Methods for Detecting Floodwater on Roadways from Ground Level Images

Recent research and statistics show that the frequency of flooding in the world has been increasing and impacting flood-prone communities severely. This natural disaster causes significant damages to human life and properties, inundates roads, overwhelms drainage systems, and disrupts essential services and economic activities. The focus of this dissertation is to use machine learning methods to automatically detect floodwater in images from ground level in support of the frequently impacted communities. The ground level images can be retrieved from multiple sources, including the ones that are taken by mobile phone cameras as communities record the state of their flooded streets. The model developed in this research processes these images in multiple levels. The first detection model investigates the presence of flood in images by developing and comparing image classifiers with various feature extractors. Local Binary Patterns (LBP), Histogram of Oriented Gradients (HOG), and pretrained convolutional neural networks are used as feature extractors. Then, decision trees, logistic regression, and K-Nearest Neighbors (K-NN) models are trained and tested for making predictions on floodwater presence in the image. Once the model detects flood in an image, it moves to the second layer to detect the presence of floodwater at a pixel level in each image. This pixel-level identification is achieved by semantic segmentation by using a super-pixel based prediction method and Fully Convolutional Neural Networks (FCNs). First, SLIC super-pixel method is used to create the super-pixels, then the same types of classifiers as the initial classification method are trained to predict the class of each super-pixel. Later, the FCN is trained end-to-end without any additional classifiers. Once these processes are done, images are segmented into regions of floodwater at pixel level. In both of the classification and semantic segmentation tasks, deep learning-based methods showed the best results. Once the model receives the confirmation of flood detection in image and pixel layers, it moves to the final task of finding the floodwater depth in images. This third and final layer of the model is critical as it can help officials deduce the severity of the flood at a given area. In order to detect the depth of the water and the severity of the flooding, the model processes the cars on streets that are in water and calculates the percentage of tires that are under water. This calculation is achieved with a mixture of deep learning and classical computer vision techniques. There are four main processes in this task: (i)-Semantic segmentation of the image into pixels that belong to background, floodwater, and wheels of vehicles. The segmentation is done by multiple FCN models that are trained with various base models. (ii)-Object detection models for detecting tires. The tires are identified by a You Only Look Once (YOLO) object detector. (iii)- Improvement of initial segmentation results. A U-Net like semantic segmentation network is proposed. It uses the tire patches from the object detector and the corresponding initial segmentation results, and it learns to fix the errors of the initial segmentation results. (iv)-Calculation of water depth as a ratio of the tire wheel under the water. This final task uses the improved segmentation results to identify the ellipses that correspond to the wheel parts of vehicles and utilizes two approaches listed below as part of a hybrid method: (i)-Using the improved segmentation results as they return the pixels belonging to the wheels. Boundaries of the wheels are found from this and used. (ii)-Finding arcs that belong to elliptical objects by applying a series of image processing methods. This method connects the arcs found to build larger structures such as two-piece (half ellipse), three-piece or four-piece (full) ellipses. Once the ellipse boundary is calculated using both methods, the ratio of the ellipse under floodwater can be calculated. This novel multi-model system allows us to attribute potential prediction errors to the different parts of the model such as semantic segmentation of the image or the calculation of the elliptical boundary. To verify the applicability of the proposed methods and to train the models, extensive hand-labeled datasets were created as part of this dissertation. The initial images were collected from the web, then the datasets were enriched by images created from virtual environments, simulations of neighborhoods under flood, using the Unity software. In conclusion, the proposed methods in this dissertation, as validated on the labeled datasets, can successfully classify images as a flood scene, semantically segment the regions of flood, and predict the depth of water to indicate severit

Video analytics for security systems

This study has been conducted to develop robust event detection and object tracking algorithms that can be implemented in real time video surveillance applications. The aim of the research has been to produce an automated video surveillance system that is able to detect and report potential security risks with minimum human intervention. Since the algorithms are designed to be implemented in real-life scenarios, they must be able to cope with strong illumination changes and occlusions. The thesis is divided into two major sections. The first section deals with event detection and edge based tracking while the second section describes colour measurement methods developed to track objects in crowded environments. The event detection methods presented in the thesis mainly focus on detection and tracking of objects that become stationary in the scene. Objects such as baggage left in public places or vehicles parked illegally can cause a serious security threat. A new pixel based classification technique has been developed to detect objects of this type in cluttered scenes. Once detected, edge based object descriptors are obtained and stored as templates for tracking purposes. The consistency of these descriptors is examined using an adaptive edge orientation based technique. Objects are tracked and alarm events are generated if the objects are found to be stationary in the scene after a certain period of time. To evaluate the full capabilities of the pixel based classification and adaptive edge orientation based tracking methods, the model is tested using several hours of real-life video surveillance scenarios recorded at different locations and time of day from our own and publically available databases (i-LIDS, PETS, MIT, ViSOR). The performance results demonstrate that the combination of pixel based classification and adaptive edge orientation based tracking gave over 95% success rate. The results obtained also yield better detection and tracking results when compared with the other available state of the art methods. In the second part of the thesis, colour based techniques are used to track objects in crowded video sequences in circumstances of severe occlusion. A novel Adaptive Sample Count Particle Filter (ASCPF) technique is presented that improves the performance of the standard Sample Importance Resampling Particle Filter by up to 80% in terms of computational cost. An appropriate particle range is obtained for each object and the concept of adaptive samples is introduced to keep the computational cost down. The objective is to keep the number of particles to a minimum and only to increase them up to the maximum, as and when required. Variable standard deviation values for state vector elements have been exploited to cope with heavy occlusion. The technique has been tested on different video surveillance scenarios with variable object motion, strong occlusion and change in object scale. Experimental results show that the proposed method not only tracks the object with comparable accuracy to existing particle filter techniques but is up to five times faster. Tracking objects in a multi camera environment is discussed in the final part of the thesis. The ASCPF technique is deployed within a multi-camera environment to track objects across different camera views. Such environments can pose difficult challenges such as changes in object scale and colour features as the objects move from one camera view to another. Variable standard deviation values of the ASCPF have been utilized in order to cope with sudden colour and scale changes. As the object moves from one scene to another, the number of particles, together with the spread value, is increased to a maximum to reduce any effects of scale and colour change. Promising results are obtained when the ASCPF technique is tested on live feeds from four different camera views. It was found that not only did the ASCPF method result in the successful tracking of the moving object across different views but also maintained the real time frame rate due to its reduced computational cost thus indicating that the method is a potential practical solution for multi camera tracking applications

Parking lot monitoring system using an autonomous quadrotor UAV

The main goal of this thesis is to develop a drone-based parking lot monitoring system using low-cost hardware and open-source software. Similar to wall-mounted surveillance cameras, a drone-based system can monitor parking lots without affecting the flow of traffic while also offering the mobility of patrol vehicles. The Parrot AR Drone 2.0 is the quadrotor drone used in this work due to its modularity and cost efficiency. Video and navigation data (including GPS) are communicated to a host computer using a Wi-Fi connection. The host computer analyzes navigation data using a custom flight control loop to determine control commands to be sent to the drone. A new license plate recognition pipeline is used to identify license plates of vehicles from video received from the drone

Electrical Optimization of a Plug-In Hybrid Electric Vehicle

Hybrid electric vehicles electrification and optimization is a prominent part of today’s automotive industry. GM and the Department of Energy challenge 16 universities across North America to redesign a Chevrolet Camaro into a hybrid electric vehicle. This thesis will address how Embry Riddle Aeronautical University’s EcoCAR team electrified and optimized the vehicle. The objective of the thesis is to optimize the electric portion of the vehicle, particularly the low voltage circuitry. Prior work is discussed in detail on the vehicle communication bus, building the power distribution unit and the approach the electrical team took when building the electric portion of the vehicle. Simulations were done based on manufacturer data and bench tests to create an ideal model. Data was collected from the vehicle and compared to the ideal model to determine errors in the electrical system. An emphasis was placed on critical and high power components to simplify the simulation model. The issues found were alleviated by conducting research, using research analysis, physically changing the system or by implementing control strategies. Most of the issues came from the power distribution unit and implementation techniques such as grounding. The MOSFETs within the power distribution unit was not fully turning on and off, and which was due to a slow RC time constant occurring on the gate of the transistors. By replacing the resistors, this issue was mitigated. Every problem found was properly mitigated to an acceptable industry or research standard

Monitoring automotive particulate matter emissions with LiDAR: A review

Automotive particulate matter (PM) causes deleterious effects on health and visibility. Physical and chemical properties of PM also influence climate change. Roadside remote sensing of automotive emissions is a valuable option for assessing the contribution of individual vehicles to the total PM burden. LiDAR represents a unique approach that allows measuring PM emissions from in-use vehicles with high sensitivity. This publication reviews vehicle emission remote sensing measurements using ultraviolet LiDAR and transmissometer systems. The paper discusses the measurement theory and documents examples of how these techniques provide a unique perspective for exhaust emissions of individual and groups of vehicles