IMUKittiExample: added infrastructure for reading and processing data - work in progress

release/4.3a0
Luca Carlone 2013-08-02 20:07:52 +00:00
parent c9c2025d52
commit 334d71ce51
1 changed files with 85 additions and 65 deletions

View File

@ -9,6 +9,9 @@ IMU_metadata = cell2struct(num2cell(IMU_metadata.data), IMU_metadata.colheaders,
IMUinBody = Pose3.Expmap([
IMU_metadata.BodyPtx; IMU_metadata.BodyPty; IMU_metadata.BodyPtz;
IMU_metadata.BodyPrx; IMU_metadata.BodyPry; IMU_metadata.BodyPrz; ]);
if ~IMUinBody.equals(Pose3, 1e-5)
error 'Currently only support IMUinBody is identity, i.e. IMU and body frame are the same';
end
VO_metadata = importdata('KittiRelativePose_metadata.txt');
VO_metadata = cell2struct(num2cell(VO_metadata.data), VO_metadata.colheaders, 2);
@ -38,19 +41,14 @@ VO_data = cell2struct(num2cell(VO_data.data), VO_data.colheaders, 2);
% Merge relative pose fields and convert to Pose3
logposes = [ [VO_data.dtx]' [VO_data.dty]' [VO_data.dtz]' [VO_data.drx]' [VO_data.dry]' [VO_data.drz]' ];
logposes = num2cell(logposes, 2);
relposes = arrayfun(@(x) {gtsam.Pose3.Expmap(x{1}')}, logposes);
% TODO: convert to IMU frame %relposes = arrayfun(
relposes = arrayfun(@(x) {gtsam.Pose3.Expmap(x{:}')}, logposes);
relposes = arrayfun(@(x) {VOinIMU.compose(x{:}).compose(VOinIMU.inverse())}, relposes);
[VO_data.RelativePose] = deal(relposes{:});
VO_data = rmfield(VO_data, { 'dtx' 'dty' 'dtz' 'drx' 'dry' 'drz' });
clear logposes relposes
GPS_data = importdata('KittiGps.txt');
GPS_data = cell2struct(num2cell(GPS_data.data), GPS_data.colheaders, 2);
%%
SummaryTemplate = gtsam.ImuFactorPreintegratedMeasurements( ...
gtsam.imuBias.ConstantBias([0;0;0], [0;0;0]), ...
1e-3 * eye(3), 1e-3 * eye(3), 1e-3 * eye(3));
%% Set initial conditions for the estimated trajectory
disp('TODO: we have GPS so this initialization is not right')
@ -69,14 +67,15 @@ factors = NonlinearFactorGraph;
values = Values;
%% Create prior on initial pose, velocity, and biases
sigma_init_x = 1.0
sigma_init_v = 1.0
sigma_init_b = 1.0
sigma_init_x = 1.0;
sigma_init_v = 1.0;
sigma_init_b = 1.0;
values.insert(symbol('x',0), currentPoseGlobal);
values.insert(symbol('v',0), LieVector(currentVelocityGlobal) );
values.insert(symbol('b',0), imuBias.ConstantBias(bias_acc,bias_omega) );
disp('TODO: we have GPS so this initialization is not right')
% Prior on initial pose
factors.add(PriorFactorPose3(symbol('x',0), ...
currentPoseGlobal, noiseModel.Isotropic.Sigma(6, sigma_init_x)));
@ -92,83 +91,104 @@ factors.add(PriorFactorConstantBias(symbol('b',0), ...
% (2) we create the corresponding factors in the graph
% (3) we solve the graph to obtain and optimal estimate of robot trajectory
i = 2;
lastTime = 0;
lastIndex = 0;
currentSummarizedMeasurement = ImuFactorPreintegratedMeasurements(summaryTemplate);
% lastTime = 0; TODO: delete?
% lastIndex = 0; TODO: delete?
currentSummarizedMeasurement = [];
times = sort([VO_data(:,1); GPS_data(:,1)]); % this are the time-stamps at which we want to initialize a new node in the graph
IMU_times = IMU_data(:,1);
% Measurement types:
% 1: VO
% 2: GPS
% 3: IMU
times = sortrows( [ ...
[VO_data.Time]' 1*ones(length([VO_data.Time]), 1); ...
%[GPS_data.Time]' 2*ones(length([GPS_data.Time]), 1); ...
[IMU_data.Time]' 3*ones(length([IMU_data.Time]), 1); ...
], 1); % this are the time-stamps at which we want to initialize a new node in the graph
disp('TODO: still needed to take care of the initial time')
for t = times
t_previous = 0;
poseIndex = 0;
for measurementIndex = 1:size(times,1)
% At each non=IMU measurement we initialize a new node in the graph
currentIndex = find( times == t );
currentPoseKey = symbol('x',currentIndex);
currentVelKey = symbol('v',currentIndex);
currentBiasKey = symbol('b',currentIndex);
currentPoseKey = symbol('x',poseIndex);
currentVelKey = symbol('v',poseIndex);
currentBiasKey = symbol('b',poseIndex);
%% add preintegrated IMU factor between previous state and current state
% =======================================================================
IMUbetweenTimesIndices = find( IMU_times>+t_previous & IMU_times<= t);
% all imu measurements occurred between t_previous and t
t = times(measurementIndex, 1);
type = times(measurementIndex, 2);
% we assume that each row of the IMU.txt file has the following structure:
% timestamp delta_t acc_x acc_y acc_z omega_x omega_y omega_z
disp('TODO: We want don t want to preintegrate with zero bias, but to use the most recent estimate')
currentSummarizedMeasurement = ImuFactorPreintegratedMeasurements(summaryTemplate);
for i=1:length(IMUbetweenTimesIndices)
index = IMUbetweenTimesIndices(i); % the row of the IMU_data matrix that we have to integrate
deltaT = IMU_data(index,2);
accMeas = IMU_data(index,3:5);
omegaMeas = IMU_data(index,6:8);
if type == 3
% Integrate IMU
if isempty(currentSummarizedMeasurement)
% Create initial empty summarized measurement
% we assume that each row of the IMU.txt file has the following structure:
% timestamp delta_t acc_x acc_y acc_z omega_x omega_y omega_z
currentBias = isam.calculateEstimate(currentBiasKey - 1);
currentSummarizedMeasurement = gtsam.ImuFactorPreintegratedMeasurements( ...
currentBias, IMU_metadata.AccelerometerSigma.^2 * eye(3), ...
IMU_metadata.GyroscopeSigma.^2 * eye(3), IMU_metadata.IntegrationSigma.^2 * eye(3));
end
% Accumulate preintegrated measurement
deltaT = IMU_data(index).dt;
accMeas = IMU_data(index).acc_omega(1:3);
omegaMeas = IMU_data(index).acc_omega(4:6);
currentSummarizedMeasurement.integrateMeasurement(accMeas, omegaMeas, deltaT);
else
% Create IMU factor
factors.add(ImuFactor( ...
currentPoseKey-1, currentVelKey-1, ...
currentPoseKey, currentVelKey, ...
currentBiasKey-1, currentSummarizedMeasurement, g, cor_v, ...
currentSummarizedMeasurement.PreintMeasCov));
% Reset summarized measurement
currentSummarizedMeasurement = [];
if type == 1
% Create VO factor
elseif type == 2
% Create GPS factor
end
poseIndex = poseIndex + 1;
end
disp('TODO: is the imu noise right?')
% Create IMU factor
factors.add(ImuFactor( ...
previousPoseKey, previousVelKey, ...
currentPoseKey, currentVelKey, ...
currentBiasKey, currentSummarizedMeasurement, g, cor_v, ...
noiseModel.Isotropic.Sigma(9, 1e-6)));
% =======================================================================
%% add factor corresponding to GPS measurements (if available at the current time)
% =======================================================================
if isempty( find(GPS_data(:,1) == t ) ) == 0 % it is a GPS measurement
if length( find(GPS_data(:,1)) ) > 1
error('more GPS measurements at the same time stamp: it should be an error')
end
index = find(GPS_data(:,1) == t ); % the row of the IMU_data matrix that we have to integrate
GPSmeas = GPS_data(index,2:4);
noiseModelGPS = ???; % noiseModelGPS.Isotropic.Sigma(6, sigma_init_x))
% add factor
disp('TODO: is the GPS noise right?')
factors.add(PriorFactor???(currentPoseKey, GPSmeas, noiseModelGPS) );
end
% % =======================================================================
% if isempty( find(GPS_data(:,1) == t ) ) == 0 % it is a GPS measurement
% if length( find(GPS_data(:,1)) ) > 1
% error('more GPS measurements at the same time stamp: it should be an error')
% end
%
% index = find(GPS_data(:,1) == t ); % the row of the IMU_data matrix that we have to integrate
% GPSmeas = GPS_data(index,2:4);
%
% noiseModelGPS = ???; % noiseModelGPS.Isotropic.Sigma(6, sigma_init_x))
%
% % add factor
% disp('TODO: is the GPS noise right?')
% factors.add(PriorFactor???(currentPoseKey, GPSmeas, noiseModelGPS) );
% end
% =======================================================================
%% add factor corresponding to VO measurements (if available at the current time)
% =======================================================================
if isempty( find(VO_data(:,1) == t ) )== 0 % it is a GPS measurement
if length( find(VO_data(:,1)) ) > 1
if isempty( find([VO_data.Time] == t, 1) )== 0 % it is a GPS measurement
if length( find([VO_data.Time] == t) ) > 1
error('more VO measurements at the same time stamp: it should be an error')
end
index = find( VO_data(:,1) == t ); % the row of the IMU_data matrix that we have to integrate
VOmeas_pos = VO_data(index,2:4)';
VOmeas_ang = VO_data(index,5:7)';
index = find([VO_data.Time] == t, 1); % the row of the IMU_data matrix that we have to integrate
VOpose = Pose3( Rot3(VOmeas_ang) , Point3(VOmeas_pos) );
noiseModelVO = ???; % noiseModelGPS.Isotropic.Sigma(6, sigma_init_x))
VOpose = VO_data(index).RelativePose;
noiseModelVO = noiseModel.Diagonal.Sigmas([ IMU_metadata.RotationSigma * [1;1;1]; IMU_metadata.TranslationSigma * [1;1;1] ]);
% add factor
disp('TODO: is the VO noise right?')