# Copyright (c) 2022-2024, The Isaac Lab Project Developers.
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
"""Termination manager for computing done signals for a given world."""
from __future__ import annotations
import torch
from collections.abc import Sequence
from prettytable import PrettyTable
from typing import TYPE_CHECKING
from .manager_base import ManagerBase, ManagerTermBase
from .manager_term_cfg import TerminationTermCfg
if TYPE_CHECKING:
from omni.isaac.lab.envs import ManagerBasedRLEnv
[docs]class TerminationManager(ManagerBase):
"""Manager for computing done signals for a given world.
The termination manager computes the termination signal (also called dones) as a combination
of termination terms. Each termination term is a function which takes the environment as an
argument and returns a boolean tensor of shape (num_envs,). The termination manager
computes the termination signal as the union (logical or) of all the termination terms.
Following the `Gymnasium API <https://gymnasium.farama.org/tutorials/gymnasium_basics/handling_time_limits/>`_,
the termination signal is computed as the logical OR of the following signals:
* **Time-out**: This signal is set to true if the environment has ended after an externally defined condition
(that is outside the scope of a MDP). For example, the environment may be terminated if the episode has
timed out (i.e. reached max episode length).
* **Terminated**: This signal is set to true if the environment has reached a terminal state defined by the
environment. This state may correspond to task success, task failure, robot falling, etc.
These signals can be individually accessed using the :attr:`time_outs` and :attr:`terminated` properties.
The termination terms are parsed from a config class containing the manager's settings and each term's
parameters. Each termination term should instantiate the :class:`TerminationTermCfg` class. The term's
configuration :attr:`TerminationTermCfg.time_out` decides whether the term is a timeout or a termination term.
"""
_env: ManagerBasedRLEnv
"""The environment instance."""
[docs] def __init__(self, cfg: object, env: ManagerBasedRLEnv):
"""Initializes the termination manager.
Args:
cfg: The configuration object or dictionary (``dict[str, TerminationTermCfg]``).
env: An environment object.
"""
# create buffers to parse and store terms
self._term_names: list[str] = list()
self._term_cfgs: list[TerminationTermCfg] = list()
self._class_term_cfgs: list[TerminationTermCfg] = list()
# call the base class constructor (this will parse the terms config)
super().__init__(cfg, env)
# prepare extra info to store individual termination term information
self._term_dones = dict()
for term_name in self._term_names:
self._term_dones[term_name] = torch.zeros(self.num_envs, device=self.device, dtype=torch.bool)
# create buffer for managing termination per environment
self._truncated_buf = torch.zeros(self.num_envs, device=self.device, dtype=torch.bool)
self._terminated_buf = torch.zeros_like(self._truncated_buf)
def __str__(self) -> str:
"""Returns: A string representation for termination manager."""
msg = f"<TerminationManager> contains {len(self._term_names)} active terms.\n"
# create table for term information
table = PrettyTable()
table.title = "Active Termination Terms"
table.field_names = ["Index", "Name", "Time Out"]
# set alignment of table columns
table.align["Name"] = "l"
# add info on each term
for index, (name, term_cfg) in enumerate(zip(self._term_names, self._term_cfgs)):
table.add_row([index, name, term_cfg.time_out])
# convert table to string
msg += table.get_string()
msg += "\n"
return msg
"""
Properties.
"""
@property
def active_terms(self) -> list[str]:
"""Name of active termination terms."""
return self._term_names
@property
def dones(self) -> torch.Tensor:
"""The net termination signal. Shape is (num_envs,)."""
return self._truncated_buf | self._terminated_buf
@property
def time_outs(self) -> torch.Tensor:
"""The timeout signal (reaching max episode length). Shape is (num_envs,).
This signal is set to true if the environment has ended after an externally defined condition
(that is outside the scope of a MDP). For example, the environment may be terminated if the episode has
timed out (i.e. reached max episode length).
"""
return self._truncated_buf
@property
def terminated(self) -> torch.Tensor:
"""The terminated signal (reaching a terminal state). Shape is (num_envs,).
This signal is set to true if the environment has reached a terminal state defined by the environment.
This state may correspond to task success, task failure, robot falling, etc.
"""
return self._terminated_buf
"""
Operations.
"""
[docs] def reset(self, env_ids: Sequence[int] | None = None) -> dict[str, torch.Tensor]:
"""Returns the episodic counts of individual termination terms.
Args:
env_ids: The environment ids. Defaults to None, in which case
all environments are considered.
Returns:
Dictionary of episodic sum of individual reward terms.
"""
# resolve environment ids
if env_ids is None:
env_ids = slice(None)
# add to episode dict
extras = {}
for key in self._term_dones.keys():
# store information
extras["Episode_Termination/" + key] = torch.count_nonzero(self._term_dones[key][env_ids]).item()
# reset all the reward terms
for term_cfg in self._class_term_cfgs:
term_cfg.func.reset(env_ids=env_ids)
# return logged information
return extras
[docs] def compute(self) -> torch.Tensor:
"""Computes the termination signal as union of individual terms.
This function calls each termination term managed by the class and performs a logical OR operation
to compute the net termination signal.
Returns:
The combined termination signal of shape (num_envs,).
"""
# reset computation
self._truncated_buf[:] = False
self._terminated_buf[:] = False
# iterate over all the termination terms
for name, term_cfg in zip(self._term_names, self._term_cfgs):
value = term_cfg.func(self._env, **term_cfg.params)
# store timeout signal separately
if term_cfg.time_out:
self._truncated_buf |= value
else:
self._terminated_buf |= value
# add to episode dones
self._term_dones[name][:] = value
# return combined termination signal
return self._truncated_buf | self._terminated_buf
[docs] def get_term(self, name: str) -> torch.Tensor:
"""Returns the termination term with the specified name.
Args:
name: The name of the termination term.
Returns:
The corresponding termination term value. Shape is (num_envs,).
"""
return self._term_dones[name]
"""
Operations - Term settings.
"""
[docs] def set_term_cfg(self, term_name: str, cfg: TerminationTermCfg):
"""Sets the configuration of the specified term into the manager.
Args:
term_name: The name of the termination term.
cfg: The configuration for the termination term.
Raises:
ValueError: If the term name is not found.
"""
if term_name not in self._term_names:
raise ValueError(f"Termination term '{term_name}' not found.")
# set the configuration
self._term_cfgs[self._term_names.index(term_name)] = cfg
[docs] def get_term_cfg(self, term_name: str) -> TerminationTermCfg:
"""Gets the configuration for the specified term.
Args:
term_name: The name of the termination term.
Returns:
The configuration of the termination term.
Raises:
ValueError: If the term name is not found.
"""
if term_name not in self._term_names:
raise ValueError(f"Termination term '{term_name}' not found.")
# return the configuration
return self._term_cfgs[self._term_names.index(term_name)]
"""
Helper functions.
"""
def _prepare_terms(self):
# check if config is dict already
if isinstance(self.cfg, dict):
cfg_items = self.cfg.items()
else:
cfg_items = self.cfg.__dict__.items()
# iterate over all the terms
for term_name, term_cfg in cfg_items:
# check for non config
if term_cfg is None:
continue
# check for valid config type
if not isinstance(term_cfg, TerminationTermCfg):
raise TypeError(
f"Configuration for the term '{term_name}' is not of type TerminationTermCfg."
f" Received: '{type(term_cfg)}'."
)
# resolve common parameters
self._resolve_common_term_cfg(term_name, term_cfg, min_argc=1)
# add function to list
self._term_names.append(term_name)
self._term_cfgs.append(term_cfg)
# check if the term is a class
if isinstance(term_cfg.func, ManagerTermBase):
self._class_term_cfgs.append(term_cfg)
