304 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			Matlab
		
	
	
			
		
		
	
	
			304 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			Matlab
		
	
	
clear all;
 | 
						|
clf;
 | 
						|
 | 
						|
import gtsam.*;
 | 
						|
 | 
						|
write_video = true;
 | 
						|
 | 
						|
use_camera = true;
 | 
						|
use_camera_transform_noise = true;
 | 
						|
gps_noise = 0.5;           % normally distributed (meters)
 | 
						|
landmark_noise = 0.2;      % normally distributed (meters)
 | 
						|
nrLandmarks = 1000;         % Number of randomly generated landmarks
 | 
						|
 | 
						|
% ground-truth IMU-camera transform
 | 
						|
camera_transform = Pose3(Rot3.RzRyRx(-pi, 0, -pi/2),Point3());
 | 
						|
 | 
						|
% noise to compose onto the above for initialization
 | 
						|
camera_transform_noise = Pose3(Rot3.RzRyRx(0.1,0.1,0.1),Point3(0,0.02,0));
 | 
						|
 | 
						|
if(write_video)
 | 
						|
    videoObj = VideoWriter('FlightCameraIMU_transform_GPS0_5_lm0_2_robust.avi');
 | 
						|
    videoObj.Quality = 100;
 | 
						|
    videoObj.FrameRate = 10;
 | 
						|
    open(videoObj);
 | 
						|
end
 | 
						|
 | 
						|
% IMU parameters
 | 
						|
IMU_metadata.AccelerometerSigma = 1e-2;    
 | 
						|
IMU_metadata.GyroscopeSigma = 1e-2;
 | 
						|
IMU_metadata.AccelerometerBiasSigma = 1e-6;
 | 
						|
IMU_metadata.GyroscopeBiasSigma = 1e-6;
 | 
						|
IMU_metadata.IntegrationSigma = 1e-1;
 | 
						|
 | 
						|
transformKey = 1000;
 | 
						|
calibrationKey = 2000;
 | 
						|
 | 
						|
fg = NonlinearFactorGraph;
 | 
						|
initial = Values;
 | 
						|
 | 
						|
%% some noise models
 | 
						|
trans_cov = noiseModel.Diagonal.Sigmas([5*pi/180; 5*pi/180; 5*pi/180; 20; 20; 0.1]);
 | 
						|
GPS_trans_cov = noiseModel.Diagonal.Sigmas([3; 3; 4]);
 | 
						|
K_cov = noiseModel.Diagonal.Sigmas([20; 20; 0.001; 20; 20]);
 | 
						|
 | 
						|
l_cov = noiseModel.Diagonal.Sigmas([landmark_noise; landmark_noise; landmark_noise]);
 | 
						|
z_cov = noiseModel.Diagonal.Sigmas([1.0;1.0]);
 | 
						|
% z_cov = noiseModel.Robust(noiseModel.mEstimator.Huber(1.0), noiseModel.Diagonal.Sigmas([1.0;1.0]));
 | 
						|
 | 
						|
%% calibration initialization
 | 
						|
K = Cal3_S2(20,1280,960);
 | 
						|
 | 
						|
% initialize K incorrectly
 | 
						|
K_corrupt = Cal3_S2(K.fx()+10,K.fy()+10,0,K.px(),K.py());
 | 
						|
 | 
						|
isamParams = gtsam.ISAM2Params;
 | 
						|
isamParams.setFactorization('QR');
 | 
						|
isam = ISAM2(isamParams);
 | 
						|
 | 
						|
%% Get initial conditions for the estimated trajectory
 | 
						|
currentVelocityGlobal = [10;0;0];    % (This is slightly wrong!) Zhaoyang: Fixed
 | 
						|
currentBias = imuBias.ConstantBias(zeros(3,1), zeros(3,1));
 | 
						|
 | 
						|
sigma_init_v = noiseModel.Isotropic.Sigma(3, 1.0);
 | 
						|
sigma_init_b = noiseModel.Isotropic.Sigmas([ 0.100; 0.100; 0.100; 5.00e-05; 5.00e-05; 5.00e-05 ]);
 | 
						|
sigma_between_b = [ IMU_metadata.AccelerometerBiasSigma * ones(3,1); IMU_metadata.GyroscopeBiasSigma * ones(3,1) ];
 | 
						|
g = [0;0;-9.8];
 | 
						|
w_coriolis = [0;0;0];
 | 
						|
 | 
						|
%% generate trajectory and landmarks
 | 
						|
trajectory = flight_trajectory();
 | 
						|
landmarks = ground_landmarks(nrLandmarks);
 | 
						|
 | 
						|
figure(1);
 | 
						|
% 3D map subplot
 | 
						|
a1 = subplot(2,2,1);
 | 
						|
grid on;
 | 
						|
 | 
						|
plot3DTrajectory(trajectory,'-b',true,5);
 | 
						|
plot3DPoints(landmarks,'*g');
 | 
						|
axis([-800 800 -800 800 0 1600]);
 | 
						|
axis equal;
 | 
						|
hold on;
 | 
						|
view(-37,40);
 | 
						|
 | 
						|
% camera subplot
 | 
						|
a2 = subplot(2,2,2);
 | 
						|
if ~use_camera
 | 
						|
    title('Camera Off');
 | 
						|
end
 | 
						|
 | 
						|
% IMU-cam transform subplot
 | 
						|
a3 = subplot(2,2,3);
 | 
						|
view(-37,40);
 | 
						|
axis([-1 1 -1 1 -1 1]);
 | 
						|
grid on;
 | 
						|
xlabel('x');
 | 
						|
ylabel('y');
 | 
						|
zlabel('z');
 | 
						|
title('Estimated vs. actual IMU-cam transform');
 | 
						|
axis equal;
 | 
						|
 | 
						|
for i=1:size(trajectory)-1
 | 
						|
    xKey = symbol('x',i);
 | 
						|
    pose = trajectory.atPose3(xKey);     % GT pose
 | 
						|
    pose_t = pose.translation();    % GT pose-translation
 | 
						|
    
 | 
						|
    if exist('h_cursor','var')
 | 
						|
        delete(h_cursor);
 | 
						|
    end
 | 
						|
    
 | 
						|
    % current ground-truth position indicator
 | 
						|
    h_cursor = plot3(a1, pose_t.x,pose_t.y,pose_t.z,'*');
 | 
						|
 
 | 
						|
    camera_pose = pose.compose(camera_transform);
 | 
						|
    
 | 
						|
    axes(a2);
 | 
						|
    if use_camera
 | 
						|
        % project (and plot 2D camera view inside)
 | 
						|
        measurements = project_landmarks(camera_pose,landmarks, K);
 | 
						|
        % plot red landmarks in 3D plot
 | 
						|
        plot_projected_landmarks(a1, landmarks, measurements);
 | 
						|
    else
 | 
						|
        measurements = Values;
 | 
						|
    end
 | 
						|
    
 | 
						|
    %% ISAM stuff
 | 
						|
    currentVelKey =  symbol('v',i);
 | 
						|
    currentBiasKey = symbol('b',i);
 | 
						|
    
 | 
						|
    initial.insert(currentVelKey, currentVelocityGlobal);
 | 
						|
    initial.insert(currentBiasKey, currentBias);
 | 
						|
    
 | 
						|
    % prior on translation, sort of like GPS with noise!
 | 
						|
    gps_pose = pose.retract([0; 0; 0; normrnd(0,gps_noise,3,1)]);
 | 
						|
    fg.add(PoseTranslationPrior3D(xKey, gps_pose, GPS_trans_cov));
 | 
						|
    
 | 
						|
    if i==1
 | 
						|
        % camera transform
 | 
						|
        if use_camera_transform_noise
 | 
						|
            camera_transform_init = camera_transform.compose(camera_transform_noise);
 | 
						|
        else
 | 
						|
            camera_transform_init = camera_transform;
 | 
						|
        end
 | 
						|
        initial.insert(transformKey,camera_transform_init);
 | 
						|
        fg.add(PriorFactorPose3(transformKey,camera_transform_init,trans_cov));
 | 
						|
        
 | 
						|
        % calibration
 | 
						|
        initial.insert(2000, K_corrupt);
 | 
						|
        fg.add(PriorFactorCal3_S2(calibrationKey,K_corrupt,K_cov));
 | 
						|
        
 | 
						|
        initial.insert(xKey, pose);
 | 
						|
        
 | 
						|
        result = initial;
 | 
						|
    end
 | 
						|
    
 | 
						|
    % priors on first two poses
 | 
						|
    if i < 3        
 | 
						|
%         fg.add(PriorFactorLieVector(currentVelKey, currentVelocityGlobal, sigma_init_v));
 | 
						|
        fg.add(PriorFactorConstantBias(currentBiasKey, currentBias, sigma_init_b));
 | 
						|
        
 | 
						|
        
 | 
						|
    end
 | 
						|
   
 | 
						|
    %% the 'normal' case
 | 
						|
    if i > 1
 | 
						|
     
 | 
						|
        xKey_prev = symbol('x',i-1);
 | 
						|
        pose_prev = trajectory.atPose3(xKey_prev);
 | 
						|
        
 | 
						|
        step = pose_prev.between(pose);
 | 
						|
                
 | 
						|
        % insert estimate for current pose with some normal noise on
 | 
						|
        % translation
 | 
						|
        initial.insert(xKey,result.atPose3(xKey_prev).compose(step.retract([0; 0; 0; normrnd(0,0.2,3,1)])));
 | 
						|
        
 | 
						|
        % visual measurements
 | 
						|
        if measurements.size > 0 && use_camera
 | 
						|
            measurementKeys = KeyVector(measurements.keys);
 | 
						|
 | 
						|
            for zz = 0:measurementKeys.size-1
 | 
						|
                zKey = measurementKeys.at(zz);
 | 
						|
                lKey = symbol('l',symbolIndex(zKey));
 | 
						|
 | 
						|
                fg.add(TransformCalProjectionFactorCal3_S2(measurements.atPoint2(zKey), ...
 | 
						|
                    z_cov, xKey, transformKey, lKey, calibrationKey, false, true));
 | 
						|
 | 
						|
                % only add landmark to values if doesn't exist yet
 | 
						|
                if ~result.exists(lKey)
 | 
						|
                    noisy_landmark = landmarks.atPoint3(lKey).compose(Point3(normrnd(0,landmark_noise,3,1)));
 | 
						|
                    initial.insert(lKey, noisy_landmark);
 | 
						|
 | 
						|
                    % and add a prior since its position is known
 | 
						|
                    fg.add(PriorFactorPoint3(lKey, noisy_landmark,l_cov));
 | 
						|
                end
 | 
						|
            end
 | 
						|
        end % end landmark observations 
 | 
						|
        
 | 
						|
 | 
						|
        %% IMU
 | 
						|
        deltaT = 1;
 | 
						|
        logmap = Pose3.Logmap(step);
 | 
						|
        omega = logmap(1:3);
 | 
						|
        velocity = logmap(4:6);
 | 
						|
       
 | 
						|
       
 | 
						|
        % Simulate IMU measurements, considering Coriolis effect 
 | 
						|
        % (in this simple example we neglect gravity and there are no other forces acting on the body)
 | 
						|
        acc_omega = imuSimulator.calculateIMUMeas_coriolis( ...
 | 
						|
        omega, omega, velocity, velocity, deltaT);
 | 
						|
    
 | 
						|
%         [ currentIMUPoseGlobal, currentVelocityGlobal ] = imuSimulator.integrateTrajectory( ...
 | 
						|
%     currentIMUPoseGlobal, omega, velocity, velocity, deltaT);
 | 
						|
 | 
						|
        currentSummarizedMeasurement = gtsam.ImuFactorPreintegratedMeasurements( ...
 | 
						|
        currentBias, IMU_metadata.AccelerometerSigma.^2 * eye(3), ...
 | 
						|
        IMU_metadata.GyroscopeSigma.^2 * eye(3), IMU_metadata.IntegrationSigma.^2 * eye(3));
 | 
						|
    
 | 
						|
        accMeas = acc_omega(1:3)-g;
 | 
						|
        omegaMeas = acc_omega(4:6);
 | 
						|
        currentSummarizedMeasurement.integrateMeasurement(accMeas, omegaMeas, deltaT);
 | 
						|
 | 
						|
        %% create IMU factor
 | 
						|
        fg.add(ImuFactor( ...
 | 
						|
        xKey_prev, currentVelKey-1, ...
 | 
						|
        xKey, currentVelKey, ...
 | 
						|
        currentBiasKey, currentSummarizedMeasurement, g, w_coriolis));
 | 
						|
    
 | 
						|
        % Bias evolution as given in the IMU metadata
 | 
						|
        fg.add(BetweenFactorConstantBias(currentBiasKey-1, currentBiasKey, imuBias.ConstantBias(zeros(3,1), zeros(3,1)), ...
 | 
						|
        noiseModel.Diagonal.Sigmas(sqrt(10) * sigma_between_b)));
 | 
						|
    
 | 
						|
        % ISAM update
 | 
						|
        isam.update(fg, initial);
 | 
						|
        result = isam.calculateEstimate();
 | 
						|
        
 | 
						|
        %% reset 
 | 
						|
        initial = Values;
 | 
						|
        fg = NonlinearFactorGraph;
 | 
						|
        
 | 
						|
        currentVelocityGlobal = result.at(currentVelKey);
 | 
						|
        currentBias = result.at(currentBiasKey);
 | 
						|
        
 | 
						|
        %% plot current pose result
 | 
						|
        isam_pose = result.at(xKey);
 | 
						|
        pose_t = isam_pose.translation();
 | 
						|
 | 
						|
        if exist('h_result','var')
 | 
						|
            delete(h_result);
 | 
						|
        end
 | 
						|
 | 
						|
        h_result = plot3(a1, pose_t.x,pose_t.y,pose_t.z,'^b', 'MarkerSize', 10);
 | 
						|
        title(a1, sprintf('Step %d', i));
 | 
						|
        
 | 
						|
        if exist('h_text1(1)', 'var')
 | 
						|
            delete(h_text1(1));
 | 
						|
%             delete(h_text2(1));
 | 
						|
        end
 | 
						|
        ty = result.at(transformKey).translation().y();
 | 
						|
        K_estimate = result.at(calibrationKey);
 | 
						|
        K_errors = K.localCoordinates(K_estimate);
 | 
						|
        
 | 
						|
        camera_transform_estimate = result.at(transformKey);
 | 
						|
        
 | 
						|
        fx = result.at(calibrationKey).fx();
 | 
						|
        fy = result.at(calibrationKey).fy();
 | 
						|
%         h_text1 = text(-600,0,0,sprintf('Y-Transform(0.0): %0.2f',ty));
 | 
						|
        text(0,1300,0,sprintf('Calibration and IMU-cam transform errors:'));
 | 
						|
        
 | 
						|
        entries = [{' f_x', ' f_y', ' s', 'p_x', 'p_y'}; num2cell(K_errors')];
 | 
						|
        h_text1 = text(0,1750,0,sprintf('%s = %0.1f\n', entries{:}));
 | 
						|
        
 | 
						|
        camera_transform_errors = camera_transform.localCoordinates(camera_transform_estimate);
 | 
						|
        entries1 = [{'ax', 'ay', 'az', 'tx', 'ty', 'tz'}; num2cell(camera_transform_errors')];
 | 
						|
        h_text2 = text(600,1700,0,sprintf('%s = %0.2f\n', entries1{:}));
 | 
						|
        
 | 
						|
        % marginal is really huge
 | 
						|
%         marginal_camera_transform = isam.marginalCovariance(transformKey);
 | 
						|
        % plot transform
 | 
						|
        axes(a3);
 | 
						|
        cla;
 | 
						|
  
 | 
						|
        plotPose3(camera_transform,[],1);
 | 
						|
        plotPose3(camera_transform_estimate,[],0.5);
 | 
						|
 | 
						|
    end
 | 
						|
    
 | 
						|
    drawnow;
 | 
						|
    if(write_video)
 | 
						|
        currFrame = getframe(gcf);
 | 
						|
        writeVideo(videoObj, currFrame)
 | 
						|
    else
 | 
						|
        pause(0.00001);
 | 
						|
    end
 | 
						|
  
 | 
						|
    
 | 
						|
end
 | 
						|
 | 
						|
% print out final camera transform
 | 
						|
result.at(transformKey);
 | 
						|
 | 
						|
 | 
						|
if(write_video)
 | 
						|
    close(videoObj);
 | 
						|
end |