[Example 14] Modular robot with actuators not providing states

README.md

@@ -62,6 +62,8 @@ The following examples are part of this demo repository:
 
 * Example 13: "Multi-robot example (tba.)"
 
+* Example 14: ["Modular robots with actuators not providing states and with additional sensors"](example_14)
+
 ## Getting started
 
 The repository is structured into `example_XY` folders that fully contained packages with names `ros2_control_demos_example_XY`.

doc/index.rst

@@ -52,10 +52,10 @@ Example 3: "RRBot with multiple interfaces"
 Example 4: "Industrial robot with integrated sensor"
    *RRBot* with an integrated sensor.
 
-Example 5: "Industrial Robots with externally connected sensor"
+Example 5: "Industrial robot with externally connected sensor"
    *RRBot* with an externally connected sensor.
 
-Example 6: "Modular Robots with separate communication to each actuator"
+Example 6: "Modular robot with separate communication to each actuator"
    The example shows how to implement robot hardware with separate communication to each actuator.
 
 Example 7: "6-DOF robot"
@@ -67,9 +67,18 @@ Example 8: "Using transmissions"
 Example 9: "Gazebo Classic"
    Demonstrates how to switch between simulation and hardware.
 
+Example 10: "RRbot with GPIO interfaces (tba.)"
+
+Example 11: "Car-like robot using steering controller library (tba.)"
+
 Example 12: "Controller chaining"
    The example shows a simple chainable controller and its integration to form a controller chain to control the joints of *RRBot*.
 
+Example 13: "Multi-robot example (tba.)"
+
+Example 14: "Modular robots with actuators not providing states and with additional sensors"
+
+
 .. _ros2_control_demos_install:
 
 =====================
@@ -257,3 +266,4 @@ Examples
    Example 8: Using transmissions <../example_8/doc/userdoc.rst>
    Example 9: Gazebo classic <../example_9/doc/userdoc.rst>
    Example 12: Controller chaining <../example_12/doc/userdoc.rst>
+   Example 14: Modular robots with actuators not providing states <../example_14/doc/userdoc.rst>

example_14/CMakeLists.txt

@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.16)
+project(ros2_control_demo_example_14 LANGUAGES CXX)
+
+if(CMAKE_CXX_COMPILER_ID MATCHES "(GNU|Clang)")
+  add_compile_options(-Wall -Wextra)
+endif()
+
+# find dependencies
+set(THIS_PACKAGE_INCLUDE_DEPENDS
+  hardware_interface
+  pluginlib
+  rclcpp
+  rclcpp_lifecycle
+  realtime_tools
+)
+
+# find dependencies
+find_package(ament_cmake REQUIRED)
+foreach(Dependency IN ITEMS ${THIS_PACKAGE_INCLUDE_DEPENDS})
+  find_package(${Dependency} REQUIRED)
+endforeach()
+
+
+## COMPILE
+add_library(
+  ros2_control_demo_example_14
+  SHARED
+  hardware/rrbot_actuator_without_feedback.cpp
+  hardware/rrbot_sensor_for_position_feedback.cpp
+)
+target_compile_features(ros2_control_demo_example_14 PUBLIC cxx_std_17)
+target_include_directories(ros2_control_demo_example_14 PUBLIC
+$<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/hardware/include>
+$<INSTALL_INTERFACE:include/ros2_control_demo_example_14>
+)
+ament_target_dependencies(
+  ros2_control_demo_example_14 PUBLIC
+  ${THIS_PACKAGE_INCLUDE_DEPENDS}
+)
+
+# Causes the visibility macros to use dllexport rather than dllimport,
+# which is appropriate when building the dll but not consuming it.
+target_compile_definitions(${PROJECT_NAME} PRIVATE "ROS2_CONTROL_DEMO_EXAMPLE_14_BUILDING_DLL")
+
+# Export hardware plugins
+pluginlib_export_plugin_description_file(hardware_interface ros2_control_demo_example_14.xml)
+
+# INSTALL
+install(
+  DIRECTORY hardware/include/
+  DESTINATION include/ros2_control_demo_example_14
+)
+install(
+  DIRECTORY description/launch description/ros2_control description/urdf description/rviz
+  DESTINATION share/ros2_control_demo_example_14
+)
+install(
+  DIRECTORY bringup/launch bringup/config
+  DESTINATION share/ros2_control_demo_example_14
+)
+install(TARGETS ros2_control_demo_example_14
+  EXPORT export_ros2_control_demo_example_14
+  ARCHIVE DESTINATION lib
+  LIBRARY DESTINATION lib
+  RUNTIME DESTINATION bin
+)
+
+if(BUILD_TESTING)
+  find_package(ament_cmake_gtest REQUIRED)
+endif()
+
+## EXPORTS
+ament_export_targets(export_ros2_control_demo_example_14 HAS_LIBRARY_TARGET)
+ament_export_dependencies(${THIS_PACKAGE_INCLUDE_DEPENDS})
+ament_package()

example_14/README.md

@@ -0,0 +1,5 @@
+# ros2_control_demo_example_14
+
+   The example shows how to implement robot hardware with actuators not providing states and with additional sensors.
+
+Find the documentation in [doc/userdoc.rst](doc/userdoc.rst) or on [control.ros.org](https://control.ros.org/master/doc/ros2_control_demos/example_14/doc/userdoc.html).

example_14/bringup/config/rrbot_modular_actuators_without_feedback_sensors_for_position_feedback.yaml

@@ -0,0 +1,17 @@
+controller_manager:
+  ros__parameters:
+    update_rate: 100  # Hz
+
+    joint_state_broadcaster:
+      type: joint_state_broadcaster/JointStateBroadcaster
+
+    forward_velocity_controller:
+      type: forward_command_controller/ForwardCommandController
+
+
+forward_velocity_controller:
+  ros__parameters:
+    joints:
+      - joint1
+      - joint2
+    interface_name: velocity

example_14/bringup/launch/rrbot_base.launch.py

@@ -0,0 +1,216 @@
+# Copyright 2021 Stogl Robotics Consulting UG (haftungsbeschränkt)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument, RegisterEventHandler
+from launch.conditions import IfCondition
+from launch.event_handlers import OnProcessExit
+from launch.substitutions import Command, FindExecutable, LaunchConfiguration, PathJoinSubstitution
+
+from launch_ros.actions import Node
+from launch_ros.substitutions import FindPackageShare
+
+
+def generate_launch_description():
+    # Declare arguments
+    declared_arguments = []
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "runtime_config_package",
+            default_value="ros2_control_demo_example_14",
+            description='Package with the controller\'s configuration in "config" folder. \
+        Usually the argument is not set, it enables use of a custom setup.',
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "controllers_file",
+            default_value="rrbot_controllers.yaml",
+            description="YAML file with the controllers configuration.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "description_package",
+            default_value="ros2_control_demo_example_14",
+            description="Description package with robot URDF/xacro files. Usually the argument \
+        is not set, it enables use of a custom description.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "description_file",
+            description="URDF/XACRO description file with the robot.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "prefix",
+            default_value='""',
+            description="Prefix of the joint names, useful for \
+        multi-robot setup. If changed than also joint names in the controllers' configuration \
+        have to be updated.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "use_gazebo",
+            default_value="false",
+            description="Start robot in Gazebo simulation.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "use_fake_hardware",
+            default_value="true",
+            description="Start robot with fake hardware mirroring command to its states.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "mock_sensor_commands",
+            default_value="false",
+            description="Enable fake command interfaces for sensors used for simple simulations. \
+            Used only if 'use_fake_hardware' parameter is true.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "slowdown", default_value="3.0", description="Slowdown factor of the RRbot."
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "robot_controller",
+            default_value="forward_position_controller",
+            description="Robot controller to start.",
+        )
+    )
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "start_rviz",
+            default_value="true",
+            description="Start RViz2 automatically with this launch file.",
+        )
+    )
+
+    # Initialize Arguments
+    runtime_config_package = LaunchConfiguration("runtime_config_package")
+    controllers_file = LaunchConfiguration("controllers_file")
+    description_package = LaunchConfiguration("description_package")
+    description_file = LaunchConfiguration("description_file")
+    prefix = LaunchConfiguration("prefix")
+    use_gazebo = LaunchConfiguration("use_gazebo")
+    use_fake_hardware = LaunchConfiguration("use_fake_hardware")
+    mock_sensor_commands = LaunchConfiguration("mock_sensor_commands")
+    slowdown = LaunchConfiguration("slowdown")
+    robot_controller = LaunchConfiguration("robot_controller")
+    start_rviz = LaunchConfiguration("start_rviz")
+
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare(description_package), "urdf", description_file]
+            ),
+            " ",
+            "prefix:=",
+            prefix,
+            " ",
+            "use_gazebo:=",
+            use_gazebo,
+            " ",
+            "use_fake_hardware:=",
+            use_fake_hardware,
+            " ",
+            "mock_sensor_commands:=",
+            mock_sensor_commands,
+            " ",
+            "slowdown:=",
+            slowdown,
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
+
+    robot_controllers = PathJoinSubstitution(
+        [
+            FindPackageShare(runtime_config_package),
+            "config",
+            controllers_file,
+        ]
+    )
+    rviz_config_file = PathJoinSubstitution(
+        [FindPackageShare(description_package), "rviz", "rrbot.rviz"]
+    )
+
+    control_node = Node(
+        package="controller_manager",
+        executable="ros2_control_node",
+        parameters=[robot_description, robot_controllers],
+        output="both",
+    )
+    robot_state_pub_node = Node(
+        package="robot_state_publisher",
+        executable="robot_state_publisher",
+        output="both",
+        parameters=[robot_description],
+    )
+    rviz_node = Node(
+        package="rviz2",
+        executable="rviz2",
+        name="rviz2",
+        output="log",
+        arguments=["-d", rviz_config_file],
+        condition=IfCondition(start_rviz),
+    )
+
+    joint_state_broadcaster_spawner = Node(
+        package="controller_manager",
+        executable="spawner",
+        arguments=["joint_state_broadcaster", "--controller-manager", "/controller_manager"],
+    )
+
+    robot_controller_spawner = Node(
+        package="controller_manager",
+        executable="spawner",
+        arguments=[robot_controller, "-c", "/controller_manager"],
+    )
+
+    # Delay rviz start after `joint_state_broadcaster`
+    delay_rviz_after_joint_state_broadcaster_spawner = RegisterEventHandler(
+        event_handler=OnProcessExit(
+            target_action=joint_state_broadcaster_spawner,
+            on_exit=[rviz_node],
+        )
+    )
+
+    # Delay start of robot_controller after `joint_state_broadcaster`
+    delay_robot_controller_spawner_after_joint_state_broadcaster_spawner = RegisterEventHandler(
+        event_handler=OnProcessExit(
+            target_action=joint_state_broadcaster_spawner,
+            on_exit=[robot_controller_spawner],
+        )
+    )
+
+    nodes = [
+        control_node,
+        robot_state_pub_node,
+        joint_state_broadcaster_spawner,
+        delay_rviz_after_joint_state_broadcaster_spawner,
+        delay_robot_controller_spawner_after_joint_state_broadcaster_spawner,
+    ]
+
+    return LaunchDescription(declared_arguments + nodes)