用python编写基于强化学习的pid控制倒立摆的代码
时间: 2024-05-01 11:20:09 浏览: 242
pid控制倒立摆
好的,下面是基于强化学习的PID控制倒立摆的Python代码。这个代码使用了深度强化学习库TensorFlow和OpenAI Gym环境。
首先,我们需要安装依赖库:
```python
!pip install tensorflow gym
```
接下来,我们编写代码:
```python
import gym
import numpy as np
import tensorflow as tf
# 定义PID控制器
class PIDController:
def __init__(self, P=0.1, I=0.0, D=0.0):
self.Kp = P
self.Ki = I
self.Kd = D
self.last_error = 0.0
self.integral_error = 0.0
def control(self, error, dt):
self.integral_error += error * dt
derivative_error = (error - self.last_error) / dt
output = self.Kp * error + self.Ki * self.integral_error + self.Kd * derivative_error
self.last_error = error
return output
# 定义神经网络模型
class NeuralNetwork:
def __init__(self, input_size, output_size, hidden_size=64, learning_rate=0.001):
self.input_size = input_size
self.output_size = output_size
self.hidden_size = hidden_size
self.learning_rate = learning_rate
self.x = tf.placeholder(tf.float32, shape=[None, self.input_size])
self.y = tf.placeholder(tf.float32, shape=[None, self.output_size])
self.W1 = tf.Variable(tf.random_normal([self.input_size, self.hidden_size]))
self.b1 = tf.Variable(tf.random_normal([self.hidden_size]))
self.W2 = tf.Variable(tf.random_normal([self.hidden_size, self.output_size]))
self.b2 = tf.Variable(tf.random_normal([self.output_size]))
self.hidden_layer = tf.nn.relu(tf.add(tf.matmul(self.x, self.W1), self.b1))
self.output_layer = tf.add(tf.matmul(self.hidden_layer, self.W2), self.b2)
self.loss = tf.reduce_mean(tf.square(self.y - self.output_layer))
self.optimizer = tf.train.AdamOptimizer(learning_rate=self.learning_rate).minimize(self.loss)
self.sess = tf.Session()
self.sess.run(tf.global_variables_initializer())
def train(self, inputs, targets):
_, loss = self.sess.run([self.optimizer, self.loss], feed_dict={self.x: inputs, self.y: targets})
return loss
def predict(self, inputs):
return self.sess.run(self.output_layer, feed_dict={self.x: inputs})
# 定义环境和参数
env = gym.make('InvertedPendulum-v2')
state_size = env.observation_space.shape[0]
action_size = env.action_space.shape[0]
PID = PIDController(P=5.0, I=0.0, D=0.5)
NN = NeuralNetwork(state_size, action_size)
max_episodes = 1000
max_steps = 1000
gamma = 0.99
epsilon = 1.0
epsilon_min = 0.01
epsilon_decay = 0.995
# 训练模型
for episode in range(max_episodes):
state = env.reset()
total_reward = 0
for step in range(max_steps):
if np.random.random() < epsilon:
action = env.action_space.sample()
else:
action = NN.predict([state])[0]
next_state, reward, done, _ = env.step(action)
error = next_state[2] # 使用摆杆的角速度作为误差信号
control_signal = PID.control(error, env.dt)
target = action + gamma * control_signal
target = np.clip(target, -1.0, 1.0)
target = np.expand_dims(target, axis=0)
loss = NN.train(np.array([state]), target)
state = next_state
total_reward += reward
if done:
break
print("Episode: {} Total Reward: {:.2f} Epsilon: {:.2f} Loss: {:.4f}".format(
episode + 1, total_reward, epsilon, loss))
epsilon = max(epsilon_min, epsilon_decay * epsilon)
```
代码的思路是:在每个时间步中,使用神经网络预测下一个动作,并使用PID控制器根据摆杆的角速度计算控制信号。然后将控制信号作为目标值,与神经网络预测的动作值计算损失值,并使用反向传播算法训练神经网络模型。
代码中使用了OpenAI Gym中的倒立摆环境,可以使用以下代码进行安装:
```python
!pip install gym
```
然后,可以使用以下代码运行倒立摆环境:
```python
import gym
env = gym.make('InvertedPendulum-v2')
env.reset()
for _ in range(1000):
env.render()
env.step(env.action_space.sample())
env.close()
```
以上就是基于强化学习的PID控制倒立摆的Python代码。
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