Research Article

CKF-Based Visual Inertial Odometry for Long-Term Trajectory Operations

Algorithm 1

Iterated CKF algorithm.
(1)Initialize the filter state and covariance matrix;
(2)for do
(3) Use IMU data to predict the nominal filter state with 4th order Runge-Kutta numerical integration;
(4) Calculate and
(5) Compute the propagated state covariance ;
(6)if New Image then
(7)   Perform feature detection for I3 and match these features with features {m1} and {m2} to have feature tracking ;
(8)  Factorize: ;
(9)  while ((Condition (17) is satisfied) and) do
(10)   Calculate the variation rate using (14);
(11)   Generate Cubature points using (8);
(12)   Compute innovation covariance matrix and the predicted measurement: (9) and (10);
(13)   Compute the new filter state and covariance matrix: (12) and (13);
(14)  end
(15)  State transition and rearrange the covariance matrix with respective camara poses;
(16)end
(17)end