Grasp Execution Configuration Files¶

Grasp Execution has many features and capabilities that can be turned on and off, and customized to the your liking. This is done in the configuration files, that are typically stored in the config folder of your package. The YAML format is used for this file for better understanding and readability.

Below lists the configuration files in the package that change different parameters in the grasp execution pipeline.

Changing the start positions
Changing the fake object published
Changing the grasp execution parameters
Changing the dynamic safety execution parameters
Changing the workcell configurations

Changing the start positions¶

To change the home state, edit the values of each joint in the file grasp_execution/example/config/start_positions.yaml:

initial_positions:
  shoulder_pan_joint: 1.57
  shoulder_lift_joint: -2.35
  elbow_joint: 1.83
  wrist_1_joint: -1.03
  wrist_2_joint: -1.57
  wrist_3_joint: 0.0

Changing the fake object published¶

To change the location and dimensions of the fake object published, edit following parameters in the file grasp_execution/example/config/fake_grasp_pose_publisher.yaml:

fake_grasp_pose_publisher:
  ros__parameters:
    interface: service
    frame_id: camera_frame
    ee_id: robotiq_2f
    grasp_pose: [0.0126, 0.0322, 0.442,
                 0.0, 0.0, 0.9997, 0.0250]

    object_pose: [0.0128, 0.0330, 0.443,
                  0.0, 0.0, 0.9997, 0.0250]

    object_dimensions: [0.087, 0.167, 0.023]

    delay: 1.5

Name	Type	Description
frame_id	String	Base frame
grasp_pose	double array	Location that the robot will plan to
object_pose	double array	Location that the object will spawn at
object_dimensions	double array	Dimensions of the object (x,y,z)
delay	double

Changing the grasp execution parameters¶

To change the configuration of the default grasp execution, edit following parameters in the file grasp_execution/example/config/grasp_execution.yaml:

grasp_execution_node:
  ros__parameters:
    planning_scene_monitor_options:
      name: "planning_scene_monitor"
      robot_description: "robot_description"
      joint_state_topic: "/joint_states"
      attached_collision_object_topic: "/moveit_cpp/planning_scene_monitor"
      publish_planning_scene_topic: "/moveit_cpp/publish_planning_scene"
      monitored_planning_scene_topic: "/moveit_cpp/monitored_planning_scene"
      wait_for_initial_state_timeout: 10.0

    planning_pipelines:
      #namespace: "moveit_cpp"  # optional, default is ~
      pipeline_names: ["ompl"]

    plan_request_params:
      planning_attempts: 1
      planning_time: 0.5
      planning_pipeline: ompl
      max_velocity_scaling_factor: 1.0
      max_acceleration_scaling_factor: 1.0

planning_scene_monitor_options¶
Name	Type	Description
name	string
robot_description	string
joint_state_topic	string
attached_collision_object_topic	string
publish_planning_scene_topic	string
monitored_planning_scene_topic	string
wait_for_initial_state_timeout	double

planning_pipelines¶
Name	Type	Description
pipeline_names	string array	Planning pipelines to be used (as of now only ompl is supported)

plan_request_params¶
Name	Type	Description
planning_attempts	int	Number of planning attempts
planning_pipeline	string	planning pipeline used
max_velocity_scaling_factor	double	Maximum velocity scale
max_acceleration_scaling_factor	double	Maximum acceleration scale

Changing the dynamic safety execution parameters¶

To change the configuration of the grasp execution with dynamic safety, edit following parameters in the file grasp_execution/example/config/dynamic_safety_demo.yaml:

dynamic_safety_demo_node:
  ros__parameters:
    planning_scene_monitor_options:
      name: "planning_scene_monitor"
      robot_description: "robot_description"
      joint_state_topic: "/joint_states"
      attached_collision_object_topic: "/moveit_cpp/planning_scene_monitor"
      publish_planning_scene_topic: "/moveit_cpp/publish_planning_scene"
      monitored_planning_scene_topic: "/moveit_cpp/monitored_planning_scene"
      wait_for_initial_state_timeout: 10.0

    planning_pipelines:
      #namespace: "moveit_cpp"  # optional, default is ~
      pipeline_names: ["ompl"]

    plan_request_params:
      planning_attempts: 1
      planning_time: 0.5
      planning_pipeline: ompl
      max_velocity_scaling_factor: 1.0
      max_acceleration_scaling_factor: 1.0

    # Load octomap
    load_octomap: true

    # Dynamic safety parameters
    rate: 20
    allow_replan: true
    visualize: true

    safety_zone:
      manual: true
      unit_type: second
      collision_checking_deadline: 0.05
      slow_down_time: 0.2
      replan_deadline: 1.2
      look_ahead_time: 1.65

    collision_checker:
      distance: false
      continuous: false
      step: 0.1
      thread_count: 8
      realtime: false

    next_point_publisher:
      command_out_type: "trajectory_msgs/JointTrajectory"
      publish_joint_position: true
      publish_joint_velocity: false
      publish_joint_effort: false

    replanner:
      planner_name: ompl

    visualizer:
      publish_frequency: 10
      step: 0.1
      topic: "/dynamic_safety/displayed_state"

The first half of the parameters are the same as described in grasp_execution.yaml

Name	Type	Description
load_octomap	bool	Load the octomap

Name	Type	Description
rate	double
allow_replan	bool	Replan if collision is detected. If set to false the robot will simply stop to avoid collision
visualize	bool

safety_zone¶
Name	Type	Description
manual	bool
unit_type	string
collision_checking_deadline	double
slow_down_time	double
replan_deadline	double
look_ahead_time	double

collision_checker¶
Name	Type	Description
distance	bool
continuous	bool
step	double
thread_count	int
realtime	bool

next_point_publisher¶
Name	Type	Description
command_out_type	string
publish_joint_position	bool
publish_joint_velocity	bool
publish_joint_effort	bool

replanner¶
Name	Type	Description
planner_name	string

visualizer¶
Name	Type	Description
publish_frequency	double
step	double
topic	string

Changing the workcell configurations¶

To change the configuration of your workcell, edit following parameters in the file grasp_execution/example/config/dynamic_safety_demo.yaml:

workcell:
- group_name: manipulator
  executors:
    default:
      plugin: grasp_execution/DefaultExecutor
    ds_async:
      plugin: grasp_execution/DynamicSafetyAsyncExecutor
      controller: ur5_arm_controller
  end_effectors:
    robotiq_2f0:
      brand: robotiq_2f
      link: ee_palm
      clearance: 0.1
      driver:
        plugin: grasp_execution/DummyGripperDriver
        controller: ""

Name	Type	Description
group_name	string
end_effectors.robotiq_2f0.link	string	Tip link of end effector
end_effectors.robotiq_2f0.clearance	double	Distance above the object that the end effector would plan to before moving down to pick the object up