Optic flow based reactive collision prevention for MAVs using the fictitious obstacle hypothesis
Author(s)
Xiao, Feng
Zheng, Peter
Di Tria, Julien
Kocer, Basaran Bahadir
Kovac, Mirko
Type
Journal Article
Abstract
Optical flow sensors and optical flow divergence (OFD) have offered partial solutions for obstacle avoidance, landing, and perching with micro aerial vehicles. Theoretically, OFD can indicate the risk of collision, providing that the sensors’ field of view is bounded within a single flat surface on the obstacle. However, in the real world, directly measuring the risk of collision with OFD generates false alarms due to rapidly changing speeds and irregular surroundings. In this letter, we present a new obstacle detection strategy based on an extended Kalman filter (EKF) combining the OFD with inertial sensing. The introduction of a fictitious obstacle hypothesis and the use of the EKF estimates enable us to differentiate the surrounding-generated OFD from the OFD caused by the actual obstacle. An embedded constant zero-OFD controller is then used for post-detection emergency deceleration. The ultra-light OFD estimation and control system, with a mass of 20 g , estimates OFD at 160 Hz . The system was validated on a 158 g mini quadrotor in both laboratory and field tests. Experimental results illustrate that the presented system can achieve accurate obstacle detection, near-obstacle distance estimation, and controlled deceleration to prevent collisions. 1 1
Video attachment: https://youtu.be/yIyYHYN0jOw.
Video attachment: https://youtu.be/yIyYHYN0jOw.
Date Issued
2021-02-25
Date Acceptance
2021-02-08
Citation
IEEE Robotics and Automation Letters, 2021, 6 (2), pp.3144-3151
ISSN
2377-3766
Publisher
Institute of Electrical and Electronics Engineers
Start Page
3144
End Page
3151
Journal / Book Title
IEEE Robotics and Automation Letters
Volume
6
Issue
2
Copyright Statement
© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
Engineering & Physical Science Research Council (E
Commission of the European Communities
Engineering and Physical Sciences Research Council
EPSRC
Identifier
https://ieeexplore.ieee.org/document/9363555
Grant Number
EP/R026173/1
810321
EP/R009953/1
EP/N018494/1
Subjects
0913 Mechanical Engineering
Publication Status
Published
Date Publish Online
2021-02-25