gtsam/cython/gtsam_unstable/tests/test_FixedLagSmootherExampl...

105 lines
4.0 KiB
Python

import unittest
import gtsam
import gtsam_unstable
import numpy as np
def _timestamp_key_value(key, value):
return gtsam_unstable.FixedLagSmootherKeyTimestampMapValue(
key, value
)
class TestFixedLagSmootherExample(unittest.TestCase):
'''
Tests the fixed lag smoother wrapper
'''
def test_FixedLagSmootherExample(self):
'''
Simple test that checks for equality between C++ example
file and the Python implementation. See
gtsam_unstable/examples/FixedLagSmootherExample.cpp
'''
# Define a batch fixed lag smoother, which uses
# Levenberg-Marquardt to perform the nonlinear optimization
lag = 2.0
smoother_batch = gtsam_unstable.BatchFixedLagSmoother(lag)
# Create containers to store the factors and linearization points
# that will be sent to the smoothers
new_factors = gtsam.NonlinearFactorGraph()
new_values = gtsam.Values()
new_timestamps = gtsam_unstable.FixedLagSmootherKeyTimestampMap()
# Create a prior on the first pose, placing it at the origin
prior_mean = gtsam.Pose2(0, 0, 0)
prior_noise = gtsam.noiseModel_Diagonal.Sigmas(np.array([0.3, 0.3, 0.1]))
X1 = 0
new_factors.push_back(gtsam.PriorFactorPose2(X1, prior_mean, prior_noise))
new_values.insert(X1, prior_mean)
new_timestamps.insert(_timestamp_key_value(X1, 0.0))
delta_time = 0.25
time = 0.25
i = 0
ground_truth = [
gtsam.Pose2(0.49792, 0.007802, 0.015),
gtsam.Pose2(0.99547, 0.023019, 0.03),
gtsam.Pose2(1.4928, 0.045725, 0.045),
gtsam.Pose2(1.9898, 0.075888, 0.06),
gtsam.Pose2(2.4863, 0.1135, 0.075),
gtsam.Pose2(2.9821, 0.15856, 0.09),
gtsam.Pose2(3.4772, 0.21105, 0.105),
gtsam.Pose2(3.9715, 0.27096, 0.12),
gtsam.Pose2(4.4648, 0.33827, 0.135),
gtsam.Pose2(4.957, 0.41298, 0.15),
gtsam.Pose2(5.4481, 0.49506, 0.165),
gtsam.Pose2(5.9379, 0.5845, 0.18),
]
# Iterates from 0.25s to 3.0s, adding 0.25s each loop
# In each iteration, the agent moves at a constant speed
# and its two odometers measure the change. The smoothed
# result is then compared to the ground truth
while time <= 3.0:
previous_key = 1000 * (time - delta_time)
current_key = 1000 * time
# assign current key to the current timestamp
new_timestamps.insert(_timestamp_key_value(current_key, time))
# Add a guess for this pose to the new values
# Assume that the robot moves at 2 m/s. Position is time[s] * 2[m/s]
current_pose = gtsam.Pose2(time * 2, 0, 0)
new_values.insert(current_key, current_pose)
# Add odometry factors from two different sources with different error stats
odometry_measurement_1 = gtsam.Pose2(0.61, -0.08, 0.02)
odometry_noise_1 = gtsam.noiseModel_Diagonal.Sigmas(np.array([0.1, 0.1, 0.05]))
new_factors.push_back(gtsam.BetweenFactorPose2(
previous_key, current_key, odometry_measurement_1, odometry_noise_1
))
odometry_measurement_2 = gtsam.Pose2(0.47, 0.03, 0.01)
odometry_noise_2 = gtsam.noiseModel_Diagonal.Sigmas(np.array([0.05, 0.05, 0.05]))
new_factors.push_back(gtsam.BetweenFactorPose2(
previous_key, current_key, odometry_measurement_2, odometry_noise_2
))
# Update the smoothers with the new factors
smoother_batch.update(new_factors, new_values, new_timestamps)
estimate = smoother_batch.calculateEstimatePose2(current_key)
self.assertTrue(estimate.equals(ground_truth[i], 1e-4))
new_timestamps.clear()
new_values.clear()
new_factors.resize(0)
time += delta_time
i += 1
if __name__ == "__main__":
unittest.main()