nbv_sim/active_grasp/simulation.py
2021-07-22 11:05:30 +02:00

169 lines
6.2 KiB
Python

from pathlib import Path
import pybullet as p
import pybullet_data
import rospkg
from active_grasp.bbox import AABBox
from robot_helpers.bullet import *
from robot_helpers.model import Model
from robot_helpers.spatial import Rotation, Transform
class Simulation:
def __init__(self, gui):
self.configure_physics_engine(gui, 60, 4)
self.configure_visualizer()
self.find_urdfs()
self.load_table()
self.load_robot()
self.load_controller()
self.object_uids = []
def configure_physics_engine(self, gui, rate, sub_step_count):
self.rate = rate
self.dt = 1.0 / self.rate
p.connect(p.GUI if gui else p.DIRECT)
p.setAdditionalSearchPath(pybullet_data.getDataPath())
p.setPhysicsEngineParameter(fixedTimeStep=self.dt, numSubSteps=sub_step_count)
p.setGravity(0.0, 0.0, -9.81)
def configure_visualizer(self):
# p.configureDebugVisualizer(p.COV_ENABLE_GUI, 0)
p.resetDebugVisualizerCamera(1.4, 50, -35, [0.0, 0.0, 0.6])
def find_urdfs(self):
rospack = rospkg.RosPack()
assets_path = Path(rospack.get_path("active_grasp")) / "assets"
self.panda_urdf = assets_path / "urdfs/franka/panda_arm_hand.urdf"
root = Path(rospack.get_path("vgn")) / "assets/urdfs/packed/test"
self.urdfs = [str(f) for f in root.iterdir() if f.suffix == ".urdf"]
def load_table(self):
p.loadURDF("plane.urdf")
ori = Rotation.from_rotvec(np.array([0, 0, np.pi / 2])).as_quat()
p.loadURDF("table/table.urdf", baseOrientation=ori, useFixedBase=True)
self.length = 0.3
self.origin = [-0.3, -0.5 * self.length, 0.5]
def load_robot(self):
self.T_W_B = Transform(Rotation.identity(), np.r_[-0.6, 0.0, 0.4])
self.arm = BtPandaArm(self.panda_urdf, self.T_W_B)
self.gripper = BtPandaGripper(self.arm)
self.model = Model(self.panda_urdf, self.arm.base_frame, self.arm.ee_frame)
self.camera = BtCamera(320, 240, 1.047, 0.1, 1.0, self.arm.uid, 11)
def load_controller(self):
q, _ = self.arm.get_state()
x0 = self.model.pose(self.arm.ee_frame, q)
self.controller = CartesianPoseController(self.model, self.arm.ee_frame, x0)
def seed(self, seed):
self.rng = np.random.default_rng(seed)
def reset(self):
self.remove_all_objects()
self.set_initial_arm_configuration()
self.load_random_object_arrangement()
uid = self.select_target()
return self.get_target_bbox(uid)
def step(self):
p.stepSimulation()
def set_initial_arm_configuration(self):
q = [
self.rng.uniform(-0.17, 0.17), # 0.0
self.rng.uniform(-0.96, -0.62), # -0.79,
self.rng.uniform(-0.17, 0.17), # 0.0
self.rng.uniform(-2.36, -2.19), # -2.36,
0.0,
self.rng.uniform(1.57, 1.91), # 1.57
self.rng.uniform(0.62, 0.96), # 0.79,
]
for i, q_i in enumerate(q):
p.resetJointState(self.arm.uid, i, q_i, 0)
p.resetJointState(self.arm.uid, 9, 0.04, 0)
p.resetJointState(self.arm.uid, 10, 0.04, 0)
x0 = self.model.pose(self.arm.ee_frame, q)
self.controller.x_d = x0
def load_object(self, urdf, ori, pos, scale=1.0):
uid = p.loadURDF(str(urdf), pos, ori.as_quat(), globalScaling=scale)
self.object_uids.append(uid)
return uid
def remove_object(self, uid):
p.removeBody(uid)
self.object_uids.remove(uid)
def remove_all_objects(self):
for uid in list(self.object_uids):
self.remove_object(uid)
def load_random_object_arrangement(self, attempts=10):
origin = np.r_[self.origin[:2], 0.625]
scale = 0.8
urdfs = self.rng.choice(self.urdfs, 4)
for urdf in urdfs:
# Load the object
uid = self.load_object(urdf, Rotation.identity(), [0.0, 0.0, 0.0], scale)
lower, upper = p.getAABB(uid)
z_offset = 0.5 * (upper[2] - lower[2]) + 0.002
state_id = p.saveState()
for _ in range(attempts):
# Try to place the object without collision
ori = Rotation.from_rotvec([0.0, 0.0, self.rng.uniform(0, 2 * np.pi)])
offset = np.r_[self.rng.uniform(0.2, 0.8, 2) * self.length, z_offset]
p.resetBasePositionAndOrientation(uid, origin + offset, ori.as_quat())
self.step()
if not p.getContactPoints(uid):
break
else:
p.restoreState(stateId=state_id)
else:
# No placement found, remove the object
self.remove_object(uid)
def select_target(self):
_, _, mask = self.camera.get_image()
uids, counts = np.unique(mask, return_counts=True)
mask = np.isin(uids, self.object_uids) # remove ids of the floor, table, etc
uids, counts = uids[mask], counts[mask]
target_uid = uids[np.argmin(counts)]
p.changeVisualShape(target_uid, -1, rgbaColor=[1, 0, 0, 1])
return target_uid
def get_target_bbox(self, uid):
aabb_min, aabb_max = p.getAABB(uid)
aabb_min = np.array(aabb_min) - self.origin
aabb_max = np.array(aabb_max) - self.origin
return AABBox(aabb_min, aabb_max)
class CartesianPoseController:
def __init__(self, model, frame, x0):
self._model = model
self._frame = frame
self.kp = np.ones(6) * 4.0
self.max_linear_vel = 0.2
self.max_angular_vel = 1.57
self.x_d = x0
def update(self, q):
x = self._model.pose(self._frame, q)
error = np.zeros(6)
error[:3] = self.x_d.translation - x.translation
error[3:] = (self.x_d.rotation * x.rotation.inv()).as_rotvec()
dx = self._limit_rate(self.kp * error)
J_pinv = np.linalg.pinv(self._model.jacobian(self._frame, q))
cmd = np.dot(J_pinv, dx)
return cmd
def _limit_rate(self, dx):
linear, angular = dx[:3], dx[3:]
linear = np.clip(linear, -self.max_linear_vel, self.max_linear_vel)
angular = np.clip(angular, -self.max_angular_vel, self.max_angular_vel)
return np.r_[linear, angular]