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icm_reward_model.py
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icm_reward_model.py
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from typing import Union, Tuple, List, Dict
from easydict import EasyDict
import random
import torch
import torch.nn as nn
import torch.optim as optim
from ding.utils import SequenceType, REWARD_MODEL_REGISTRY
from ding.model import FCEncoder, ConvEncoder
from ding.torch_utils import one_hot
from .base_reward_model import BaseRewardModel
def collect_states(iterator: list) -> Tuple[list, list, list]:
states = []
next_states = []
actions = []
for item in iterator:
state = item['obs']
next_state = item['next_obs']
action = item['action']
states.append(state)
next_states.append(next_state)
actions.append(action)
return states, next_states, actions
class ICMNetwork(nn.Module):
"""
Intrinsic Curiosity Model (ICM Module)
Implementation of:
[1] Curiosity-driven Exploration by Self-supervised Prediction
Pathak, Agrawal, Efros, and Darrell - UC Berkeley - ICML 2017.
https://arxiv.org/pdf/1705.05363.pdf
[2] Code implementation reference:
https://github.com/pathak22/noreward-rl
https://github.com/jcwleo/curiosity-driven-exploration-pytorch
1) Embedding observations into a latent space
2) Predicting the action logit given two consecutive embedded observations
3) Predicting the next embedded obs, given the embeded former observation and action
"""
def __init__(self, obs_shape: Union[int, SequenceType], hidden_size_list: SequenceType, action_shape: int) -> None:
super(ICMNetwork, self).__init__()
if isinstance(obs_shape, int) or len(obs_shape) == 1:
self.feature = FCEncoder(obs_shape, hidden_size_list)
elif len(obs_shape) == 3:
self.feature = ConvEncoder(obs_shape, hidden_size_list)
else:
raise KeyError(
"not support obs_shape for pre-defined encoder: {}, please customize your own ICM model".
format(obs_shape)
)
self.action_shape = action_shape
feature_output = hidden_size_list[-1]
self.inverse_net = nn.Sequential(nn.Linear(feature_output * 2, 512), nn.ReLU(), nn.Linear(512, action_shape))
self.residual = nn.ModuleList(
[
nn.Sequential(
nn.Linear(action_shape + 512, 512),
nn.LeakyReLU(),
nn.Linear(512, 512),
) for _ in range(8)
]
)
self.forward_net_1 = nn.Sequential(nn.Linear(action_shape + feature_output, 512), nn.LeakyReLU())
self.forward_net_2 = nn.Linear(action_shape + 512, feature_output)
def forward(self, state: torch.Tensor, next_state: torch.Tensor,
action_long: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
r"""
Overview:
Use observation, next_observation and action to genearte ICM module
Parameter updates with ICMNetwork forward setup.
Arguments:
- state (:obj:`torch.Tensor`):
The current state batch
- next_state (:obj:`torch.Tensor`):
The next state batch
- action_long (:obj:`torch.Tensor`):
The action batch
Returns:
- real_next_state_feature (:obj:`torch.Tensor`):
Run with the encoder. Return the real next_state's embedded feature.
- pred_next_state_feature (:obj:`torch.Tensor`):
Run with the encoder and residual network. Return the predicted next_state's embedded feature.
- pred_action_logit (:obj:`torch.Tensor`):
Run with the encoder. Return the predicted action logit.
Shapes:
- state (:obj:`torch.Tensor`): :math:`(B, N)`, where B is the batch size and N is ''obs_shape''
- next_state (:obj:`torch.Tensor`): :math:`(B, N)`, where B is the batch size and N is ''obs_shape''
- action_long (:obj:`torch.Tensor`): :math:`(B)`, where B is the batch size''
- real_next_state_feature (:obj:`torch.Tensor`): :math:`(B, M)`, where B is the batch size
and M is embedded feature size
- pred_next_state_feature (:obj:`torch.Tensor`): :math:`(B, M)`, where B is the batch size
and M is embedded feature size
- pred_action_logit (:obj:`torch.Tensor`): :math:`(B, A)`, where B is the batch size
and A is the ''action_shape''
"""
action = one_hot(action_long, num=self.action_shape)
encode_state = self.feature(state)
encode_next_state = self.feature(next_state)
# get pred action logit
concat_state = torch.cat((encode_state, encode_next_state), 1)
pred_action_logit = self.inverse_net(concat_state)
# ---------------------
# get pred next state
pred_next_state_feature_orig = torch.cat((encode_state, action), 1)
pred_next_state_feature_orig = self.forward_net_1(pred_next_state_feature_orig)
# residual
for i in range(4):
pred_next_state_feature = self.residual[i * 2](torch.cat((pred_next_state_feature_orig, action), 1))
pred_next_state_feature_orig = self.residual[i * 2 + 1](
torch.cat((pred_next_state_feature, action), 1)
) + pred_next_state_feature_orig
pred_next_state_feature = self.forward_net_2(torch.cat((pred_next_state_feature_orig, action), 1))
real_next_state_feature = encode_next_state
return real_next_state_feature, pred_next_state_feature, pred_action_logit
@REWARD_MODEL_REGISTRY.register('icm')
class ICMRewardModel(BaseRewardModel):
"""
Overview:
The ICM reward model class (https://arxiv.org/pdf/1705.05363.pdf)
Interface:
``estimate``, ``train``, ``collect_data``, ``clear_data``, \
``__init__``, ``_train``, ``load_state_dict``, ``state_dict``
Config:
== ==================== ======== ============= ==================================== =======================
ID Symbol Type Default Value Description Other(Shape)
== ==================== ======== ============= ==================================== =======================
1 ``type`` str icm | Reward model register name, |
| refer to registry |
| ``REWARD_MODEL_REGISTRY`` |
2 | ``intrinsic_`` str add | the intrinsic reward type | including add, new
| ``reward_type`` | | , or assign
3 | ``learning_rate`` float 0.001 | The step size of gradient descent |
4 | ``obs_shape`` Tuple( 6 | the observation shape |
[int,
list])
5 | ``action_shape`` int 7 | the action space shape |
6 | ``batch_size`` int 64 | Training batch size |
7 | ``hidden`` list [64, 64, | the MLP layer shape |
| ``_size_list`` (int) 128] | |
8 | ``update_per_`` int 100 | Number of updates per collect |
| ``collect`` | |
9 | ``reverse_scale`` float 1 | the importance weight of the |
| forward and reverse loss |
10 | ``intrinsic_`` float 0.003 | the weight of intrinsic reward | r = w*r_i + r_e
``reward_weight``
11 | ``extrinsic_`` bool True | Whether to normlize
``reward_norm`` | extrinsic reward
12 | ``extrinsic_`` int 1 | the upper bound of the reward
``reward_norm_max`` | normalization
13 | ``clear_buffer`` int 1 | clear buffer per fixed iters | make sure replay
``_per_iters`` | buffer's data count
| isn't too few.
| (code work in entry)
== ==================== ======== ============= ==================================== =======================
"""
config = dict(
# (str) Reward model register name, refer to registry ``REWARD_MODEL_REGISTRY``.
type='icm',
# (str) The intrinsic reward type, including add, new, or assign.
intrinsic_reward_type='add',
# (float) The step size of gradient descent.
learning_rate=1e-3,
# (Tuple[int, list]), The observation shape.
obs_shape=6,
# (int) The action shape, support discrete action only in this version.
action_shape=7,
# (float) Batch size.
batch_size=64,
# (list) The MLP layer shape.
hidden_size_list=[64, 64, 128],
# (int) How many updates(iterations) to train after collector's one collection.
# Bigger "update_per_collect" means bigger off-policy.
# collect data -> update policy-> collect data -> ...
update_per_collect=100,
# (float) The importance weight of the forward and reverse loss.
reverse_scale=1,
# (float) The weight of intrinsic reward.
# r = intrinsic_reward_weight * r_i + r_e.
intrinsic_reward_weight=0.003, # 1/300
# (bool) Whether to normlize extrinsic reward.
# Normalize the reward to [0, extrinsic_reward_norm_max].
extrinsic_reward_norm=True,
# (int) The upper bound of the reward normalization.
extrinsic_reward_norm_max=1,
# (int) Clear buffer per fixed iters.
clear_buffer_per_iters=100,
)
def __init__(self, config: EasyDict, device: str, tb_logger: 'SummaryWriter') -> None: # noqa
super(ICMRewardModel, self).__init__()
self.cfg = config
assert device == "cpu" or device.startswith("cuda")
self.device = device
self.tb_logger = tb_logger
self.reward_model = ICMNetwork(config.obs_shape, config.hidden_size_list, config.action_shape)
self.reward_model.to(self.device)
self.intrinsic_reward_type = config.intrinsic_reward_type
assert self.intrinsic_reward_type in ['add', 'new', 'assign']
self.train_data = []
self.train_states = []
self.train_next_states = []
self.train_actions = []
self.opt = optim.Adam(self.reward_model.parameters(), config.learning_rate)
self.ce = nn.CrossEntropyLoss(reduction="mean")
self.forward_mse = nn.MSELoss(reduction='none')
self.reverse_scale = config.reverse_scale
self.res = nn.Softmax(dim=-1)
self.estimate_cnt_icm = 0
self.train_cnt_icm = 0
def _train(self) -> None:
self.train_cnt_icm += 1
train_data_list = [i for i in range(0, len(self.train_states))]
train_data_index = random.sample(train_data_list, self.cfg.batch_size)
data_states: list = [self.train_states[i] for i in train_data_index]
data_states: torch.Tensor = torch.stack(data_states).to(self.device)
data_next_states: list = [self.train_next_states[i] for i in train_data_index]
data_next_states: torch.Tensor = torch.stack(data_next_states).to(self.device)
data_actions: list = [self.train_actions[i] for i in train_data_index]
data_actions: torch.Tensor = torch.cat(data_actions).to(self.device)
real_next_state_feature, pred_next_state_feature, pred_action_logit = self.reward_model(
data_states, data_next_states, data_actions
)
inverse_loss = self.ce(pred_action_logit, data_actions.long())
forward_loss = self.forward_mse(pred_next_state_feature, real_next_state_feature.detach()).mean()
self.tb_logger.add_scalar('icm_reward/forward_loss', forward_loss, self.train_cnt_icm)
self.tb_logger.add_scalar('icm_reward/inverse_loss', inverse_loss, self.train_cnt_icm)
action = torch.argmax(self.res(pred_action_logit), -1)
accuracy = torch.sum(action == data_actions.squeeze(-1)).item() / data_actions.shape[0]
self.tb_logger.add_scalar('icm_reward/action_accuracy', accuracy, self.train_cnt_icm)
loss = self.reverse_scale * inverse_loss + forward_loss
self.tb_logger.add_scalar('icm_reward/total_loss', loss, self.train_cnt_icm)
loss = self.reverse_scale * inverse_loss + forward_loss
self.opt.zero_grad()
loss.backward()
self.opt.step()
def train(self) -> None:
for _ in range(self.cfg.update_per_collect):
self._train()
def estimate(self, data: list) -> List[Dict]:
# NOTE: deepcopy reward part of data is very important,
# otherwise the reward of data in the replay buffer will be incorrectly modified.
train_data_augmented = self.reward_deepcopy(data)
states, next_states, actions = collect_states(train_data_augmented)
states = torch.stack(states).to(self.device)
next_states = torch.stack(next_states).to(self.device)
actions = torch.cat(actions).to(self.device)
with torch.no_grad():
real_next_state_feature, pred_next_state_feature, _ = self.reward_model(states, next_states, actions)
raw_icm_reward = self.forward_mse(real_next_state_feature, pred_next_state_feature).mean(dim=1)
self.estimate_cnt_icm += 1
self.tb_logger.add_scalar('icm_reward/raw_icm_reward_max', raw_icm_reward.max(), self.estimate_cnt_icm)
self.tb_logger.add_scalar('icm_reward/raw_icm_reward_mean', raw_icm_reward.mean(), self.estimate_cnt_icm)
self.tb_logger.add_scalar('icm_reward/raw_icm_reward_min', raw_icm_reward.min(), self.estimate_cnt_icm)
self.tb_logger.add_scalar('icm_reward/raw_icm_reward_std', raw_icm_reward.std(), self.estimate_cnt_icm)
icm_reward = (raw_icm_reward - raw_icm_reward.min()) / (raw_icm_reward.max() - raw_icm_reward.min() + 1e-8)
self.tb_logger.add_scalar('icm_reward/icm_reward_max', icm_reward.max(), self.estimate_cnt_icm)
self.tb_logger.add_scalar('icm_reward/icm_reward_mean', icm_reward.mean(), self.estimate_cnt_icm)
self.tb_logger.add_scalar('icm_reward/icm_reward_min', icm_reward.min(), self.estimate_cnt_icm)
self.tb_logger.add_scalar('icm_reward/icm_reward_std', icm_reward.std(), self.estimate_cnt_icm)
icm_reward = (raw_icm_reward - raw_icm_reward.min()) / (raw_icm_reward.max() - raw_icm_reward.min() + 1e-8)
icm_reward = icm_reward.to(self.device)
for item, icm_rew in zip(train_data_augmented, icm_reward):
if self.intrinsic_reward_type == 'add':
if self.cfg.extrinsic_reward_norm:
item['reward'] = item[
'reward'] / self.cfg.extrinsic_reward_norm_max + icm_rew * self.cfg.intrinsic_reward_weight
else:
item['reward'] = item['reward'] + icm_rew * self.cfg.intrinsic_reward_weight
elif self.intrinsic_reward_type == 'new':
item['intrinsic_reward'] = icm_rew
if self.cfg.extrinsic_reward_norm:
item['reward'] = item['reward'] / self.cfg.extrinsic_reward_norm_max
elif self.intrinsic_reward_type == 'assign':
item['reward'] = icm_rew
return train_data_augmented
def collect_data(self, data: list) -> None:
self.train_data.extend(collect_states(data))
states, next_states, actions = collect_states(data)
self.train_states.extend(states)
self.train_next_states.extend(next_states)
self.train_actions.extend(actions)
def clear_data(self) -> None:
self.train_data.clear()
self.train_states.clear()
self.train_next_states.clear()
self.train_actions.clear()
def state_dict(self) -> Dict:
return self.reward_model.state_dict()
def load_state_dict(self, _state_dict: Dict) -> None:
self.reward_model.load_state_dict(_state_dict)