added IMU example, still debugging

release/4.3a0
Luca 2016-06-07 19:57:34 -04:00
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/*
@author Garrett (ghemann@gmail.com), Luca Carlone
@date 08.13.15
@brief Test example for using GTSAM ImuFactor and ImuCombinedFactor navigation code.
*/
// Standard includes.
#include <fstream>
#include <iostream>
// GTSAM related includes.
#include <gtsam/slam/dataset.h>
#include <gtsam/inference/Symbol.h>
#include <gtsam/navigation/CombinedImuFactor.h>
#include <gtsam/navigation/GPSFactor.h>
#include <gtsam/navigation/ImuFactor.h>
#include <gtsam/nonlinear/LevenbergMarquardtOptimizer.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/slam/BetweenFactor.h>
#include <gtsam/slam/PriorFactor.h>
// A row starting with i is the first inital position formatted with
// N, E, D, qx, qY, qZ, qW, velN, velE, velD
// A row starting with a 0 is an imu measurement
// linAccN, linAccE, linAccD, angVelN, angVelE, angVelD
// A row starting with a 1 is a gps correction formatted with
// N, E, D, qX, qY, qZ, qW
// Note that for correction, we're only using the point not the rotation. The
// rotation is provided for ground truth comparison.
// Uncomment line below to use the CombinedIMUFactor as opposed to the standard ImuFactor.
#define USE_COMBINED
using namespace gtsam;
using namespace Eigen;
using namespace std;
using symbol_shorthand::X; // Pose3 (x,y,z,r,p,y)
using symbol_shorthand::V; // Vel (xdot,ydot,zdot)
using symbol_shorthand::B; // Bias (ax,ay,az,gx,gy,gz)
const string output_filename = "imuFactorExampleResults.csv";
// This will either be PreintegratedImuMeasurements (for ImuFactor) or
// PreintegratedCombinedMeasurements (for CombinedImuFactor).
PreintegrationType *imu_preintegrated_;
int main(int argc, char* argv[])
{
string data_filename;
if (argc < 2) {
printf("using default CSV file\n");
data_filename = findExampleDataFile("imuAndGPSdata.csv");
} else {
data_filename = argv[1];
}
printf("1\n");
// Set up output file for plotting errors
FILE* fp_out = fopen(output_filename.c_str(), "w+");
printf("2\n");
fprintf(fp_out, "#time(s),x(m),y(m),z(m),qx,qy,qz,qw,gt_x(m),gt_y(m),gt_z(m),gt_qx,gt_qy,gt_qz,gt_qw\n");
// Begin parsing the CSV file. Input the first line for initialization.
// From there, we'll iterate through the file and we'll preintegrate the IMU
// or add in the GPS given the input.
std::ifstream file(data_filename.c_str());
std::string value;
// Format is (N,E,D,qX,qY,qZ,qW,velN,velE,velD)
Eigen::Matrix<double,10,1> initial_state = Eigen::Matrix<double,10,1>::Zero();
getline(file, value, ','); // i
for (int i=0; i<9; i++) {
getline(file, value, ',');
initial_state(i) = std::atof(value.c_str());
}
getline(file, value, '\n');
initial_state(9) = std::atof(value.c_str());
std::cout << "initial state:\n" << initial_state << "\n\n";
// Assemble initial quaternion through gtsam constructor ::quaternion(w,x,y,z);
Rot3 prior_rotation = Rot3::Quaternion(initial_state(6), initial_state(3),
initial_state(4), initial_state(5));
Point3 prior_point(initial_state.head<3>());
Pose3 prior_pose(prior_rotation, prior_point);
Vector3 prior_velocity(initial_state.tail<3>());
imuBias::ConstantBias prior_imu_bias; // assume zero initial bias
Values initial_values;
int correction_count = 0;
initial_values.insert(X(correction_count), prior_pose);
initial_values.insert(V(correction_count), prior_velocity);
initial_values.insert(B(correction_count), prior_imu_bias);
// Assemble prior noise model and add it the graph.
noiseModel::Diagonal::shared_ptr pose_noise_model = noiseModel::Diagonal::Sigmas((Vector(6) << 0.01, 0.01, 0.01, 0.5, 0.5, 0.5).finished()); // m, m, m, deg, deg, deg
noiseModel::Diagonal::shared_ptr velocity_noise_model = noiseModel::Diagonal::Sigmas((Vector(3) << 0.1, 0.1, 0.1).finished()); // m/s
noiseModel::Diagonal::shared_ptr bias_noise_model = noiseModel::Diagonal::Sigmas((Vector(6) << 0.001, 0.001, 0.001, 0.001, 0.001, 0.001).finished());
// Add all prior factors (pose, velocity, bias) to the graph.
NonlinearFactorGraph *graph = new NonlinearFactorGraph();
graph->add(PriorFactor<Pose3>(X(correction_count), prior_pose, pose_noise_model));
graph->add(PriorFactor<Vector3>(V(correction_count), prior_velocity,
velocity_noise_model));
graph->add(PriorFactor<imuBias::ConstantBias>(B(correction_count), prior_imu_bias,
bias_noise_model));
// We use the sensor specs to build the noise model for the IMU factor.
double accel_noise_sigma = 0.0003924;
double gyro_noise_sigma = 0.000205689024915;
double accel_bias_rw_sigma = 0.004905;
double gyro_bias_rw_sigma = 0.000001454441043;
Matrix3d measured_acc_cov = Matrix3d::Identity(3,3) * std::pow(accel_noise_sigma,2);
Matrix3d measured_omega_cov = Matrix3d::Identity(3,3) * std::pow(gyro_noise_sigma,2);
Matrix3d integration_error_cov = Matrix3d::Identity(3,3)*100000; // ?
Matrix3d bias_acc_cov = Matrix3d::Identity(3,3) * std::pow(accel_bias_rw_sigma,2);
Matrix3d bias_omega_cov = Matrix3d::Identity(3,3) * std::pow(gyro_bias_rw_sigma,2);
Eigen::Matrix<double,6,6> bias_acc_omega_int = MatrixXd::Identity(6,6)*0.001; // ?
//#ifdef USE_COMBINED
boost::shared_ptr<PreintegratedCombinedMeasurements::Params> p = PreintegratedCombinedMeasurements::Params::MakeSharedD(0.0);
// PreintegrationBase params:
p->accelerometerCovariance = measured_acc_cov; // acc white noise in continuous
p->integrationCovariance = integration_error_cov; // integration uncertainty continuous
// should be using 2nd order integration
// PreintegratedRotation params:
p->gyroscopeCovariance = measured_omega_cov; // gyro white noise in continuous
// PreintegrationCombinedMeasurements params:
p->biasAccCovariance = bias_acc_cov; // acc bias in continuous
p->biasOmegaCovariance = bias_omega_cov; // gyro bias in continuous
p->biasAccOmegaInt = bias_acc_omega_int;
#ifdef USE_COMBINED
imu_preintegrated_ = new PreintegratedCombinedMeasurements(p, prior_imu_bias);
#else
imu_preintegrated_ = new PreintegratedImuMeasurements(p, prior_imu_bias);
#endif
// Store previous state for the imu integration and the latest predicted outcome.
NavState prev_state(prior_pose, prior_velocity);
NavState prop_state = prev_state;
imuBias::ConstantBias prev_bias = prior_imu_bias;
// Keep track of the total error over the entire run for a simple performance metric.
double pose_error_sum = 0.0, orientation_error_sum = 0.0;
double output_time = 0.0;
double dt = 0.005; // The real system has noise, but here, results are nearly
// exactly the same, so keeping this for simplicity.
// All priors have been set up, now iterate through the data file.
while (file.good()) {
// Parse out first value
getline(file, value, ',');
int type = std::atoi(value.c_str());
if (type == 0) { // IMU measurement
Eigen::Matrix<double,6,1> imu = Eigen::Matrix<double,6,1>::Zero();
for (int i=0; i<5; ++i) {
getline(file, value, ',');
imu(i) = std::atof(value.c_str());
}
getline(file, value, '\n');
imu(5) = std::atof(value.c_str());
// Adding the IMU preintegration.
imu_preintegrated_->integrateMeasurement(imu.head<3>(), imu.tail<3>(), dt);
prop_state = imu_preintegrated_->predict(prev_state, prev_bias);
} else if (type == 1) { // GPS measurement
Eigen::Matrix<double,7,1> gps = Eigen::Matrix<double,7,1>::Zero();
for (int i=0; i<6; ++i) {
getline(file, value, ',');
gps(i) = std::atof(value.c_str());
}
getline(file, value, '\n');
gps(6) = std::atof(value.c_str());
correction_count++;
// Adding IMU factor and GPS factor and optimizing.
#ifdef USE_COMBINED
PreintegratedCombinedMeasurements *preint_imu_combined = dynamic_cast<PreintegratedCombinedMeasurements*>(imu_preintegrated_);
CombinedImuFactor imu_factor(X(correction_count-1), V(correction_count-1),
X(correction_count ), V(correction_count ),
B(correction_count-1), B(correction_count ),
*preint_imu_combined);
graph->add(imu_factor);
#else
PreintegratedImuMeasurements *preint_imu = dynamic_cast<PreintegratedImuMeasurements*>(imu_preintegrated_);
ImuFactor imu_factor(X(correction_count-1), V(correction_count-1),
X(correction_count ), V(correction_count ),
B(correction_count-1),
*preint_imu);
graph->add(imu_factor);
imuBias::ConstantBias zero_bias(Vector3(0, 0, 0), Vector3(0, 0, 0));
graph->add(BetweenFactor<imuBias::ConstantBias>(B(correction_count-1),
B(correction_count ),
zero_bias, bias_noise_model));
#endif
noiseModel::Diagonal::shared_ptr correction_noise = noiseModel::Diagonal::Variances((Vector(3) << 1, 1, 1).finished());
GPSFactor gps_factor(X(correction_count),
Point3(gps(0), // N,
gps(1), // E,
gps(2)), // D,
correction_noise);
graph->add(gps_factor);
// Now optimize and compare results.
initial_values.insert(X(correction_count), prop_state.pose());
initial_values.insert(V(correction_count), prop_state.v());
initial_values.insert(B(correction_count), prev_bias);
LevenbergMarquardtOptimizer optimizer(*graph, initial_values);
Values result = optimizer.optimize();
// Overwrite the beginning of the preintegration for the next step.
prev_state = NavState(result.at<Pose3>(X(correction_count)),
result.at<Vector3>(V(correction_count)));
prev_bias = result.at<imuBias::ConstantBias>(B(correction_count));
// Reset the preintegration object.
imu_preintegrated_->resetIntegrationAndSetBias(prev_bias);
//prev_bias.print();
// Print out the position and orientation error for comparison.
Vector3d gtsam_pose = prev_state.pose().translation().vector();
Quaterniond gtsam_quat = prev_state.pose().rotation().toQuaternion();
Quaterniond gps_quat(gps(6), gps(3), gps(4), gps(5));
Vector3d position_error = gtsam_pose - gps.head<3>();
Quaterniond quat_error = gtsam_quat * gps_quat.inverse();
quat_error.normalize();
Vector3d euler_angle_error(quat_error.x()*2,
quat_error.y()*2,
quat_error.z()*2);
pose_error_sum += position_error.norm();
orientation_error_sum += euler_angle_error.norm();
std::cout << pose_error_sum << "\t " << orientation_error_sum << "\n";
//std::cout << "For correction " << correction_count-1 << ", pose error is:\n" << position_error << "\n(in meters, NED), and quaternion error is:\n" << euler_angle_error*(180/M_PI) << "\n(in degrees)\n\n";
fprintf(fp_out, "%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f\n",
output_time, gtsam_pose(0), gtsam_pose(1), gtsam_pose(2),
gtsam_quat.x(), gtsam_quat.y(), gtsam_quat.z(), gtsam_quat.w(),
gps(0), gps(1), gps(2),
gps_quat.x(), gps_quat.y(), gps_quat.z(), gps_quat.w());
output_time += 1.0;
} else {
std::cerr << "ERROR parsing file\n";
return 1;
}
}
fclose(fp_out);
std::cout << "Complete, results written to " << output_filename << "\n\n";;
return 0;
}