first release pose_optimization_slam

This commit is contained in:
Atsushi Sakai
2019-05-31 10:42:36 +09:00
parent a5db2fe793
commit 40e5c2cbb0
4 changed files with 328 additions and 0 deletions

1
.gitignore vendored
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*.csv
*.gif
*.g2o
# Byte-compiled / optimized / DLL files
__pycache__/

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# How to use
1. Download data
python data_downloader.py
2. run SLAM
python pose_optimization_slam.py

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"""
Data down loader for pose optimization
author: Atsushi Sakai
"""
import subprocess
def main():
print("start!!")
cmd = "wget https://www.dropbox.com/s/vcz8cag7bo0zlaj/input_INTEL_g2o.g2o?dl=0 -O intel.g2o -nc"
subprocess.call(cmd, shell=True)
cmd = "wget https://www.dropbox.com/s/d8fcn1jg1mebx8f/input_MITb_g2o.g2o?dl=0 -O mit_killian.g2o -nc"
subprocess.call(cmd, shell=True)
cmd = "wget https://www.dropbox.com/s/gmdzo74b3tzvbrw/input_M3500_g2o.g2o?dl=0 -O manhattan3500.g2o -nc"
subprocess.call(cmd, shell=True)
print("done!!")
if __name__ == '__main__':
main()

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"""
2D (x, y, yaw) pose optimization SLAM
author: Atsushi Sakai
Ref:
- [A Compact and Portable Implementation of Graph\-based SLAM](https://www.researchgate.net/publication/321287640_A_Compact_and_Portable_Implementation_of_Graph-based_SLAM)
- [GitHub \- furo\-org/p2o: Single header 2D/3D graph\-based SLAM library](https://github.com/furo-org/p2o)
"""
import sys
import time
import math
import numpy as np
import matplotlib.pyplot as plt
from scipy import sparse
from scipy.sparse import linalg
class Optimizer2D:
def __init__(self):
self.verbose = False
self.animation = False
self.p_lambda = 0.0
self.init_w = 1e10
self.stop_thre = 1e-3
self.dim = 3 # state dimension
def optimize_path(self, nodes, consts, max_iter, min_iter):
graph_nodes = nodes[:]
prev_cost = sys.float_info.max
for i in range(max_iter):
start = time.time()
cost, graph_nodes = self.optimize_path_one_step(
graph_nodes, consts)
elapsed = time.time() - start
if self.verbose:
print("step ", i, " cost: ", cost, " time:", elapsed, "s")
# check convergence
if (i > min_iter) and (prev_cost - cost < self.stop_thre):
if self.verbose:
print("converged:", prev_cost
- cost, " < ", self.stop_thre)
break
prev_cost = cost
if self.animation:
plt.cla()
plot_nodes(nodes, color="-b")
plot_nodes(graph_nodes)
plt.axis("equal")
plt.pause(1.0)
return graph_nodes
def optimize_path_one_step(self, graph_nodes, constraints):
indlist = [i for i in range(self.dim)]
numnodes = len(graph_nodes)
bf = np.zeros(numnodes * self.dim)
tripletList = TripletList()
for con in constraints:
ida = con.id1
idb = con.id2
assert 0 <= ida and ida < numnodes, "ida is invalid"
assert 0 <= idb and idb < numnodes, "idb is invalid"
r, Ja, Jb = self.calc_error(
graph_nodes[ida], graph_nodes[idb], con.t)
trJaInfo = Ja.transpose() @ con.info_mat
trJaInfoJa = trJaInfo @ Ja
trJbInfo = Jb.transpose() @ con.info_mat
trJbInfoJb = trJbInfo @ Jb
trJaInfoJb = trJaInfo @ Jb
for k in indlist:
for m in indlist:
tripletList.push_back(
ida * self.dim + k, ida * self.dim + m, trJaInfoJa[k, m])
tripletList.push_back(
idb * self.dim + k, idb * self.dim + m, trJbInfoJb[k, m])
tripletList.push_back(
ida * self.dim + k, idb * self.dim + m, trJaInfoJb[k, m])
tripletList.push_back(
idb * self.dim + k, ida * self.dim + m, trJaInfoJb[m, k])
bf[ida * self.dim: ida * self.dim + 3] += trJaInfo @ r
bf[idb * self.dim: idb * self.dim + 3] += trJbInfo @ r
for k in indlist:
tripletList.push_back(k, k, self.init_w)
for i in range(self.dim * numnodes):
tripletList.push_back(i, i, self.p_lambda)
mat = sparse.coo_matrix((tripletList.data, (tripletList.row, tripletList.col)),
shape=(numnodes * self.dim, numnodes * self.dim))
x = linalg.spsolve(mat.tocsr(), -bf)
out_nodes = []
for i in range(len(graph_nodes)):
u_i = i * self.dim
pos = Pose2D(
graph_nodes[i].x + x[u_i],
graph_nodes[i].y + x[u_i + 1],
graph_nodes[i].theta + x[u_i + 2]
)
out_nodes.append(pos)
cost = self.calc_global_cost(out_nodes, constraints)
return cost, out_nodes
def calc_global_cost(self, nodes, constraints):
cost = 0.0
for c in constraints:
diff = self.error_func(nodes[c.id1], nodes[c.id2], c.t)
cost += diff.transpose() @ c.info_mat @ diff
return cost
def error_func(self, pa, pb, t):
ba = self.calc_constraint_pose(pb, pa)
error = np.array([ba.x - t.x,
ba.y - t.y,
self.pi2pi(ba.theta - t.theta)])
return error
def calc_constraint_pose(self, l, r):
diff = np.array([l.x - r.x, l.y - r.y, l.theta - r.theta])
v = self.rot_mat_2d(-r.theta) @ diff
v[2] = self.pi2pi(l.theta - r.theta)
return Pose2D(v[0], v[1], v[2])
def rot_mat_2d(self, theta):
return np.array([[math.cos(theta), -math.sin(theta), 0.0],
[math.sin(theta), math.cos(theta), 0.0],
[0.0, 0.0, 1.0]
])
def calc_error(self, pa, pb, t):
e0 = self.error_func(pa, pb, t)
dx = pb.x - pa.x
dy = pb.y - pa.y
dxdt = -math.sin(pa.theta) * dx + math.cos(pa.theta) * dy
dydt = -math.cos(pa.theta) * dx - math.sin(pa.theta) * dy
Ja = np.array([[-math.cos(pa.theta), -math.sin(pa.theta), dxdt],
[math.sin(pa.theta), -math.cos(pa.theta), dydt],
[0.0, 0.0, -1.0]
])
Jb = np.array([[math.cos(pa.theta), math.sin(pa.theta), 0.0],
[-math.sin(pa.theta), math.cos(pa.theta), 0.0],
[0.0, 0.0, 1.0]
])
return e0, Ja, Jb
def pi2pi(self, rad):
val = math.fmod(rad, 2.0 * math.pi)
if val > math.pi:
val -= 2.0 * math.pi
elif val < -math.pi:
val += 2.0 * math.pi
return val
class TripletList:
def __init__(self):
self.row = []
self.col = []
self.data = []
def push_back(self, irow, icol, idata):
self.row.append(irow)
self.col.append(icol)
self.data.append(idata)
class Pose2D:
def __init__(self, x, y, theta):
self.x = x
self.y = y
self.theta = theta
class Constrant2D:
def __init__(self, id1, id2, t, info_mat):
self.id1 = id1
self.id2 = id2
self.t = t
self.info_mat = info_mat
def plot_nodes(nodes, color ="-r", label = ""):
x, y = [], []
for n in nodes:
x.append(n.x)
y.append(n.y)
plt.plot(x, y, color, label=label)
def load_data(fname):
nodes, consts = [], []
for line in open(fname):
sline = line.split()
tag = sline[0]
if tag == "VERTEX_SE2":
data_id = int(sline[1])
x = float(sline[2])
y = float(sline[3])
theta = float(sline[4])
nodes.append(Pose2D(x, y, theta))
elif tag == "EDGE_SE2":
id1 = int(sline[1])
id2 = int(sline[2])
x = float(sline[3])
y = float(sline[4])
th = float(sline[5])
c1 = float(sline[6])
c2 = float(sline[7])
c3 = float(sline[8])
c4 = float(sline[9])
c5 = float(sline[10])
c6 = float(sline[11])
t = Pose2D(x, y, th)
info_mat = np.array([[c1, c2, c3],
[c2, c4, c5],
[c3, c5, c6]
])
consts.append(Constrant2D(id1, id2, t, info_mat))
print("n_nodes:", len(nodes))
print("n_consts:", len(consts))
return nodes, consts
def main():
print("start!!")
fnames = ["intel.g2o",
"manhattan3500.g2o",
"mit_killian.g2o"
]
max_iter = 20
min_iter = 3
# parameter setting
optimizer = Optimizer2D()
optimizer.p_lambda = 1e-6
optimizer.verbose = True
optimizer.animation = True
for f in fnames:
nodes, consts = load_data(f)
start = time.time()
final_nodes = optimizer.optimize_path(nodes, consts, max_iter, min_iter)
print("elapsed_time", time.time() - start, "sec")
# plotting
plt.cla()
plot_nodes(nodes, color="-b", label="before")
plot_nodes(final_nodes, label="after")
plt.axis("equal")
plt.grid(True)
plt.legend()
plt.pause(3.0)
print("done!!")
if __name__ == '__main__':
main()