import numpy as np
import tensorflow as tf
from collections import deque
import random
class QLearningCNN:
def init(self, state_shape, action_size, learning_rate=0.001,
gamma=0.99, epsilon=1.0, epsilon_min=0.01,
epsilon_decay=0.995, memory_size=10000, batch_size=32):
self.state_shape = state_shape # 输入状态的形状，例如(84, 84, 4)
self.action_size = action_size # 动作空间大小
self.learning_rate = learning_rate
self.gamma = gamma # 折扣因子
self.epsilon = epsilon # 探索率
self.epsilon_min = epsilon_min
self.epsilon_decay = epsilon_decay
self.memory = deque(maxlen=memory_size) # 经验回放缓冲区
self.batch_size = batch_size
创建主网络和目标网络
self.model = self._build_model()
self.target_model = self._build_model()
self.update_target_model()
def _build_model(self):
"""构建用于Q值近似的CNN模型"""
model = tf.keras.Sequential([
卷积层1
tf.keras.layers.Conv2D(32, (8, 8), strides=(4, 4), activation='relu',
input_shape=self.state_shape),
卷积层2
tf.keras.layers.Conv2D(64, (4, 4), strides=(2, 2), activation='relu'),
卷积层3
tf.keras.layers.Conv2D(64, (3, 3), strides=(1, 1), activation='relu'),
全连接层
tf.keras.layers.Flatten(),
tf.keras.layers.Dense(512, activation='relu'),
输出层，每个动作对应一个Q值
tf.keras.layers.Dense(self.action_size, activation='linear')
])
model.compile(loss='mse', optimizer=tf.keras.optimizers.Adam(learning_rate=self.learning_rate))
return model
def update_target_model(self):
"""更新目标网络权重，从主网络复制权重"""
self.target_model.set_weights(self.model.get_weights())
def remember(self, state, action, reward, next_state, done):
"""将经验存储到回放缓冲区"""
self.memory.append((state, action, reward, next_state, done))
def act(self, state):
"""根据当前状态选择动作，使用ε-贪婪策略"""
if np.random.rand() <= self.epsilon:
随机探索
return random.randrange(self.action_size)
利用当前模型选择最优动作
act_values = self.model.predict(state, verbose=0)
return np.argmax(act_values0)
def replay(self):
"""从经验回放中学习"""
if len(self.memory) < self.batch_size:
return
从经验回放缓冲区中随机采样一批数据
minibatch = random.sample(self.memory, self.batch_size)
states = np.array(i\[0 for i in minibatch])
actions = np.array(i\[1 for i in minibatch])
rewards = np.array(i\[2 for i in minibatch])
next_states = np.array(i\[3 for i in minibatch])
dones = np.array(i\[4 for i in minibatch])
states = np.squeeze(states)
next_states = np.squeeze(next_states)
计算目标Q值
target = rewards + self.gamma * np.amax(self.target_model.predict_on_batch(next_states), axis=1) * (1 - dones)
选择当前预测值
target_f = self.model.predict_on_batch(states)
更新目标动作的Q值
for i, action in enumerate(actions):
target_fiaction = targeti
训练网络
self.model.fit(states, target_f, epochs=1, verbose=0)
衰减探索率
if self.epsilon > self.epsilon_min:
self.epsilon *= self.epsilon_decay
def load(self, name):
"""加载模型权重"""
self.model.load_weights(name)
self.update_target_model()
def save(self, name):
"""保存模型权重"""
self.model.save_weights(name)
使用示例
if name == "main":
示例参数，适用于处理84x84像素的游戏画面
state_shape = (84, 84, 4) # 4帧堆叠的游戏画面
action_size = 4 # 假设游戏有4个可能的动作
创建代理
agent = QLearningCNN(state_shape, action_size)
训练循环（伪代码示例）
episodes = 1000
for e in range(episodes):
初始化环境
state = env.reset() # 假设env是游戏环境
state = np.reshape(state, 1, 84, 84, 4)
done = False
total_reward = 0
while not done:
选择动作
action = agent.act(state)
执行动作
next_state, reward, done, _ = env.step(action)
next_state = np.reshape(next_state, 1, 84, 84, 4)
存储经验
agent.remember(state, action, reward, next_state, done)
更新状态
state = next_state
total_reward += reward
训练网络
agent.replay()
定期更新目标网络
if e % 10 == 0:
agent.update_target_model()
print(f"Episode: {e+1}/{episodes}, Total Reward: {total_reward}, Epsilon: {agent.epsilon:.2f}")
这个实现包含了以下关键组件：
- CNN 网络结构：使用三层卷积层处理图像输入，提取特征
- Q-Learning 算法：使用 ε- 贪婪策略进行探索和利用
- 经验回放机制：通过存储和随机采样历史经验提高学习效率
- 目标网络：使用独立的目标网络提高训练稳定性
要使用这个代码，你需要安装以下依赖：
- tensorflow >= 2.0
- numpy
- random