gtsam/matlab/unstable_examples/+imuSimulator/covarianceAnalysisCreateFac...

165 lines
7.1 KiB
Matlab

function [ graph ] = covarianceAnalysisCreateFactorGraph( measurements, values, noiseModels, measurementNoise, options, metadata)
% Create a factor graph based on provided measurements, values, and noises.
% Used for covariance analysis scripts.
% 'options' contains fields for including various factor types.
% 'metadata' is a storage variable for miscellaneous factor-specific values
% Authors: Luca Carlone, David Jensen
% Date: 2014/04/16
import gtsam.*;
graph = NonlinearFactorGraph;
% Iterate through the trajectory
for i=0:length(measurements)
% Get the current pose
currentPoseKey = symbol('x', i);
currentPose = values.at(currentPoseKey);
if i==0
%% first time step, add priors
% Pose prior (poses used for all factors)
initialPose = Pose3.Expmap(measurementNoise.poseNoiseVector .* randn(6,1));
graph.add(PriorFactorPose3(currentPoseKey, initialPose, noiseModels.noisePose));
% IMU velocity and bias priors
if options.includeIMUFactors == 1
currentVelKey = symbol('v', 0);
currentVel = values.at(currentVelKey).vector;
graph.add(PriorFactorLieVector(currentVelKey, LieVector(currentVel), noiseModels.noiseVel));
currentBiasKey = symbol('b', 0);
currentBias = values.at(currentBiasKey);
graph.add(PriorFactorConstantBias(currentBiasKey, currentBias, noiseModels.noisePriorBias));
end
% Camera priors
if options.includeCameraFactors == 1
pointNoiseSigma = 0.1;
pointPriorNoise = noiseModel.Isotropic.Sigma(3,pointNoiseSigma);
graph.add(PriorFactorPoint3(symbol('p',1), gtLandmarkPoints(1), pointPriorNoise));
end
else
%% Add Between factors
if options.includeBetweenFactors == 1
prevPoseKey = symbol('x', i-1);
% Create the noisy pose estimate
deltaPose = Pose3.Expmap(measurements(i).deltaVector ...
+ (measurementNoise.poseNoiseVector .* randn(6,1))); % added noise
% Add the between factor to the graph
graph.add(BetweenFactorPose3(prevPoseKey, currentPoseKey, deltaPose, noiseModels.noisePose));
end % end of Between pose factor creation
%% Add IMU factors
if options.includeIMUFactors == 1
% Update keys
currentVelKey = symbol('v', i); % not used if includeIMUFactors is false
currentBiasKey = symbol('b', i); % not used if includeIMUFactors is false
if options.imuFactorType == 1
use2ndOrderIntegration = true;
% Initialize preintegration
imuMeasurement = gtsam.ImuFactorPreintegratedMeasurements(...
metadata.imu.zeroBias, ...
metadata.imu.AccelerometerSigma.^2 * eye(3), ...
metadata.imu.GyroscopeSigma.^2 * eye(3), ...
metadata.imu.IntegrationSigma.^2 * eye(3), ...
use2ndOrderIntegration);
% Generate IMU measurements with noise
for j=1:length(measurements(i).imu) % all measurements to preintegrate
imuAccel = measurements(i).imu(j).accel ...
+ (measurementNoise.imu.accelNoiseVector .* randn(3,1))... % added noise
+ metadata.imu.accelConstantBiasVector; % constant bias
imuGyro = measurements(i).imu(j).gyro ...
+ (measurementNoise.imu.gyroNoiseVector .* randn(3,1))... % added noise
+ metadata.imu.gyroConstantBiasVector; % constant bias
% Preintegrate
imuMeasurement.integrateMeasurement(imuAccel, imuGyro, measurements(i).imu(j).deltaT);
end
%imuMeasurement.print('imuMeasurement');
% Add Imu factor
graph.add(ImuFactor(currentPoseKey-1, currentVelKey-1, currentPoseKey, currentVelKey, ...
currentBiasKey-1, imuMeasurement, metadata.imu.g, metadata.imu.omegaCoriolis));
% Add between factor on biases
graph.add(BetweenFactorConstantBias(currentBiasKey-1, currentBiasKey, metadata.imu.zeroBias, ...
noiseModels.noiseBiasBetween));
end
if options.imuFactorType == 2
use2ndOrderIntegration = true;
% Initialize preintegration
imuMeasurement = gtsam.CombinedImuFactorPreintegratedMeasurements(...
metadata.imu.zeroBias, ...
metadata.imu.AccelerometerSigma.^2 * eye(3), ...
metadata.imu.GyroscopeSigma.^2 * eye(3), ...
metadata.imu.IntegrationSigma.^2 * eye(3), ...
metadata.imu.BiasAccelerometerSigma.^2 * eye(3), ... % how bias changes over time
metadata.imu.BiasGyroscopeSigma.^2 * eye(3), ... % how bias changes over time
diag(metadata.imu.BiasAccOmegaInit.^2), ... % prior on bias
use2ndOrderIntegration);
% Generate IMU measurements with noise
for j=1:length(measurements(i).imu) % all measurements to preintegrate
imuAccel = measurements(i).imu(j).accel ...
+ (measurementNoise.imu.accelNoiseVector .* randn(3,1))... % added noise
+ metadata.imu.accelConstantBiasVector; % constant bias
imuGyro = measurements(i).imu(j).gyro ...
+ (measurementNoise.imu.gyroNoiseVector .* randn(3,1))... % added noise
+ metadata.imu.gyroConstantBiasVector; % constant bias
% Preintegrate
imuMeasurement.integrateMeasurement(imuAccel, imuGyro, measurements(i).imu(j).deltaT);
end
% Add Imu factor
graph.add(CombinedImuFactor( ...
currentPoseKey-1, currentVelKey-1, ...
currentPoseKey, currentVelKey, ...
currentBiasKey-1, currentBiasKey, ...
imuMeasurement, ...
metadata.imu.g, metadata.imu.omegaCoriolis, ...
noiseModel.Isotropic.Sigma(15, metadata.imu.epsBias)));
end
end % end of IMU factor creation
%% Add Camera factors - UNDER CONSTRUCTION !!!! -
if options.includeCameraFactors == 1
% Create camera with the current pose and calibration K (specified above)
gtCamera = SimpleCamera(currentPose, K);
% Project landmarks into the camera
numSkipped = 0;
for j = 1:length(gtLandmarkPoints)
landmarkKey = symbol('p', j);
try
Z = gtCamera.project(gtLandmarkPoints(j));
% TO-DO probably want to do some type of filtering on the measurement values, because
% they might not all be valid
graph.add(GenericProjectionFactorCal3_S2(Z, cameraMeasurementNoise, currentPoseKey, landmarkKey, K));
catch
% Most likely the point is not within the camera's view, which
% is fine
numSkipped = numSkipped + 1;
end
end
%fprintf('(Pose %d) %d landmarks behind the camera\n', i, numSkipped);
end % end of Camera factor creation
%% Add GPS factors
if options.includeGPSFactors == 1 && i >= options.gpsStartPose
gpsPosition = measurements(i).gpsPositionVector ...
+ measurementNoise.gpsNoiseVector .* randn(3,1);
graph.add(PriorFactorPose3(currentPoseKey, ...
Pose3(currentPose.rotation, Point3(gpsPosition)), ...
noiseModels.noiseGPS));
end % end of GPS factor creation
end % end of else (i=0)
end % end of for over trajectory
end % end of function