_rightwheel">
    <inertial>
      <mass value="10.3358"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0.107579" ixy="0" ixz="0" iyy="0.107579" iyz="0" izz="0.206717"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_rightwheel0">
    <inertial>
      <mass value="10.3358"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="0.107579" ixy="0" ixz="0" iyy="0.107579" iyz="0" izz="0.206717"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <geometry>
        <cylinder radius="0.2" length="0.07"/>
      </geometry>
    </visual>
  </link>
  <link name="AGV__link_topplate">
    <inertial>
      <mass value="432.31"/>
      <origin xyz="0 0 0" rpy="0 0 0"/>
      <inertia ixx="26.0634" ixy="0" ixz="0" iyy="184.903" iyz="0" izz="158.909"/>
    </inertial>
    <collision name="AGV__collision">
      <origin xyz="0 0 0" rpy="0   -0.01  0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </collision>
    <visual name="AGV__visual">
      <origin xyz="0 0 0" rpy="0   -0.01  0"/>
      <geometry>
        <box size="2.1 0.01 0.85"/>
      </geometry>
    </visual>
  </link>
</robot>

    mesh는 package로 넣어야 하는 듯 한다. urdf로 R2D2를 만든 사람은 공간 감각이 뛰어나다.

    http://wiki.ros.org/urdf/Tutorials/Building%20a%20Visual%20Robot%20Model%20with%20URDF%20from%20Scratch

    잘 되다고 생각했으나, 문제가 있었다. 로봇이 제대로 움직이는지 확인하기 위해 joint_state_publisher를 실행해야 하는데, 프로세스가 죽는다. 왜 그런지 확인하기 어려웠는데, python 코드를 수정하여 어디에서 문제되는지 확인했다.

    833 [rospy.simtime][INFO] 2022-10-09 13:09:14,685: initializing /clock core topic
834 [rospy.simtime][INFO] 2022-10-09 13:09:14,688: connected to core topic /clock
835 [rosout][INFO] 2022-10-09 13:09:14,760: Centering
836 [rospy.core][INFO] 2022-10-09 13:09:14,798: signal_shutdown [atexit]
837 [rospy.impl.masterslave][INFO] 2022-10-09 13:09:14,801: atexit

    여기를 보면 centering 하다가 죽었음을 알았다. 왜 그런지 알 수 없으니, stdout에 표시된 코드를 보면 joint_state_publiser_gui의 182번 줄에서 죽었음을 확인했다.

    QStandardPaths: wrong ownership on runtime directory /run/user/1000, 1000 instead of 0
QStandardPaths: wrong ownership on runtime directory /run/user/1000, 1000 instead of 0
Traceback (most recent call last):
  File "/opt/ros/noetic/lib/joint_state_publisher_gui/joint_state_publisher_gui", line 52, in <module>
    jsp_gui = joint_state_publisher_gui.JointStatePublisherGui("Node: " + rospy.get_name(),
  File "/opt/ros/noetic/lib/python3/dist-packages/joint_state_publisher_gui/__init__.py", line 125, in __init__
    self.center()
  File "/opt/ros/noetic/lib/python3/dist-packages/joint_state_publisher_gui/__init__.py", line 182, in center
    joint_info['slider'].setValue(self.valueToSlider(joint['zero'], joint))
TypeError: setValue(self, int): argument 1 has unexpected type 'float'
[joint_state_publisher_gui-1] process has died [pid 11275, exit code 1, cmd /opt/ros/noetic/lib/joint_state_publisher_gui/joint_state_publisher_gui __name:=joint_state_publisher_gui __log:=/root/.ros/log/b95997f0-47a6-11ed-a96e-2cf05d88e0ec/joint_state_publisher_gui-1.log].
log file: /root/.ros/log/b95997f0-47a6-11ed-a96e-2cf05d88e0ec/joint_state_publisher_gui-1*.log

    해당부 코드를 고쳐보고, 로그를 출력시켜 보면

    75     def center_event(self, event):
176         self.center()
177 
178     def center(self):
179         rospy.loginfo("Centering")
180         for name, joint_info in self.joint_map.items():
181             ##debug
182             rospy.loginfo("debug")
183             joint = joint_info['joint']
184             rospy.loginfo(joint)
185             joint_info['slider'].setValue(self.valueToSlider(joi    nt['zero'], joint))

    결과를 다시 보면 argument 1이 min으로 들어온 -1.79..e+308임을 알았다.

    866 [rosout][INFO] 2022-10-09 13:13:17,733: Centering
867 [rosout][INFO] 2022-10-09 13:13:17,735: debug
868 [rosout][INFO] 2022-10-09 13:13:17,736: {'min': -1.79769e+308, 'max': 1.79769e+308, 'zero': 0, 'position': 0}
869 [rospy.core][INFO] 2022-10-09 13:13:17,780: signal_shutdown [atexit]

    limit를 적은 값으로 수정하면 된다.

     24   <joint name="AGV__link_bottomplate_JOINT_4" type="revolute">
 25     <parent link="AGV__link_bottomplate"/>
 26     <child link="AGV__link_leftwheel"/>
 27     <origin xyz="0.73669 -0.27702  1.05254" rpy="1.5708 0     0"/>
 28     <axis xyz="0 0 1"/>
 29     <limit lower="-0.2" upper="0.5" effort="-1.0" velocity="-1.0"/>
 30   </joint>

    그런데 해당 부분은 바퀴라서 type을 continuous로 수정해도 된다. sdf가 continuous type을 선택할 수 없었다. 이거 찾는다고 거의 4시간을 썼다. TF 표시는 gazebo가 실행되면 제대로 표시된다.

  • gmapping slam으로 지도 만들기

    여기 있는 gmapping, slam 튜토리얼을 했다. 튜토리얼은 상당히 쉽게 구성되어 있으나, 내가 실재로 해보면 잘 안된다. 왜 그런지 확인하기 위해 삽질을 했다. 해당 사이트에서 다운로드 받을 수 있는 rosbag 파일에 어떤 토픽이 저장되어 있는지 궁금했다. rqt가 제공하는 rosbag 플러그인으로 어떤 데이터가 있는지 확인했다.

    rosbag play로 실행하면 뭐가 잘못 되었는지 다음 메세지를 보았다. debug 레벨을 켜라는 소리인 듯 한데…

    [ WARN] [1664664315.511464153]: MessageFilter [target=odom ]: Dropped 100.00% of messages so far. Please turn the [ros.gmapping.message_filter] rosconsole logger to DEBUG for more information.

    rosconsole로 message filter 현재 상태를 확인하고 변경할 수 있다.

    root:workspace$rosconsole get /slam_gmapping ros.gmapping.message_filter
info
root:workspace$rosconsole set slam_gmapping ros.gmapping.message_filter debug

    rosbag에 -a 옵션을 주고 모든 데이터를 저장하면 지도를 만들 수 있다. 아래와 같이 tf와 scan 데이터만 저장한 다음 rosbag play를 실행하면 tf tree가 끊어져 있다. 정확하게는 basefoot_print와 base_link가 끊겨져 있고, scanner_link가 없다.

    ros@workspace$rosbag record /tf /laser/scan
[ INFO] [1664767902.638118674]: Subscribing to /laser/scan
[ INFO] [1664767902.642276643]: Subscribing to /tf
[ INFO] [1664767902.645339564]: Recording to '2022-10-03-03-31-42.bag'.
    ros@workspace$ros@bag$rosbag play --clock 2022-10-03-03-31-42.bag

    하나씩 해 보다가 /tf_static까지 record 해 보았다. 아, 힘들었다^^!

    ros@bag$rosbag record -o mydata /tf /tf_static /laser/scan
[ INFO] [1664769638.007469286]: Subscribing to /laser/scan
[ INFO] [1664769638.011680347]: Subscribing to /tf
[ INFO] [1664769638.014193685]: Subscribing to /tf_static
[ INFO] [1664769638.298793651, 1626.350000000]: Recording to 'mydata_2022-10-03-04-00-38.bag'.

    record한 결과를 보면 지도가 잘 생성됨을 확인했다. tf_tree를 보면

    위 빠진 tf_tree와 다르게 base_footprint와 base_link가, base_link와 scanner_link가 연결되었다. 왜 이렇게 결정되었는지 확인해 보면, urdf에 fixed라고 joint를 정의해서 그렇다. 아래 urdf를 정의한 부분을 확인해 보면 fixed로 joint를 정의했기 때문에 tf_static을 필요로 한다.

     42 
 43         <joint name = "base_footprint_fixed" type = "fixed">
 44                 <origin xyz = "0 0 0.03" rpy = "0 0 0"/>
 45                 <parent link = "base_footprint"/>
 46                 <child link = "base_link"/>
 47         </joint>
 48 

146         <joint name = "left_wheel_joint" type = "continuous">
147                 <origin xyz = "0.1 0.15 0" rpy = "0 0 0"/>
148                 <parent link = "base_link"/>
149                 <child link = "left_wheel"/>
150                 <axis xyz = "0 1 0"/>
151 
152         </joint>
153 
154         <joint name = "left_wheel_joint_back" type = "continuous">
155                 <origin xyz = "-0.1 0.15 0" rpy = "0 0 0"/>
156                 <parent link = "base_link"/>
157                 <child link = "left_wheel_back"/>
158                 <axis xyz = "0 1 0"/>
159 
160         </joint>
161 
162 


205         <joint name = "head_scanner" type = "fixed">
206                 <!-- rpy를 수정하면 카메라 각도가 바뀜-->
207                 <origin xyz = "0.15 0 0" rpy = "0 0 0"/>
208                 <parent link = "base_link"/>
209                 <child link = "scanner_link"/>
210         </joint>
211

    기록한 rosbag 파이을 보면, scan, tf, tf_static 3개가 들어가 있다.

    Coordinate Frames and Transforms for ROS-based Mobile Robots

  • gazebo plug in으로 robot move

    로봇을 불렀으면, cmd_vel 토픽으로 움직이고 싶다. 찾다보니 gazebo가 제공하는 plugin로 움직일 수 있음을 알았다. 플러그인 설정으로 어느 토픽을 읽어서 모델을 움직일지 결정한다.

    https://classic.gazebosim.org/tutorials?tut=ros_gzplugins

    gcamp_gazebo 샘플 프로그램을 참조 했다. gazebo로 로봇을 움직이려면 필요한 몇 개 파일을 만들어야 한다.

    now0930@amd2004:~/ros_test/workspace/src/wander_bot$ tree
.
├── CMakeLists.txt
├── gazebo_world.launch
├── launch
│   ├── hello.launch
│   ├── my_world.launch
│   └── robot_description.launch
├── log.txt
├── package.xml
├── src
│   └── red_green_light.py
├── urdf
│   ├── robot.gazebo
│   ├── robot.xacro
│   └── test.urdf
└── worlds
    ├── my_world
    └── my_world2

4 directories, 13 files

    roslaunch로 launch에 있는 my_world.launch에서 시작한다.

    oot@amd2004:/home/ros_test/workspace/src/wander_bot# cat launch/my_world.launch 
<?xml version="1.0" encoding="UTF-8"?>

<launch>
	<!-- Robot pose -->
	<arg name="x" default="0"/>
	<arg name="y" default="0"/>
	<arg name="z" default="0"/>
	<arg name="roll" default="0"/>
	<arg name="pitch" default="0"/>
	<arg name="yaw" default="0"/>
	<arg name="model_name"   default="agv_number1"/>



			<!-- We resume the logic in empty_world.launch, changing only the name of the world to be launched -->
		<include file="$(find gazebo_ros)/launch/empty_world.launch">
			<arg name="world_name" value="$(find wander_bot)/worlds/my_world2"/>
			<arg name="use_sim_time" value="true"/>
				<!-- more default parameters can be changed here -->
		</include>
		<arg name="package_name"  default="wander_bot" />
		<arg name="path"   value="(find $(arg package_name))" />
		<arg name="dollar" value="$" />

		<include file="$(arg dollar)$(arg path)/launch/robot_description.launch"/> 

			<!-- Spawn My Robot -->
			<!--
				<node name="urdf_spawner" pkg="gazebo_ros" type="spawn_model" respawn="false" output="screen" 
				args="-urdf -param robot_description -model $(arg model_name) 
				-x $(arg x) -y $(arg y) -z $(arg z)
				-R $(arg roll) -P $(arg pitch) -Y $(arg yaw)"/>
			-->
				<node name="urdf_spawner" pkg="gazebo_ros" type="spawn_model" respawn="false" output="screen" 
					args="-urdf -param robot_description -model $(arg model_name) 
					-x $(arg x) -y $(arg y) -z $(arg z)
					-R $(arg roll) -P $(arg pitch) -Y $(arg yaw)"/>


				<node name="test_node" pkg="wander_bot" type="red_green_light.py"
					args="/cmd_vel">
			</node>
		</launch>

        <include file="$(arg dollar)$(arg path)/launch/robot_description.launch"/>

    launch가 robot description을 실행하는데, command로 robot.xacro로 세부 설정을 한다. command가 아닌 다른 방식으로는 모델이 움직이지 않는다. robot description 내부에는 robot_description, joint_state_publisher, robot_state_publisher 3개를 설정한다.

    now0930@amd2004:~/ros_test/workspace/src/wander_bot$ cat launch/robot_description.launch 
<?xml version="1.0"?>
<launch>

	<!-- send urdf to param server -->
	<!-- xacro -->

	<param name="robot_description" command="$(find xacro)/xacro --inorder '$(find wander_bot)/urdf/robot.xacro'" />

		<!-- urdf or raw xml file -->
		<!-- <param name="robot_description" command="cat $(find museumGuide)/urdf_model/peoplebot.xml" /> -->

			<!-- Send fake joint values-->
		<node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
			<param name="use_gui" value="False"/>
		</node>

		<!-- Send robot states to tf -->
		<node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" respawn="false" output="screen"/>

	</launch>

    robot.xacro를 보면 

    now0930@amd2004:~/ros_test/workspace/src/wander_bot$ cat urdf/robot.xacro 
<?xml version="1.0" ?>
<robot name="mobile_robot" xmlns:xacro="http://www.ros.org/wiki/xacro">
	<material name="blue">
		<color rgba = "0 0 0.8 1"/>
	</material>

	<material name="gray">
		<color rgba = "1 1 1 1"/>
	</material>

	<material name="blueviolet">
		<color rgba = "0.54 0.16 0.88 1"/>
	</material>

	<link name = "base_footprint"/>

	<xacro:include filename="$(find wander_bot)/urdf/robot.gazebo" />

	<link name="base_link">
		<visual>
			<origin xyz="0 0 0" rpy = "0 0 0"/>
			<geometry>
				<box size = "0.3 0.24 0.1" rpy = "0 0 0" />
			</geometry>
			<material name = "gray"/>

		</visual>
		<collision>
			<origin xyz="0 0 0.03" rpy = "0 0 0"/>
			<geometry>
				<box size = "0.3 0.25 0.1" />
			</geometry>

		</collision>
		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="1.0"  iyz="0.0"  izz="1.0" />
		</inertial>

	</link>


	<joint name = "base_footprint_fixed" type = "fixed">
		<origin xyz = "0 0 0.03" rpy = "0 0 0"/>
		<parent link = "base_footprint"/>
		<child link = "base_link"/>
	</joint>


	<link name = "left_wheel">
		<visual>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>
			<material name ="blue"/>

		</visual>
		<collision>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>

		</collision>
		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="1.0"  iyz="0.0"  izz="1.0" />
		</inertial>



	</link>

	<link name = "right_wheel">
		<visual>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>
			<material name ="blue"/>

		</visual>
		<collision>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>

		</collision>

		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="1.0"  iyz="0.0"  izz="1.0" />
		</inertial>

	</link>


	<joint name = "left_wheel_joint" type = "continuous">
		<origin xyz = "0.1 0.15 0" rpy = "0 0 0"/>
		<parent link = "base_link"/>
		<child link = "left_wheel"/>
		<axis xyz = "0 1 0"/>

	</joint>

	<joint name = "right_wheel_joint" type = "continuous">
		<origin xyz = "0.1 -0.15 0" rpy = "0 0 0"/>
		<parent link = "base_link"/>
		<child link = "right_wheel"/>
		<axis xyz = "0 1 0" />

	</joint>

	<link name="scanner_link">
		<visual>
			<origin xyz="0 0 0" rpy = "0 0 0"/>
			<geometry>
				<cylinder length="0.05" radius="0.035"/>
			</geometry>
			<material name = "blueviolet"/>

		</visual>
		<collision>
			<origin xyz="0 0 0" rpy = "0 0 0"/>
			<geometry>
				<cylinder length="0.05" radius="0.035"/>
			</geometry>

		</collision>
		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="10.0"  iyz="0.0"  izz="1.0" />
		</inertial>

	</link>

	<joint name = "head_scanner" type = "fixed">
		<origin xyz = "0.15 0 0" rpy = "0 1.5708 0"/>
		<parent link = "base_link"/>
		<child link = "scanner_link"/>
	</joint>


	<ros>
		<namespace>/</namespace>
		<argument>/cmd_vel:=cmd_vel</argument>
	</ros>

</robot>

    여기에 gazebo 파일을 설정해야 한다.

    now0930@amd2004:~/ros_test/workspace/src/wander_bot/urdf$ cat robot.gazebo 
<?xml version="1.0"?>
<robot>
	<gazebo>
		<plugin name="differential_drive_controller" filename="libgazebo_ros_diff_drive.so">
			<legacyMode>false</legacyMode>
			<updateRate>10</updateRate>
			<alwaysOn>true</alwaysOn>
			<leftJoint>left_wheel_joint</leftJoint>
			<rightJoint>right_wheel_joint</rightJoint>
			<torque>10</torque>
			<robotBaseFrame>base_footprint</robotBaseFrame>
			<wheelSeparation>0.4</wheelSeparation>
			<wheelDiameter>0.2</wheelDiameter>
			<publishWheelTF>false</publishWheelTF>
			<publishTf>1</publishTf>
			<commandTopic>cmd_vel</commandTopic>
			<odometryTopic>odom</odometryTopic>
			<odometryFrame>odom</odometryFrame>
			<publishWheelJointState>false</publishWheelJointState>
			<rosDebugLevel>na</rosDebugLevel>
			<wheelAcceleration>0</wheelAcceleration>
			<wheelTorque>5</wheelTorque>
			<odometrySource>world</odometrySource>
			<publishOdomTF>true</publishOdomTF>

		</plugin>
	</gazebo>

</robot>

    모두 설정하고 roslaunch를 하면, 관성 모멘트가 잘못 되었는지 이상하게 움직인다.

  • gazebo에서 spawn model

    gazebo에서 spawn model

    물리 엔진을 가지고 있는 gazebo로 로봇을 만들지 않고도 쉽게 테스트 해 볼 수 있다. 기본 설정 파일이 있는데, 사용자가 취향에 맞춰 자유롭게 환경 설정을 할 수도 있다. 빈 공간에 각종 모듈을 불러 내 공간에 넣고, gazebo tutorial을 따르면 로봇도 spawn 가능하다.

    Programming Robots With Ros 책 144p에 보면 간단한 python 파일을 만들고 gazebo에 로딩하는 내용이 있다.

    http://wiki.ros.org/simulator_gazebo/Tutorials/SpawningObjectInSimulation

    https://github.com/ros-simulation/gazebo_ros_pkgs/issues/864

    사용자가 만든 urdf 파일을 gazebo 가상 환경에 spawn 할 수 있다. 다만 inetia를 모두 입력해야(틀린 값이라도 입력해야) gazebo가 인식한다. spawn_model가 gazebo_ros 패키지에 포함되어 있다. inetia 값을 입력하지 않으면 로딩이 안된다. 중간에 나오는 spawn service failed는 무시해도 괜찮은 듯 하다. 어쨋든 굴러 가니까.

    [INFO] [1662392890.824294, 55.975000]: Spawn status: SpawnModel: Entity pushed to spawn queue, but spawn service timed out waiting for entity to appear in simulation under the name agv_number1
[ERROR] [1662392890.827400, 55.975000]: Spawn service failed. Exiting.
    https://github.com/ros-simulation/gazebo_ros_pkgs/issues/864

    launch 파일이다.

    <?xml version="1.0" encoding="UTF-8"?>

<launch>
	<!-- Robot pose -->
	<arg name="x" default="0"/>
	<arg name="y" default="0"/>
	<arg name="z" default="1"/>
	<arg name="roll" default="3.14"/>
	<arg name="pitch" default="2"/>
	<arg name="yaw" default="0"/>
	<arg name="model_name"   default="agv_number1"/>

		<!--<param name="robot_description" command = "cat $(find wander_bot)/urdf/robot.urdf"/>-->

			<!-- We resume the logic in empty_world.launch, changing only the name of the world to be launched -->
		<include file="$(find gazebo_ros)/launch/empty_world.launch">
			<arg name="world_name" value="$(find wander_bot)/worlds/my_world"/>
			<arg name="use_sim_time" value="true"/>
				<!-- more default parameters can be changed here -->
		</include>

		<param name="robot_description" textfile = "$(find wander_bot)/urdf/robot.urdf" /> 
			<!-- Spawn My Robot -->
			<!--
				<node name="urdf_spawner" pkg="gazebo_ros" type="spawn_model" respawn="false" output="screen" 
				args="-urdf -param robot_description -model $(arg model_name) 
				-x $(arg x) -y $(arg y) -z $(arg z)
				-R $(arg roll) -P $(arg pitch) -Y $(arg yaw)"/>
			-->
				<node name="urdf_spawner" pkg="gazebo_ros" type="spawn_model" respawn="false" output="screen" 
					args="-urdf -param robot_description -model $(arg model_name) 
					-x $(arg x) -y $(arg y) -z $(arg z)
					-R $(arg roll) -P $(arg pitch) -Y $(arg yaw)"/>


				<node name="test_node" pkg="wander_bot" type="red_green_light.py"
					args="/cmd_vel">
			</node>
		</launch>

    urdf 파일이다.

    <?xml version="1.0" ?>
<robot name="mobile_robot" xmlns:xacro="http://www.ros.org/wiki/xacro">
	<material name="blue">
		<color rgba = "0 0 0.8 1"/>
	</material>

	<material name="gray">
		<color rgba = "1 1 1 1"/>
	</material>

	<material name="blueviolet">
		<color rgba = "0.54 0.16 0.88 1"/>
	</material>



	<link name = "base_footprint"/>

	<link name="base_link">
		<visual>
			<origin xyz="0 0 0" rpy = "0 0 0"/>
			<geometry>
				<box size = "0.3 0.24 0.1" rpy = "0 0 0" />
			</geometry>
			<material name = "gray"/>

		</visual>
		<collision>
			<origin xyz="0 0 0.03" rpy = "0 0 0"/>
			<geometry>
				<box size = "0.3 0.25 0.1" />
			</geometry>

		</collision>
		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="100.0"  iyz="0.0"  izz="1.0" />
		</inertial>

	</link>


	<joint name = "base_footprint_fixed" type = "fixed">
		<origin xyz = "0 0 0.03" rpy = "0 0 0"/>
		<parent link = "base_footprint"/>
		<child link = "base_link"/>
	</joint>


	<link name = "left_wheel">
		<visual>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>
			<material name ="blue"/>

		</visual>
		<collision>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>

		</collision>
		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="100.0"  iyz="0.0"  izz="1.0" />
		</inertial>



	</link>

	<link name = "right_wheel">
		<visual>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>
			<material name ="blue"/>

		</visual>
		<collision>
			<origin xyz = "0 0 0" rpy = "1.570796 0 0" />
			<geometry>
				<cylinder length = "0.05" radius = "0.08" />
			</geometry>

		</collision>

		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="100.0"  iyz="0.0"  izz="1.0" />
		</inertial>

	</link>


	<joint name = "left_wheel_joint" type = "continuous">
		<origin xyz = "0.1 0.15 0" rpy = "0 0 0"/>
		<parent link = "base_link"/>
		<child link = "left_wheel"/>
		<axis xyz = "0 1 0"/>

	</joint>

	<joint name = "right_wheel_joint" type = "continuous">
		<origin xyz = "0.1 -0.15 0" rpy = "0 0 0"/>
		<parent link = "base_link"/>
		<child link = "right_wheel"/>
		<axis xyz = "0 1 0" />

	</joint>

	<link name="scanner_link">
		<visual>
			<origin xyz="0 0 0" rpy = "0 0 0"/>
			<geometry>
				<cylinder length="0.05" radius="0.035"/>
			</geometry>
			<material name = "blueviolet"/>

		</visual>
		<collision>
			<origin xyz="0 0 0" rpy = "0 0 0"/>
			<geometry>
				<cylinder length="0.05" radius="0.035"/>
			</geometry>

		</collision>
		<inertial>
			<mass value = "1.0" />
			<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="100.0"  iyz="0.0"  izz="1.0" />
		</inertial>

	</link>

	<joint name = "head_scanner" type = "fixed">
		<origin xyz = "0.15 0 0" rpy = "0 1.5708 0"/>
		<parent link = "base_link"/>
		<child link = "scanner_link"/>
	</joint>

</robot>

    직접 해보기도 좋지만, 남이 한 프로젝트를 보는게 더 빠르다.

  • 코로나 디바이드 시대가 온다

    코로나 디바이드 시대가 온다

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