222 lines
8.6 KiB
Python
222 lines
8.6 KiB
Python
#!/usr/bin/env python
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# coding=utf-8
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'''
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Author: JiangJi
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Email: johnjim0816@gmail.com
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Date: 2021-04-29 12:53:54
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LastEditor: JiangJi
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LastEditTime: 2021-12-22 15:41:19
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Discription:
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Environment:
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'''
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import copy
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import torch
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import torch.nn as nn
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import torch.optim as optim
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import torch.nn.functional as F
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from torch.distributions import Normal
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import numpy as np
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import random
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device=torch.device("cuda" if torch.cuda.is_available() else "cpu")
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class ReplayBuffer:
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def __init__(self, capacity):
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self.capacity = capacity # 经验回放的容量
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self.buffer = [] # 缓冲区
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self.position = 0
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def push(self, state, action, reward, next_state, done):
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''' 缓冲区是一个队列，容量超出时去掉开始存入的转移(transition)
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'''
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if len(self.buffer) < self.capacity:
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self.buffer.append(None)
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self.buffer[self.position] = (state, action, reward, next_state, done)
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self.position = (self.position + 1) % self.capacity
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def sample(self, batch_size):
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batch = random.sample(self.buffer, batch_size) # 随机采出小批量转移
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state, action, reward, next_state, done = zip(*batch) # 解压成状态，动作等
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return state, action, reward, next_state, done
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def __len__(self):
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''' 返回当前存储的量
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'''
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return len(self.buffer)
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class ValueNet(nn.Module):
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def __init__(self, n_states, hidden_dim, init_w=3e-3):
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super(ValueNet, self).__init__()
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self.linear1 = nn.Linear(n_states, hidden_dim)
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self.linear2 = nn.Linear(hidden_dim, hidden_dim)
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self.linear3 = nn.Linear(hidden_dim, 1)
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self.linear3.weight.data.uniform_(-init_w, init_w)
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self.linear3.bias.data.uniform_(-init_w, init_w)
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def forward(self, state):
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x = F.relu(self.linear1(state))
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x = F.relu(self.linear2(x))
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x = self.linear3(x)
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return x
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class SoftQNet(nn.Module):
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def __init__(self, n_states, n_actions, hidden_dim, init_w=3e-3):
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super(SoftQNet, self).__init__()
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self.linear1 = nn.Linear(n_states + n_actions, hidden_dim)
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self.linear2 = nn.Linear(hidden_dim, hidden_dim)
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self.linear3 = nn.Linear(hidden_dim, 1)
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self.linear3.weight.data.uniform_(-init_w, init_w)
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self.linear3.bias.data.uniform_(-init_w, init_w)
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def forward(self, state, action):
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x = torch.cat([state, action], 1)
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x = F.relu(self.linear1(x))
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x = F.relu(self.linear2(x))
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x = self.linear3(x)
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return x
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class PolicyNet(nn.Module):
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def __init__(self, n_states, n_actions, hidden_dim, init_w=3e-3, log_std_min=-20, log_std_max=2):
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super(PolicyNet, self).__init__()
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self.log_std_min = log_std_min
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self.log_std_max = log_std_max
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self.linear1 = nn.Linear(n_states, hidden_dim)
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self.linear2 = nn.Linear(hidden_dim, hidden_dim)
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self.mean_linear = nn.Linear(hidden_dim, n_actions)
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self.mean_linear.weight.data.uniform_(-init_w, init_w)
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self.mean_linear.bias.data.uniform_(-init_w, init_w)
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self.log_std_linear = nn.Linear(hidden_dim, n_actions)
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self.log_std_linear.weight.data.uniform_(-init_w, init_w)
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self.log_std_linear.bias.data.uniform_(-init_w, init_w)
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def forward(self, state):
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x = F.relu(self.linear1(state))
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x = F.relu(self.linear2(x))
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mean = self.mean_linear(x)
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log_std = self.log_std_linear(x)
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log_std = torch.clamp(log_std, self.log_std_min, self.log_std_max)
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return mean, log_std
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def evaluate(self, state, epsilon=1e-6):
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mean, log_std = self.forward(state)
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std = log_std.exp()
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normal = Normal(mean, std)
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z = normal.sample()
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action = torch.tanh(z)
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log_prob = normal.log_prob(z) - torch.log(1 - action.pow(2) + epsilon)
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log_prob = log_prob.sum(-1, keepdim=True)
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return action, log_prob, z, mean, log_std
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def get_action(self, state):
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state = torch.FloatTensor(state).unsqueeze(0).to(device)
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mean, log_std = self.forward(state)
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std = log_std.exp()
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normal = Normal(mean, std)
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z = normal.sample()
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action = torch.tanh(z)
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action = action.detach().cpu().numpy()
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return action[0]
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class SAC:
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def __init__(self,n_states,n_actions,cfg) -> None:
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self.batch_size = cfg.batch_size
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self.memory = ReplayBuffer(cfg.capacity)
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self.device = cfg.device
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self.value_net = ValueNet(n_states, cfg.hidden_dim).to(self.device)
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self.target_value_net = ValueNet(n_states, cfg.hidden_dim).to(self.device)
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self.soft_q_net = SoftQNet(n_states, n_actions, cfg.hidden_dim).to(self.device)
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self.policy_net = PolicyNet(n_states, n_actions, cfg.hidden_dim).to(self.device)
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self.value_optimizer = optim.Adam(self.value_net.parameters(), lr=cfg.value_lr)
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self.soft_q_optimizer = optim.Adam(self.soft_q_net.parameters(), lr=cfg.soft_q_lr)
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self.policy_optimizer = optim.Adam(self.policy_net.parameters(), lr=cfg.policy_lr)
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for target_param, param in zip(self.target_value_net.parameters(), self.value_net.parameters()):
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target_param.data.copy_(param.data)
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self.value_criterion = nn.MSELoss()
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self.soft_q_criterion = nn.MSELoss()
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def update(self, gamma=0.99,mean_lambda=1e-3,
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std_lambda=1e-3,
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z_lambda=0.0,
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soft_tau=1e-2,
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):
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if len(self.memory) < self.batch_size:
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return
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state, action, reward, next_state, done = self.memory.sample(self.batch_size)
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state = torch.FloatTensor(state).to(self.device)
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next_state = torch.FloatTensor(next_state).to(self.device)
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action = torch.FloatTensor(action).to(self.device)
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reward = torch.FloatTensor(reward).unsqueeze(1).to(self.device)
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done = torch.FloatTensor(np.float32(done)).unsqueeze(1).to(self.device)
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expected_q_value = self.soft_q_net(state, action)
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expected_value = self.value_net(state)
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new_action, log_prob, z, mean, log_std = self.policy_net.evaluate(state)
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target_value = self.target_value_net(next_state)
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next_q_value = reward + (1 - done) * gamma * target_value
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q_value_loss = self.soft_q_criterion(expected_q_value, next_q_value.detach())
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expected_new_q_value = self.soft_q_net(state, new_action)
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next_value = expected_new_q_value - log_prob
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value_loss = self.value_criterion(expected_value, next_value.detach())
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log_prob_target = expected_new_q_value - expected_value
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policy_loss = (log_prob * (log_prob - log_prob_target).detach()).mean()
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mean_loss = mean_lambda * mean.pow(2).mean()
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std_loss = std_lambda * log_std.pow(2).mean()
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z_loss = z_lambda * z.pow(2).sum(1).mean()
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policy_loss += mean_loss + std_loss + z_loss
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self.soft_q_optimizer.zero_grad()
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q_value_loss.backward()
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self.soft_q_optimizer.step()
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self.value_optimizer.zero_grad()
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value_loss.backward()
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self.value_optimizer.step()
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self.policy_optimizer.zero_grad()
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policy_loss.backward()
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self.policy_optimizer.step()
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for target_param, param in zip(self.target_value_net.parameters(), self.value_net.parameters()):
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target_param.data.copy_(
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target_param.data * (1.0 - soft_tau) + param.data * soft_tau
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)
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def save(self, path):
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torch.save(self.value_net.state_dict(), path + "sac_value")
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torch.save(self.value_optimizer.state_dict(), path + "sac_value_optimizer")
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torch.save(self.soft_q_net.state_dict(), path + "sac_soft_q")
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torch.save(self.soft_q_optimizer.state_dict(), path + "sac_soft_q_optimizer")
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torch.save(self.policy_net.state_dict(), path + "sac_policy")
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torch.save(self.policy_optimizer.state_dict(), path + "sac_policy_optimizer")
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def load(self, path):
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self.value_net.load_state_dict(torch.load(path + "sac_value"))
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self.value_optimizer.load_state_dict(torch.load(path + "sac_value_optimizer"))
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self.target_value_net = copy.deepcopy(self.value_net)
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self.soft_q_net.load_state_dict(torch.load(path + "sac_soft_q"))
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self.soft_q_optimizer.load_state_dict(torch.load(path + "sac_soft_q_optimizer"))
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self.policy_net.load_state_dict(torch.load(path + "sac_policy"))
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self.policy_optimizer.load_state_dict(torch.load(path + "sac_policy_optimizer")) |