Task Trees API Reference

task_trees.task_trees_manager module

class task_trees.task_trees_manager.BasicTask(param=None)

Bases: object

It defines the essential parameters for the lifecycle management by the TaskTreesManager :meta private:

cancel(wait=True) → bool

cancel the task

Returns:

True if the task has been submitted and the cancellation is sucessful.

Return type:

bool

get_commander_feedback() → str

return the final feedback from the commander for error checking :return: the final message :rtype: str

get_param()

returns the param of the task

Returns:

the param of the task

Return type:

arbitrary, dependent on the subclass definition

get_state() → TaskStates

return the state of the task :return: the current state of the task :rtype: TaskStates

get_time_since_submit() → float

return the time lapse since submission :return: the time lapse since submission, or -1 if the task has not been submitted :rtype: float

update_state(new_state: TaskStates)

update the state (thread-safe)

Parameters:

new_state (TaskStates) – the new state

wait_for_completion(until_states: list = None)

a blocking function that returns when the task has entered into one of the :param:until_states

Parameters:

until_states (list, optional) – _description_, defaults to None

Returns:

_description_

Return type:

_type_

wait_for_working()

a blocking function that returns when the task has entered into WORKING state or GUARDED_ABORTED state

class task_trees.task_trees_manager.BasicTaskTreesManager

Bases: object

subclass the BasicTaskTreesManager to develop a project specific task trees manager and its behaviour trees.

display_tree()

renders the behaviour tree of this task trees manager as a dot file

get_submitted_task() → BasicTask

Return the submitted task :return: The submitted task, or None :rtype: BasicTask

shutdown()

Shutdown the task trees manager immediately

spin()
stop(*args, **kwargs)
submit_task(the_task: BasicTask) → bool

The window for task submission. :param the_task: The task to be executed :type the_task: a subclass of robotarchi.BasicTask :return: True if the task trees manager is in the states that can accept the task submission :rtype: bool

class task_trees.task_trees_manager.GuardedTaskTreesManager(arm_commander: arm_commander.commander_moveit.GeneralCommander, guard_reset=True)

Bases: TaskTreesManager

subclass the TaskTreesManager to develop application specific behaviour trees that are structures to support the plug-in of tasks, timeout, and on-shot initialization branches

is_global_guard_activated()

Returns True if the global guard has been activated

is_task_guard_activated()

Returns True if the task subtree guard has been activated

reset_guard()

Reset the guard that has been switched on

set_global_guard_condition_fn(global_guard_condition_fn)

Set the function that returns the global guard condition

Parameters:

global_guard_condition_fn – a function definition that returns a bool

set_task_guard_condition_fn(task_guard_condition_fn)

Set the function that returns the task subtree guard condition

Parameters:

task_guard_condition_fn – a function definition that returns a bool

submit_task(the_task: BasicTask) → bool

Submit a task to the task trees manager for execution

Parameters:

the_task – the task to be execution

Returns:

True if the submission is accepted

class task_trees.task_trees_manager.TaskTreesManager(arm_commander)

Bases: BasicTaskTreesManager

subclass the TaskTreesManager to develop application specific behaviour trees that are structures to support the plug-in of tasks, timeout, and on-shot initialization branches

display_tree(branch=None, target_directory=None)

Save a graphical representation of the given branch of a behaviour tree to the target directory

Parameters:

  • branch – the branch to be drawn, defaults to None which means the whole behaviour tree

  • target_directory – the output directory, defaults to None

shutdown()

Shutdown the task trees manager, including the behaviour tree and then terminate the program

task_trees.behaviours_move module

task_trees.behaviours_move_sense module

task_trees.behaviours_base module

class task_trees.behaviours_base.ConditionalBehaviour(*args: Any, **kwargs: Any)

Bases: Behaviour

The base class that extends PyTrees Behaviour with support for the conditional behaviour model. The model significantly improves the reusability of behaviours and the readability of their roles in a behaviour tree. This class should not be instantiated

class ConditionSpec(fn, inverted, kwargs)

Bases: tuple

fn

Alias for field number 0

inverted

Alias for field number 1

kwargs

Alias for field number 2

class Policies(value, names=<not given>, *values, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: Enum

FAILURE_IF_FALSE_POLICY = 1
SUCCESS_IF_FALSE_POLICY = 0
update() → py_trees.common.Status
Specialized update function for ConditionalBehaviour. Maybe overrided by subclasses and in such case checks the condition

using the function _is_condition_satisfied()

Returns:

the new PyTrees status

Return type:

Status

update_if_true() → py_trees.common.Status

A placeholder function that should be overridden in a subclass :return: The new PyTrees status :rtype: Status

class task_trees.behaviours_base.ConditionalCommanderBehaviour(*args: Any, **kwargs: Any)

Bases: ConditionalBehaviour

The base Behaviour class supporting the implementation of Behaviour subclasses that uses the General Commander, and it has included logic for managing the states of the General Commander

initialise()
terminate(new_status)
tidy_up()
update()
Specialized update function for ConditionalBehaviour. Maybe overrided by subclasses and in such case checks the condition

using the function _is_condition_satisfied()

Returns:

the new PyTrees status

Return type:

Status

update_when_busy()
update_when_ready()
class task_trees.behaviours_base.HandleTaskCancelled(*args: Any, **kwargs: Any)

Bases: Behaviour

A utility Behaviour that handles task cancelled placed after the EternalGuard (with FailureIsSuccess)

terminate(new_status)
update()
class task_trees.behaviours_base.HandleTaskFailure(*args: Any, **kwargs: Any)

Bases: Behaviour

A utility Behaviour that handles task failure situation that has happened in a subclass of CommanderBehaviour or ConditionalCommanderBehaviour

terminate(new_status)
update()
class task_trees.behaviours_base.Print(*args: Any, **kwargs: Any)

Bases: Behaviour

a utility Behaviour used for tracing and debugging. It prints a string message from a constant or a function that returns a string and optionally the status of the subtree rooted at the parent of this behaviour.

update()
class task_trees.behaviours_base.PrintPose(*args: Any, **kwargs: Any)

Bases: Behaviour

a utility Behaviour used for tracing and debugging. It prints the pose of the end-effector in the world frame and the joint values

update()
class task_trees.behaviours_base.PrintPosesInFrame(*args: Any, **kwargs: Any)

Bases: PrintPose

A utility Behaviour used for tracing and debugging. It prints a string message from a constant or a function that returns a string and optionally the status of the subtree rooted at the parent of this behaviour.

update()
class task_trees.behaviours_base.SceneConditionalCommanderBehaviour(*args: Any, **kwargs: Any)

Bases: ConditionalCommanderBehaviour

The base Behaviour class supporting the implementation of Behaviour subclasses that uses the General Commander and the Scene Configuration

compute_physical_target(composite_target, logical_lookup_fn=None, default_target=None) → list
class task_trees.behaviours_base.SimAttachObject(*args: Any, **kwargs: Any)

Bases: ConditionalCommanderBehaviour

This behaviour attachs a collision object to the end effector

update_when_ready()
class task_trees.behaviours_base.SimDetachObject(*args: Any, **kwargs: Any)

Bases: ConditionalCommanderBehaviour

This behaviour detachs a collision object from the behaviour

update_when_ready()

task_trees.task_scene module

class task_trees.task_scene.FrameConfig(name, type, xyz, rpy, parent_frame)

Bases: tuple

name

Alias for field number 0

parent_frame

Alias for field number 4

rpy

Alias for field number 3

type

Alias for field number 1

xyz

Alias for field number 2

class task_trees.task_scene.LinkConfig(name, type, model_file, dimensions, xyz, rpy, parent_frame)

Bases: tuple

dimensions

Alias for field number 3

model_file

Alias for field number 2

name

Alias for field number 0

parent_frame

Alias for field number 6

rpy

Alias for field number 5

type

Alias for field number 1

xyz

Alias for field number 4

class task_trees.task_scene.Scene(scene_config_file: str = None)

Bases: object

The base model provides mapping between physical/joint-space pose and various named/logical poses.

exists_config(key: str) → bool

returns True of the given config name exists :param key: The config name :type key: str :return: True if the given config name exists :rtype: bool

get_frame_config_as_dict(frame_name: str) → dict

return the frame configuration as a dict, or None if the scene not exists :param frame_name: name of the frame :type frame_name: str :return: the configuration of the frame type scene or None if not exists :rtype: dict

return the object configuration as ObjectConfig tuple, or None if the name not exists :param frame_name: name of the frame :type frame_name: str :return: the LinkConfig of the frame or None if not exists :rtype: LinkConfig

return the object configuration as ObjectConfig tuple, or None if the name not exists :param scene_name: name of the scene :type scene_name: str :return: the LinkConfig of the scene or None if not exists :rtype: LinkConfig

get_named_poses_of_root_as_dict() → dict

return the named poses defined in the scene configuration as a dict

Returns:

dict containing key value pairs of named poses

get_scene_config_as_dict(scene_name: str) → dict

return the scene configuration as a dict, or None if the scene not exists :param scene_name: name of the object :type scene_name: str :return: the configuration of the scene as a dict or None if not exists :rtype: dict

key_list_under_config_key(key: str) → list

returns a list of keys specified under the config name or an empty list :param key: The config name :type key: str :return: a list of keys specified under the config name :rtype: list

len_of_key_list_under_config_key(key: str) → int

returns the length of the list under the config name :param key: The config name :type key: str :return: the length of the list the config name :rtype: int

list_frame_names() → list

return the list of frame type scene defined in the scene configuration :return: a list of frame names as strings :rtype: list

list_scene_names() → list

return the list of objects defined in the scene configuration :return: a list of object names as strings :rtype: list

query_config(key: str, default=None)

returns the value of any named config given as a dot-separated path :param key: the dot-separated key, the root scene may have the “root” omitted :type key: str :param default: the default value if nothing is found in the key, defaults to None :type default: any :return: the value of the config :rtype: any

class task_trees.task_scene.SceneKeyParts(scene, parts)

Bases: tuple

parts

Alias for field number 1

scene

Alias for field number 0

task_trees.scene_to_rviz module