Source code for omni.isaac.lab.devices.gamepad.se2_gamepad

# Copyright (c) 2022-2024, The Isaac Lab Project Developers.
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause

"""Gamepad controller for SE(2) control."""

import numpy as np
import weakref
from collections.abc import Callable

import carb
import omni

from ..device_base import DeviceBase


[docs]class Se2Gamepad(DeviceBase): r"""A gamepad controller for sending SE(2) commands as velocity commands. This class is designed to provide a gamepad controller for mobile base (such as quadrupeds). It uses the Omniverse gamepad interface to listen to gamepad events and map them to robot's task-space commands. The command comprises of the base linear and angular velocity: :math:`(v_x, v_y, \omega_z)`. Key bindings: ====================== ========================= ======================== Command Key (+ve axis) Key (-ve axis) ====================== ========================= ======================== Move along x-axis left stick up left stick down Move along y-axis left stick right left stick left Rotate along z-axis right stick right right stick left ====================== ========================= ======================== .. seealso:: The official documentation for the gamepad interface: `Carb Gamepad Interface <https://docs.omniverse.nvidia.com/dev-guide/latest/programmer_ref/input-devices/gamepad.html>`__. """
[docs] def __init__( self, v_x_sensitivity: float = 1.0, v_y_sensitivity: float = 1.0, omega_z_sensitivity: float = 1.0, dead_zone: float = 0.01, ): """Initialize the gamepad layer. Args: v_x_sensitivity: Magnitude of linear velocity along x-direction scaling. Defaults to 1.0. v_y_sensitivity: Magnitude of linear velocity along y-direction scaling. Defaults to 1.0. omega_z_sensitivity: Magnitude of angular velocity along z-direction scaling. Defaults to 1.0. dead_zone: Magnitude of dead zone for gamepad. An event value from the gamepad less than this value will be ignored. Defaults to 0.01. """ # turn off simulator gamepad control carb_settings_iface = carb.settings.get_settings() carb_settings_iface.set_bool("/persistent/app/omniverse/gamepadCameraControl", False) # store inputs self.v_x_sensitivity = v_x_sensitivity self.v_y_sensitivity = v_y_sensitivity self.omega_z_sensitivity = omega_z_sensitivity self.dead_zone = dead_zone # acquire omniverse interfaces self._appwindow = omni.appwindow.get_default_app_window() self._input = carb.input.acquire_input_interface() self._gamepad = self._appwindow.get_gamepad(0) # note: Use weakref on callbacks to ensure that this object can be deleted when its destructor is called self._gamepad_sub = self._input.subscribe_to_gamepad_events( self._gamepad, lambda event, *args, obj=weakref.proxy(self): obj._on_gamepad_event(event, *args), ) # bindings for gamepad to command self._create_key_bindings() # command buffers # When using the gamepad, two values are provided for each axis. # For example: when the left stick is moved down, there are two evens: `left_stick_down = 0.8` # and `left_stick_up = 0.0`. If only the value of left_stick_up is used, the value will be 0.0, # which is not the desired behavior. Therefore, we save both the values into the buffer and use # the maximum value. # (positive, negative), (x, y, yaw) self._base_command_raw = np.zeros([2, 3]) # dictionary for additional callbacks self._additional_callbacks = dict()
def __del__(self): """Unsubscribe from gamepad events.""" self._input.unsubscribe_from_gamepad_events(self._gamepad, self._gamepad_sub) self._gamepad_sub = None def __str__(self) -> str: """Returns: A string containing the information of joystick.""" msg = f"Gamepad Controller for SE(2): {self.__class__.__name__}\n" msg += f"\tDevice name: {self._input.get_gamepad_name(self._gamepad)}\n" msg += "\t----------------------------------------------\n" msg += "\tMove in X-Y plane: left stick\n" msg += "\tRotate in Z-axis: right stick\n" return msg """ Operations """
[docs] def reset(self): # default flags self._base_command_raw.fill(0.0)
[docs] def add_callback(self, key: carb.input.GamepadInput, func: Callable): """Add additional functions to bind gamepad. A list of available gamepad keys are present in the `carb documentation <https://docs.omniverse.nvidia.com/dev-guide/latest/programmer_ref/input-devices/gamepad.html>`__. Args: key: The gamepad button to check against. func: The function to call when key is pressed. The callback function should not take any arguments. """ self._additional_callbacks[key] = func
[docs] def advance(self) -> np.ndarray: """Provides the result from gamepad event state. Returns: A 3D array containing the linear (x,y) and angular velocity (z). """ return self._resolve_command_buffer(self._base_command_raw)
""" Internal helpers. """ def _on_gamepad_event(self, event: carb.input.GamepadEvent, *args, **kwargs): """Subscriber callback to when kit is updated. Reference: https://docs.omniverse.nvidia.com/dev-guide/latest/programmer_ref/input-devices/gamepad.html """ # check if the event is a button press cur_val = event.value if abs(cur_val) < self.dead_zone: cur_val = 0 # -- left and right stick if event.input in self._INPUT_STICK_VALUE_MAPPING: direction, axis, value = self._INPUT_STICK_VALUE_MAPPING[event.input] # change the value only if the stick is moved (soft press) self._base_command_raw[direction, axis] = value * cur_val # additional callbacks if event.input in self._additional_callbacks: self._additional_callbacks[event.input]() # since no error, we are fine :) return True def _create_key_bindings(self): """Creates default key binding.""" self._INPUT_STICK_VALUE_MAPPING = { # forward command carb.input.GamepadInput.LEFT_STICK_UP: (0, 0, self.v_x_sensitivity), # backward command carb.input.GamepadInput.LEFT_STICK_DOWN: (1, 0, self.v_x_sensitivity), # right command carb.input.GamepadInput.LEFT_STICK_RIGHT: (0, 1, self.v_y_sensitivity), # left command carb.input.GamepadInput.LEFT_STICK_LEFT: (1, 1, self.v_y_sensitivity), # yaw command (positive) carb.input.GamepadInput.RIGHT_STICK_RIGHT: (0, 2, self.omega_z_sensitivity), # yaw command (negative) carb.input.GamepadInput.RIGHT_STICK_LEFT: (1, 2, self.omega_z_sensitivity), } def _resolve_command_buffer(self, raw_command: np.ndarray) -> np.ndarray: """Resolves the command buffer. Args: raw_command: The raw command from the gamepad. Shape is (2, 3) This is a 2D array since gamepad dpad/stick returns two values corresponding to the positive and negative direction. The first index is the direction (0: positive, 1: negative) and the second index is value (absolute) of the command. Returns: Resolved command. Shape is (3,) """ # compare the positive and negative value decide the sign of the value # if the positive value is larger, the sign is positive (i.e. False, 0) # if the negative value is larger, the sign is positive (i.e. True, 1) command_sign = raw_command[1, :] > raw_command[0, :] # extract the command value command = raw_command.max(axis=0) # apply the sign # if the sign is positive, the value is already positive. # if the sign is negative, the value is negative after applying the sign. command[command_sign] *= -1 return command