tia/Dreamer/local_dm_control_suite/ball_in_cup.py

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2021-06-30 01:20:44 +00:00
# Copyright 2017 The dm_control Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================
"""Ball-in-Cup Domain."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import collections
from dm_control import mujoco
from dm_control.rl import control
from local_dm_control_suite import base
from local_dm_control_suite import common
from dm_control.utils import containers
_DEFAULT_TIME_LIMIT = 20 # (seconds)
_CONTROL_TIMESTEP = .02 # (seconds)
SUITE = containers.TaggedTasks()
def get_model_and_assets():
"""Returns a tuple containing the model XML string and a dict of assets."""
return common.read_model('ball_in_cup.xml'), common.ASSETS
@SUITE.add('benchmarking', 'easy')
def catch(time_limit=_DEFAULT_TIME_LIMIT, random=None, environment_kwargs=None):
"""Returns the Ball-in-Cup task."""
physics = Physics.from_xml_string(*get_model_and_assets())
task = BallInCup(random=random)
environment_kwargs = environment_kwargs or {}
return control.Environment(
physics, task, time_limit=time_limit, control_timestep=_CONTROL_TIMESTEP,
**environment_kwargs)
class Physics(mujoco.Physics):
"""Physics with additional features for the Ball-in-Cup domain."""
def ball_to_target(self):
"""Returns the vector from the ball to the target."""
target = self.named.data.site_xpos['target', ['x', 'z']]
ball = self.named.data.xpos['ball', ['x', 'z']]
return target - ball
def in_target(self):
"""Returns 1 if the ball is in the target, 0 otherwise."""
ball_to_target = abs(self.ball_to_target())
target_size = self.named.model.site_size['target', [0, 2]]
ball_size = self.named.model.geom_size['ball', 0]
return float(all(ball_to_target < target_size - ball_size))
class BallInCup(base.Task):
"""The Ball-in-Cup task. Put the ball in the cup."""
def initialize_episode(self, physics):
"""Sets the state of the environment at the start of each episode.
Args:
physics: An instance of `Physics`.
"""
# Find a collision-free random initial position of the ball.
penetrating = True
while penetrating:
# Assign a random ball position.
physics.named.data.qpos['ball_x'] = self.random.uniform(-.2, .2)
physics.named.data.qpos['ball_z'] = self.random.uniform(.2, .5)
# Check for collisions.
physics.after_reset()
penetrating = physics.data.ncon > 0
super(BallInCup, self).initialize_episode(physics)
def get_observation(self, physics):
"""Returns an observation of the state."""
obs = collections.OrderedDict()
obs['position'] = physics.position()
obs['velocity'] = physics.velocity()
return obs
def get_reward(self, physics):
"""Returns a sparse reward."""
return physics.in_target()