Robot integration tutorial (#1285)

lerobot/common/robots/robot.py

@@ -27,7 +27,16 @@ from .config import RobotConfig
 # TODO(aliberts): action/obs typing such as Generic[ObsType, ActType] similar to gym.Env ?
 # https://github.com/Farama-Foundation/Gymnasium/blob/3287c869f9a48d99454306b0d4b4ec537f0f35e3/gymnasium/core.py#L23
 class Robot(abc.ABC):
-    """The main LeRobot class for implementing robots."""
+    """
+    The base abstract class for all LeRobot-compatible robots.
+
+    This class provides a standardized interface for interacting with physical robots.
+    Subclasses must implement all abstract methods and properties to be usable.
+
+    Attributes:
+        config_class (RobotConfig): The expected configuration class for this robot.
+        name (str): The unique robot name used to identify this robot type.
+    """
 
     # Set these in ALL subclasses
     config_class: RobotConfig
@@ -52,58 +61,124 @@ class Robot(abc.ABC):
     @property
     @abc.abstractmethod
     def observation_features(self) -> dict:
+        """
+        A dictionary describing the structure and types of the observations produced by the robot.
+        Its structure (keys) should match the structure of what is returned by :pymeth:`get_observation`.
+        Values for the dict should either be:
+            - The type of the value if it's a simple value, e.g. `float` for single proprioceptive value (a joint's position/velocity)
+            - A tuple representing the shape if it's an array-type value, e.g. `(height, width, channel)` for images
+
+        Note: this property should be able to be called regardless of whether the robot is connected or not.
+        """
         pass
 
     @property
     @abc.abstractmethod
     def action_features(self) -> dict:
+        """
+        A dictionary describing the structure and types of the actions expected by the robot. Its structure
+        (keys) should match the structure of what is passed to :pymeth:`send_action`. Values for the dict
+        should be the type of the value if it's a simple value, e.g. `float` for single proprioceptive value
+        (a joint's goal position/velocity)
+
+        Note: this property should be able to be called regardless of whether the robot is connected or not.
+        """
         pass
 
     @property
     @abc.abstractmethod
     def is_connected(self) -> bool:
+        """
+        Whether the robot is currently connected or not. If `False`, calling :pymeth:`get_observation` or
+        :pymeth:`send_action` should raise an error.
+        """
         pass
 
     @abc.abstractmethod
     def connect(self, calibrate: bool = True) -> None:
-        """Connects to the robot."""
+        """
+        Establish communication with the robot.
+
+        Args:
+            calibrate (bool): If True, automatically calibrate the robot after connecting if it's not
+                calibrated or needs calibration (this is hardware-dependant).
+        """
         pass
 
     @property
     @abc.abstractmethod
     def is_calibrated(self) -> bool:
+        """Whether the robot is currently calibrated or not. Should be always `True` if not applicable"""
         pass
 
     @abc.abstractmethod
     def calibrate(self) -> None:
-        """Calibrates the robot."""
+        """
+        Calibrate the robot if applicable. If not, this should be a no-op.
+
+        This method should collect any necessary data (e.g., motor offsets) and update the
+        :pyattr:`calibration` dictionary accordingly.
+        """
         pass
 
     def _load_calibration(self, fpath: Path | None = None) -> None:
+        """
+        Helper to load calibration data from the specified file.
+
+        Args:
+            fpath (Path | None): Optional path to the calibration file. Defaults to `self.calibration_fpath`.
+        """
         fpath = self.calibration_fpath if fpath is None else fpath
         with open(fpath) as f, draccus.config_type("json"):
             self.calibration = draccus.load(dict[str, MotorCalibration], f)
 
     def _save_calibration(self, fpath: Path | None = None) -> None:
+        """
+        Helper to save calibration data to the specified file.
+
+        Args:
+            fpath (Path | None): Optional path to save the calibration file. Defaults to `self.calibration_fpath`.
+        """
         fpath = self.calibration_fpath if fpath is None else fpath
         with open(fpath, "w") as f, draccus.config_type("json"):
             draccus.dump(self.calibration, f, indent=4)
 
     @abc.abstractmethod
     def configure(self) -> None:
+        """
+        Apply any one-time or runtime configuration to the robot.
+        This may include setting motor parameters, control modes, or initial state.
+        """
         pass
 
     @abc.abstractmethod
     def get_observation(self) -> dict[str, Any]:
-        """Gets observation from the robot."""
+        """
+        Retrieve the current observation from the robot.
+
+        Returns:
+            dict[str, Any]: A flat dictionary representing the robot's current sensory state. Its structure
+                should match :pymeth:`observation_features`.
+        """
+
         pass
 
     @abc.abstractmethod
     def send_action(self, action: dict[str, Any]) -> dict[str, Any]:
-        """Sends actions to the robot."""
+        """
+        Send an action command to the robot.
+
+        Args:
+            action (dict[str, Any]): Dictionary representing the desired action. Its structure should match
+                :pymeth:`action_features`.
+
+        Returns:
+            dict[str, Any]: The action actually sent to the motors potentially clipped or modified, e.g. by
+                safety limits on velocity.
+        """
         pass
 
     @abc.abstractmethod
     def disconnect(self) -> None:
-        """Disconnects from the robot."""
+        """Disconnect from the robot and perform any necessary cleanup."""
         pass