fix(ppo): 修正日志概率维度与状态张量格式

修复 replay buffer 中 log_probs 的维度错误,从 (buffer_size, action_dim) 改为 buffer_size
修正训练时状态张量格式,从 (N, H, W, C) 转换为 (N, C, H, W)
更新 collect_rollout 返回观测值并修正 log_prob 计算
添加项目配置文件和训练曲线生成脚本
This commit is contained in:
2026-04-30 20:30:40 +08:00
parent d353133b31
commit b32490ae03
19 changed files with 185 additions and 22 deletions
@@ -1,4 +1,8 @@
"""Evaluation script for trained PPO agent."""
import sys
import os
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import torch
import numpy as np
import gymnasium as gym
+16 -10
View File
@@ -1,4 +1,5 @@
"""Neural network architectures for Actor and Critic."""
import torch
import torch.nn as nn
import torch.nn.functional as F
@@ -9,7 +10,11 @@ class Actor(nn.Module):
def __init__(self, state_shape=(84, 84, 4), action_dim=3):
super().__init__()
c, h, w = state_shape[2], state_shape[0], state_shape[1] # channels, height, width
c, h, w = (
state_shape[2],
state_shape[0],
state_shape[1],
) # channels, height, width
self.conv = nn.Sequential(
nn.Conv2d(c, 32, kernel_size=8, stride=4),
@@ -20,8 +25,10 @@ class Actor(nn.Module):
nn.ReLU(),
)
# Calculate feature map size: 84x84 -> 20x20 after conv layers
feat_size = 64 * 20 * 20
out_h = (h - 8) // 4 + 1
out_h = (out_h - 4) // 2 + 1
out_h = (out_h - 3) // 1 + 1
feat_size = 64 * out_h * out_h
self.fc = nn.Sequential(
nn.Linear(feat_size, 512),
@@ -62,17 +69,16 @@ class Critic(nn.Module):
nn.ReLU(),
)
feat_size = 64 * 20 * 20
out_h = (h - 8) // 4 + 1
out_h = (out_h - 4) // 2 + 1
out_h = (out_h - 3) // 1 + 1
feat_size = 64 * out_h * out_h
self.fc = nn.Sequential(
nn.Linear(feat_size, 512),
nn.ReLU(),
nn.Linear(512, 1)
)
self.fc = nn.Sequential(nn.Linear(feat_size, 512), nn.ReLU(), nn.Linear(512, 1))
def forward(self, x):
"""Forward pass returning V(s)."""
x = x / 255.0
x = self.conv(x)
x = x.view(x.size(0), -1)
return self.fc(x)
return self.fc(x)
@@ -15,7 +15,7 @@ class RolloutBuffer:
self.rewards = np.zeros(buffer_size, dtype=np.float32)
self.dones = np.zeros(buffer_size, dtype=np.bool_)
self.values = np.zeros(buffer_size, dtype=np.float32)
self.log_probs = np.zeros((buffer_size, action_dim), dtype=np.float32)
self.log_probs = np.zeros(buffer_size, dtype=np.float32)
def add(self, state, action, reward, done, value, log_prob):
"""Add a transition to the buffer."""
@@ -56,8 +56,8 @@ class PPOTrainer:
# Normalize advantages
advantages = (advantages - advantages.mean()) / (advantages.std() + 1e-8)
# Convert to tensors
states_t = torch.from_numpy(states).float().to(self.device)
# Convert to tensors (states: N, H, W, C -> N, C, H, W)
states_t = torch.from_numpy(states).float().permute(0, 3, 1, 2).to(self.device)
actions_t = torch.from_numpy(actions).float().to(self.device)
log_probs_old_t = torch.from_numpy(log_probs_old).float().to(self.device)
returns_t = torch.from_numpy(returns).float().to(self.device)
@@ -75,16 +75,13 @@ class PPOTrainer:
for batch in loader:
s, a, log_pi_old, ret, adv = batch
# Get current policy distribution
mu, std = self.actor(s)
dist = torch.distributions.Normal(mu, std)
log_pi = dist.log_prob(a).sum(dim=-1, keepdim=True)
entropy = dist.entropy().sum(dim=-1, keepdim=True)
log_pi = dist.log_prob(a).sum(dim=-1)
entropy = dist.entropy().sum(dim=-1)
# Probability ratio
ratio = torch.exp(log_pi - log_pi_old)
# Clipped surrogate objective
surr1 = ratio * adv
surr2 = torch.clamp(ratio, 1 - self.clip_eps, 1 + self.clip_eps) * adv
actor_loss = -torch.min(surr1, surr2).mean()