nbv_sim/active_grasp/policy.py
2021-08-09 15:19:17 +02:00

144 lines
5.0 KiB
Python

import numpy as np
from sensor_msgs.msg import CameraInfo
from pathlib import Path
import rospy
import warnings
from .visualization import Visualizer
from robot_helpers.ros import tf
from robot_helpers.ros.conversions import *
from vgn.detection import *
from vgn.perception import UniformTSDFVolume
from vgn.utils import *
class Policy:
def activate(self, bbox):
raise NotImplementedError
def update(self, img, extrinsic):
raise NotImplementedError
class BasePolicy(Policy):
def __init__(self, rate=5, filter_grasps=False):
self.rate = rate
self.filter_grasps = filter_grasps
self.load_parameters()
self.init_visualizer()
def load_parameters(self):
self.base_frame = rospy.get_param("active_grasp/base_frame_id")
self.task_frame = "task"
info_topic = rospy.get_param("active_grasp/camera/info_topic")
msg = rospy.wait_for_message(info_topic, CameraInfo, rospy.Duration(2.0))
self.intrinsic = from_camera_info_msg(msg)
self.vgn = VGN(Path(rospy.get_param("vgn/model")))
self.score_fn = lambda g: g.pose.translation[2]
def init_visualizer(self):
self.visualizer = Visualizer(self.base_frame)
def activate(self, bbox):
self.bbox = bbox
# Define the VGN task frame s.t. the bounding box is in its center
self.center = 0.5 * (bbox.min + bbox.max)
self.T_base_task = Transform.translation(self.center - np.full(3, 0.15))
tf.broadcast(self.T_base_task, self.base_frame, self.task_frame)
rospy.sleep(0.1) # wait for the transform to be published
N, self.T = 40, 10 # spatial and temporal resolution
grid_shape = (N,) * 3
self.tsdf = UniformTSDFVolume(0.3, N)
self.qual_hist = np.zeros((self.T,) + grid_shape, np.float32)
self.rot_hist = np.zeros((self.T, 4) + grid_shape, np.float32)
self.width_hist = np.zeros((self.T,) + grid_shape, np.float32)
self.viewpoints = []
self.done = False
self.best_grasp = None
self.visualizer.clear()
self.visualizer.bbox(bbox)
def integrate_img(self, img, extrinsic):
self.viewpoints.append(extrinsic.inv())
self.tsdf.integrate(img, self.intrinsic, extrinsic * self.T_base_task)
self.visualizer.scene_cloud(self.task_frame, self.tsdf.get_scene_cloud())
self.visualizer.path(self.viewpoints)
if self.filter_grasps:
tsdf_grid = self.tsdf.get_grid()
out = self.vgn.predict(tsdf_grid)
t = (len(self.viewpoints) - 1) % self.T
self.qual_hist[t, ...] = out.qual
self.rot_hist[t, ...] = out.rot
self.width_hist[t, ...] = out.width
def compute_best_grasp(self):
if self.filter_grasps:
T = len(self.viewpoints) if len(self.viewpoints) // self.T == 0 else self.T
mask = self.qual_hist[:T, ...] > 0.0
# The next line prints a warning since some voxels have no grasp
# predictions resulting in empty slices.
qual = np.mean(self.qual_hist[:T, ...], axis=0, where=mask)
qual = threshold_quality(qual, 0.9)
index_list = select_local_maxima(qual, 3)
grasps = []
for (i, j, k) in index_list:
ts = np.flatnonzero(self.qual_hist[:T, i, j, k])
if len(ts) < 3:
continue
oris = Rotation.from_quat([self.rot_hist[t, :, i, j, k] for t in ts])
ori = oris.mean()
# TODO check variance as well
pos = np.array([i, j, k], dtype=np.float64)
width = self.width_hist[ts, i, j, k].mean()
quality = self.qual_hist[ts, i, j, k].mean()
grasps.append(Grasp(Transform(ori, pos), width, quality))
else:
tsdf_grid = self.tsdf.get_grid()
out = self.vgn.predict(tsdf_grid)
qual = threshold_quality(out.qual, 0.9)
index_list = select_local_maxima(qual, 3)
grasps = [select_at(out, i) for i in index_list]
grasps = [from_voxel_coordinates(g, self.tsdf.voxel_size) for g in grasps]
grasps = self.transform_grasps_to_base_frame(grasps)
grasps = self.select_grasps_on_target_object(grasps)
grasps = sort_grasps(grasps, self.score_fn)
return grasps[0] if len(grasps) > 0 else None
def transform_grasps_to_base_frame(self, grasps):
for grasp in grasps:
grasp.pose = self.T_base_task * grasp.pose
return grasps
def select_grasps_on_target_object(self, grasps):
result = []
for grasp in grasps:
tip = grasp.pose.rotation.apply([0, 0, 0.05]) + grasp.pose.translation
if self.bbox.is_inside(tip):
result.append(grasp)
return result
registry = {}
def register(id, cls):
global registry
registry[id] = cls
def make(id, *args, **kwargs):
if id in registry:
return registry[id](*args, **kwargs)
else:
raise ValueError("{} policy does not exist.".format(id))