MoveIt2 Configuration

Not a required course: The provided system has already been configured.

MoveIt2 is an advanced software framework for robot motion simulation, planning, and control.

1. Environment Setup

ROS2: Humble

If you are using a Jetson Nano development board, you will need to enter the commands from the tutorial into the accompanying virtual machine to run this function.

1.1. Install MoveIt2

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sudo apt install ros-humble-moveit*

Jetson Orin series boards have been tested and can directly run MoveIt2 related cases. The overall smoothness is acceptable!

1.2. Create Folder

The virtual machine has been created.

Create MoveIt2 auto-generated configuration files:

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mkdir ~/dofbot_pro_ws/src/dofbot_pro_moveit

2. MoveIt2 Configuration

MoveIt Setup Assistant is a graphical tool used to simplify and accelerate the creation and configuration of MoveIt2 configuration packages.

Through this tool, users can easily generate configuration files for robot motion planning and control without manually editing complex configuration files.

2.1. Start Assistant

Start MoveIt Setup Assistant:

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ros2 launch moveit_setup_assistant setup_assistant.launch.py

For first use, you can choose to create a new MoveIt configuration package. For later simple modifications, you can choose to edit an existing MoveIt package:

Creating a new MoveIt configuration package requires importing the robot's URDF model: Simply importing the URDF model file to MoveIt Assistant will cause an error. You need to use the compiled package (dofbot_pro_description) URDF file path

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/home/yahboom/dofbot_ws/src/dofbot_urdf/urdf/dofbot.urdf

After selecting the URDF file, click Load Files, and MoveIt Assistant will display the robot model:

2.2. Collision Detection

The self-collision matrix is a feature used to optimize motion planning. Its main purpose is to generate a matrix that describes whether various links in the robot model may collide with each other.

This matrix can help the motion planner avoid unnecessary collision detection during path planning, thereby improving planning efficiency.

To generate the self-collision matrix, you can click the auto-generate option in MoveIt Setup Assistant:

2.3. Virtual Joints

Virtual joints are used to define the relationship between the robot model and the external world.

Virtual joints are typically used to describe the connection between the robot base and a fixed reference frame (such as the world coordinate system).

Fix the robot base link base_link and world:

• Virtual Joint Name: virtual_joint
• Child Link: base_link
• Parent Frame Name: world
• Joint Type: fixed

2.4. Motion Planning Groups

Planning groups are key steps in configuring robot motion planning.

Planning groups define which joints and links in the robot can move together and how their motion is planned.

Plan robotic arm group: arm_group

• Group Name：arm_group
• Kinematic Solver：kdl_kinematics_plugin/KDLKinematicsPlugin
• Kin. Search Resolution：0.005
• Kin. Search Timeout：0.005

• Add Joints：Select the robotic arm joints

Joints：Arm1_Joint、Arm2_Joint、Arm3_Joint、Arm4_Joint、Arm5_Joint

Plan Gripper Group:grip_group

Plan gripper group: grip_group

• Group Name：grip_group
• Kinematic Solver：None
• Kin. Search Resolution：0.005
• Kin. Search Timeout：0.005

• Add Links：Select the gripper links

Links：rlink1、rlink2、rlink3

2.5. Robot Poses

Robotic Arm Positions

Set three groups of robotic arm predefined poses to the robot configuration:

You can manually move the sliders to set each joint state: up、down、init

Gripper Positions

Set two groups of gripper predefined poses to the robot configuration:

You can manually move the sliders to set gripper state: open、close

2.6. End Effector

Set the gripper group as the end effector:

End effector: gripper

• End Effector Name：gripper
• End Effector Group：gripp_group
• Parent Link：Arm5_Link
• Parent Group：None

2.7. Passive Joints

Passive joints are non-driven joints that cannot be directly controlled: The robotic arm has no passive joints, so skip this step.

2.8. URDF Files

MoveIt Setup Assistant will automatically set command interfaces and state interfaces for each joint: Use the default generated information.

2.9. ROS2 Controllers

ROS2 Controllers is a framework for robot real-time control, which can be used to automatically generate simulation controllers to drive robot joints.

Add robotic arm controller:

• Controller Name：arm_group_controller
• Controller Type：joint_trajectory_controller/JointTrajectoryController
• Add Planning Group Joints：arm_group

Add gripper controller:

• Controller Name：grip_group_controller
• Controller Type：position_controllers/GripperActionController
• Add Planning Group Joints：grip_group

2.10. MoveIt Controllers

MoveIt requires trajectory controllers with the FollowJointTrajectoryAction interface to execute planned trajectories. This interface sends the generated trajectories to the robot's ROS2 controllers.

The added MoveIt Controllers need to ensure that the controller names match the names configured in ROS2 Controllers.

Add robotic arm controller:

• Controller Name：arm_group_controller
• Controller Type：FollowJointTrajectory
• Add Planning Group Joints：arm_group

Add gripper controller:

• Controller Name：grip_group_controller
• Controller Type：Gripper Command
• Add Planning Group Joints：grip_group

2.11. Sensors

Configure the settings for 3D sensors used by the robot: No configuration needed.

2.12. Launch Files

Configure auto-generated launch files: Use default options.

2.13. Author Information

Add author information for package generation:

2.14. Generate Configuration

Generate configuration files to the specified folder:

Then click Generate Package.

3. Configuration Files

Enter the dofbot_moveit folder:

4. Configuration Verification

The configuration files generated by MoveIt Setup Assistant need simple modifications to remove startup warnings and model loading issues.

4.1. Modify Configuration Files

dofbot_urdf.ros2_control.xacro

Modify the dofbot_urdf.ros2_control.xacro file: Modify the yaml loading function

joint_limits.yaml

4.2. Compile Package

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cd ~/dofbot_ws
colcon build --packages-select dofbot_moveit
source install/setup.bash

4.3. Launch MoveIt

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ros2 launch dofbot_pro_moveit demo.launch.py

The simulation startup is relatively slow. Wait until the terminal shows You can start planning now! or the robotic arm shows trajectory balls (trajectory balls are new spheres added to the robotic arm), indicating loading is complete.

References

MoveIt2 Humble：https://moveit.picknik.ai/humble/index.html

MoveIt2：https://moveit.picknik.ai/main/index.html