在 openai cartpole 上训练一个 tensorflow 模型

training a tensorflow model on openai cartpole

我正在使用我正在实施的 tensorflow 实施我的第一个强化深度学习模型 cartpole problem

我求助于一个使用六层的深度神经网络,该网络在随机生成的数据集上进行训练,该数据集的得分高于阈值。问题是模型没有收敛,最终得分平均保持在 10 分左右。

按照阅读某些帖子后的建议,我应用了正则化和 dropout 来减少可能发生的任何过度拟合,但仍然没有成功。我也试过降低学习率。

在训练一批之后,准确率也保持在 0.60 左右,尽管在每次迭代中损失都在减少,我认为即使在这些之后它也会记住。 尽管这种模型适用于简单的深度学习任务。

这是我的代码:

import numpy as np
import tensorflow as tf
import gym
import os
import random

os.environ['TF_CPP_MIN_LOG_LEVEL'] = '2'
model_path = "C:/Users/sanka/codes/cart pole problem/tf_save3"
env = gym.make("CartPole-v0")
env.reset()


def train_set():           #training set generation function
    try:
        tx = np.load("final_trainx.npy")
        ty = np.load("final_trainy.npy")
        return tx,ty
    except:
        tx = []
        ty = []
        for _ in range(10000):
            env.reset()
            score = 0
            moves = []
            obs = []
            p = []
            for _ in range(500):
                action = np.random.randint(0, 2)
                observation, reward, done, info = env.step(action)
                if (len(p)==0):
                    p = observation
                else:
                    moves += [action]
                    obs += [observation]
                    p = observation
                score += reward
                if done:
                    break
            if (score > 50):
                tx+=obs
                for i in range(len(moves)):
                    ac = moves[i]
                    if (ac == 1):
                        ty.append([0, 1])
                    else:
                        ty.append([1, 0])
        tx=np.array(tx)
        ty=np.array(ty)
        np.save("final_trainx.npy",tx)
        np.save("final_trainy.npy",ty)
        return tx, ty


weights = {
    1: tf.Variable(tf.truncated_normal([4, 128]), dtype=tf.float32),
    2: tf.Variable(tf.truncated_normal([128, 256]), dtype=tf.float32),
    3: tf.Variable(tf.truncated_normal([256, 512]), dtype=tf.float32),
    4: tf.Variable(tf.truncated_normal([512, 256]), dtype=tf.float32),
    5: tf.Variable(tf.truncated_normal([256, 128]), dtype=tf.float32),
    6: tf.Variable(tf.truncated_normal([128, 2]), dtype=tf.float32)
}

biases = {
    1: tf.Variable(tf.truncated_normal([128]), dtype=tf.float32),
    2: tf.Variable(tf.truncated_normal([256]), dtype=tf.float32),
    3: tf.Variable(tf.truncated_normal([512]), dtype=tf.float32),
    4: tf.Variable(tf.truncated_normal([256]), dtype=tf.float32),
    5: tf.Variable(tf.truncated_normal([128]), dtype=tf.float32),
    6: tf.Variable(tf.truncated_normal([2]), dtype=tf.float32)
}


def neural_network(x):
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[1]), biases[1]))
    x = tf.nn.dropout(x, 0.8)
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[2]), biases[2]))
    x = tf.nn.dropout(x, 0.8)
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[3]), biases[3]))
    x = tf.nn.dropout(x, 0.8)
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[4]), biases[4]))
    x = tf.nn.dropout(x, 0.8)
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[5]), biases[5]))
    x = tf.nn.dropout(x, 0.8)
    x = tf.add(tf.matmul(x, weights[6]), biases[6])
    return x


def test_nn(x):
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[1]), biases[1]))
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[2]), biases[2]))
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[3]), biases[3]))
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[4]), biases[4]))
    x = tf.nn.relu(tf.add(tf.matmul(x, weights[5]), biases[5]))
    x = tf.nn.softmax(tf.add(tf.matmul(x, weights[6]), biases[6]))
    return x


def train_nn():
    prediction = neural_network(x)
    loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=prediction, labels=y))
    lo=tf.nn.l2_loss(weights[1])+tf.nn.l2_loss(weights[2])+tf.nn.l2_loss(weights[3])+tf.nn.l2_loss(weights[4])+tf.nn.l2_loss(weights[5])+tf.nn.l2_loss(weights[6])
    loss=tf.reduce_mean(loss+0.01*lo)
    optimizer = tf.train.AdamOptimizer(learning_rate=0.0001).minimize(loss)
    test_pred = test_nn(x)
    correct = tf.equal(tf.argmax(test_pred, 1), tf.argmax(y, 1))
    accuracy = tf.reduce_mean(tf.cast(correct, dtype=tf.float32))
    with tf.Session() as sess:
        sess.run(tf.global_variables_initializer())
        epoches = 5
        batch_size = 100
        for j in range(epoches):
            ep_loss=0
            for i in range(0,len(train_x),batch_size):
                epoch_x=train_x[i:min(i+batch_size,len(train_x))]
                epoch_y = train_y[i:min(i + batch_size, len(train_y))]
                _,c=sess.run([optimizer,loss],feed_dict={x:epoch_x,y:epoch_y})
                ep_loss+=c
                #print("Accuracy is {0}".format(sess.run(accuracy, feed_dict={x: epoch_x, y: epoch_y})))
            print("epoch {0} completed out of {1} with loss {2}".format(j,epoches,ep_loss))
            print("Accuracy is {0}".format(sess.run(accuracy,feed_dict={x:train_x,y:train_y})))

        scores = []
        choices = []
        for each_game in range(10):
            print("game ", each_game)
            score = 0
            game_memory = []
            prev_obs = []
            env.reset()
            for _ in range(500):
                env.render()
                if (len(prev_obs) == 0):
                    action = random.randrange(0, 2)
                else:
                    x1 = np.array([prev_obs]).reshape(-1,4)
                    a = tf.argmax(test_pred, 1)
                    action = sess.run(a, feed_dict={x: x1})
                    action=action[0]

                choices.append(action)
                new_observation, reward, done, info = env.step(action)
                prev_obs = new_observation
                game_memory.append([new_observation, action])
                score += reward
                if done:
                    break

            scores.append(score)

        print('Average Score:', sum(scores) / len(scores))
        print('choice 1:{}  choice 0:{}'.format(choices.count(1) / len(choices), choices.count(0) / len(choices)))



train_x,train_y=train_set()
print(train_x.shape)
print(train_y.shape)
x=tf.placeholder(tf.float32,[None,4])
y=tf.placeholder(tf.int32,[None,2])
train_nn()

所以您首先收集了或多或少表现良好的随机试验示例,然后根据这些示例训练您的模型?

实际上并不是强化学习。你假设随机代理采取的行动是好的,并且正在学习模仿它。所以如果你考虑一下,你的模型实际上有 60% 的时间预测随机代理的行为。考虑到这些行为是随机的,而且你的 50% 以上,你实际上很富裕。

您只能达到 50% 以上,因为您只选择了 偶然 超过 50 分的随机游戏,因此它是游戏的非随机子集。 如果你提高门槛,只考虑获得超过 100 分的随机游戏 或类似的东西,你应该会得到更好的结果。通过这种方式,您将 select 好游戏多于坏游戏。

如果您想以更强化学习的方式解决问题,即边玩边学习,而不是从别人的游戏中学习。我建议你看看 Q-Learning 或 Policy Learning。

要牢记的主要事情是,通常没有 正确的 操作可供采取。也许不同的行为会导致相同的结果。因此,与其尝试预测给定状态下哪个动作是正确的,不如尝试预测给定状态下动作的预期结果。然后选择具有最佳预期结果的操作。