Moving Vehicle Detection and Drone Velocity Estimation with a Moving Drone

Abstract

Small unmanned aerial vehicles can be effectively used for aerial video surveillance. Although the field of view of the camera mounted on the drone is limited, flying drones can expand their surveillance coverage. In this paper, we address the detection of moving targets in urban environments with a moving drone. The drone moves at a constant velocity and captures video clips of moving vehicles such as cars, buses, and bicycles. Moving vehicle detection consists of frame registration and subtraction followed by thresholding, morphological operations and false blob reduction. First, two consecutive frames are registered; the coordinates of the next frame are compensated by a displacement vector that minimizes the sum of absolute difference between the two frames. Second, the next compensated frame is subtracted from the current frame, and the binary image is generated by thresholding. Finally, morphological operations and false alarm removal extract the target blobs. In the experiments, the drone flies at a constant speed of 5.1 m/s at an altitude of 150 m while capturing video clips of nine moving targets. The detection and false alarm rates as well as the receiver operating characteristic curves are obtained, and the drone velocities in the x and y directions are estimated by the displacement vector. The average detection rate ranges from 90% to 97% while the false alarm rate ranges from 0.06 to 0.5. The root mean square error of the speed is 0.07 m/s when the reference frame is fixed, showing the robustness of the proposed method.

Moving Vehicle Tracking with a Moving Drone Based on Track Association

“…This section briefly describes the moving object detection with a moving drone studied in [8]. Moving object detection consists of frame registration and subtraction followed by thresholding, morphological operations, and removing false alarms.…”

“…Videos 1 and 2 were captured by a DJI Phantom 4 and Inspire 2 in urban environments, respectively. The drones flew at the height of 150 m in a straight line in Video 1 [8] and changed direction once in Video 2. The videos were captured in different weather and lighting conditions.…”

“…Telemetry-assisted registrations of frames from a drone were studied in [7]. In [8], the drone velocities were estimated using frame registration based on sum of absolute difference (SAD).…”

“…A track is confirmed as a valid track if it continues longer than the minimum track life, and a track is terminated after searching for the measurements for a certain number of allowed frames. During moving object detection, frame registration is performed between two consecutive frames to compensate for the drone's movement [8]. The current frame compensated for and subtracted from the previous frame, and thresholding is performed to generate a binary image of the moving object.…”

Improvement in Target Range Estimation and the Range Resolution Using Drone

“…In Reference [11], aerial image acquisition has been studied by developing an all-in-one camera-based target detection and positioning system for search and rescue missions. In Reference [12], the speed estimation for moving objects has been studied by registering and subtracting frames after capturing images using a camera mounted on a drone. Image registration is the process of matching two or more images of the same scene to the same coordinates.…”