1,591 research outputs found

    AURORA:autonomous real-time on-board video analytics

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    In this paper, we describe the design and implementation of a small light weight, low-cost and power-efficient payload system for the use in unmanned aerial vehicles (UAVs). The primary application of the payload system is that of performing real-time autonomous objects detection and tracking in the videos taken from a UAV camera. The implemented objects detection and tracking algorithms utilise Recursive Density Estimation (RDE) and Evolving Local Means (ELM) clustering to perform detection and tracking moving objects. Furthermore, experiments are presented which demonstrate that the introduced system is able to detect by on-board processing any moving objects from a UAV and start tracking them in real-time while at the same time sending important data only to a control station located on the ground

    On the Hardware/Software Design and Implementation of a High Definition Multiview Video Surveillance System

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    Unattended acoustic sensor systems for noise monitoring in national parks

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    2017 Spring.Includes bibliographical references.Detection and classification of transient acoustic signals is a difficult problem. The problem is often complicated by factors such as the variety of sources that may be encountered, the presence of strong interference and substantial variations in the acoustic environment. Furthermore, for most applications of transient detection and classification, such as speech recognition and environmental monitoring, online detection and classification of these transient events is required. This is even more crucial for applications such as environmental monitoring as it is often done at remote locations where it is unfeasible to set up a large, general-purpose processing system. Instead, some type of custom-designed system is needed which is power efficient yet able to run the necessary signal processing algorithms in near real-time. In this thesis, we describe a custom-designed environmental monitoring system (EMS) which was specifically designed for monitoring air traffic and other sources of interest in national parks. More specifically, this thesis focuses on the capabilities of the EMS and how transient detection, classification and tracking are implemented on it. The Sparse Coefficient State Tracking (SCST) transient detection and classification algorithm was implemented on the EMS board in order to detect and classify transient events. This algorithm was chosen because it was designed for this particular application and was shown to have superior performance compared to other algorithms commonly used for transient detection and classification. The SCST algorithm was implemented on an Artix 7 FPGA with parts of the algorithm running as dedicated custom logic and other parts running sequentially on a soft-core processor. In this thesis, the partitioning and pipelining of this algorithm is explained. Each of the partitions was tested independently to very their functionality with respect to the overall system. Furthermore, the entire SCST algorithm was tested in the field on actual acoustic data and the performance of this implementation was evaluated using receiver operator characteristic (ROC) curves and confusion matrices. In this test the FPGA implementation of SCST was able to achieve acceptable source detection and classification results despite a difficult data set and limited training data. The tracking of acoustic sources is done through successive direction of arrival (DOA) angle estimation using a wideband extension of the Capon beamforming algorithm. This algorithm was also implemented on the EMS in order to provide real-time DOA estimates for the detected sources. This algorithm was partitioned into several stages with some stages implemented in custom logic while others were implemented as software running on the soft-core processor. Just as with SCST, each partition of this beamforming algorithm was verified independently and then a full system test was conducted to evaluate whether it would be able to track an airborne source. For the full system test, a model airplane was flown at various trajectories relative to the EMS and the trajectories estimated by the system were compared to the ground truth. Although in this test the accuracy of the DOA estimates could not be evaluated, it was show that the algorithm was able to approximately form the general trajectory of a moving source which is sufficient for our application as only a general heading of the acoustic sources is desired

    Development of an FPGA system for parallel processing of railway non-destructive testing data

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    Cracks in rails are bad news; they cause accidents and cost money due to delays, as well as incurring repair costs. Inspection of tracks is required in order to find small cracks before they become dangerous. Early detection could also allow repair work which needs maintenance possession on railways to be planned. Non-destructive testing (NDT) is commonly used in rail crack inspection. Alternating Current Field Measurement (ACFM) is one of the latest NDT techniques to be used in crack measurement. This technique is able to detect surface breaking cracks in metals and measure them with proper processing of the non-destructive testing data. In the first part of this dissertation, the current limitations of inspection using ACFM techniques will be laid out. The content that follows describes a high-speed data processing chain for non-destructive testing data, as implemented using an FPGA development board. Multiple ACFM probes are used in practice to cover the surface of the track. Meanwhile, the data collected are parallel processed within the FPGA device. Here, the latest progress and the achievements of this project will be shown using proposed structure diagrams and initial results

    Reconfigurable architectures for beyond 3G wireless communication systems

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    Reconfigurable Vision Processing for Player Tracking in Indoor Sports

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    Ibraheem OW. Reconfigurable Vision Processing for Player Tracking in Indoor Sports. Bielefeld: Universität Bielefeld; 2018.Over the past decade, there has been an increasing growth of using vision-based systems for tracking players in sports. The tracking results are used to evaluate and enhance the performance of the players as well as to provide detailed information (e.g., on the players and team performance) to viewers. Player tracking using vision systems is a very challenging task due to the nature of sports games, which includes severe and frequent interactions (e.g., occlusions) between the players. Additionally, these vision systems have high computational demands since they require processing of a huge amount of video data based on the utilization of multiple cameras with high resolution and high frame rate. As a result, most of the existing systems based on general-purpose computers are not able to perform online real-time player tracking, but track the players offline using pre-recorded video files, limiting, e.g., direct feedback on the player performance during the game. In this thesis, a reconfigurable vision-based system for automatically tracking the players in indoor sports is presented. The proposed system targets player tracking for basketball and handball games. It processes the incoming video streams from GigE Vision cameras, achieving online real-time player tracking. The teams are identified and the players are detected based on the colors of their jerseys, using background subtraction, color thresholding, and graph clustering techniques. Moreover, the trackingby-detection approach is used to realize player tracking. FPGA technology is used to handle the compute-intensive vision processing tasks by implementing the video acquisition, video preprocessing, player segmentation, and team identification & player detection in hardware, while the less compute-intensive player tracking is performed on the CPU of a host-PC. Player detection and tracking are evaluated using basketball and handball datasets. The results of this work show that the maximum achieved frame rate for the FPGA implementation is 96.7 fps using a Xilinx Virtex-4 FPGA and 136.4 fps using a Virtex-7 device. The player tracking requires an average processing time of 2.53 ms per frame in a host-PC equipped with a 2.93 GHz Intel i7-870 CPU. As a result, the proposed reconfigurable system supports a maximum frame rate of 77.6 fps using two GigE Vision cameras with a resolution of 1392x1040 pixels each. Using the FPGA implementation, a speedup by a factor of 15.5 is achieved compared to an OpenCV-based software implementation in a host-PC. Additionally, the results show a high accuracy for player tracking. In particular, the achieved average precision and recall for player detection are up to 84.02% and 96.6%, respectively. For player tracking, the achieved average precision and recall are up to 94.85% and 94.72%, respectively. Furthermore, the proposed reconfigurable system achieves a 2.4 times higher performance per Watt than a software-based implementation (without FPGA support) for player tracking in a host-PC.Acknowledgments: I (Omar W. Ibraheem) would like to thank the German Academic Exchange Service (DAAD), the Congnitronics and Sensor Systems research group, and the Cluster of Excellence Cognitive Interaction Technology ‘CITEC’ (EXC 277) (Bielefeld University) not only for funding the work in this thesis, but also for all the help and support they gave to successfully finish my thesis

    Design and implementation of low complexity wake-up receiver for underwater acoustic sensor networks

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    This thesis designs a low-complexity dual Pseudorandom Noise (PN) scheme for identity (ID) detection and coarse frame synchronization. The two PN sequences for a node are identical and are separated by a specified length of gap which serves as the ID of different sensor nodes. The dual PN sequences are short in length but are capable of combating severe underwater acoustic (UWA) multipath fading channels that exhibit time varying impulse responses up to 100 taps. The receiver ID detection is implemented on a microcontroller MSP430F5529 by calculating the correlation between the two segments of the PN sequence with the specified separation gap. When the gap length is matched, the correlator outputs a peak which triggers the wake-up enable. The time index of the correlator peak is used as the coarse synchronization of the data frame. The correlator is implemented by an iterative algorithm that uses only one multiplication and two additions for each sample input regardless of the length of the PN sequence, thus achieving low computational complexity. The real-time processing requirement is also met via direct memory access (DMA) and two circular buffers to accelerate data transfer between the peripherals and the memory. The proposed dual PN detection scheme has been successfully tested by simulated fading channels and real-world measured channels. The results show that, in long multipath channels with more than 60 taps, the proposed scheme achieves high detection rate and low false alarm rate using maximal-length sequences as short as 31 bits to 127 bits, therefore it is suitable as a low-power wake-up receiver. The future research will integrate the wake-up receiver with Digital Signal Processors (DSP) for payload detection. --Abstract, page iv
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