An Autonomous UAV with an Optical Flow Sensor for Positioning and Navigation

Abstract

A procedure to control all six DOF (degrees of freedom) of a UAV (unmanned aerial vehicle) without an external reference system and to enable fully autonomous flight is presented here. For 2D positioning the principle of optical flow is used. Together with the output of height estimation, fusing ultrasonic, infrared and inertial and pressure sensor data, the 3D position of the UAV can be computed, controlled and steered. All data processing is done on the UAV. An external computer with a pathway planning interface is for commanding purposes only. The presented system is part of the AQopterI8 project, which aims to develop an autonomous flying quadrocopter for indoor application. The focus of this paper is 2D positioning using an optical flow sensor. As a result of the performed evaluation, it can be concluded that for position hold, the standard deviation of the position error is 10cm and after landing the position error is about 30cm.

Complementary Vision Based Data Fusion For Robust Positioning And Directed Flight Of An Autonomous Quadrocopter

“…Centre Pixel P t or P t-1 in yellow and neighbours in red [11] , an optical flow or optical mouse sensor, is used together with a This sensor works with an internal sample rate of up to 6400fps and provides good lighting conditions [4], but it cannot handle rotations. Furthermore the (as in case of outdoors) or too less light.…”

“…Two infrared sensors, one ultrasonic sensor, a pressure sensor and the IMU are fused for height over ground computation [13]. The 6 DOF (degree of freedom) control of the autonomous quadrocopter is executed on the AVR32 UC3A1512 microcontroller with 10ms sample time [4].…”

“…Main drawbacks are high computational burden [1,2] and low sample rate [3],limitations to translational movement [11,12], and bad robustness to varying lighting conditions [4]. Despite the considerable rise of computing power during the last decade, computational burden is still a concern for autonomous UAVs.…”

Ensuring the Accuracy of Traffic Monitoring Using Unmanned Aerial Vehicles Vision Systems

“…The paper by (Kong et al, 2013;Gageik, 2013) explores options for using various information sensors in navigation, such as infrared or optical sensors.…”

“…In this case, the visual navigation methods can be used (Veremeyenko et al, 2009;Sasa et al, 2000;European Commission Information note, 2002;Kong et al, 2013;Jia et al,;Gageik, 2013).…”