Files
JackBot/ml/train.py
T

257 lines
9.8 KiB
Python

import os
import argparse
from pathlib import Path
import numpy as np
from stable_baselines3.common.callbacks import BaseCallback
from stable_baselines3.common.vec_env import SubprocVecEnv, DummyVecEnv
from .env import JackBotEnv
class MilestoneCheckpointCallback(BaseCallback):
"""
Saves a model checkpoint the FIRST time total_timesteps
crosses every multiple of step_interval (e.g., 100,000).
Saves inside the matching PPO_X subfolder as created by TensorBoard.
"""
def __init__(self, save_path: str, name_prefix: str = "ppo_jackbot", step_interval: int = 100_000, verbose: int = 1):
super().__init__(verbose)
self.base_save_path = save_path
self.run_save_path = save_path
self.name_prefix = name_prefix
self.step_interval = step_interval
self.last_milestone = 0
def _on_training_start(self) -> None:
"""Executed right before training loop starts. Resolves TensorBoard's run folder name (e.g. PPO_1)."""
if self.logger and self.logger.dir:
run_folder_name = Path(self.logger.dir).name # Extracts "PPO_1", "PPO_2", etc.
self.run_save_path = os.path.join(self.base_save_path, run_folder_name)
else:
self.run_save_path = self.base_save_path
os.makedirs(self.run_save_path, exist_ok=True)
def _on_step(self) -> bool:
current_milestone = self.num_timesteps // self.step_interval
if current_milestone > self.last_milestone:
self.last_milestone = current_milestone
milestone_step = current_milestone * self.step_interval
save_file = os.path.join(
self.run_save_path,
f"{self.name_prefix}_{milestone_step}_steps.zip"
)
self.model.save(save_file)
if self.verbose > 0:
print(f"\n[Checkpoint] Saved milestone model at {self.num_timesteps} steps -> {save_file}\n")
return True
class JackBotMetricsCallback(BaseCallback):
"""
Tracks the best current alive-robot performance for the most recent rollout,
instead of logging lifetime maxima from the entire training run.
"""
def __init__(self, verbose=0):
super().__init__(verbose)
self.best_alive_speed = 0.0
self.best_alive_yaw_rate = 0.0
self.best_alive_distance = 0.0
self.best_alive_survival_steps = 0.0
self.best_alive_reward = -float('inf')
def _on_step(self) -> bool:
return True
def _on_rollout_end(self) -> bool:
try:
vec_env = self.training_env
alive_metrics = vec_env.env_method("get_current_robot_metrics")
self.best_alive_speed = 0.0
self.best_alive_yaw_rate = 0.0
self.best_alive_distance = 0.0
self.best_alive_survival_steps = 0.0
self.best_alive_reward = -float('inf')
for worker_res in alive_metrics:
for metrics in worker_res:
if not metrics.get("alive", False):
continue
if metrics["reward"] > self.best_alive_reward:
self.best_alive_reward = float(metrics["reward"])
if metrics["speed"] > self.best_alive_speed:
self.best_alive_speed = float(metrics["speed"])
if metrics["yaw_rate"] > self.best_alive_yaw_rate:
self.best_alive_yaw_rate = float(metrics["yaw_rate"])
if metrics["distance_from_start"] > self.best_alive_distance:
self.best_alive_distance = float(metrics["distance_from_start"])
if metrics["survival_steps"] > self.best_alive_survival_steps:
self.best_alive_survival_steps = float(metrics["survival_steps"])
self.logger.record("custom/best_alive_speed_mps", float(self.best_alive_speed))
self.logger.record("custom/best_alive_yaw_rate_rads", float(self.best_alive_yaw_rate))
self.logger.record("custom/best_alive_distance_from_start_m", float(self.best_alive_distance))
self.logger.record("custom/best_alive_survival_steps", float(self.best_alive_survival_steps))
self.logger.record("custom/best_alive_reward", float(self.best_alive_reward) if np.isfinite(self.best_alive_reward) else 0.0)
self.logger.record("custom/max_speed_mps", float(self.best_alive_speed))
self.logger.record("custom/max_yaw_rate_rads", float(self.best_alive_yaw_rate))
self.logger.record("custom/max_distance_from_start_m", float(self.best_alive_distance))
self.logger.record("custom/max_survival_steps", float(self.best_alive_survival_steps))
self.logger.record("custom/best_episode_reward", float(self.best_alive_reward) if np.isfinite(self.best_alive_reward) else 0.0)
except Exception:
pass
return True
def parse_args():
parser = argparse.ArgumentParser(description="Train a joint-command policy for JackBot.")
parser.add_argument("--timesteps", type=int, default=500_000, help="Total training timesteps")
parser.add_argument("--model-path", type=str, default="ml/checkpoints/ppo_joint_command", help="Where to save the trained model")
parser.add_argument("--seed", type=int, default=0, help="Random seed")
parser.add_argument("--device", type=str, default="auto", help="Device to use: 'cpu', 'cuda', or 'auto' to autodetect")
parser.add_argument("--gui", "--use-gui", dest="use_gui", action="store_true", help="Enable PyBullet GUI during training")
parser.add_argument("--num-workers", type=int, default=8, help="Number of parallel CPU worker processes")
parser.add_argument("--robot-spacing", type=float, default=3.0, help="Spacing between robots in meters")
parser.add_argument("--start-pose", type=str, choices=["init_deg", "init90_deg"], default="init_deg", help="Initial robot pose at reset")
return parser.parse_args()
def make_env(robot_spacing, start_pose, use_gui, rank, seed=0):
def _init():
env = JackBotEnv(
use_gui=use_gui if rank == 0 else False,
random_command=True,
robot_spacing=robot_spacing,
start_pose=start_pose,
)
env.reset(seed=seed + rank)
return env
return _init
def train(
total_timesteps: int,
model_path: str,
seed: int = 0,
device: str = "auto",
use_gui: bool = False,
num_workers: int = 8,
robot_spacing: float = 0.5,
start_pose: str = "init_deg",
):
try:
from stable_baselines3 import PPO
except ImportError as exc:
raise ImportError("stable-baselines3 is required. Install with: pip install stable-baselines3") from exc
if num_workers > 1:
env_fns = [
make_env(robot_spacing, start_pose, use_gui, rank=i, seed=seed)
for i in range(num_workers)
]
env = SubprocVecEnv(env_fns)
else:
env = DummyVecEnv([
make_env(robot_spacing, start_pose, use_gui, rank=0, seed=seed)
])
def resolve_device(requested_device: str) -> str:
try:
import torch
except ImportError:
if requested_device != "cpu":
raise RuntimeError("PyTorch is not installed.")
return "cpu"
hip_supported = getattr(torch.version, "hip", None) is not None
cuda_available = torch.cuda.is_available()
hip_available = hip_supported and getattr(torch.backends, "hip", None) is not None and torch.backends.hip.is_available()
if requested_device == "auto":
return "cuda" if (hip_available or cuda_available) else "cpu"
if requested_device in {"cuda", "gpu", "hip"}:
if hip_available or cuda_available:
return "cuda"
raise RuntimeError(f"GPU requested ({requested_device}) but not available.")
return "cpu"
device = resolve_device(device)
policy_kwargs = dict(
log_std_init=-1.5,
net_arch=dict(pi=[256, 256], vf=[256, 256])
)
model = PPO(
"MlpPolicy",
env,
verbose=1,
seed=seed,
learning_rate=1.5e-4,
n_steps=256,
batch_size=256,
n_epochs=10,
gamma=0.99,
gae_lambda=0.95,
clip_range=0.2,
target_kl=0.03,
ent_coef=0.03,
vf_coef=0.5,
max_grad_norm=0.5,
device=device,
policy_kwargs=policy_kwargs,
tensorboard_log=str(Path(__file__).resolve().parent / "tensorboard"),
)
# Base folder where model runs will be stored
save_dir = str(Path(model_path).parent)
model_prefix = Path(model_path).stem
milestone_cb = MilestoneCheckpointCallback(
save_path=save_dir,
name_prefix=model_prefix,
step_interval=100_000
)
metrics_callback = JackBotMetricsCallback()
model.learn(total_timesteps=total_timesteps, callback=[milestone_cb, metrics_callback])
# Save the final model inside the matching PPO_X directory as well
if model.logger and model.logger.dir:
run_folder_name = Path(model.logger.dir).name
final_dir = Path(model_path).parent / run_folder_name
else:
final_dir = Path(model_path).parent
final_dir.mkdir(parents=True, exist_ok=True)
final_save_path = final_dir / f"{model_prefix}_final.zip"
model.save(str(final_save_path))
if model.verbose > 0:
print(f"[Training Complete] Saved final model to -> {final_save_path}")
env.close()
if __name__ == "__main__":
args = parse_args()
train(
args.timesteps,
args.model_path,
seed=args.seed,
device=args.device,
use_gui=args.use_gui,
num_workers=args.num_workers,
robot_spacing=args.robot_spacing,
start_pose=args.start_pose,
)