Sequential Tasks

Tasks can be composed sequentially to form longer horizon, more complex tasks using the SequentialTaskBase class. SequentialTaskBase takes a list of TaskBase instances and automatically composes them into a single task. The order of the tasks in the list determines the order in which subtasks must be completed. Internally, the Arena Environment Builder will automatically track that each sub-task is completed successfully in turn. It will also automatically compose the sub-task metrics, resets etc.

Usage Example (Pick and Place Task and Close Door Task Composition)

pick_object = asset_registry.get_asset_by_name("mustard_bottle")()
destination = ObjectReference("refrigerator_shelf", parent_asset=kitchen)
pick_and_place_task = PickAndPlaceTask(pick_object, destination, kitchen)

openable_object = OpenableObjectReference("refrigerator", parent_asset=kitchen, openable_joint_name="fridge_door_joint")
close_door_task = CloseDoorTask(openable_object, closedness_threshold=0.10)

sequential_task = SequentialTaskBase(subtasks=[pick_and_place_task, close_door_task])

We demonstrate the use of a sequential task in one of our workflows. See GR1 Sequential Pick & Place and Close Door Task to see a sequential task is use - picking up an object and placing it in a refrigerator and then closing the door.