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Add cart-pole demo (#289) (#291)
(cherry picked from commit 27af210) Co-authored-by: Christoph Fröhlich <[email protected]>
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‎doc/index.rst

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@@ -10,12 +10,6 @@ This is a ROS 2 package for integrating the *ros2_control* controller architectu
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This package provides a Gazebo-Sim system plugin which instantiates a *ros2_control* controller manager and connects it to a Gazebo model.
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.. image:: img/gz_ros2_control.gif
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:alt: Cart
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.. image:: img/diff_drive.gif
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:alt: DiffBot
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Usage
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======
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gz_ros2_control_demos
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==========================================
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There are some examples in the *gz_ros2_control_demos* package. These examples allow to launch a cart in a 30 meter rail.
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There are some examples in the *gz_ros2_control_demos* package.
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Cart on rail
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-----------------------------------------------------------
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These examples allow to launch a cart in a 30 meter rail.
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.. image:: img/gz_ros2_control.gif
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:alt: Cart
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You can run some of the example configurations by running the following commands:
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ros2 launch gz_ros2_control_demos cart_example_position.launch.py
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ros2 launch gz_ros2_control_demos cart_example_velocity.launch.py
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ros2 launch gz_ros2_control_demos cart_example_effort.launch.py
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ros2 launch gz_ros2_control_demos diff_drive_example.launch.py
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ros2 launch gz_ros2_control_demos tricycle_drive_example.launch.py
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When the Gazebo world is launched, you can run some of the following commands to move the cart.
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ros2 run gz_ros2_control_demos example_position
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ros2 run gz_ros2_control_demos example_velocity
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ros2 run gz_ros2_control_demos example_effort
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Mobile robots
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-----------------------------------------------------------
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.. image:: img/diff_drive.gif
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:alt: DiffBot
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You can run some of the mobile robots running the following commands:
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.. code-block:: shell
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ros2 launch gz_ros2_control_demos diff_drive_example.launch.py
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ros2 launch gz_ros2_control_demos tricycle_drive_example.launch.py
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When the Gazebo world is launched you can run some of the following commands to move the robots.
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.. code-block:: shell
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ros2 run gz_ros2_control_demos example_diff_drive
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ros2 run gz_ros2_control_demos example_tricycle_drive
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The following example shows parallel gripper with mimic joint:
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Gripper
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-----------------------------------------------------------
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The following example shows a parallel gripper with a mimic joint:
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.. code-block:: shell
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Send example commands:
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.. code-block:: shell
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ros2 run gz_ros2_control_demos example_gripper
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Pendulum with passive joints (cart-pole)
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-----------------------------------------------------------
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The following example shows a cart with a pendulum arm:
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.. code-block:: shell
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ros2 launch gz_ros2_control_demos pendulum_example_effort.launch.py
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ros2 run gz_ros2_control_demos example_effort
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This uses the effort command interface for the cart's degree of freedom on the rail. To demonstrate that the physics of the passive joint of the pendulum is solved correctly even with the position command interface, run
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.. code-block:: shell
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ros2 launch gz_ros2_control_demos pendulum_example_position.launch.py
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ros2 run gz_ros2_control_demos example_position

‎gz_ros2_control_demos/launch/pendulum_example_effort.launch.py

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# Copyright 2024 ros2_control Development Team
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from launch import LaunchDescription
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from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
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from launch.actions import RegisterEventHandler
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from launch.event_handlers import OnProcessExit
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from launch.launch_description_sources import PythonLaunchDescriptionSource
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from launch.substitutions import Command, FindExecutable, LaunchConfiguration, PathJoinSubstitution
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from launch_ros.actions import Node
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from launch_ros.substitutions import FindPackageShare
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def generate_launch_description():
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# Launch Arguments
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use_sim_time = LaunchConfiguration('use_sim_time', default=True)
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# Get URDF via xacro
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robot_description_content = Command(
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[
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PathJoinSubstitution([FindExecutable(name="xacro")]),
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" ",
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PathJoinSubstitution(
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[FindPackageShare("gz_ros2_control_demos"),
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"urdf", "test_pendulum_effort.xacro.urdf"]
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),
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]
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)
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robot_description = {"robot_description": robot_description_content}
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node_robot_state_publisher = Node(
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package='robot_state_publisher',
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executable='robot_state_publisher',
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output='screen',
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parameters=[robot_description]
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)
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gz_spawn_entity = Node(
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package='ros_gz_sim',
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executable='create',
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output='screen',
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arguments=["-topic", "robot_description",
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"-name", "cart", "-allow_renaming", "true"],
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)
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load_joint_state_broadcaster = ExecuteProcess(
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cmd=['ros2', 'control', 'load_controller', '--set-state', 'active',
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'joint_state_broadcaster'],
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output='screen'
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)
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load_joint_effort_controller = ExecuteProcess(
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cmd=['ros2', 'control', 'load_controller',
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'--set-state', 'active', 'effort_controller'],
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output='screen'
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)
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return LaunchDescription([
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# Launch gazebo environment
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IncludeLaunchDescription(
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PythonLaunchDescriptionSource(
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[PathJoinSubstitution([FindPackageShare('ros_gz_sim'),
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'launch',
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'gz_sim.launch.py'])]),
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launch_arguments=[('gz_args', [' -r -v 3 empty.sdf'])]),
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RegisterEventHandler(
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event_handler=OnProcessExit(
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target_action=gz_spawn_entity,
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on_exit=[load_joint_state_broadcaster],
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)
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),
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RegisterEventHandler(
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event_handler=OnProcessExit(
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target_action=load_joint_state_broadcaster,
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on_exit=[load_joint_effort_controller],
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)
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),
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node_robot_state_publisher,
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gz_spawn_entity,
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# Launch Arguments
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DeclareLaunchArgument(
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'use_sim_time',
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default_value=use_sim_time,
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description='If true, use simulated clock'),
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])

‎gz_ros2_control_demos/launch/pendulum_example_position.launch.py

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# Copyright 2024 ros2_control Development Team
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from launch import LaunchDescription
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from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
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from launch.actions import RegisterEventHandler
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from launch.event_handlers import OnProcessExit
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from launch.launch_description_sources import PythonLaunchDescriptionSource
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from launch.substitutions import Command, FindExecutable, LaunchConfiguration, PathJoinSubstitution
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from launch_ros.actions import Node
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from launch_ros.substitutions import FindPackageShare
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def generate_launch_description():
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# Launch Arguments
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use_sim_time = LaunchConfiguration('use_sim_time', default=True)
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# Get URDF via xacro
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robot_description_content = Command(
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[
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PathJoinSubstitution([FindExecutable(name="xacro")]),
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" ",
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PathJoinSubstitution(
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[FindPackageShare("gz_ros2_control_demos"),
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"urdf", "test_pendulum_position.xacro.urdf"]
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),
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]
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)
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robot_description = {"robot_description": robot_description_content}
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node_robot_state_publisher = Node(
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package='robot_state_publisher',
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executable='robot_state_publisher',
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output='screen',
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parameters=[robot_description]
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)
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gz_spawn_entity = Node(
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package='ros_gz_sim',
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executable='create',
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output='screen',
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arguments=["-topic", "robot_description",
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"-name", "cart", "-allow_renaming", "true"],
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)
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load_joint_state_broadcaster = ExecuteProcess(
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cmd=['ros2', 'control', 'load_controller', '--set-state', 'active',
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'joint_state_broadcaster'],
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output='screen'
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)
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load_joint_trajectory_controller = ExecuteProcess(
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cmd=['ros2', 'control', 'load_controller', '--set-state', 'active',
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'joint_trajectory_controller'],
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output='screen'
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)
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return LaunchDescription([
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# Launch gazebo environment
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IncludeLaunchDescription(
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PythonLaunchDescriptionSource(
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[PathJoinSubstitution([FindPackageShare('ros_gz_sim'),
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'launch',
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'gz_sim.launch.py'])]),
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launch_arguments=[('gz_args', [' -r -v 4 empty.sdf'])]),
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RegisterEventHandler(
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event_handler=OnProcessExit(
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target_action=gz_spawn_entity,
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on_exit=[load_joint_state_broadcaster],
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)
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),
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RegisterEventHandler(
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event_handler=OnProcessExit(
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target_action=load_joint_state_broadcaster,
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on_exit=[load_joint_trajectory_controller],
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)
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),
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node_robot_state_publisher,
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gz_spawn_entity,
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# Launch Arguments
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DeclareLaunchArgument(
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'use_sim_time',
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default_value=use_sim_time,
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description='If true, use simulated clock'),
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])

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