Files
JackBot/ml/env.py
T

262 lines
9.9 KiB
Python

import math
import random
import numpy as np
import pybullet as p
import gymnasium as gym
from gymnasium import spaces
import config as cfg
import robot_init as ri
from .sim_manager import SimManager
class JackBotEnv(gym.Env):
"""Gymnasium environment for joint-command learning using SimManager for GUI and simulation control."""
metadata = {"render_modes": ["human", "rgb_array"]}
def __init__(
self,
urdf_path: str | None = None,
use_gui: bool = True,
frame_skip: int = 4,
random_command: bool = True,
max_episode_steps: int = 2000,
num_robots: int = 1,
robot_spacing: float = 0.5,
start_pose: str = "init_deg",
):
self.urdf_path = urdf_path or cfg.urdf_path
self.use_gui = use_gui
self.frame_skip = frame_skip
self.random_command = random_command
self.max_episode_steps = max_episode_steps
self.num_robots = max(1, num_robots)
self.robot_spacing = robot_spacing
self.start_pose = start_pose
self.action_scale = math.radians(8.0)
# Delegate physics simulation & GUI management
self.sim_manager = SimManager(use_gui=self.use_gui)
self.robots = []
self.plane = None
self.robot_joint_indices = []
self.joint_lower = None
self.joint_upper = None
self.initial_angles = None
self.commands = None
self.step_count = 0
self.episode_count = 0
self.cumulative_reward = 0.0
self.last_action = None
self._first_reset = True
self._min_steps_before_done = 150
self._connect_sim()
total_joints = self.num_robots * len(self.robot_joint_indices[0])
observation_dim = total_joints + self.num_robots * 4
action_dim = total_joints
self.observation_space = spaces.Box(
low=-np.inf, high=np.inf, shape=(observation_dim,), dtype=np.float32
)
self.action_space = spaces.Box(
low=-1.0, high=1.0, shape=(action_dim,), dtype=np.float32
)
def _robot_base_position(self, robot_id: int, num_robots: int = 1, spacing: float = 0.5) -> list[float]:
"""Calculates grid coordinates for spawning multiple robots in PyBullet."""
cols = int(math.sqrt(num_robots - 1)) + 1
row = robot_id // cols
col = robot_id % cols
x = (col - (cols - 1) / 2.0) * spacing
y = (row - (cols - 1) / 2.0) * spacing
return [x, y, 0.1]
def _connect_sim(self):
self.sim_manager.connect()
self.plane, self.robots, self.robot_joint_indices = self.sim_manager.load_scene(
self.urdf_path, self.num_robots, self.robot_spacing, self._robot_base_position
)
joint_count = len(self.robot_joint_indices[0])
if any(len(indices) != joint_count for indices in self.robot_joint_indices):
raise ValueError("All robots must have the same number of revolute joints.")
lower_limits, upper_limits = [], []
for joint_index in self.robot_joint_indices[0]:
info = p.getJointInfo(self.robots[0], joint_index)
lower, upper = info[8], info[9]
if lower >= upper:
lower, upper = -math.pi, math.pi
lower_limits.append(lower)
upper_limits.append(upper)
limits = np.array([lower_limits, upper_limits], dtype=np.float32)
self.joint_lower = np.tile(limits[0], (self.num_robots, 1))
self.joint_upper = np.tile(limits[1], (self.num_robots, 1))
pose = ri.init_deg if self.start_pose == "init_deg" else ri.init90_deg
initial_pose = pose.to_rad().data.flatten()
self.initial_angles = np.tile(initial_pose, (self.num_robots, 1)).astype(np.float32)
self.initial_angles = np.clip(self.initial_angles, self.joint_lower, self.joint_upper)
self.last_action = np.zeros(self.num_robots * joint_count, dtype=np.float32)
self.commands = np.zeros((self.num_robots, 4), dtype=np.float32)
def reset(self, command: np.ndarray | None = None, seed: int | None = None, options: dict | None = None):
self.episode_count += 1
self.step_count = 0
self.cumulative_reward = 0.0
if not self._first_reset:
# Reset simulation bodies without reconnecting PyBullet
p.resetSimulation()
p.setGravity(0, 0, -9.81)
self.sim_manager.reset_hud()
self.plane, self.robots, self.robot_joint_indices = self.sim_manager.load_scene(
self.urdf_path, self.num_robots, self.robot_spacing, self._robot_base_position
)
else:
self._first_reset = False
self.last_action = np.zeros(self.num_robots * len(self.robot_joint_indices[0]), dtype=np.float32)
if seed is not None:
self.seed(seed)
if command is not None:
self.commands = np.array(command, dtype=np.float32).reshape(self.num_robots, 4)
elif self.random_command:
self.commands = np.stack([self.sample_command() for _ in range(self.num_robots)])
else:
self.commands = np.zeros((self.num_robots, 4), dtype=np.float32)
self._reset_pose()
self._update_gui_hud(reward=0.0)
return self._get_obs(), {}
def seed(self, seed: int | None = None):
if seed is None:
seed = int(np.random.randint(0, 2**31 - 1))
random.seed(seed)
np.random.seed(seed)
self._seed = seed
return [seed]
def _reset_pose(self):
for robot, joint_indices, init_angles in zip(self.robots, self.robot_joint_indices, self.initial_angles):
for joint_index, target_angle in zip(joint_indices, init_angles):
p.resetJointState(robot, joint_index, target_angle)
p.setJointMotorControl2(
bodyIndex=robot,
jointIndex=joint_index,
controlMode=p.POSITION_CONTROL,
targetPosition=target_angle,
force=250,
)
for _ in range(400):
p.stepSimulation()
self.joint_angles = self.initial_angles.copy()
def sample_command(self) -> np.ndarray:
vx = np.random.uniform(-1.0, 1.0)
vy = np.random.uniform(-0.5, 0.5)
vz = 0.0
omega = np.random.uniform(-1.0, 1.0)
return np.array([vx, vy, vz, omega], dtype=np.float32)
def _get_obs(self) -> np.ndarray:
return np.concatenate([self.joint_angles.flatten(), self.commands.flatten()]).astype(np.float32)
def step(self, action: np.ndarray):
action = np.clip(action, self.action_space.low, self.action_space.high).astype(np.float32)
self.last_action = action
action_matrix = action.reshape(self.num_robots, -1)
self.joint_angles = np.clip(
self.joint_angles + action_matrix * self.action_scale,
self.joint_lower,
self.joint_upper,
)
for robot, joint_indices, angles in zip(self.robots, self.robot_joint_indices, self.joint_angles):
for joint_index, target_angle in zip(joint_indices, angles):
p.setJointMotorControl2(
bodyIndex=robot,
jointIndex=joint_index,
controlMode=p.POSITION_CONTROL,
targetPosition=target_angle,
force=250,
)
for _ in range(self.frame_skip):
p.stepSimulation()
self.step_count += 1
observation = self._get_obs()
reward = self._compute_reward()
self.cumulative_reward += reward
done = self._is_done()
if self.step_count <= self._min_steps_before_done:
done = False
self._update_gui_hud(reward=reward)
terminated = done
truncated = False
info = {"step": self.step_count, "episode_reward": self.cumulative_reward}
return observation, float(reward), terminated, truncated, info
def _update_gui_hud(self, reward: float):
"""Passes current state metrics to the SimManager HUD renderer."""
linear_vel, _ = p.getBaseVelocity(self.robots[0])
cmd = self.commands[0]
stats = {
"Episode": self.episode_count,
"Step": f"{self.step_count} / {self.max_episode_steps}",
"Step Reward": reward,
"Total Reward": self.cumulative_reward,
"Target Cmd (vx,vy,w)": [cmd[0], cmd[1], cmd[3]],
"Actual Vel (vx,vy)": [linear_vel[0], linear_vel[1]],
}
self.sim_manager.update_hud(stats)
def _compute_reward(self) -> float:
rewards = []
for robot_id, robot in enumerate(self.robots):
linear_vel, angular_vel = p.getBaseVelocity(robot)
_, orientation = p.getBasePositionAndOrientation(robot)
roll, pitch, _ = p.getEulerFromQuaternion(orientation)
command = self.commands[robot_id]
forward_reward = command[0] * linear_vel[0] + command[1] * linear_vel[1]
rotation_reward = command[3] * angular_vel[2]
stability_penalty = abs(roll) + abs(pitch)
action_penalty = float(np.sum(np.square(self.last_action.reshape(self.num_robots, -1)[robot_id]))) * 0.01
rewards.append(0.1 + forward_reward + rotation_reward - 0.2 * stability_penalty - action_penalty)
return float(np.sum(rewards))
def _is_done(self) -> bool:
for robot in self.robots:
_, orientation = p.getBasePositionAndOrientation(robot)
roll, pitch, _ = p.getEulerFromQuaternion(orientation)
if abs(roll) > 0.7 or abs(pitch) > 0.7:
return True
position, _ = p.getBasePositionAndOrientation(robot)
if position[2] < 0.02:
return True
return self.step_count >= self.max_episode_steps
def close(self):
self.sim_manager.disconnect()