Skip to content

Latest commit

 

History

History
187 lines (126 loc) · 5.34 KB

README.md

File metadata and controls

187 lines (126 loc) · 5.34 KB

KnowRob Designator Action Interfaces

These interfaces enable robots to semantically log and track the lifecycle of CRAM designators during task execution. Each stage of a designator's usage is logged via a separate ROS action.

1. /knowrob/designator/init

Action Type: DesignatorInitAction Purpose: Registers a new (typically symbolic) designator with KnowRob.

When to Use

Call this when a designator is first created. It represents an abstract intention, such as “bring the milk to the table,” and may contain nested symbolic sub-designators.

Goal Fields

  • designator_id: Unique identifier for this designator.
  • parent_id: Optional ID of a parent designator (use "" for root).
  • json_designator: The symbolic JSON designator.
  • stamp: Time the designator was created.

Example

goal = DesignatorInitGoal()
goal.designator_id = "desig_123"
goal.parent_id = ""
goal.json_designator = '{"anAction": {"type": "Transporting", "objectActedOn": {"anObject": {"type": "Milk"}}, "target": {"theLocation": {"goal": {"theObject": {"name": "Table1"}}}}}}'
goal.stamp = rospy.Time.now()

2. /knowrob/designator/resolving_started

Action Type: DesignatorResolutionStartAction Purpose: Signals that resolution (e.g., grounding of symbolic references) has started.

When to Use

Call this before resolving the symbolic designator into a grounded one (e.g., a pose in space).

Goal Fields

  • designator_id: ID of the designator being resolved.
  • json_designator: The original symbolic JSON.
  • stamp: Time resolution started.

Example

goal = DesignatorResolutionStartGoal()
goal.designator_id = "desig_123"
goal.json_designator = same_json_as_init
goal.stamp = rospy.Time.now()

3. /knowrob/designator/resolving_finished

Action Type: DesignatorResolutionFinishedAction Purpose: Logs the grounded (resolved) version of a symbolic designator.

When to Use

After successful resolution of a symbolic designator, use this to log its grounded form.

Goal Fields

  • designator_id: ID of the new, resolved designator.
  • resolved_from_id: ID of the original symbolic designator.
  • json_designator: The resolved JSON designator (e.g., with pose data).
  • stamp: Time resolution completed.

Example

goal = DesignatorResolutionFinishedGoal()
goal.designator_id = "desig_456"
goal.resolved_from_id = "desig_123"
goal.json_designator = '{"anAction": {"type": "Transporting", "objectActedOn": {"anObject": {"type": "Milk"}}, "target": {"pose": {"x": 1.2, "y": 0.8, "z": 0.75, "frame": "map"}}}}'
goal.stamp = rospy.Time.now()

4. /knowrob/designator/execution_start

Action Type: DesignatorExecutionStartAction Purpose: Signals that the execution of a resolved designator has started.

When to Use

Once the robot begins acting on the resolved designator (e.g., starts moving to pick up an object), log the execution start.

Goal Fields

  • designator_id: ID of the resolved designator being executed.
  • json_designator: The grounded designator (e.g., with numeric poses).
  • stamp: Time execution began.

Example

goal = DesignatorExecutionStartGoal()
goal.designator_id = "desig_456"
goal.json_designator = "" # Allowed to be empty, if not different from the last logged version
goal.stamp = rospy.Time.now()

5. /knowrob/designator/execution_finished

Action Type: DesignatorExecutionFinishedAction Purpose: Logs that the execution of the designator has been completed.

When to Use

After the task related to the designator is complete (e.g., object placed on table), log this event.

Goal Fields

  • designator_id: ID of the resolved designator that was executed.
  • json_designator: Same designator content as before (for traceability).
  • stamp: Time execution finished.

Example

goal = DesignatorExecutionFinishedGoal()
goal.designator_id = "desig_456"
goal.json_designator = ""
goal.stamp = rospy.Time.now()

6. /knowrob/designator/push_object_designator

Action Type: PushObjectDesignatorAction Purpose: Adds or updates an object designator in the KnowRob knowledge base.

When to Use

Use this action to assert the presence or update the semantic state of a physical object in the environment. This can be done after object detection, tracking, or perception to inform KnowRob about the current scene.

Goal Fields

  • json_designator: JSON description of the object (type, pose, name, etc.).
  • stamp: Timestamp when the object was perceived.

Result Fields

  • success: Whether the object was successfully added.
  • message: Informational message for logging or debugging.

Feedback Fields

  • status: Optional feedback status.

Example

push_client = actionlib.SimpleActionClient('/knowrob/designator/push_object_designator', PushObjectDesignatorAction)

push_goal = PushObjectDesignatorGoal()
push_goal.json_designator = """
{
  "anObject": {
    "type": "Milk",
    "pose": {
      "x": 1.0, 
      "y": 0.5,
      "z": 0.75,
      "frame": "map"
    }
  }
}
"""
push_goal.stamp = rospy.Time.now()

send_action(push_client, push_goal, "PushObjectDesignator")

Note: This action can be called repeatedly to update object poses or semantic types during runtime. It is typically decoupled from task-level designator flows.