Source code for bigym.loco.adapters.binding
"""What a lower-body backend provides to put its controller in the env's loop.
Each backend is a :class:`BackendBinding` registered under its name with
:func:`bigym.loco.register_backend` (the built-in ``groot_wbc_g1`` included),
or named by a ``"pkg.module:ATTR"`` string. Robot facts that hold for every
backend stay in the robot config (``bigym/robots/configs``).
"""
from __future__ import annotations
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from bigym.bigym_env import BiGymEnv
from bigym.loco.config import ControllerConfig
from bigym.loco.controller import LowerBodyController
from bigym.robots.robot import Robot
[docs]
class BackendBinding:
"""A lower-body backend's hooks into env construction.
The env calls the hooks in this order:
:meth:`robot_cls` while building the task env, then
:meth:`build_controller` and :meth:`configure_model` on the built env.
``env`` is the task's :class:`~bigym.bigym_env.BiGymEnv`; a controller
may rely on ``env.model``, ``env.data``, ``env.robot`` and
``env.action_space``. ``config`` is the env's
:class:`~bigym.loco.config.ControllerConfig`: a backend reads the fields
that apply to it and may ignore the rest.
Subclass it and set :attr:`robot_models`; override
:meth:`build_controller`. The controller implements
:class:`~bigym.loco.controller.LowerBodyController`, most easily by
subclassing :class:`~bigym.loco.base.LowerBodyBase`.
"""
#: ``EnvConfig.robot_model`` names the backend drives.
robot_models: tuple[str, ...] = ()
#: True when the backend can run with the pelvis roll/pitch left passive
#: (``ControllerConfig.passive_base_tilt``).
supports_passive_base_tilt: bool = False
[docs]
def robot_cls(
self, robot_cls: type[Robot], config: ControllerConfig
) -> type[Robot]:
"""The robot class to build the task env with.
``robot_cls`` is the robot model's floating-base class. Return it
(the default), or a variant with the joints the controller drives
actuated and their PD gains set (``G1Dex1.variant``).
"""
return robot_cls
[docs]
def build_controller(
self, env: BiGymEnv, config: ControllerConfig, *, control_dt: float
) -> LowerBodyController:
"""Build the controller on the freshly built task env.
``control_dt`` is the env's control step in seconds.
"""
raise NotImplementedError
