Merged in fix/ImuFactor (pull request #325)

close issue #280
TBB/cython bug on Mac seems unrelated
release/4.3a0
Frank Dellaert 2018-10-18 13:40:57 +00:00
commit c6d9baf3ce
6 changed files with 413 additions and 32 deletions

View File

@ -0,0 +1,176 @@
"""
iSAM2 example with ImuFactor.
Author: Robert Truax (C++), Frank Dellaert (Python)
"""
# pylint: disable=invalid-name, E1101
from __future__ import print_function
import math
import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.mplot3d import Axes3D # pylint: disable=W0611
import gtsam
import gtsam.utils.plot as gtsam_plot
def X(key):
"""Create symbol for pose key."""
return gtsam.symbol(ord('x'), key)
def V(key):
"""Create symbol for velocity key."""
return gtsam.symbol(ord('v'), key)
def vector3(x, y, z):
"""Create 3d double numpy array."""
return np.array([x, y, z], dtype=np.float)
def ISAM2_plot(values, fignum=0):
"""Plot poses."""
fig = plt.figure(fignum)
axes = fig.gca(projection='3d')
plt.cla()
i = 0
min_bounds = 0, 0, 0
max_bounds = 0, 0, 0
while values.exists(X(i)):
pose_i = values.atPose3(X(i))
gtsam_plot.plot_pose3(fignum, pose_i, 10)
position = pose_i.translation().vector()
min_bounds = [min(v1, v2) for (v1, v2) in zip(position, min_bounds)]
max_bounds = [max(v1, v2) for (v1, v2) in zip(position, max_bounds)]
# max_bounds = min(pose_i.x(), max_bounds[0]), 0, 0
i += 1
# draw
axes.set_xlim3d(min_bounds[0]-1, max_bounds[0]+1)
axes.set_ylim3d(min_bounds[1]-1, max_bounds[1]+1)
axes.set_zlim3d(min_bounds[2]-1, max_bounds[2]+1)
plt.pause(1)
# IMU preintegration parameters
# Default Params for a Z-up navigation frame, such as ENU: gravity points along negative Z-axis
g = 9.81
n_gravity = vector3(0, 0, -g)
PARAMS = gtsam.PreintegrationParams.MakeSharedU(g)
I = np.eye(3)
PARAMS.setAccelerometerCovariance(I * 0.1)
PARAMS.setGyroscopeCovariance(I * 0.1)
PARAMS.setIntegrationCovariance(I * 0.1)
PARAMS.setUse2ndOrderCoriolis(False)
PARAMS.setOmegaCoriolis(vector3(0, 0, 0))
BIAS_COVARIANCE = gtsam.noiseModel_Isotropic.Variance(6, 0.1)
DELTA = gtsam.Pose3(gtsam.Rot3.Rodrigues(0, 0, 0),
gtsam.Point3(0.05, -0.10, 0.20))
def IMU_example():
"""Run iSAM 2 example with IMU factor."""
# Start with a camera on x-axis looking at origin
radius = 30
up = gtsam.Point3(0, 0, 1)
target = gtsam.Point3(0, 0, 0)
position = gtsam.Point3(radius, 0, 0)
camera = gtsam.SimpleCamera.Lookat(position, target, up, gtsam.Cal3_S2())
pose_0 = camera.pose()
# Create the set of ground-truth landmarks and poses
angular_velocity = math.radians(180) # rad/sec
delta_t = 1.0/18 # makes for 10 degrees per step
angular_velocity_vector = vector3(0, -angular_velocity, 0)
linear_velocity_vector = vector3(radius * angular_velocity, 0, 0)
scenario = gtsam.ConstantTwistScenario(
angular_velocity_vector, linear_velocity_vector, pose_0)
# Create a factor graph
newgraph = gtsam.NonlinearFactorGraph()
# Create (incremental) ISAM2 solver
isam = gtsam.ISAM2()
# Create the initial estimate to the solution
# Intentionally initialize the variables off from the ground truth
initialEstimate = gtsam.Values()
# Add a prior on pose x0. This indirectly specifies where the origin is.
# 30cm std on x,y,z 0.1 rad on roll,pitch,yaw
noise = gtsam.noiseModel_Diagonal.Sigmas(
np.array([0.3, 0.3, 0.3, 0.1, 0.1, 0.1]))
newgraph.push_back(gtsam.PriorFactorPose3(X(0), pose_0, noise))
# Add imu priors
biasKey = gtsam.symbol(ord('b'), 0)
biasnoise = gtsam.noiseModel_Isotropic.Sigma(6, 0.1)
biasprior = gtsam.PriorFactorConstantBias(biasKey, gtsam.imuBias_ConstantBias(),
biasnoise)
newgraph.push_back(biasprior)
initialEstimate.insert(biasKey, gtsam.imuBias_ConstantBias())
velnoise = gtsam.noiseModel_Isotropic.Sigma(3, 0.1)
# Calculate with correct initial velocity
n_velocity = vector3(0, angular_velocity * radius, 0)
velprior = gtsam.PriorFactorVector(V(0), n_velocity, velnoise)
newgraph.push_back(velprior)
initialEstimate.insert(V(0), n_velocity)
accum = gtsam.PreintegratedImuMeasurements(PARAMS)
# Simulate poses and imu measurements, adding them to the factor graph
for i in range(80):
t = i * delta_t # simulation time
if i == 0: # First time add two poses
pose_1 = scenario.pose(delta_t)
initialEstimate.insert(X(0), pose_0.compose(DELTA))
initialEstimate.insert(X(1), pose_1.compose(DELTA))
elif i >= 2: # Add more poses as necessary
pose_i = scenario.pose(t)
initialEstimate.insert(X(i), pose_i.compose(DELTA))
if i > 0:
# Add Bias variables periodically
if i % 5 == 0:
biasKey += 1
factor = gtsam.BetweenFactorConstantBias(
biasKey - 1, biasKey, gtsam.imuBias_ConstantBias(), BIAS_COVARIANCE)
newgraph.add(factor)
initialEstimate.insert(biasKey, gtsam.imuBias_ConstantBias())
# Predict acceleration and gyro measurements in (actual) body frame
nRb = scenario.rotation(t).matrix()
bRn = np.transpose(nRb)
measuredAcc = scenario.acceleration_b(t) - np.dot(bRn, n_gravity)
measuredOmega = scenario.omega_b(t)
accum.integrateMeasurement(measuredAcc, measuredOmega, delta_t)
# Add Imu Factor
imufac = gtsam.ImuFactor(
X(i - 1), V(i - 1), X(i), V(i), biasKey, accum)
newgraph.add(imufac)
# insert new velocity, which is wrong
initialEstimate.insert(V(i), n_velocity)
accum.resetIntegration()
# Incremental solution
isam.update(newgraph, initialEstimate)
result = isam.calculateEstimate()
ISAM2_plot(result)
# reset
newgraph = gtsam.NonlinearFactorGraph()
initialEstimate.clear()
if __name__ == '__main__':
IMU_example()

View File

@ -0,0 +1,36 @@
import math
import unittest
import numpy as np
import gtsam
class TestScenario(unittest.TestCase):
def setUp(self):
pass
def test_loop(self):
# Forward velocity 2m/s
# Pitch up with angular velocity 6 degree/sec (negative in FLU)
v = 2
w = math.radians(6)
W = np.array([0, -w, 0])
V = np.array([v, 0, 0])
scenario = gtsam.ConstantTwistScenario(W, V)
T = 30
np.testing.assert_almost_equal(W, scenario.omega_b(T))
np.testing.assert_almost_equal(V, scenario.velocity_b(T))
np.testing.assert_almost_equal(
np.cross(W, V), scenario.acceleration_b(T))
# R = v/w, so test if loop crests at 2*R
R = v / w
T30 = scenario.pose(T)
np.testing.assert_almost_equal(
np.array([math.pi, 0, math.pi]), T30.rotation().xyz())
self.assert_(gtsam.Point3(0, 0, 2 * R).equals(T30.translation(), 1e-9))
if __name__ == '__main__':
unittest.main()

View File

@ -0,0 +1,136 @@
#include <gtsam/geometry/SimpleCamera.h>
#include <gtsam/inference/Symbol.h>
#include <gtsam/navigation/ImuBias.h>
#include <gtsam/navigation/ImuFactor.h>
#include <gtsam/navigation/Scenario.h>
#include <gtsam/nonlinear/ISAM2.h>
#include <gtsam/slam/BetweenFactor.h>
#include <gtsam/slam/PriorFactor.h>
#include <vector>
using namespace std;
using namespace gtsam;
// Shorthand for velocity and pose variables
using symbol_shorthand::V;
using symbol_shorthand::X;
const double kGravity = 9.81;
/* ************************************************************************* */
int main(int argc, char* argv[]) {
auto params = PreintegrationParams::MakeSharedU(kGravity);
params->setAccelerometerCovariance(I_3x3 * 0.1);
params->setGyroscopeCovariance(I_3x3 * 0.1);
params->setIntegrationCovariance(I_3x3 * 0.1);
params->setUse2ndOrderCoriolis(false);
params->setOmegaCoriolis(Vector3(0, 0, 0));
Pose3 delta(Rot3::Rodrigues(-0.1, 0.2, 0.25), Point3(0.05, -0.10, 0.20));
// Start with a camera on x-axis looking at origin
double radius = 30;
const Point3 up(0, 0, 1), target(0, 0, 0);
const Point3 position(radius, 0, 0);
const SimpleCamera camera = SimpleCamera::Lookat(position, target, up);
const auto pose_0 = camera.pose();
// Now, create a constant-twist scenario that makes the camera orbit the
// origin
double angular_velocity = M_PI, // rad/sec
delta_t = 1.0 / 18; // makes for 10 degrees per step
Vector3 angular_velocity_vector(0, -angular_velocity, 0);
Vector3 linear_velocity_vector(radius * angular_velocity, 0, 0);
auto scenario = ConstantTwistScenario(angular_velocity_vector,
linear_velocity_vector, pose_0);
// Create a factor graph
NonlinearFactorGraph newgraph;
// Create (incremental) ISAM2 solver
ISAM2 isam;
// Create the initial estimate to the solution
// Intentionally initialize the variables off from the ground truth
Values initialEstimate, totalEstimate, result;
// Add a prior on pose x0. This indirectly specifies where the origin is.
// 30cm std on x,y,z 0.1 rad on roll,pitch,yaw
auto noise = noiseModel::Diagonal::Sigmas(
(Vector(6) << Vector3::Constant(0.3), Vector3::Constant(0.1)).finished());
newgraph.push_back(PriorFactor<Pose3>(X(0), pose_0, noise));
// Add imu priors
Key biasKey = Symbol('b', 0);
auto biasnoise = noiseModel::Diagonal::Sigmas(Vector6::Constant(0.1));
PriorFactor<imuBias::ConstantBias> biasprior(biasKey, imuBias::ConstantBias(),
biasnoise);
newgraph.push_back(biasprior);
initialEstimate.insert(biasKey, imuBias::ConstantBias());
auto velnoise = noiseModel::Diagonal::Sigmas(Vector3(0.1, 0.1, 0.1));
Vector n_velocity(3);
n_velocity << 0, angular_velocity * radius, 0;
PriorFactor<Vector> velprior(V(0), n_velocity, velnoise);
newgraph.push_back(velprior);
initialEstimate.insert(V(0), n_velocity);
// IMU preintegrator
PreintegratedImuMeasurements accum(params);
// Simulate poses and imu measurements, adding them to the factor graph
for (size_t i = 0; i < 36; ++i) {
double t = i * delta_t;
if (i == 0) { // First time add two poses
auto pose_1 = scenario.pose(delta_t);
initialEstimate.insert(X(0), pose_0.compose(delta));
initialEstimate.insert(X(1), pose_1.compose(delta));
} else if (i >= 2) { // Add more poses as necessary
auto pose_i = scenario.pose(t);
initialEstimate.insert(X(i), pose_i.compose(delta));
}
if (i > 0) {
// Add Bias variables periodically
if (i % 5 == 0) {
biasKey++;
Symbol b1 = biasKey - 1;
Symbol b2 = biasKey;
Vector6 covvec;
covvec << 0.1, 0.1, 0.1, 0.1, 0.1, 0.1;
auto cov = noiseModel::Diagonal::Variances(covvec);
Vector6 zerovec;
zerovec << 0, 0, 0, 0, 0, 0;
auto f = boost::make_shared<BetweenFactor<imuBias::ConstantBias> >(
b1, b2, imuBias::ConstantBias(), cov);
newgraph.add(f);
initialEstimate.insert(biasKey, imuBias::ConstantBias());
}
// Predict acceleration and gyro measurements in (actual) body frame
auto measuredAcc = scenario.acceleration_b(t) -
scenario.rotation(t).transpose() * params->n_gravity;
auto measuredOmega = scenario.omega_b(t);
accum.integrateMeasurement(measuredAcc, measuredOmega, delta_t);
// Add Imu Factor
ImuFactor imufac(X(i - 1), V(i - 1), X(i), V(i), biasKey, accum);
newgraph.add(imufac);
// insert new velocity, which is wrong
initialEstimate.insert(V(i), n_velocity);
accum.resetIntegration();
}
// Incremental solution
isam.update(newgraph, initialEstimate);
result = isam.calculateEstimate();
newgraph = NonlinearFactorGraph();
initialEstimate.clear();
}
GTSAM_PRINT(result);
return 0;
}
/* ************************************************************************* */

61
gtsam.h
View File

@ -568,7 +568,7 @@ class Pose2 {
static gtsam::Pose2 Expmap(Vector v);
static Vector Logmap(const gtsam::Pose2& p);
Matrix AdjointMap() const;
Vector Adjoint(const Vector& xi) const;
Vector Adjoint(Vector xi) const;
static Matrix wedge(double vx, double vy, double w);
// Group Actions on Point2
@ -865,7 +865,7 @@ class CalibratedCamera {
// Standard Constructors and Named Constructors
CalibratedCamera();
CalibratedCamera(const gtsam::Pose3& pose);
CalibratedCamera(const Vector& v);
CalibratedCamera(Vector v);
static gtsam::CalibratedCamera Level(const gtsam::Pose2& pose2, double height);
// Testable
@ -875,7 +875,7 @@ class CalibratedCamera {
// Manifold
static size_t Dim();
size_t dim() const;
gtsam::CalibratedCamera retract(const Vector& d) const;
gtsam::CalibratedCamera retract(Vector d) const;
Vector localCoordinates(const gtsam::CalibratedCamera& T2) const;
// Action on Point3
@ -911,7 +911,7 @@ class PinholeCamera {
CALIBRATION calibration() const;
// Manifold
This retract(const Vector& d) const;
This retract(Vector d) const;
Vector localCoordinates(const This& T2) const;
size_t dim() const;
static size_t Dim();
@ -950,7 +950,7 @@ virtual class SimpleCamera {
gtsam::Cal3_S2 calibration() const;
// Manifold
gtsam::SimpleCamera retract(const Vector& d) const;
gtsam::SimpleCamera retract(Vector d) const;
Vector localCoordinates(const gtsam::SimpleCamera& T2) const;
size_t dim() const;
static size_t Dim();
@ -992,7 +992,7 @@ class StereoCamera {
gtsam::Cal3_S2Stereo calibration() const;
// Manifold
gtsam::StereoCamera retract(const Vector& d) const;
gtsam::StereoCamera retract(Vector d) const;
Vector localCoordinates(const gtsam::StereoCamera& T2) const;
size_t dim() const;
static size_t Dim();
@ -1227,12 +1227,12 @@ virtual class Diagonal : gtsam::noiseModel::Gaussian {
};
virtual class Constrained : gtsam::noiseModel::Diagonal {
static gtsam::noiseModel::Constrained* MixedSigmas(const Vector& mu, const Vector& sigmas);
static gtsam::noiseModel::Constrained* MixedSigmas(double m, const Vector& sigmas);
static gtsam::noiseModel::Constrained* MixedVariances(const Vector& mu, const Vector& variances);
static gtsam::noiseModel::Constrained* MixedVariances(const Vector& variances);
static gtsam::noiseModel::Constrained* MixedPrecisions(const Vector& mu, const Vector& precisions);
static gtsam::noiseModel::Constrained* MixedPrecisions(const Vector& precisions);
static gtsam::noiseModel::Constrained* MixedSigmas(Vector mu, Vector sigmas);
static gtsam::noiseModel::Constrained* MixedSigmas(double m, Vector sigmas);
static gtsam::noiseModel::Constrained* MixedVariances(Vector mu, Vector variances);
static gtsam::noiseModel::Constrained* MixedVariances(Vector variances);
static gtsam::noiseModel::Constrained* MixedPrecisions(Vector mu, Vector precisions);
static gtsam::noiseModel::Constrained* MixedPrecisions(Vector precisions);
static gtsam::noiseModel::Constrained* All(size_t dim);
static gtsam::noiseModel::Constrained* All(size_t dim, double mu);
@ -1415,12 +1415,12 @@ virtual class JacobianFactor : gtsam::GaussianFactor {
pair<Matrix, Vector> jacobianUnweighted() const;
Matrix augmentedJacobianUnweighted() const;
void transposeMultiplyAdd(double alpha, const Vector& e, gtsam::VectorValues& x) const;
void transposeMultiplyAdd(double alpha, Vector e, gtsam::VectorValues& x) const;
gtsam::JacobianFactor whiten() const;
pair<gtsam::GaussianConditional*, gtsam::JacobianFactor*> eliminate(const gtsam::Ordering& keys) const;
void setModel(bool anyConstrained, const Vector& sigmas);
void setModel(bool anyConstrained, Vector sigmas);
gtsam::noiseModel::Diagonal* get_model() const;
@ -2665,10 +2665,12 @@ virtual class Rot3AttitudeFactor : gtsam::NonlinearFactor{
gtsam::Unit3 bRef() const;
};
virtual class Pose3AttitudeFactor : gtsam::NonlinearFactor{
Pose3AttitudeFactor(size_t key, const gtsam::Unit3& nZ, const gtsam::noiseModel::Diagonal* model,
const gtsam::Unit3& bRef);
Pose3AttitudeFactor(size_t key, const gtsam::Unit3& nZ, const gtsam::noiseModel::Diagonal* model);
virtual class Pose3AttitudeFactor : gtsam::NonlinearFactor {
Pose3AttitudeFactor(size_t key, const gtsam::Unit3& nZ,
const gtsam::noiseModel::Diagonal* model,
const gtsam::Unit3& bRef);
Pose3AttitudeFactor(size_t key, const gtsam::Unit3& nZ,
const gtsam::noiseModel::Diagonal* model);
Pose3AttitudeFactor();
void print(string s) const;
bool equals(const gtsam::NonlinearFactor& expected, double tol) const;
@ -2677,24 +2679,27 @@ virtual class Pose3AttitudeFactor : gtsam::NonlinearFactor{
};
#include <gtsam/navigation/Scenario.h>
virtual class Scenario {};
virtual class ConstantTwistScenario : gtsam::Scenario {
ConstantTwistScenario(const Vector& w, const Vector& v);
virtual class Scenario {
gtsam::Pose3 pose(double t) const;
Vector omega_b(double t) const;
Vector velocity_n(double t) const;
Vector acceleration_n(double t) const;
gtsam::Rot3 rotation(double t) const;
gtsam::NavState navState(double t) const;
Vector velocity_b(double t) const;
Vector acceleration_b(double t) const;
};
virtual class ConstantTwistScenario : gtsam::Scenario {
ConstantTwistScenario(Vector w, Vector v);
ConstantTwistScenario(Vector w, Vector v,
const Pose3& nTb0);
};
virtual class AcceleratingScenario : gtsam::Scenario {
AcceleratingScenario(const gtsam::Rot3& nRb, const gtsam::Point3& p0,
const Vector& v0, const Vector& a_n,
const Vector& omega_b);
gtsam::Pose3 pose(double t) const;
Vector omega_b(double t) const;
Vector velocity_n(double t) const;
Vector acceleration_n(double t) const;
Vector v0, Vector a_n,
Vector omega_b);
};
//*************************************************************************

View File

@ -57,10 +57,13 @@ class Scenario {
class ConstantTwistScenario : public Scenario {
public:
/// Construct scenario with constant twist [w,v]
ConstantTwistScenario(const Vector3& w, const Vector3& v)
: twist_((Vector6() << w, v).finished()), a_b_(w.cross(v)) {}
ConstantTwistScenario(const Vector3& w, const Vector3& v,
const Pose3& nTb0 = Pose3())
: twist_((Vector6() << w, v).finished()), a_b_(w.cross(v)), nTb0_(nTb0) {}
Pose3 pose(double t) const override { return Pose3::Expmap(twist_ * t); }
Pose3 pose(double t) const override {
return nTb0_ * Pose3::Expmap(twist_ * t);
}
Vector3 omega_b(double t) const override { return twist_.head<3>(); }
Vector3 velocity_n(double t) const override {
return rotation(t).matrix() * twist_.tail<3>();
@ -70,6 +73,7 @@ class ConstantTwistScenario : public Scenario {
private:
const Vector6 twist_;
const Vector3 a_b_; // constant centripetal acceleration in body = w_b * v_b
const Pose3 nTb0_;
};
/// Accelerating from an arbitrary initial state, with optional rotation

View File

@ -15,8 +15,8 @@
* @author Frank Dellaert
*/
#include <gtsam/navigation/Scenario.h>
#include <gtsam/base/numericalDerivative.h>
#include <gtsam/navigation/Scenario.h>
#include <CppUnitLite/TestHarness.h>
#include <boost/bind.hpp>
@ -96,9 +96,33 @@ TEST(Scenario, Loop) {
const double R = v / w;
const Pose3 T30 = scenario.pose(30);
EXPECT(assert_equal(Rot3::Rodrigues(0, M_PI, 0), T30.rotation(), 1e-9));
EXPECT(assert_equal(Vector3(M_PI, 0, M_PI), T30.rotation().xyz()));
EXPECT(assert_equal(Point3(0, 0, 2 * R), T30.translation(), 1e-9));
}
/* ************************************************************************* */
TEST(Scenario, LoopWithInitialPose) {
// Forward velocity 2m/s
// Pitch up with angular velocity 6 kDegree/sec (negative in FLU)
const double v = 2, w = 6 * kDegree;
const Vector3 W(0, -w, 0), V(v, 0, 0);
const Rot3 nRb0 = Rot3::yaw(M_PI);
const Pose3 nTb0(nRb0, Point3(1, 2, 3));
const ConstantTwistScenario scenario(W, V, nTb0);
const double T = 30;
EXPECT(assert_equal(W, scenario.omega_b(T), 1e-9));
EXPECT(assert_equal(V, scenario.velocity_b(T), 1e-9));
EXPECT(assert_equal(W.cross(V), scenario.acceleration_b(T), 1e-9));
// R = v/w, so test if loop crests at 2*R
const double R = v / w;
const Pose3 T30 = scenario.pose(30);
EXPECT(
assert_equal(nRb0 * Rot3::Rodrigues(0, M_PI, 0), T30.rotation(), 1e-9));
EXPECT(assert_equal(Point3(1, 2, 3 + 2 * R), T30.translation(), 1e-9));
}
/* ************************************************************************* */
TEST(Scenario, Accelerating) {
// Set up body pointing towards y axis, and start at 10,20,0 with velocity