Title
High-precision, consistent EKF-based visual-inertial odometry
Abstract
In this paper, we focus on the problem of motion tracking in unknown environments using visual and inertial sensors. We term this estimation task visual-inertial odometry (VIO), in analogy to the well-known visual-odometry problem. We present a detailed study of extended Kalman filter (EKF)-based VIO algorithms, by comparing both their theoretical properties and empirical performance. We show that an EKF formulation where the state vector comprises a sliding window of poses (the multi-state-constraint Kalman filter (MSCKF)) attains better accuracy, consistency, and computational efficiency than the simultaneous localization and mapping (SLAM) formulation of the EKF, in which the state vector contains the current pose and the features seen by the camera. Moreover, we prove that both types of EKF approaches are inconsistent, due to the way in which Jacobians are computed. Specifically, we show that the observability properties of the EKF's linearized system models do not match those of the underlying system, which causes the filters to underestimate the uncertainty in the state estimates. Based on our analysis, we propose a novel, real-time EKF-based VIO algorithm, which achieves consistent estimation by (i) ensuring the correct observability properties of its linearized system model, and (ii) performing online estimation of the camera-to-inertial measurement unit (IMU) calibration parameters. This algorithm, which we term MSCKF 2.0, is shown to achieve accuracy and consistency higher than even an iterative, sliding-window fixed-lag smoother, in both Monte Carlo simulations and real-world testing.
Year
DOI
Venue
2013
10.1177/0278364913481251
I. J. Robotic Res.
Keywords
Field
DocType
vision-aided inertial navigation,visual-inertial odometry,extended Kalman filter consistency,visual-inertial SLAM
Observability,Extended Kalman filter,State vector,Control theory,Odometry,Kalman filter,Invariant extended Kalman filter,Simultaneous localization and mapping,Mathematics,Match moving
Journal
Volume
Issue
ISSN
32
6
0278-3649
Citations 
PageRank 
References 
121
4.24
34
Authors
2
Search Limit
100121
Name
Order
Citations
PageRank
Mingyang Li127017.60
Anastasios I. Mourikis2101857.50