Unity-Robotics-Hub/tutorials/pick_and_place/moveit_file_descriptions.md

MoveIt Launch & Config Files

In an attempt to make this tutorial a little more comprehensive and shed some light as to the different components of MoveIt, we have provided a minimal amount of files taken from the Niryo ROS Stack repo to successfully complete a pick-and-place task.

NOTE: The flow of which launch files call other launch files was not changed so that the workflow here would still resemble that of the original Niryo One repo even though some of the lines and arguments have been removed or changed.

MoveIt Launch Files

demo.launch

Single launch file for all MoveIt and Niryo requirements for the pick-and-place tutorial.

• Loads niryo_one_base.launch while passing in urdf_without_meshes argument set to false
• Loads controllers.launch with simulation_mode set to true
• Loads move_group.launch
• Set rosparam move_group/trajectory_execution/execution_duration_monitoring to false
• Set rosparam /move_group/trajectory_execution/allowed_start_tolerance to 0.0
• Set rosparam /move_group/start_state_max_bounds_error to 0.3

controllers.launch

Starts the Niryo One driver, controller manager, and robot state publisher nodes

• Starts ROS node niryo_one_driver with debugging arguments

  • Loads niryo_one_driver.yaml into rosparam

• Loads niryo_one_controllers.yaml into rosparam

• Starts ROS node controller_manager with arguments joint_state_controller niryo_one_follow_joint_trajectory_controller --shutdown-timeout 1

• Starts ROS node robot_state_publisher package.

  • Ex. rosrun robot_state_publisher robot_state_publisher

move_group.launch

Starts the Move Group node which is the entry point into using MoveIt. Also calls planning pipeline, planning context, and trajectory execution to load their relevant parameters.

• Call planning_pipeline.launch.xml with pipeline argument set to ompl

• Call trajectory_execution.launch.xml with arguments:

  • moveit_manage_controllers set to true
  • moveit_controller_manager set to niryo_one

• Call planning_context.launch

• Start ROS node moveit_ros_move_group

  • Set rosparam allow_trajectory_execution to true
  • Set rosparam max_safe_path_cost to 1
  • Set rosparam jiggle_fraction to 0.05
  • Set rosparamplanning_scene_monitor/publish_planning_scene to true
  • Set rosparamplanning_scene_monitor/publish_geometry_updates to true
  • Set rosparamplanning_scene_monitor/publish_state_updates to true
  • Set rosparamplanning_scene_monitor/publish_transforms_updates to true

niryo_one_base.launch

Loads the Niryo One URDF with accompanying parameters for command validation, service timeouts, and motor groupings

• Sets rosparams hardware_version to 2 and reboot_when_auto_change_version. to true for niryo_one namespace

• Loads robot_command_validation.yaml into rosparams for namespace niryo_one/robot_command_validation

• Load the niryo_one_motors.yaml and stepper_params.yaml files as rosparams for niryo_one/motors namespace

• Sets rosparams service_timeout to 2, action_connection_timeout to 2, action_execute_timeout to 15, and action_preempt_timeout to 3 for niryo_one/python_api namespace

• Sets rosparams rate_tf_listener to 5.0 and rate_publish_state to 5.0 for niryo_one/robot_state namespace

• Loads niryo_one_urdf.xacro as rosparams robot_description and robot_description_tf2

niryo_one_moveit_controller_manager.launch.xml

Set controllers available to MoveIt

• Sets rosparam moveit_controller_manager to moveit_simple_controller_manager/MoveItSimpleControllerManager

• Reads controllers.yaml into rosparam

ompl_planning_pipeline.launch.xml

Sets ROS params and topics for OMPL pipeline communication

• Set rosparam planning_plugin with value of ompl_interface/OMPLPlanner

• Set rosparam planning_adapters with value of:

  default_planner_request_adapters/AddTimeParameterization
                         default_planner_request_adapters/FixWorkspaceBounds
                         default_planner_request_adapters/FixStartStateBounds
                         default_planner_request_adapters/FixStartStateCollision
                         default_planner_request_adapters/FixStartStatePathConstraints
  

• Set rosparam start_state_max_bounds_error with value of 0.1

• Load ompl_planning.yaml as rosparam

planning_context.launch

Loads config files required for the joints of the Niryo One.

• Argument load_robot_description defaults to false
• Load kinematics.yaml as rosparam with namespace robot_description_kinematics
• Load joint_limits.yaml as rosparam with namespace robot_description_planning
• Load niryo_one.srdf as robot_description_semantic rosparam
• Load niryo_one.urdf.xacro as robot_description rosparam if argument load_robot_description is true

planning_pipeline.launch.xml

Calls for OMPL pipeline launch

• Argument pipeline defaults to ompl
• Launch ompl_planning_pipeline.launch.xml using pipeline argument in name

trajectory_execution.launch.xml

Sets ROS params required for trajectory execution and then calls controller manager launch

• Sets rosparam moveit_manage_controllers to true
• Sets rosparam trajectory_execution/allowed_execution_duration_scaling to 1.2
• Sets rosparam trajectory_execution/allowed_goal_duration_margin to 0.5
• Sets rosparam trajectory_execution/allowed_start_tolerance to 0.0
• Loads niryo_moveit_controller_manager.launch.xml

MoveIt Config Files

controllers.yaml

• List of robot controllers available to MoveIt.

joint_limits.yaml

• Velocity and acceleration limits for individual joints on robot used when planning a trajectory that is time constrained.

kinematics.yaml

• File generated by MoveIt Setup Assistant and contains parameters for kinematic solvers in MoveIt.
• MoveIt Documentation

niryo_one.srdf

• Defines joint groups, group states, and disables collisions between joints and links that are impossible to collide.
• MoveIt SRDF Documentation

niryo_one_controllers.yaml

• Ties niryo_one_follow_joint_trajectory_controller to the controller_manager node

niryo_one_driver.yaml

• Settings for communication with Niryo One motors
  • Ex. Read/Write/Check frequencies

niryo_one_motors.yaml

• Groups the different Niryo One motors

ompl_planning.yaml

• Settings required for OMPL trajectory planning.
• MoveIt OMPL Documentation

robot_command_validation.yaml

• Settings for minimum and maximum joint rotations as wel as gripper speed

stepper_params.yaml

• Settings for stepper motors like gear ratios and direction values.