DBC/local_dm_control_suite/manipulator.py

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2020-10-12 22:39:25 +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.
# ============================================================================
"""Planar Manipulator 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
from dm_control.utils import rewards
from dm_control.utils import xml_tools
from lxml import etree
import numpy as np
_CLOSE = .01 # (Meters) Distance below which a thing is considered close.
_CONTROL_TIMESTEP = .01 # (Seconds)
_TIME_LIMIT = 10 # (Seconds)
_P_IN_HAND = .1 # Probabillity of object-in-hand initial state
_P_IN_TARGET = .1 # Probabillity of object-in-target initial state
_ARM_JOINTS = ['arm_root', 'arm_shoulder', 'arm_elbow', 'arm_wrist',
'finger', 'fingertip', 'thumb', 'thumbtip']
_ALL_PROPS = frozenset(['ball', 'target_ball', 'cup',
'peg', 'target_peg', 'slot'])
SUITE = containers.TaggedTasks()
def make_model(use_peg, insert):
"""Returns a tuple containing the model XML string and a dict of assets."""
xml_string = common.read_model('manipulator.xml')
parser = etree.XMLParser(remove_blank_text=True)
mjcf = etree.XML(xml_string, parser)
# Select the desired prop.
if use_peg:
required_props = ['peg', 'target_peg']
if insert:
required_props += ['slot']
else:
required_props = ['ball', 'target_ball']
if insert:
required_props += ['cup']
# Remove unused props
for unused_prop in _ALL_PROPS.difference(required_props):
prop = xml_tools.find_element(mjcf, 'body', unused_prop)
prop.getparent().remove(prop)
return etree.tostring(mjcf, pretty_print=True), common.ASSETS
@SUITE.add('benchmarking', 'hard')
def bring_ball(fully_observable=True, time_limit=_TIME_LIMIT, random=None,
environment_kwargs=None):
"""Returns manipulator bring task with the ball prop."""
use_peg = False
insert = False
physics = Physics.from_xml_string(*make_model(use_peg, insert))
task = Bring(use_peg=use_peg, insert=insert,
fully_observable=fully_observable, random=random)
environment_kwargs = environment_kwargs or {}
return control.Environment(
physics, task, control_timestep=_CONTROL_TIMESTEP, time_limit=time_limit,
**environment_kwargs)
@SUITE.add('hard')
def bring_peg(fully_observable=True, time_limit=_TIME_LIMIT, random=None,
environment_kwargs=None):
"""Returns manipulator bring task with the peg prop."""
use_peg = True
insert = False
physics = Physics.from_xml_string(*make_model(use_peg, insert))
task = Bring(use_peg=use_peg, insert=insert,
fully_observable=fully_observable, random=random)
environment_kwargs = environment_kwargs or {}
return control.Environment(
physics, task, control_timestep=_CONTROL_TIMESTEP, time_limit=time_limit,
**environment_kwargs)
@SUITE.add('hard')
def insert_ball(fully_observable=True, time_limit=_TIME_LIMIT, random=None,
environment_kwargs=None):
"""Returns manipulator insert task with the ball prop."""
use_peg = False
insert = True
physics = Physics.from_xml_string(*make_model(use_peg, insert))
task = Bring(use_peg=use_peg, insert=insert,
fully_observable=fully_observable, random=random)
environment_kwargs = environment_kwargs or {}
return control.Environment(
physics, task, control_timestep=_CONTROL_TIMESTEP, time_limit=time_limit,
**environment_kwargs)
@SUITE.add('hard')
def insert_peg(fully_observable=True, time_limit=_TIME_LIMIT, random=None,
environment_kwargs=None):
"""Returns manipulator insert task with the peg prop."""
use_peg = True
insert = True
physics = Physics.from_xml_string(*make_model(use_peg, insert))
task = Bring(use_peg=use_peg, insert=insert,
fully_observable=fully_observable, random=random)
environment_kwargs = environment_kwargs or {}
return control.Environment(
physics, task, control_timestep=_CONTROL_TIMESTEP, time_limit=time_limit,
**environment_kwargs)
class Physics(mujoco.Physics):
"""Physics with additional features for the Planar Manipulator domain."""
def bounded_joint_pos(self, joint_names):
"""Returns joint positions as (sin, cos) values."""
joint_pos = self.named.data.qpos[joint_names]
return np.vstack([np.sin(joint_pos), np.cos(joint_pos)]).T
def joint_vel(self, joint_names):
"""Returns joint velocities."""
return self.named.data.qvel[joint_names]
def body_2d_pose(self, body_names, orientation=True):
"""Returns positions and/or orientations of bodies."""
if not isinstance(body_names, str):
body_names = np.array(body_names).reshape(-1, 1) # Broadcast indices.
pos = self.named.data.xpos[body_names, ['x', 'z']]
if orientation:
ori = self.named.data.xquat[body_names, ['qw', 'qy']]
return np.hstack([pos, ori])
else:
return pos
def touch(self):
return np.log1p(self.data.sensordata)
def site_distance(self, site1, site2):
site1_to_site2 = np.diff(self.named.data.site_xpos[[site2, site1]], axis=0)
return np.linalg.norm(site1_to_site2)
class Bring(base.Task):
"""A Bring `Task`: bring the prop to the target."""
def __init__(self, use_peg, insert, fully_observable, random=None):
"""Initialize an instance of the `Bring` task.
Args:
use_peg: A `bool`, whether to replace the ball prop with the peg prop.
insert: A `bool`, whether to insert the prop in a receptacle.
fully_observable: A `bool`, whether the observation should contain the
position and velocity of the object being manipulated and the target
location.
random: Optional, either a `numpy.random.RandomState` instance, an
integer seed for creating a new `RandomState`, or None to select a seed
automatically (default).
"""
self._use_peg = use_peg
self._target = 'target_peg' if use_peg else 'target_ball'
self._object = 'peg' if self._use_peg else 'ball'
self._object_joints = ['_'.join([self._object, dim]) for dim in 'xzy']
self._receptacle = 'slot' if self._use_peg else 'cup'
self._insert = insert
self._fully_observable = fully_observable
super(Bring, self).__init__(random=random)
def initialize_episode(self, physics):
"""Sets the state of the environment at the start of each episode."""
# Local aliases
choice = self.random.choice
uniform = self.random.uniform
model = physics.named.model
data = physics.named.data
# Find a collision-free random initial configuration.
penetrating = True
while penetrating:
# Randomise angles of arm joints.
is_limited = model.jnt_limited[_ARM_JOINTS].astype(np.bool)
joint_range = model.jnt_range[_ARM_JOINTS]
lower_limits = np.where(is_limited, joint_range[:, 0], -np.pi)
upper_limits = np.where(is_limited, joint_range[:, 1], np.pi)
angles = uniform(lower_limits, upper_limits)
data.qpos[_ARM_JOINTS] = angles
# Symmetrize hand.
data.qpos['finger'] = data.qpos['thumb']
# Randomise target location.
target_x = uniform(-.4, .4)
target_z = uniform(.1, .4)
if self._insert:
target_angle = uniform(-np.pi/3, np.pi/3)
model.body_pos[self._receptacle, ['x', 'z']] = target_x, target_z
model.body_quat[self._receptacle, ['qw', 'qy']] = [
np.cos(target_angle/2), np.sin(target_angle/2)]
else:
target_angle = uniform(-np.pi, np.pi)
model.body_pos[self._target, ['x', 'z']] = target_x, target_z
model.body_quat[self._target, ['qw', 'qy']] = [
np.cos(target_angle/2), np.sin(target_angle/2)]
# Randomise object location.
object_init_probs = [_P_IN_HAND, _P_IN_TARGET, 1-_P_IN_HAND-_P_IN_TARGET]
init_type = choice(['in_hand', 'in_target', 'uniform'],
p=object_init_probs)
if init_type == 'in_target':
object_x = target_x
object_z = target_z
object_angle = target_angle
elif init_type == 'in_hand':
physics.after_reset()
object_x = data.site_xpos['grasp', 'x']
object_z = data.site_xpos['grasp', 'z']
grasp_direction = data.site_xmat['grasp', ['xx', 'zx']]
object_angle = np.pi-np.arctan2(grasp_direction[1], grasp_direction[0])
else:
object_x = uniform(-.5, .5)
object_z = uniform(0, .7)
object_angle = uniform(0, 2*np.pi)
data.qvel[self._object + '_x'] = uniform(-5, 5)
data.qpos[self._object_joints] = object_x, object_z, object_angle
# Check for collisions.
physics.after_reset()
penetrating = physics.data.ncon > 0
super(Bring, self).initialize_episode(physics)
def get_observation(self, physics):
"""Returns either features or only sensors (to be used with pixels)."""
obs = collections.OrderedDict()
obs['arm_pos'] = physics.bounded_joint_pos(_ARM_JOINTS)
obs['arm_vel'] = physics.joint_vel(_ARM_JOINTS)
obs['touch'] = physics.touch()
if self._fully_observable:
obs['hand_pos'] = physics.body_2d_pose('hand')
obs['object_pos'] = physics.body_2d_pose(self._object)
obs['object_vel'] = physics.joint_vel(self._object_joints)
obs['target_pos'] = physics.body_2d_pose(self._target)
return obs
def _is_close(self, distance):
return rewards.tolerance(distance, (0, _CLOSE), _CLOSE*2)
def _peg_reward(self, physics):
"""Returns a reward for bringing the peg prop to the target."""
grasp = self._is_close(physics.site_distance('peg_grasp', 'grasp'))
pinch = self._is_close(physics.site_distance('peg_pinch', 'pinch'))
grasping = (grasp + pinch) / 2
bring = self._is_close(physics.site_distance('peg', 'target_peg'))
bring_tip = self._is_close(physics.site_distance('target_peg_tip',
'peg_tip'))
bringing = (bring + bring_tip) / 2
return max(bringing, grasping/3)
def _ball_reward(self, physics):
"""Returns a reward for bringing the ball prop to the target."""
return self._is_close(physics.site_distance('ball', 'target_ball'))
def get_reward(self, physics):
"""Returns a reward to the agent."""
if self._use_peg:
return self._peg_reward(physics)
else:
return self._ball_reward(physics)