Optical Flow Based Collision Avoidance of Multi-Rotor UAVs in Urban Environments

  • Yoo, Dong-Wan (Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology) ;
  • Won, Dae-Yeon (Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology) ;
  • Tahk, Min-Jea (Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology)
  • Received : 2011.04.29
  • Accepted : 2011.09.08
  • Published : 2011.09.30


This paper is focused on dynamic modeling and control system design as well as vision based collision avoidance for multi-rotor unmanned aerial vehicles (UAVs). Multi-rotor UAVs are defined as rotary-winged UAVs with multiple rotors. These multi-rotor UAVs can be utilized in various military situations such as surveillance and reconnaissance. They can also be used for obtaining visual information from steep terrains or disaster sites. In this paper, a quad-rotor model is introduced as well as its control system, which is designed based on a proportional-integral-derivative controller and vision-based collision avoidance control system. Additionally, in order for a UAV to navigate safely in areas such as buildings and offices with a number of obstacles, there must be a collision avoidance algorithm installed in the UAV's hardware, which should include the detection of obstacles, avoidance maneuvering, etc. In this paper, the optical flow method, one of the vision-based collision avoidance techniques, is introduced, and multi-rotor UAV's collision avoidance simulations are described in various virtual environments in order to demonstrate its avoidance performance.


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