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Create a demo that uses transmissions (backport #226) (#241)
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* Create a demo that uses transmissions (#226)

* add copy for transmission demo and set in the urdf

* Renamed to rrbot_transmissions

* Changed reduction value of transmission2

* Added the rrbot_transmissions_system_position_only

Exact copy of rrbot_system_position_only for now. Using it
from the transmission demo

* Moved logger into its own variable

* Uncrustify

* Renamed hw interface to joint. Added actuator interfaces

* Formatting. Remove comments

* Using transmissions for joint and actuator interfaces

Added a helper object to manage the joint to transmissions to actuator
data handling

* Propagating data between all the interfaces

* Cleanup. Added some consts

* Simulate motor motion

* Added logging to periodically show interface data

* Refactored the parameters a bit. Removed unused ones

* Added try/catches where needed

Checking joint consistency in the description not required. Already done
by the parser

* Added transmission demo to README

* Use clang-format instead

* rename transmissions ros2_control macro

* Remove unnecessary actuator parameters

* Typo

* Removed gazebo, mock hardware and fake sensors from the transmission
demo

* Missing 'explicit' from constructor

* Further cleanup of gazebo, mock hardware and fake sensors from the transmission demo

* branding fix

* Remove pointer definitions

Co-authored-by: Bence Magyar <[email protected]>

* Fixed comment about reserve

Co-authored-by: Bence Magyar <[email protected]>

* Renamed member variable and added description

---------

Co-authored-by: Noel Jimenez <[email protected]>
Co-authored-by: Bence Magyar <[email protected]>
(cherry picked from commit 1007b1d)

* Fix preformatted block

* fix header guard

---------

Co-authored-by: Jordan Palacios <[email protected]>
Co-authored-by: Bence Magyar <[email protected]>
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24 changes: 24 additions & 0 deletions README.md
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Expand Up @@ -475,6 +475,30 @@ Available controllers:
Commanding the robot: see the commands below.


### Example 6: "Industrial Robots with an exposed transmission interface"

Files:
- Launch file: [rrbot_transmissions_system_position_only.launch.py](ros2_control_demo_bringup/launch/rrbot_transmissions_system_position_only.launch.py)
- Controllers yaml: [rrbot_controllers.yaml](ros2_control_demo_bringup/config/rrbot_controllers.yaml)
- URDF: [rrbot_transmissions_system_position_only.urdf.xacro](ros2_control_demo_description/rrbot_description/urdf/rrbot_transmissions_system_position_only.urdf.xacro)
- `ros2_control` URDF tag: [rrbot_transmissions_system_position_only.ros2_control.xacro](ros2_control_demo_description/rrbot_description/ros2_control/rrbot_transmissions_system_position_only.ros2_control.xacro)

Interfaces:
- Command interfaces:
- joint1/position
- joint2/position
- State interfaces:
- joint1/position
- joint2/position

Available controllers:
- `joint_state_broadcaster[joint_state_broadcaster/JointStateBroadcaster]`
- `forward_position_controller[forward_command_controller/ForwardCommandController]` (position)

Moving the robot:
- see below description of `forward_position_controller`


## Controllers and moving hardware

To move the robot you should load and start controllers.
Expand Down
40 changes: 20 additions & 20 deletions example_1/README.rst
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Expand Up @@ -5,17 +5,17 @@ TODO(destogl): This is not adjusted yet!!

*RRBot*, or ''Revolute-Revolute Manipulator Robot'', is a simple 3-linkage, 2-joint arm that we will use to demonstrate various features.
It is essentially a double inverted pendulum and demonstrates some fun control concepts within a simulator and was originally introduced for Gazebo tutorials.
The *RRBot* URDF files can be found in the `urdf` folder of `rrbot_description` package.
The *RRBot* URDF files can be found in the ``urdf`` folder of ``rrbot_description`` package.

1. To check that *RRBot* descriptions are working properly use following launch commands:

*RRBot*
```
ros2 launch rrbot_description view_robot.launch.py
```
**NOTE**: Getting the following output in terminal is OK: `Warning: Invalid frame ID "odom" passed to canTransform argument target_frame - frame does not exist`.
This happens because `joint_state_publisher_gui` node need some time to start.
The `joint_state_publisher_gui` provides a GUI to generate a random configuration for rrbot. It is immediately displayed in `Rviz`.
**NOTE**: Getting the following output in terminal is OK: ``Warning: Invalid frame ID "odom" passed to canTransform argument target_frame - frame does not exist``.
This happens because ``joint_state_publisher_gui`` node need some time to start.
The ``joint_state_publisher_gui`` provides a GUI to generate a random configuration for rrbot. It is immediately displayed in ``Rviz``.


1. To check that *RRBot* descriptions are working properly use following launch commands:
Expand All @@ -24,37 +24,37 @@ The *RRBot* URDF files can be found in the `urdf` folder of `rrbot_description`
```
ros2 launch rrbot_description view_robot.launch.py
```
**NOTE**: Getting the following output in terminal is OK: `Warning: Invalid frame ID "odom" passed to canTransform argument target_frame - frame does not exist`.
This happens because `joint_state_publisher_gui` node need some time to start.
The `joint_state_publisher_gui` provides a GUI to generate a random configuration for rrbot. It is immediately displayed in `Rviz`.
**NOTE**: Getting the following output in terminal is OK: ``Warning: Invalid frame ID "odom" passed to canTransform argument target_frame - frame does not exist``.
This happens because ``joint_state_publisher_gui`` node need some time to start.
The ``joint_state_publisher_gui`` provides a GUI to generate a random configuration for rrbot. It is immediately displayed in ``Rviz``.


1. To start *RRBot* example open a terminal, source your ROS2-workspace and execute its launch file with:
```
ros2 launch ros2_control_demo_bringup rrbot.launch.py
```
The launch file loads and starts the robot hardware, controllers and opens `RViz`.
The launch file loads and starts the robot hardware, controllers and opens ``RViz``.
In starting terminal you will see a lot of output from the hardware implementation showing its internal states.
This is only of exemplary purposes and should be avoided as much as possible in a hardware interface implementation.

If you can see two orange and one yellow rectangle in in `RViz` everything has started properly.
If you can see two orange and one yellow rectangle in in ``RViz`` everything has started properly.
Still, to be sure, let's introspect the control system before moving *RRBot*.

1. Check if the hardware interface loaded properly, by opening another terminal and executing:
```
ros2 control list_hardware_interfaces
```
You should get:
```
command interfaces

You should get::

command interfaces
joint1/position [claimed]
joint2/position [claimed]
state interfaces
joint1/position
joint2/position
state interfaces
joint1/position
joint2/position

```
Marker `[claimed]` by command interfaces means that a controller has access to command *RRBot*.
Marker ``[claimed]`` by command interfaces means that a controller has access to command *RRBot*.

1. Check is controllers are running:
```
Expand All @@ -78,7 +78,7 @@ The *RRBot* URDF files can be found in the `urdf` folder of `rrbot_description`
```
ros2 launch ros2_control_demo_bringup test_forward_position_controller.launch.py
```
You should now see orange and yellow blocks moving in `RViz`.
You should now see orange and yellow blocks moving in ``RViz``.
Also, you should see changing states in the terminal where launch file is started.


Expand All @@ -94,5 +94,5 @@ Files used for this demos:


Controllers from this demo:
- `Joint State Broadcaster` ([`ros2_controllers` repository](https://github.com/ros-controls/ros2_controllers)): [doc](https://ros-controls.github.io/control.ros.org/ros2_controllers/joint_state_broadcaster/doc/userdoc.html)
- `Forward Command Controller` ([`ros2_controllers` repository](https://github.com/ros-controls/ros2_controllers)): [doc](https://ros-controls.github.io/control.ros.org/ros2_controllers/forward_command_controller/doc/userdoc.html)
- ``Joint State Broadcaster`` ([``ros2_controllers`` repository](https://github.com/ros-controls/ros2_controllers)): [doc](https://ros-controls.github.io/control.ros.org/ros2_controllers/joint_state_broadcaster/doc/userdoc.html)
- ``Forward Command Controller`` ([``ros2_controllers`` repository](https://github.com/ros-controls/ros2_controllers)): [doc](https://ros-controls.github.io/control.ros.org/ros2_controllers/forward_command_controller/doc/userdoc.html)
6 changes: 3 additions & 3 deletions example_1/hardware/rrbot.hpp
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Expand Up @@ -12,8 +12,8 @@
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef ROS2_CONTROL_DEMO_HARDWARE__RRBOT_SYSTEM_POSITION_ONLY_HPP_
#define ROS2_CONTROL_DEMO_HARDWARE__RRBOT_SYSTEM_POSITION_ONLY_HPP_
#ifndef EXAMPLE_1__HARDWARE__RRBOT_HPP_
#define EXAMPLE_1__HARDWARE__RRBOT_HPP_

#include <memory>
#include <string>
Expand Down Expand Up @@ -78,4 +78,4 @@ class RRBotSystemPositionOnlyHardware : public hardware_interface::SystemInterfa

} // namespace ros2_control_demo_hardware

#endif // ROS2_CONTROL_DEMO_HARDWARE__RRBOT_SYSTEM_POSITION_ONLY_HPP_
#endif // EXAMPLE_1__HARDWARE__RRBOT_HPP_
Original file line number Diff line number Diff line change
@@ -0,0 +1,70 @@
# 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, IncludeLaunchDescription
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.substitutions import LaunchConfiguration, ThisLaunchFileDir


def generate_launch_description():
# Declare arguments
declared_arguments = []
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(
"slowdown", default_value="50.0", 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
prefix = LaunchConfiguration("prefix")
slowdown = LaunchConfiguration("slowdown")
robot_controller = LaunchConfiguration("robot_controller")
start_rviz = LaunchConfiguration("start_rviz")

base_launch = IncludeLaunchDescription(
PythonLaunchDescriptionSource([ThisLaunchFileDir(), "/rrbot_base.launch.py"]),
launch_arguments={
"description_file": "rrbot_transmissions_system_position_only.urdf.xacro",
"prefix": prefix,
"slowdown": slowdown,
"robot_controller": robot_controller,
"start_rviz": start_rviz,
}.items(),
)

return LaunchDescription(declared_arguments + [base_launch])
Original file line number Diff line number Diff line change
@@ -0,0 +1,50 @@
<?xml version="1.0"?>
<robot xmlns:xacro="http://www.ros.org/wiki/xacro">

<xacro:macro name="rrbot_transmissions_system_position_only" params="name prefix use_gazebo:=^|false use_fake_hardware:=^|true mock_sensor_commands:=^|false slowdown:=2.0">

<ros2_control name="${name}" type="system">

<hardware>
<plugin>ros2_control_demo_hardware/RRBotTransmissionsSystemPositionOnlyHardware</plugin>
<param name="actuator_slowdown">${slowdown}</param>
</hardware>

<joint name="${prefix}joint1">
<command_interface name="position">
<param name="min">-1</param>
<param name="max">1</param>
</command_interface>
<state_interface name="position"/>
</joint>

<joint name="${prefix}joint2">
<command_interface name="position">
<param name="min">-1</param>
<param name="max">1</param>
</command_interface>
<state_interface name="position"/>
</joint>

<transmission name="transmission1">
<plugin>transmission_interface/SimpleTransmission</plugin>
<actuator name="actuator1" role="actuator1"/>
<joint name="joint1" role="joint1">
<mechanical_reduction>2.0</mechanical_reduction>
<offset>0.0</offset>
</joint>
</transmission>

<transmission name="transmission2">
<plugin>transmission_interface/SimpleTransmission</plugin>
<actuator name="actuator2" role="actuator2"/>
<joint name="joint2" role="joint2">
<mechanical_reduction>4.0</mechanical_reduction>
<offset>0.0</offset>
</joint>
</transmission>
</ros2_control>

</xacro:macro>

</robot>
Original file line number Diff line number Diff line change
@@ -0,0 +1,38 @@
<?xml version="1.0"?>
<!-- Revolute-Revolute Manipulator -->
<!--
Copied and modified from ROS1 example -
https://github.com/ros-simulation/gazebo_ros_demos/blob/kinetic-devel/rrbot_description/urdf/rrbot.xacro
-->
<robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="2dof_robot">

<!-- Enable setting arguments from the launch file -->
<xacro:arg name="prefix" default="" />
<xacro:arg name="slowdown" default="100.0" />

<!-- Import RRBot macro -->
<xacro:include filename="$(find rrbot_description)/urdf/rrbot_description.urdf.xacro" />

<!-- Import Rviz colors -->
<xacro:include filename="$(find rrbot_description)/gazebo/rrbot.materials.xacro" />

<!-- Import RRBot ros2_control description -->
<xacro:include filename="$(find rrbot_description)/ros2_control/rrbot_transmissions_system_position_only.ros2_control.xacro" />

<!-- Used for fixing robot -->
<link name="world"/>
<gazebo reference="world">
<static>true</static>
</gazebo>

<xacro:rrbot parent="world" prefix="$(arg prefix)">
<origin xyz="0 0 0" rpy="0 0 0" />
</xacro:rrbot>

<xacro:rrbot_transmissions_system_position_only
name="RRBotTransmissionsSystemPositionOnly" prefix="$(arg prefix)"
use_fake_hardware="$(arg use_fake_hardware)"
mock_sensor_commands="$(arg mock_sensor_commands)"
slowdown="$(arg slowdown)" />

</robot>
6 changes: 5 additions & 1 deletion ros2_control_demo_hardware/CMakeLists.txt
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@ find_package(hardware_interface REQUIRED)
find_package(pluginlib REQUIRED)
find_package(rclcpp REQUIRED)
find_package(rclcpp_lifecycle REQUIRED)
find_package(transmission_interface REQUIRED)


## COMPILE
Expand All @@ -26,6 +27,7 @@ add_library(
src/rrbot_system_position_only.cpp
src/rrbot_system_multi_interface.cpp
src/rrbot_system_with_sensor.cpp
src/rrbot_transmissions_system_position_only.cpp
src/rrbot_actuator.cpp
src/external_rrbot_force_torque_sensor.cpp
)
Expand All @@ -40,13 +42,14 @@ ament_target_dependencies(
pluginlib
rclcpp
rclcpp_lifecycle
transmission_interface
)

# 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_HARDWARE_BUILDING_DLL")

# Export hardware pligins
# Export hardware plugins
pluginlib_export_plugin_description_file(hardware_interface ros2_control_demo_hardware.xml)

# INSTALL
Expand Down Expand Up @@ -75,5 +78,6 @@ ament_export_dependencies(
pluginlib
rclcpp
rclcpp_lifecycle
transmission_interface
)
ament_package()
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