Source code for isaaclab.envs.mdp.actions.binary_joint_actions

# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause

from __future__ import annotations

import logging
from collections.abc import Sequence
from typing import TYPE_CHECKING

import torch

import isaaclab.utils.string as string_utils
from isaaclab.assets.articulation import Articulation
from isaaclab.managers.action_manager import ActionTerm

if TYPE_CHECKING:
    from isaaclab.envs import ManagerBasedEnv
    from isaaclab.envs.utils.io_descriptors import GenericActionIODescriptor

    from . import actions_cfg

# import logger
logger = logging.getLogger(__name__)


[docs] class BinaryJointAction(ActionTerm): """Base class for binary joint actions. This action term maps a binary action to the *open* or *close* joint configurations. These configurations are specified through the :class:`BinaryJointActionCfg` object. If the input action is a float vector, the action is considered binary based on the sign of the action values. Based on above, we follow the following convention for the binary action: 1. Open action: 1 (bool) or positive values (float). 2. Close action: 0 (bool) or negative values (float). The action term can mostly be used for gripper actions, where the gripper is either open or closed. This helps in devising a mimicking mechanism for the gripper, since in simulation it is often not possible to add such constraints to the gripper. """ cfg: actions_cfg.BinaryJointActionCfg """The configuration of the action term.""" _asset: Articulation """The articulation asset on which the action term is applied.""" _clip: torch.Tensor """The clip applied to the input action."""
[docs] def __init__(self, cfg: actions_cfg.BinaryJointActionCfg, env: ManagerBasedEnv) -> None: # initialize the action term super().__init__(cfg, env) # resolve the joints over which the action term is applied joint_ids, self._joint_names = self._asset.find_joints(self.cfg.joint_names, as_proxy=True) self._num_joints = len(joint_ids) self._joint_ids = joint_ids.warp # log the resolved joint names for debugging logger.info( f"Resolved joint names for the action term {self.__class__.__name__}:" f" {self._joint_names} [{self._joint_ids}]" ) # create tensors for raw and processed actions self._raw_actions = torch.zeros(self.num_envs, 1, device=self.device) self._processed_actions = torch.zeros(self.num_envs, self._num_joints, device=self.device) # parse open command self._open_command = torch.zeros(self._num_joints, device=self.device) index_list, name_list, value_list = string_utils.resolve_matching_names_values( self.cfg.open_command_expr, self._joint_names ) if len(index_list) != self._num_joints: raise ValueError( f"Could not resolve all joints for the action term. Missing: {set(self._joint_names) - set(name_list)}" ) self._open_command[index_list] = torch.tensor(value_list, device=self.device) # parse close command self._close_command = torch.zeros_like(self._open_command) index_list, name_list, value_list = string_utils.resolve_matching_names_values( self.cfg.close_command_expr, self._joint_names ) if len(index_list) != self._num_joints: raise ValueError( f"Could not resolve all joints for the action term. Missing: {set(self._joint_names) - set(name_list)}" ) self._close_command[index_list] = torch.tensor(value_list, device=self.device) # parse clip if self.cfg.clip is not None: if isinstance(cfg.clip, dict): self._clip = torch.tensor([[-float("inf"), float("inf")]], device=self.device).repeat( self.num_envs, self.action_dim, 1 ) index_list, _, value_list = string_utils.resolve_matching_names_values(self.cfg.clip, self._joint_names) self._clip[:, index_list] = torch.tensor(value_list, device=self.device) else: raise ValueError(f"Unsupported clip type: {type(cfg.clip)}. Supported types are dict.")
""" Properties. """ @property def action_dim(self) -> int: return 1 @property def raw_actions(self) -> torch.Tensor: return self._raw_actions @property def processed_actions(self) -> torch.Tensor: return self._processed_actions @property def IO_descriptor(self) -> GenericActionIODescriptor: super().IO_descriptor self._IO_descriptor.shape = (self.action_dim,) self._IO_descriptor.dtype = str(self.raw_actions.dtype) self._IO_descriptor.action_type = "JointAction" self._IO_descriptor.joint_names = self._joint_names return self._IO_descriptor """ Operations. """ def process_actions(self, actions: torch.Tensor): # store the raw actions self._raw_actions[:] = actions # compute the binary mask if actions.dtype == torch.bool: # true: close, false: open binary_mask = actions == 0 else: # true: close, false: open binary_mask = actions < 0 # compute the command self._processed_actions = torch.where(binary_mask, self._close_command, self._open_command) if self.cfg.clip is not None: self._processed_actions = torch.clamp( self._processed_actions, min=self._clip[:, :, 0], max=self._clip[:, :, 1] ) def reset(self, env_ids: Sequence[int] | None = None) -> None: self._raw_actions[env_ids] = 0.0
[docs] class BinaryJointPositionAction(BinaryJointAction): """Binary joint action that sets the binary action into joint position targets.""" cfg: actions_cfg.BinaryJointPositionActionCfg """The configuration of the action term.""" def apply_actions(self): self._asset.set_joint_position_target_index(target=self._processed_actions, joint_ids=self._joint_ids)
[docs] class BinaryJointVelocityAction(BinaryJointAction): """Binary joint action that sets the binary action into joint velocity targets.""" cfg: actions_cfg.BinaryJointVelocityActionCfg """The configuration of the action term.""" def apply_actions(self): self._asset.set_joint_velocity_target_index(target=self._processed_actions, joint_ids=self._joint_ids)
[docs] class AbsBinaryJointPositionAction(BinaryJointAction): """Absolute Binary joint action that sets the binary action into joint position targets. This class extends :class:`BinaryJointAction` to accept absolute joint-position actions [m or rad, depending on joint type] for gripper control. It compares each continuous action with the configured threshold and selects the open or closed joint-position target. """ cfg: actions_cfg.AbsBinaryJointPositionActionCfg """The configuration of the action term.""" def process_actions(self, actions: torch.Tensor): # store the raw actions self._raw_actions[:] = actions # compute the binary mask if self.cfg.positive_threshold: # true: open 0.785, false: close 0.0 binary_mask = actions > self.cfg.threshold else: # true: close 0.0, false: open 0.785 binary_mask = actions < self.cfg.threshold # compute the command self._processed_actions = torch.where(binary_mask, self._open_command, self._close_command) if self.cfg.clip is not None: self._processed_actions = torch.clamp( self._processed_actions, min=self._clip[:, :, 0], max=self._clip[:, :, 1] ) def apply_actions(self): self._asset.set_joint_position_target_index(target=self._processed_actions, joint_ids=self._joint_ids)