2,284 research outputs found
Visual-inertial self-calibration on informative motion segments
Environmental conditions and external effects, such as shocks, have a
significant impact on the calibration parameters of visual-inertial sensor
systems. Thus long-term operation of these systems cannot fully rely on factory
calibration. Since the observability of certain parameters is highly dependent
on the motion of the device, using short data segments at device initialization
may yield poor results. When such systems are additionally subject to energy
constraints, it is also infeasible to use full-batch approaches on a big
dataset and careful selection of the data is of high importance. In this paper,
we present a novel approach for resource efficient self-calibration of
visual-inertial sensor systems. This is achieved by casting the calibration as
a segment-based optimization problem that can be run on a small subset of
informative segments. Consequently, the computational burden is limited as only
a predefined number of segments is used. We also propose an efficient
information-theoretic selection to identify such informative motion segments.
In evaluations on a challenging dataset, we show our approach to significantly
outperform state-of-the-art in terms of computational burden while maintaining
a comparable accuracy
Observability-aware Self-Calibration of Visual and Inertial Sensors for Ego-Motion Estimation
External effects such as shocks and temperature variations affect the
calibration of visual-inertial sensor systems and thus they cannot fully rely
on factory calibrations. Re-calibrations performed on short user-collected
datasets might yield poor performance since the observability of certain
parameters is highly dependent on the motion. Additionally, on
resource-constrained systems (e.g mobile phones), full-batch approaches over
longer sessions quickly become prohibitively expensive.
In this paper, we approach the self-calibration problem by introducing
information theoretic metrics to assess the information content of trajectory
segments, thus allowing to select the most informative parts from a dataset for
calibration purposes. With this approach, we are able to build compact
calibration datasets either: (a) by selecting segments from a long session with
limited exciting motion or (b) from multiple short sessions where a single
sessions does not necessarily excite all modes sufficiently. Real-world
experiments in four different environments show that the proposed method
achieves comparable performance to a batch calibration approach, yet, at a
constant computational complexity which is independent of the duration of the
session
Sampling-based Motion Planning for Active Multirotor System Identification
This paper reports on an algorithm for planning trajectories that allow a
multirotor micro aerial vehicle (MAV) to quickly identify a set of unknown
parameters. In many problems like self calibration or model parameter
identification some states are only observable under a specific motion. These
motions are often hard to find, especially for inexperienced users. Therefore,
we consider system model identification in an active setting, where the vehicle
autonomously decides what actions to take in order to quickly identify the
model. Our algorithm approximates the belief dynamics of the system around a
candidate trajectory using an extended Kalman filter (EKF). It uses
sampling-based motion planning to explore the space of possible beliefs and
find a maximally informative trajectory within a user-defined budget. We
validate our method in simulation and on a real system showing the feasibility
and repeatability of the proposed approach. Our planner creates trajectories
which reduce model parameter convergence time and uncertainty by a factor of
four.Comment: Published at ICRA 2017. Video available at
https://www.youtube.com/watch?v=xtqrWbgep5
Accurate and Interactive Visual-Inertial Sensor Calibration with Next-Best-View and Next-Best-Trajectory Suggestion
Visual-Inertial (VI) sensors are popular in robotics, self-driving vehicles,
and augmented and virtual reality applications. In order to use them for any
computer vision or state-estimation task, a good calibration is essential.
However, collecting informative calibration data in order to render the
calibration parameters observable is not trivial for a non-expert. In this
work, we introduce a novel VI calibration pipeline that guides a non-expert
with the use of a graphical user interface and information theory in collecting
informative calibration data with Next-Best-View and Next-Best-Trajectory
suggestions to calibrate the intrinsics, extrinsics, and temporal misalignment
of a VI sensor. We show through experiments that our method is faster, more
accurate, and more consistent than state-of-the-art alternatives. Specifically,
we show how calibrations with our proposed method achieve higher accuracy
estimation results when used by state-of-the-art VI Odometry as well as VI-SLAM
approaches. The source code of our software can be found on:
https://github.com/chutsu/yac.Comment: 8 pages, 11 figures, IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS 2023
Humans use Optokinetic Eye Movements to Track Waypoints for Steering
It is well-established how visual stimuli and self-motion in laboratory conditions reliably elicit retinal image stabilizing compensatory eye movements (CEM). Their organization and roles in natural-task gaze strategies is much less understood: are CEM applied in active sampling of visual information in human locomotion in the wild? If so, how? And what are the implications for guidance? Here, we directly compare gaze behavior in the real world (driving a car) and a fixed base simulation steering task. A strong and quantifiable correspondence between self-rotation and CEM counter-rotation is found across a range of speeds. This gaze behavior is “optokinetic”, i.e. optic flow is a sufficient stimulus to spontaneously elicit it in naïve subjects and vestibular stimulation or stereopsis are not critical. Theoretically, the observed nystagmus behavior is consistent with tracking waypoints on the future path, and predicted by waypoint models of locomotor control - but inconsistent with travel point models, such as the popular tangent point model.It is well-established how visual stimuli and self-motion in laboratory conditions reliably elicit retinal-image-stabilizing compensatory eye movements (CEM). Their organization and roles in natural-task gaze strategies is much less understood: are CEM applied in active sampling of visual information in human locomotion in the wild? If so, how? And what are the implications for guidance? Here, we directly compare gaze behavior in the real world (driving a car) and a fixed base simulation steering task. A strong and quantifiable correspondence between self-rotation and CEM counter-rotation is found across a range of speeds. This gaze behavior is “optokinetic”, i.e. optic flow is a sufficient stimulus to spontaneously elicit it in naïve subjects and vestibular stimulation or stereopsis are not critical. Theoretically, the observed nystagmus behavior is consistent with tracking waypoints on the future path, and predicted by waypoint models of locomotor control - but inconsistent with travel point models, such as the popular tangent point model.Peer reviewe
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