diff --git a/examples/IMUKittiExampleGPS.cpp b/examples/IMUKittiExampleGPS.cpp index e2ca49647..cb60b2516 100644 --- a/examples/IMUKittiExampleGPS.cpp +++ b/examples/IMUKittiExampleGPS.cpp @@ -11,21 +11,23 @@ /** * @file IMUKittiExampleGPS - * @brief Example of application of ISAM2 for GPS-aided navigation on the KITTI VISION BENCHMARK SUITE - * @author Ported by Thomas Jespersen (thomasj@tkjelectronics.dk), TKJ Electronics + * @brief Example of application of ISAM2 for GPS-aided navigation on the KITTI + * VISION BENCHMARK SUITE + * @author Ported by Thomas Jespersen (thomasj@tkjelectronics.dk), TKJ + * Electronics */ // GTSAM related includes. +#include #include #include #include -#include -#include -#include #include #include #include -#include +#include +#include +#include #include #include @@ -34,35 +36,35 @@ using namespace std; using namespace gtsam; -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) +using symbol_shorthand::V; // Vel (xdot,ydot,zdot) +using symbol_shorthand::X; // Pose3 (x,y,z,r,p,y) struct KittiCalibration { - double body_ptx; - double body_pty; - double body_ptz; - double body_prx; - double body_pry; - double body_prz; - double accelerometer_sigma; - double gyroscope_sigma; - double integration_sigma; - double accelerometer_bias_sigma; - double gyroscope_bias_sigma; - double average_delta_t; + double body_ptx; + double body_pty; + double body_ptz; + double body_prx; + double body_pry; + double body_prz; + double accelerometer_sigma; + double gyroscope_sigma; + double integration_sigma; + double accelerometer_bias_sigma; + double gyroscope_bias_sigma; + double average_delta_t; }; struct ImuMeasurement { - double time; - double dt; - Vector3 accelerometer; - Vector3 gyroscope; // omega + double time; + double dt; + Vector3 accelerometer; + Vector3 gyroscope; // omega }; struct GpsMeasurement { - double time; - Vector3 position; // x,y,z + double time; + Vector3 position; // x,y,z }; const string output_filename = "IMUKittiExampleGPSResults.csv"; @@ -70,290 +72,313 @@ const string output_filename = "IMUKittiExampleGPSResults.csv"; void loadKittiData(KittiCalibration& kitti_calibration, vector& imu_measurements, vector& gps_measurements) { - string line; + string line; - // Read IMU metadata and compute relative sensor pose transforms - // BodyPtx BodyPty BodyPtz BodyPrx BodyPry BodyPrz AccelerometerSigma GyroscopeSigma IntegrationSigma - // AccelerometerBiasSigma GyroscopeBiasSigma AverageDeltaT - string imu_metadata_file = findExampleDataFile("KittiEquivBiasedImu_metadata.txt"); - ifstream imu_metadata(imu_metadata_file.c_str()); + // Read IMU metadata and compute relative sensor pose transforms + // BodyPtx BodyPty BodyPtz BodyPrx BodyPry BodyPrz AccelerometerSigma + // GyroscopeSigma IntegrationSigma AccelerometerBiasSigma GyroscopeBiasSigma + // AverageDeltaT + string imu_metadata_file = + findExampleDataFile("KittiEquivBiasedImu_metadata.txt"); + ifstream imu_metadata(imu_metadata_file.c_str()); - printf("-- Reading sensor metadata\n"); + printf("-- Reading sensor metadata\n"); - getline(imu_metadata, line, '\n'); // ignore the first line + getline(imu_metadata, line, '\n'); // ignore the first line - // Load Kitti calibration - getline(imu_metadata, line, '\n'); - sscanf(line.c_str(), "%lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf", - &kitti_calibration.body_ptx, - &kitti_calibration.body_pty, - &kitti_calibration.body_ptz, - &kitti_calibration.body_prx, - &kitti_calibration.body_pry, - &kitti_calibration.body_prz, - &kitti_calibration.accelerometer_sigma, - &kitti_calibration.gyroscope_sigma, - &kitti_calibration.integration_sigma, - &kitti_calibration.accelerometer_bias_sigma, - &kitti_calibration.gyroscope_bias_sigma, - &kitti_calibration.average_delta_t); - printf("IMU metadata: %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf\n", - kitti_calibration.body_ptx, - kitti_calibration.body_pty, - kitti_calibration.body_ptz, - kitti_calibration.body_prx, - kitti_calibration.body_pry, - kitti_calibration.body_prz, - kitti_calibration.accelerometer_sigma, - kitti_calibration.gyroscope_sigma, - kitti_calibration.integration_sigma, - kitti_calibration.accelerometer_bias_sigma, - kitti_calibration.gyroscope_bias_sigma, - kitti_calibration.average_delta_t); + // Load Kitti calibration + getline(imu_metadata, line, '\n'); + sscanf(line.c_str(), "%lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf", + &kitti_calibration.body_ptx, &kitti_calibration.body_pty, + &kitti_calibration.body_ptz, &kitti_calibration.body_prx, + &kitti_calibration.body_pry, &kitti_calibration.body_prz, + &kitti_calibration.accelerometer_sigma, + &kitti_calibration.gyroscope_sigma, + &kitti_calibration.integration_sigma, + &kitti_calibration.accelerometer_bias_sigma, + &kitti_calibration.gyroscope_bias_sigma, + &kitti_calibration.average_delta_t); + printf("IMU metadata: %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf\n", + kitti_calibration.body_ptx, kitti_calibration.body_pty, + kitti_calibration.body_ptz, kitti_calibration.body_prx, + kitti_calibration.body_pry, kitti_calibration.body_prz, + kitti_calibration.accelerometer_sigma, + kitti_calibration.gyroscope_sigma, kitti_calibration.integration_sigma, + kitti_calibration.accelerometer_bias_sigma, + kitti_calibration.gyroscope_bias_sigma, + kitti_calibration.average_delta_t); - // Read IMU data - // Time dt accelX accelY accelZ omegaX omegaY omegaZ - string imu_data_file = findExampleDataFile("KittiEquivBiasedImu.txt"); - printf("-- Reading IMU measurements from file\n"); - { - ifstream imu_data(imu_data_file.c_str()); - getline(imu_data, line, '\n'); // ignore the first line + // Read IMU data + // Time dt accelX accelY accelZ omegaX omegaY omegaZ + string imu_data_file = findExampleDataFile("KittiEquivBiasedImu.txt"); + printf("-- Reading IMU measurements from file\n"); + { + ifstream imu_data(imu_data_file.c_str()); + getline(imu_data, line, '\n'); // ignore the first line - double time = 0, dt = 0, acc_x = 0, acc_y = 0, acc_z = 0, gyro_x = 0, gyro_y = 0, gyro_z = 0; - while (!imu_data.eof()) { - getline(imu_data, line, '\n'); - sscanf(line.c_str(), "%lf %lf %lf %lf %lf %lf %lf %lf", - &time, &dt, - &acc_x, &acc_y, &acc_z, - &gyro_x, &gyro_y, &gyro_z); + double time = 0, dt = 0, acc_x = 0, acc_y = 0, acc_z = 0, gyro_x = 0, + gyro_y = 0, gyro_z = 0; + while (!imu_data.eof()) { + getline(imu_data, line, '\n'); + sscanf(line.c_str(), "%lf %lf %lf %lf %lf %lf %lf %lf", &time, &dt, + &acc_x, &acc_y, &acc_z, &gyro_x, &gyro_y, &gyro_z); - ImuMeasurement measurement; - measurement.time = time; - measurement.dt = dt; - measurement.accelerometer = Vector3(acc_x, acc_y, acc_z); - measurement.gyroscope = Vector3(gyro_x, gyro_y, gyro_z); - imu_measurements.push_back(measurement); - } + ImuMeasurement measurement; + measurement.time = time; + measurement.dt = dt; + measurement.accelerometer = Vector3(acc_x, acc_y, acc_z); + measurement.gyroscope = Vector3(gyro_x, gyro_y, gyro_z); + imu_measurements.push_back(measurement); } + } - // Read GPS data - // Time,X,Y,Z - string gps_data_file = findExampleDataFile("KittiGps_converted.txt"); - printf("-- Reading GPS measurements from file\n"); - { - ifstream gps_data(gps_data_file.c_str()); - getline(gps_data, line, '\n'); // ignore the first line + // Read GPS data + // Time,X,Y,Z + string gps_data_file = findExampleDataFile("KittiGps_converted.txt"); + printf("-- Reading GPS measurements from file\n"); + { + ifstream gps_data(gps_data_file.c_str()); + getline(gps_data, line, '\n'); // ignore the first line - double time = 0, gps_x = 0, gps_y = 0, gps_z = 0; - while (!gps_data.eof()) { - getline(gps_data, line, '\n'); - sscanf(line.c_str(), "%lf,%lf,%lf,%lf", &time, &gps_x, &gps_y, &gps_z); + double time = 0, gps_x = 0, gps_y = 0, gps_z = 0; + while (!gps_data.eof()) { + getline(gps_data, line, '\n'); + sscanf(line.c_str(), "%lf,%lf,%lf,%lf", &time, &gps_x, &gps_y, &gps_z); - GpsMeasurement measurement; - measurement.time = time; - measurement.position = Vector3(gps_x, gps_y, gps_z); - gps_measurements.push_back(measurement); - } + GpsMeasurement measurement; + measurement.time = time; + measurement.position = Vector3(gps_x, gps_y, gps_z); + gps_measurements.push_back(measurement); } + } } int main(int argc, char* argv[]) { - KittiCalibration kitti_calibration; - vector imu_measurements; - vector gps_measurements; - loadKittiData(kitti_calibration, imu_measurements, gps_measurements); + KittiCalibration kitti_calibration; + vector imu_measurements; + vector gps_measurements; + loadKittiData(kitti_calibration, imu_measurements, gps_measurements); - Vector6 BodyP = (Vector6() << kitti_calibration.body_ptx, kitti_calibration.body_pty, kitti_calibration.body_ptz, - kitti_calibration.body_prx, kitti_calibration.body_pry, kitti_calibration.body_prz) - .finished(); - auto body_T_imu = Pose3::Expmap(BodyP); - if (!body_T_imu.equals(Pose3(), 1e-5)) { - printf("Currently only support IMUinBody is identity, i.e. IMU and body frame are the same"); - exit(-1); - } + Vector6 BodyP = + (Vector6() << kitti_calibration.body_ptx, kitti_calibration.body_pty, + kitti_calibration.body_ptz, kitti_calibration.body_prx, + kitti_calibration.body_pry, kitti_calibration.body_prz) + .finished(); + auto body_T_imu = Pose3::Expmap(BodyP); + if (!body_T_imu.equals(Pose3(), 1e-5)) { + printf( + "Currently only support IMUinBody is identity, i.e. IMU and body frame " + "are the same"); + exit(-1); + } - // Configure different variables - // double t_offset = gps_measurements[0].time; - size_t first_gps_pose = 1; - size_t gps_skip = 10; // Skip this many GPS measurements each time - double g = 9.8; - auto w_coriolis = Vector3::Zero(); // zero vector + // Configure different variables + // double t_offset = gps_measurements[0].time; + size_t first_gps_pose = 1; + size_t gps_skip = 10; // Skip this many GPS measurements each time + double g = 9.8; + auto w_coriolis = Vector3::Zero(); // zero vector - // Configure noise models - auto noise_model_gps = noiseModel::Diagonal::Precisions((Vector6() << Vector3::Constant(0), - Vector3::Constant(1.0/0.07)) - .finished()); + // Configure noise models + auto noise_model_gps = noiseModel::Diagonal::Precisions( + (Vector6() << Vector3::Constant(0), Vector3::Constant(1.0 / 0.07)) + .finished()); - // Set initial conditions for the estimated trajectory - // initial pose is the reference frame (navigation frame) - auto current_pose_global = Pose3(Rot3(), gps_measurements[first_gps_pose].position); - // the vehicle is stationary at the beginning at position 0,0,0 - Vector3 current_velocity_global = Vector3::Zero(); - auto current_bias = imuBias::ConstantBias(); // init with zero bias + // Set initial conditions for the estimated trajectory + // initial pose is the reference frame (navigation frame) + auto current_pose_global = + Pose3(Rot3(), gps_measurements[first_gps_pose].position); + // the vehicle is stationary at the beginning at position 0,0,0 + Vector3 current_velocity_global = Vector3::Zero(); + auto current_bias = imuBias::ConstantBias(); // init with zero bias - auto sigma_init_x = noiseModel::Diagonal::Precisions((Vector6() << Vector3::Constant(0), - Vector3::Constant(1.0)) - .finished()); - auto sigma_init_v = noiseModel::Diagonal::Sigmas(Vector3::Constant(1000.0)); - auto sigma_init_b = noiseModel::Diagonal::Sigmas((Vector6() << Vector3::Constant(0.100), - Vector3::Constant(5.00e-05)) - .finished()); + auto sigma_init_x = noiseModel::Diagonal::Precisions( + (Vector6() << Vector3::Constant(0), Vector3::Constant(1.0)).finished()); + auto sigma_init_v = noiseModel::Diagonal::Sigmas(Vector3::Constant(1000.0)); + auto sigma_init_b = noiseModel::Diagonal::Sigmas( + (Vector6() << Vector3::Constant(0.100), Vector3::Constant(5.00e-05)) + .finished()); - // Set IMU preintegration parameters - Matrix33 measured_acc_cov = I_3x3 * pow(kitti_calibration.accelerometer_sigma, 2); - Matrix33 measured_omega_cov = I_3x3 * pow(kitti_calibration.gyroscope_sigma, 2); - // error committed in integrating position from velocities - Matrix33 integration_error_cov = I_3x3 * pow(kitti_calibration.integration_sigma, 2); + // Set IMU preintegration parameters + Matrix33 measured_acc_cov = + I_3x3 * pow(kitti_calibration.accelerometer_sigma, 2); + Matrix33 measured_omega_cov = + I_3x3 * pow(kitti_calibration.gyroscope_sigma, 2); + // error committed in integrating position from velocities + Matrix33 integration_error_cov = + I_3x3 * pow(kitti_calibration.integration_sigma, 2); - auto imu_params = PreintegratedImuMeasurements::Params::MakeSharedU(g); - imu_params->accelerometerCovariance = measured_acc_cov; // acc white noise in continuous - imu_params->integrationCovariance = integration_error_cov; // integration uncertainty continuous - imu_params->gyroscopeCovariance = measured_omega_cov; // gyro white noise in continuous - imu_params->omegaCoriolis = w_coriolis; + auto imu_params = PreintegratedImuMeasurements::Params::MakeSharedU(g); + imu_params->accelerometerCovariance = + measured_acc_cov; // acc white noise in continuous + imu_params->integrationCovariance = + integration_error_cov; // integration uncertainty continuous + imu_params->gyroscopeCovariance = + measured_omega_cov; // gyro white noise in continuous + imu_params->omegaCoriolis = w_coriolis; - std::shared_ptr current_summarized_measurement = nullptr; + std::shared_ptr current_summarized_measurement = + nullptr; - // Set ISAM2 parameters and create ISAM2 solver object - ISAM2Params isam_params; - isam_params.factorization = ISAM2Params::CHOLESKY; - isam_params.relinearizeSkip = 10; + // Set ISAM2 parameters and create ISAM2 solver object + ISAM2Params isam_params; + isam_params.factorization = ISAM2Params::CHOLESKY; + isam_params.relinearizeSkip = 10; - ISAM2 isam(isam_params); + ISAM2 isam(isam_params); - // Create the factor graph and values object that will store new factors and values to add to the incremental graph - NonlinearFactorGraph new_factors; - Values new_values; // values storing the initial estimates of new nodes in the factor graph + // Create the factor graph and values object that will store new factors and + // values to add to the incremental graph + NonlinearFactorGraph new_factors; + Values new_values; // values storing the initial estimates of new nodes in + // the factor graph - /// Main loop: - /// (1) we read the measurements - /// (2) we create the corresponding factors in the graph - /// (3) we solve the graph to obtain and optimal estimate of robot trajectory - printf("-- Starting main loop: inference is performed at each time step, but we plot trajectory every 10 steps\n"); - size_t j = 0; - for (size_t i = first_gps_pose; i < gps_measurements.size() - 1; i++) { - // At each non=IMU measurement we initialize a new node in the graph - auto current_pose_key = X(i); - auto current_vel_key = V(i); - auto current_bias_key = B(i); - double t = gps_measurements[i].time; + /// Main loop: + /// (1) we read the measurements + /// (2) we create the corresponding factors in the graph + /// (3) we solve the graph to obtain and optimal estimate of robot trajectory + printf( + "-- Starting main loop: inference is performed at each time step, but we " + "plot trajectory every 10 steps\n"); + size_t j = 0; + size_t included_imu_measurement_count = 0; - if (i == first_gps_pose) { - // Create initial estimate and prior on initial pose, velocity, and biases - new_values.insert(current_pose_key, current_pose_global); - new_values.insert(current_vel_key, current_velocity_global); - new_values.insert(current_bias_key, current_bias); - new_factors.emplace_shared>(current_pose_key, current_pose_global, sigma_init_x); - new_factors.emplace_shared>(current_vel_key, current_velocity_global, sigma_init_v); - new_factors.emplace_shared>(current_bias_key, current_bias, sigma_init_b); - } else { - double t_previous = gps_measurements[i-1].time; + for (size_t i = first_gps_pose; i < gps_measurements.size() - 1; i++) { + // At each non=IMU measurement we initialize a new node in the graph + auto current_pose_key = X(i); + auto current_vel_key = V(i); + auto current_bias_key = B(i); + double t = gps_measurements[i].time; - // Summarize IMU data between the previous GPS measurement and now - current_summarized_measurement = std::make_shared(imu_params, current_bias); - static size_t included_imu_measurement_count = 0; - while (j < imu_measurements.size() && imu_measurements[j].time <= t) { - if (imu_measurements[j].time >= t_previous) { - current_summarized_measurement->integrateMeasurement(imu_measurements[j].accelerometer, - imu_measurements[j].gyroscope, - imu_measurements[j].dt); - included_imu_measurement_count++; - } - j++; - } + if (i == first_gps_pose) { + // Create initial estimate and prior on initial pose, velocity, and biases + new_values.insert(current_pose_key, current_pose_global); + new_values.insert(current_vel_key, current_velocity_global); + new_values.insert(current_bias_key, current_bias); + new_factors.emplace_shared>( + current_pose_key, current_pose_global, sigma_init_x); + new_factors.emplace_shared>( + current_vel_key, current_velocity_global, sigma_init_v); + new_factors.emplace_shared>( + current_bias_key, current_bias, sigma_init_b); + } else { + double t_previous = gps_measurements[i - 1].time; - // Create IMU factor - auto previous_pose_key = X(i-1); - auto previous_vel_key = V(i-1); - auto previous_bias_key = B(i-1); + // Summarize IMU data between the previous GPS measurement and now + current_summarized_measurement = + std::make_shared(imu_params, + current_bias); - new_factors.emplace_shared(previous_pose_key, previous_vel_key, - current_pose_key, current_vel_key, - previous_bias_key, *current_summarized_measurement); - - // Bias evolution as given in the IMU metadata - auto sigma_between_b = noiseModel::Diagonal::Sigmas((Vector6() << - Vector3::Constant(sqrt(included_imu_measurement_count) * kitti_calibration.accelerometer_bias_sigma), - Vector3::Constant(sqrt(included_imu_measurement_count) * kitti_calibration.gyroscope_bias_sigma)) - .finished()); - new_factors.emplace_shared>(previous_bias_key, - current_bias_key, - imuBias::ConstantBias(), - sigma_between_b); - - // Create GPS factor - auto gps_pose = Pose3(current_pose_global.rotation(), gps_measurements[i].position); - if ((i % gps_skip) == 0) { - new_factors.emplace_shared>(current_pose_key, gps_pose, noise_model_gps); - new_values.insert(current_pose_key, gps_pose); - - printf("################ POSE INCLUDED AT TIME %lf ################\n", t); - cout << gps_pose.translation(); - printf("\n\n"); - } else { - new_values.insert(current_pose_key, current_pose_global); - } - - // Add initial values for velocity and bias based on the previous estimates - new_values.insert(current_vel_key, current_velocity_global); - new_values.insert(current_bias_key, current_bias); - - // Update solver - // ======================================================================= - // We accumulate 2*GPSskip GPS measurements before updating the solver at - // first so that the heading becomes observable. - if (i > (first_gps_pose + 2*gps_skip)) { - printf("################ NEW FACTORS AT TIME %lf ################\n", t); - new_factors.print(); - - isam.update(new_factors, new_values); - - // Reset the newFactors and newValues list - new_factors.resize(0); - new_values.clear(); - - // Extract the result/current estimates - Values result = isam.calculateEstimate(); - - current_pose_global = result.at(current_pose_key); - current_velocity_global = result.at(current_vel_key); - current_bias = result.at(current_bias_key); - - printf("\n################ POSE AT TIME %lf ################\n", t); - current_pose_global.print(); - printf("\n\n"); - } + while (j < imu_measurements.size() && imu_measurements[j].time <= t) { + if (imu_measurements[j].time >= t_previous) { + current_summarized_measurement->integrateMeasurement( + imu_measurements[j].accelerometer, imu_measurements[j].gyroscope, + imu_measurements[j].dt); + included_imu_measurement_count++; } + j++; + } + + // Create IMU factor + auto previous_pose_key = X(i - 1); + auto previous_vel_key = V(i - 1); + auto previous_bias_key = B(i - 1); + + new_factors.emplace_shared( + previous_pose_key, previous_vel_key, current_pose_key, + current_vel_key, previous_bias_key, *current_summarized_measurement); + + // Bias evolution as given in the IMU metadata + auto sigma_between_b = noiseModel::Diagonal::Sigmas( + (Vector6() << Vector3::Constant( + sqrt(included_imu_measurement_count) * + kitti_calibration.accelerometer_bias_sigma), + Vector3::Constant(sqrt(included_imu_measurement_count) * + kitti_calibration.gyroscope_bias_sigma)) + .finished()); + new_factors.emplace_shared>( + previous_bias_key, current_bias_key, imuBias::ConstantBias(), + sigma_between_b); + + // Create GPS factor + auto gps_pose = + Pose3(current_pose_global.rotation(), gps_measurements[i].position); + if ((i % gps_skip) == 0) { + new_factors.emplace_shared>( + current_pose_key, gps_pose, noise_model_gps); + new_values.insert(current_pose_key, gps_pose); + + printf("############ POSE INCLUDED AT TIME %.6lf ############\n", + t); + cout << gps_pose.translation(); + printf("\n\n"); + } else { + new_values.insert(current_pose_key, current_pose_global); + } + + // Add initial values for velocity and bias based on the previous + // estimates + new_values.insert(current_vel_key, current_velocity_global); + new_values.insert(current_bias_key, current_bias); + + // Update solver + // ======================================================================= + // We accumulate 2*GPSskip GPS measurements before updating the solver at + // first so that the heading becomes observable. + if (i > (first_gps_pose + 2 * gps_skip)) { + printf("############ NEW FACTORS AT TIME %.6lf ############\n", + t); + new_factors.print(); + + isam.update(new_factors, new_values); + + // Reset the newFactors and newValues list + new_factors.resize(0); + new_values.clear(); + + // Extract the result/current estimates + Values result = isam.calculateEstimate(); + + current_pose_global = result.at(current_pose_key); + current_velocity_global = result.at(current_vel_key); + current_bias = result.at(current_bias_key); + + printf("\n############ POSE AT TIME %lf ############\n", t); + current_pose_global.print(); + printf("\n\n"); + } } + } - // Save results to file - printf("\nWriting results to file...\n"); - FILE* fp_out = fopen(output_filename.c_str(), "w+"); - fprintf(fp_out, "#time(s),x(m),y(m),z(m),qx,qy,qz,qw,gt_x(m),gt_y(m),gt_z(m)\n"); + // Save results to file + printf("\nWriting results to file...\n"); + FILE* fp_out = fopen(output_filename.c_str(), "w+"); + fprintf(fp_out, + "#time(s),x(m),y(m),z(m),qx,qy,qz,qw,gt_x(m),gt_y(m),gt_z(m)\n"); - Values result = isam.calculateEstimate(); - for (size_t i = first_gps_pose; i < gps_measurements.size() - 1; i++) { - auto pose_key = X(i); - auto vel_key = V(i); - auto bias_key = B(i); + Values result = isam.calculateEstimate(); + for (size_t i = first_gps_pose; i < gps_measurements.size() - 1; i++) { + auto pose_key = X(i); + auto vel_key = V(i); + auto bias_key = B(i); - auto pose = result.at(pose_key); - auto velocity = result.at(vel_key); - auto bias = result.at(bias_key); + auto pose = result.at(pose_key); + auto velocity = result.at(vel_key); + auto bias = result.at(bias_key); - auto pose_quat = pose.rotation().toQuaternion(); - auto gps = gps_measurements[i].position; + auto pose_quat = pose.rotation().toQuaternion(); + auto gps = gps_measurements[i].position; - cout << "State at #" << i << endl; - cout << "Pose:" << endl << pose << endl; - cout << "Velocity:" << endl << velocity << endl; - cout << "Bias:" << endl << bias << endl; + cout << "State at #" << i << endl; + cout << "Pose:" << endl << pose << endl; + cout << "Velocity:" << endl << velocity << endl; + cout << "Bias:" << endl << bias << endl; - fprintf(fp_out, "%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f\n", - gps_measurements[i].time, - pose.x(), pose.y(), pose.z(), - pose_quat.x(), pose_quat.y(), pose_quat.z(), pose_quat.w(), - gps(0), gps(1), gps(2)); - } + fprintf(fp_out, "%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f\n", + gps_measurements[i].time, pose.x(), pose.y(), pose.z(), + pose_quat.x(), pose_quat.y(), pose_quat.z(), pose_quat.w(), gps(0), + gps(1), gps(2)); + } - fclose(fp_out); + fclose(fp_out); } diff --git a/python/gtsam/examples/IMUKittiExampleGPS.py b/python/gtsam/examples/IMUKittiExampleGPS.py new file mode 100644 index 000000000..8b6b4fdf0 --- /dev/null +++ b/python/gtsam/examples/IMUKittiExampleGPS.py @@ -0,0 +1,366 @@ +""" +Example of application of ISAM2 for GPS-aided navigation on the KITTI VISION BENCHMARK SUITE + +Author: Varun Agrawal +""" +import argparse +from typing import List, Tuple + +import gtsam +import numpy as np +from gtsam import ISAM2, Pose3, noiseModel +from gtsam.symbol_shorthand import B, V, X + +GRAVITY = 9.8 + + +class KittiCalibration: + """Class to hold KITTI calibration info.""" + def __init__(self, body_ptx: float, body_pty: float, body_ptz: float, + body_prx: float, body_pry: float, body_prz: float, + accelerometer_sigma: float, gyroscope_sigma: float, + integration_sigma: float, accelerometer_bias_sigma: float, + gyroscope_bias_sigma: float, average_delta_t: float): + self.bodyTimu = Pose3(gtsam.Rot3.RzRyRx(body_prx, body_pry, body_prz), + gtsam.Point3(body_ptx, body_pty, body_ptz)) + self.accelerometer_sigma = accelerometer_sigma + self.gyroscope_sigma = gyroscope_sigma + self.integration_sigma = integration_sigma + self.accelerometer_bias_sigma = accelerometer_bias_sigma + self.gyroscope_bias_sigma = gyroscope_bias_sigma + self.average_delta_t = average_delta_t + + +class ImuMeasurement: + """An instance of an IMU measurement.""" + def __init__(self, time: float, dt: float, accelerometer: gtsam.Point3, + gyroscope: gtsam.Point3): + self.time = time + self.dt = dt + self.accelerometer = accelerometer + self.gyroscope = gyroscope + + +class GpsMeasurement: + """An instance of a GPS measurement.""" + def __init__(self, time: float, position: gtsam.Point3): + self.time = time + self.position = position + + +def loadImuData(imu_data_file: str) -> List[ImuMeasurement]: + """Helper to load the IMU data.""" + # Read IMU data + # Time dt accelX accelY accelZ omegaX omegaY omegaZ + imu_data_file = gtsam.findExampleDataFile(imu_data_file) + imu_measurements = [] + + print("-- Reading IMU measurements from file") + with open(imu_data_file, encoding='UTF-8') as imu_data: + data = imu_data.readlines() + for i in range(1, len(data)): # ignore the first line + time, dt, acc_x, acc_y, acc_z, gyro_x, gyro_y, gyro_z = map( + float, data[i].split(' ')) + imu_measurement = ImuMeasurement( + time, dt, np.asarray([acc_x, acc_y, acc_z]), + np.asarray([gyro_x, gyro_y, gyro_z])) + imu_measurements.append(imu_measurement) + + return imu_measurements + + +def loadGpsData(gps_data_file: str) -> List[GpsMeasurement]: + """Helper to load the GPS data.""" + # Read GPS data + # Time,X,Y,Z + gps_data_file = gtsam.findExampleDataFile(gps_data_file) + gps_measurements = [] + + print("-- Reading GPS measurements from file") + with open(gps_data_file, encoding='UTF-8') as gps_data: + data = gps_data.readlines() + for i in range(1, len(data)): + time, x, y, z = map(float, data[i].split(',')) + gps_measurement = GpsMeasurement(time, np.asarray([x, y, z])) + gps_measurements.append(gps_measurement) + + return gps_measurements + + +def loadKittiData( + imu_data_file: str = "KittiEquivBiasedImu.txt", + gps_data_file: str = "KittiGps_converted.txt", + imu_metadata_file: str = "KittiEquivBiasedImu_metadata.txt" +) -> Tuple[KittiCalibration, List[ImuMeasurement], List[GpsMeasurement]]: + """ + Load the KITTI Dataset. + """ + # Read IMU metadata and compute relative sensor pose transforms + # BodyPtx BodyPty BodyPtz BodyPrx BodyPry BodyPrz AccelerometerSigma + # GyroscopeSigma IntegrationSigma AccelerometerBiasSigma GyroscopeBiasSigma + # AverageDeltaT + imu_metadata_file = gtsam.findExampleDataFile(imu_metadata_file) + with open(imu_metadata_file, encoding='UTF-8') as imu_metadata: + print("-- Reading sensor metadata") + line = imu_metadata.readline() # Ignore the first line + line = imu_metadata.readline().strip() + data = list(map(float, line.split(' '))) + kitti_calibration = KittiCalibration(*data) + print("IMU metadata:", data) + + imu_measurements = loadImuData(imu_data_file) + gps_measurements = loadGpsData(gps_data_file) + + return kitti_calibration, imu_measurements, gps_measurements + + +def getImuParams(kitti_calibration: KittiCalibration): + """Get the IMU parameters from the KITTI calibration data.""" + w_coriolis = np.zeros(3) + + # Set IMU preintegration parameters + measured_acc_cov = np.eye(3) * np.power( + kitti_calibration.accelerometer_sigma, 2) + measured_omega_cov = np.eye(3) * np.power( + kitti_calibration.gyroscope_sigma, 2) + # error committed in integrating position from velocities + integration_error_cov = np.eye(3) * np.power( + kitti_calibration.integration_sigma, 2) + + imu_params = gtsam.PreintegrationParams.MakeSharedU(GRAVITY) + # acc white noise in continuous + imu_params.setAccelerometerCovariance(measured_acc_cov) + # integration uncertainty continuous + imu_params.setIntegrationCovariance(integration_error_cov) + # gyro white noise in continuous + imu_params.setGyroscopeCovariance(measured_omega_cov) + imu_params.setOmegaCoriolis(w_coriolis) + + return imu_params + + +def save_results(isam: gtsam.ISAM2, output_filename: str, first_gps_pose: int, + gps_measurements: List[GpsMeasurement]): + """Write the results from `isam` to `output_filename`.""" + # Save results to file + print("Writing results to file...") + with open(output_filename, 'w', encoding='UTF-8') as fp_out: + fp_out.write( + "#time(s),x(m),y(m),z(m),qx,qy,qz,qw,gt_x(m),gt_y(m),gt_z(m)\n") + + result = isam.calculateEstimate() + for i in range(first_gps_pose, len(gps_measurements)): + pose_key = X(i) + vel_key = V(i) + bias_key = B(i) + + pose = result.atPose3(pose_key) + velocity = result.atVector(vel_key) + bias = result.atConstantBias(bias_key) + + pose_quat = pose.rotation().toQuaternion() + gps = gps_measurements[i].position + + print(f"State at #{i}") + print(f"Pose:\n{pose}") + print(f"Velocity:\n{velocity}") + print(f"Bias:\n{bias}") + + fp_out.write("{},{},{},{},{},{},{},{},{},{},{}\n".format( + gps_measurements[i].time, pose.x(), pose.y(), pose.z(), + pose_quat.x(), pose_quat.y(), pose_quat.z(), pose_quat.w(), + gps[0], gps[1], gps[2])) + + +def parse_args() -> argparse.Namespace: + """Parse command line arguments.""" + parser = argparse.ArgumentParser() + parser.add_argument("--output_filename", + default="IMUKittiExampleGPSResults.csv") + return parser.parse_args() + + +def optimize(gps_measurements: List[GpsMeasurement], + imu_measurements: List[ImuMeasurement], + sigma_init_x: gtsam.noiseModel.Diagonal, + sigma_init_v: gtsam.noiseModel.Diagonal, + sigma_init_b: gtsam.noiseModel.Diagonal, + noise_model_gps: gtsam.noiseModel.Diagonal, + kitti_calibration: KittiCalibration, first_gps_pose: int, + gps_skip: int) -> gtsam.ISAM2: + """Run ISAM2 optimization on the measurements.""" + # Set initial conditions for the estimated trajectory + # initial pose is the reference frame (navigation frame) + current_pose_global = Pose3(gtsam.Rot3(), + gps_measurements[first_gps_pose].position) + + # the vehicle is stationary at the beginning at position 0,0,0 + current_velocity_global = np.zeros(3) + current_bias = gtsam.imuBias.ConstantBias() # init with zero bias + + imu_params = getImuParams(kitti_calibration) + + # Set ISAM2 parameters and create ISAM2 solver object + isam_params = gtsam.ISAM2Params() + isam_params.setFactorization("CHOLESKY") + isam_params.setRelinearizeSkip(10) + + isam = gtsam.ISAM2(isam_params) + + # Create the factor graph and values object that will store new factors and + # values to add to the incremental graph + new_factors = gtsam.NonlinearFactorGraph() + # values storing the initial estimates of new nodes in the factor graph + new_values = gtsam.Values() + + # Main loop: + # (1) we read the measurements + # (2) we create the corresponding factors in the graph + # (3) we solve the graph to obtain and optimal estimate of robot trajectory + print("-- Starting main loop: inference is performed at each time step, " + "but we plot trajectory every 10 steps") + + j = 0 + included_imu_measurement_count = 0 + + for i in range(first_gps_pose, len(gps_measurements)): + # At each non=IMU measurement we initialize a new node in the graph + current_pose_key = X(i) + current_vel_key = V(i) + current_bias_key = B(i) + t = gps_measurements[i].time + + if i == first_gps_pose: + # Create initial estimate and prior on initial pose, velocity, and biases + new_values.insert(current_pose_key, current_pose_global) + new_values.insert(current_vel_key, current_velocity_global) + new_values.insert(current_bias_key, current_bias) + + new_factors.addPriorPose3(current_pose_key, current_pose_global, + sigma_init_x) + new_factors.addPriorVector(current_vel_key, + current_velocity_global, sigma_init_v) + new_factors.addPriorConstantBias(current_bias_key, current_bias, + sigma_init_b) + else: + t_previous = gps_measurements[i - 1].time + + # Summarize IMU data between the previous GPS measurement and now + current_summarized_measurement = gtsam.PreintegratedImuMeasurements( + imu_params, current_bias) + + while (j < len(imu_measurements) + and imu_measurements[j].time <= t): + if imu_measurements[j].time >= t_previous: + current_summarized_measurement.integrateMeasurement( + imu_measurements[j].accelerometer, + imu_measurements[j].gyroscope, imu_measurements[j].dt) + included_imu_measurement_count += 1 + j += 1 + + # Create IMU factor + previous_pose_key = X(i - 1) + previous_vel_key = V(i - 1) + previous_bias_key = B(i - 1) + + new_factors.push_back( + gtsam.ImuFactor(previous_pose_key, previous_vel_key, + current_pose_key, current_vel_key, + previous_bias_key, + current_summarized_measurement)) + + # Bias evolution as given in the IMU metadata + sigma_between_b = gtsam.noiseModel.Diagonal.Sigmas( + np.asarray([ + np.sqrt(included_imu_measurement_count) * + kitti_calibration.accelerometer_bias_sigma + ] * 3 + [ + np.sqrt(included_imu_measurement_count) * + kitti_calibration.gyroscope_bias_sigma + ] * 3)) + + new_factors.push_back( + gtsam.BetweenFactorConstantBias(previous_bias_key, + current_bias_key, + gtsam.imuBias.ConstantBias(), + sigma_between_b)) + + # Create GPS factor + gps_pose = Pose3(current_pose_global.rotation(), + gps_measurements[i].position) + if (i % gps_skip) == 0: + new_factors.addPriorPose3(current_pose_key, gps_pose, + noise_model_gps) + new_values.insert(current_pose_key, gps_pose) + + print(f"############ POSE INCLUDED AT TIME {t} ############") + print(gps_pose.translation(), "\n") + else: + new_values.insert(current_pose_key, current_pose_global) + + # Add initial values for velocity and bias based on the previous + # estimates + new_values.insert(current_vel_key, current_velocity_global) + new_values.insert(current_bias_key, current_bias) + + # Update solver + # ======================================================================= + # We accumulate 2*GPSskip GPS measurements before updating the solver at + # first so that the heading becomes observable. + if i > (first_gps_pose + 2 * gps_skip): + print(f"############ NEW FACTORS AT TIME {t:.6f} ############") + new_factors.print() + + isam.update(new_factors, new_values) + + # Reset the newFactors and newValues list + new_factors.resize(0) + new_values.clear() + + # Extract the result/current estimates + result = isam.calculateEstimate() + + current_pose_global = result.atPose3(current_pose_key) + current_velocity_global = result.atVector(current_vel_key) + current_bias = result.atConstantBias(current_bias_key) + + print(f"############ POSE AT TIME {t} ############") + current_pose_global.print() + print("\n") + + return isam + + +def main(): + """Main runner.""" + args = parse_args() + kitti_calibration, imu_measurements, gps_measurements = loadKittiData() + + if not kitti_calibration.bodyTimu.equals(Pose3(), 1e-8): + raise ValueError( + "Currently only support IMUinBody is identity, i.e. IMU and body frame are the same" + ) + + # Configure different variables + first_gps_pose = 1 + gps_skip = 10 + + # Configure noise models + noise_model_gps = noiseModel.Diagonal.Precisions( + np.asarray([0, 0, 0] + [1.0 / 0.07] * 3)) + + sigma_init_x = noiseModel.Diagonal.Precisions( + np.asarray([0, 0, 0, 1, 1, 1])) + sigma_init_v = noiseModel.Diagonal.Sigmas(np.ones(3) * 1000.0) + sigma_init_b = noiseModel.Diagonal.Sigmas( + np.asarray([0.1] * 3 + [5.00e-05] * 3)) + + isam = optimize(gps_measurements, imu_measurements, sigma_init_x, + sigma_init_v, sigma_init_b, noise_model_gps, + kitti_calibration, first_gps_pose, gps_skip) + + save_results(isam, args.output_filename, first_gps_pose, gps_measurements) + + +if __name__ == "__main__": + main()